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Energy Storage Systems

Posted By David Conover, Wednesday, November 13, 2013

Energy storage has been in use for centuries, as evidenced by dams and the use of the stored water to drive mechanical devices associated with grain milling. Energy storage provides the ability to balance the energy capabilities and resultant outputs of variable energy sources with the needed energy inputs of differing and variable loads. For example, if the availability of the sun’s energy could be directly matched continuously over time with the electrical lighting loads in a building, then there would be no need to store the sun’s energy as converted into electrical power through a photovoltaic (PV) system; the electrical energy would go directly to the lighting system, and demand and PV capacity would be in total agreement. The variability associated with building operations, climate, and the lack of 24-hour sunlight necessitates some way to store the electrical energy generated by the PV system for future use. In this case, the storage technology is a battery to store the electrical energy.

 

  Courtesy of Portland General Electric

Electrical storage today is not fundamentally different—in concept—than it was 100 years or more ago; just the range and type of technologies used, the size of the systems, their location and ownership/operational situations (grid or customer side of the meter), their interconnection with other systems, and their intended applications are increasing in depth and breadth. Due to factors spurring market demand for energy storage technology, North America is expected to see the most growth in energy storage over the next five years. Grid-scale storage will increase globally upwards of 10 gigawatts over that same period. This includes not just grid or commercial size systems but residentially focused systems in the 5 to 25 kW range.1 The projected US market for energy storage in 2015 is estimated at $10 billion annually.2

What might have involved the assessment of some wiring, conduit and electrical connections, and a determination of the safe installation of one or more lead-acid batteries just over 100 years ago is changing. This necessitates the need for those responsible for ensuring the safety and performance of electrical systems to understand what is coming. Principles that are applied to any electrical system are no different; it is just that the application may not look as familiar as more traditional electrical technology.

The purpose of this article is to provide an update on energy storage technology, making electrical inspectors less likely to be surprised when seeing new energy storage system technologies and better positioned to foster the acceptance of new storage technology.

History

Energy storage has been used in a number of ways for centuries; not necessarily in the manner in which we would think of it within the context of today’s built environment. More contemporary applications storing electricity have been around for about 200 years, beginning with the invention of the modern battery by Volta in 1799. Building on that initial work, lead-acid batteries were applied in the 19th century for a number of applications, most notably to store generated power during the day. Then, that storage for example could supply overnight lighting loads as was done in New York City when they first started to use electricity to light the city using dc current.With the first applications of electric power in the US, including storage batteries, the first National Electrical Code (NEC or NFPA 70) was published in 1887.

Other than for emergency electrical backup, and for time-shift from coal to replace natural gas during non-peak periods in electrical generation, and the increasing use of pumped hydro to generate power, there was little change until about 30 years ago. By the mid-1980s there was increasing interest by utilities to develop batteries and other storage technologies to support the electrical grid. During this time, there was increased emphasis on demand side management that fostered increased use of renewable energy and the application of combined heat and power systems in and around buildings. These and other factors have created a demand for energy storage systems; a demand that is fostering significant growth in storage technology research, development, availability, application and use, not only on the grid side of the meter but on the customer side of the meter where both stationary and vehicular systems are in play.

 

Courtesy of  Green Energy Futures

Market drivers

Energy, environmental and economic challenges here in the US and globally are spurring activity associated with new energy-related technology. Electric power plays a critical role here in the US and globally. It is something we cannot do without, but with increases in energy demand, the need to improve power reliability, flexibility and to reduce costs associated with electric power delivery there is an increasing need to be smarter about what we do and how we do it. Electrical storage has a more important and critical role to play; a role much larger than providing backup power or helping utilities effectively use energy sources in generating electric power as it has in the past. This is driving the investment in storage technology development and deployment, even to the point of looking at how vehicular systems can also serve stationary energy needs. Certainly, there is an increasing need for utilities to upgrade their investments in generation, transmission and distribution services. Customers also have an increased emphasis on power quality, reliability, and the ability to time-shift and manage demand charges. In addition, movement toward a Smart Grid that seeks through automation the improvement of the grid to address the above challenges is heavily dependent on the availability of energy storage technology and is helping to drive technology development. Efforts to deploy renewable technologies such as solar PV are also driving demand for energy storage. Of note, the biggest challenges hindering adoption of this storage technology are cost, deployability, and lack of standards.1

 

Figure 1. Energy Storage Technologies1 

One could argue that standards (and codes)—or the lack thereof—have a direct impact on cost and the ability to deploy the technology. The absence of criteria upon which to evaluate technology performance and safety leaves advocates and granters of technology approval with little to go on other than evaluating the technology on the basis that it is "no more hazardous nor less safe and it performs at least as well as other technologies that are specifically covered by existing standards and codes.” For instance the increased deployment of PV systems and energy storage are driving the need for revisions to the NEC with respect to criteria for dc systems; something new in buildings and to many of the NEC code-making panels. As covered above, the technology is here now and is likely to enjoy increased deployment in the future. Electrical inspectors can benefit from having a basic familiarity with energy storage technology. More importantly, they need to know that standards and codes and the infrastructure that supports the use of those documents are being addressed now with the goal of having the necessary criteria and programs in place and upon which system approvals can be readily considered when the availability of systems begins to fully address these increasing energy, environmental and economic challenges.

Energy storage technologies

There are a myriad of energy storage technologies in terms of design, capacity and function. They include batteries, pumped hydro, electrochemical capacitors, compressed air, flywheels and thermal storage. Essentially anything that can store energy (electrical, thermal, kinetic) for future use can be considered energy storage. Within battery storage there are lithium-ion, fuel cell, lead-acid, nickel metal hydride, alkaline and potassium-ion types.

The Department of Energy (DOE) International Energy Storage Database provides considerable information on the energy storage projects operating or planned in the US, North America and globally (ihttp://www.energystorageexchange.org). Further information on energy storage technologies is available in the DOE/EPRI 2012 Energy Storage Handbook in Collaboration with NRECA that was released June 2013.

Currently available storage technologies include batteries and other non-battery technologies such as pumped hydro, thermal storage, flywheels and compressed air, as shown in figure 1.

Battery story technologies, which will be of primary interest to electrical inspectors, include the following:

Sodium-sulfur (NaS), which have a discharge period of about six hours, can provide prompt and precise response, and operate at 300 to 350°C. They use metallic sodium that is combustible if exposed to water, hence they are constructed in airtight, double-walled stainless-steel enclosures. Where cells are combined, they are surrounded by sand to mitigate fire.

Sodium-nickel-chloride (NaNICl2) are high-temperature devices like NaS with cells hermetically sealed and packaged into 20 kWh+/- modules.

Vanadium redox batteries (redox) are a type of flow battery in which at least one of the active materials associated with the battery is in solution in the electrolyte at all times. The electrolytes are stored in external tanks and pumped to the cells as needed. Each cell has an open-circuit voltage on the order of 1.4 V with higher voltages achieved by connecting cells in series to create cell stacks. Useful life is estimated at about 10 years.

Iron-chromium (Fe-Cr) redox batteries are another type of flow battery, but are in the R&D stage and just entering field demonstration.

Zinc-bromine (ZnBr2) are also flow batteries in the 5 kW to 1000 kW range that are in the early stages of field-testing and have a storage duration from two to six hours. Each cell has two electrode surfaces and two flow streams; noting that the bromine is extremely corrosive. During normal operation they are not unusually environmentally hazardous, but the materials they contain can become contaminants.

Zinc-air batteries are metal to air electrochemical cells where oxygen in the surrounding environment serves as an electrode.

Lead-acid batteries, originally invented over 150 years ago, are widely used and comprised of carbon-based and advanced technologies, the latter using enhancements such as granular silica electrolyte retention systems.

Lithium-ion (Li-ion) are most common now in electric vehicles and for portable power applications. Field demonstrations are underway in the 5 to 10 kW/20 kWh for distributed system and 1 MW/15 minute fast responding systems for frequency regulation. Some are able to provide backup power for up to three hours during a grid outage.

Figure 2 provides a number of data associated with energy storage systems used for frequency regulation. Data for other system applications such as bulk storage and residential applications are also shown in the cited reference.

 

Figure 2. Battery Storage System Type, Size and Cost Data.1

Beyond the battery chemistry and "what is happening inside” individual cells, cell stacks and pre-packaged battery systems there are a number of other components that include switching systems, power conversion and conditioning systems, transformers, motors, controls and communications systems, and related software. For some of these systems there will also be fluid piping, tanks and associated pumps, motors and controls. Within the boundary that defines the system, electrical safety and other health and life safety issues will need to be addressed. In addition, across that system boundary there will be electrical, and possibly also thermal, fluid and gaseous inputs and outputs to consider; not just with respect to how the system could impact its surroundings but how an event associated with the surrounding (such as a fire) could impact the system. Some will focus specifically on electrical safety and others will also require consideration of other health and life safety issues.

The Electrical Inspector’s role in energy storage

The goal of an electrical inspector is to ensure the safety of the built environment as well as the public to the degree that they can be directly or indirectly affected by electrical systems or equipment, products and components associated with those systems. With respect to energy storage systems that involve electrical energy as inputs and/or outputs there are a few conditions to consider in framing a discussion on the role of the electrical inspector; noting that as with other types of equipment and systems there may be as much emphasis on protecting the storage technology from the surrounding environment than the other way around.

System size – is the system unitary in nature, composed of a matched set of components or simply designed, assembled and installed from a number of different "parts”?

System complexity – is the system simply a "box of battery cells” and some wiring and controls or are there also fluid and/or gas storage, piping, and controls involved?

System installation and location – what is the proximity of the system to buildings, facilities and the general public and is it stationary or mobile?

System relation to the grid – is the system on the customer or grid side of the meter and if on the customer side how is it interconnected with the grid?

System ownership and operation – is the system owned and/or operated by a utility (e.g., under PUC jurisdiction), a federal, state or local governmental agency, a contracted third-party energy provider, or a building owner/facility manager?

One way to get a handle on this issue is to contrast the extremes and how the electrical inspector would likely address them. Those extremes are a pre-packaged singular unitary system (kW size) that is installed in, on, or adjacent to a building that is accessible to the general public. Then, a much larger system (Mw size) is assembled and installed on site, from a number of separate "parts”; both are on the customer side of the meter and are owned and operated by the building owner. To frame another set of extremes, consider those above, but on, the utility side, and not necessarily located in, on, or adjacent to buildings accessible to the general public. Simply stated, the former NOT latter in this case could be residential in size, pre-packaged (unitary) and simply be "delivered and hooked up.” The latter could be grid-size and located adjacent to a utility transmission station or a large utility-owned PV farm.

With those extremes, it is also important to recognize any key differences from more traditional electrical equipment and systems. One of those is that storage systems, or at least certain components of the system, will always be energized and cannot be simply turned off. This affects commissioning and operation of systems, but may also necessitate treating the installation differently than more traditional "off/on/off” equipment. Another difference is that the storage systems can contain exotic materials that may be affected by fire, water/flooding, seismic events, and other external factors. In this instance, the electrical inspector would be focused more on the location and installation of the system to protect the system from its environment as opposed to the opposite condition. As noted above, they can also involve stored and/or moving fluids and/or gases as inputs and outputs from the system.

 

Transformers of the new Salem Smart Power Center that houses a 5-megawatt battery and is operated by Portland General Electric, a research partner of Pacific Northwest National Laboratory. Courtesy of Portland General Electric

In the simplest of situations, the electrical inspector would verify that the system (e.g., unitary pre-packaged) had been "tested and listed” by an approved third-party agency thereby validating that the system and its components satisfied a particular standard or number of standards where conformance with those standards supports that the system is "safe”. Then the inspector would determine that the system was installed in accordance with the terms of its listing and any adopted codes that are relevant (e.g., the NEC). Wiring methods, circuits, disconnecting means, grounding, clearances, ventilation of interior spaces, marking/signage, the existence of live parts, current limiting/overcurrent protection, etc., would essentially be conducted no differently than if the device was an electric furnace instead of an electrical storage system.

As the system increases in size and capacity, its installation and location scenarios change, and its relationship to the grid and the ownership and operation conditions can also vary. The role of the electrical inspector may become more challenging; however, the fundamentals will remain the same as with the simplest of situations. Building on the information above for unitary-type systems, there would be virtually little difference in the roles and responsibilities of the electrical inspector if the system was composed of matched "tested and listed” components. The only additional effort is to ensure that each component of the system is connected in conformance with the terms and conditions of the listing and adopted codes as to clearances, ventilation, signage, etc. When those components are not a matched "package” but instead the system is essentially assembled on site from various "parts” then all of the above items (acceptability of the components, their proper connection and compliant installation) must still be addressed. The challenge is that the criteria for doing so are not likely to be provided by a single entity (e.g., a manufacturer of the system). Instead, the criteria will come from each component manufacturer and the guidance on the assembly of the components and their individual and collective assembly will be guided by adopted codes such as the NEC or from other standards that may be written specifically to address the installation of such systems; as is the case for instance for NFPA 853 for stationary fuel cells.

There are also the same exact scenarios above on the customer side of the meter but with a utility actually owning a system that is located in, on, or adjacent to a private or public sector building or facility. In those instances, even though the utility is involved, the same considerations above would be applicable, although the inspector would be more likely to also be dealing with utility personnel in the review, inspection and approval process. There is a similar issue with utilities, utility property, and part of the utility systems and equipment that make up and support the business of generating, transmitting, and/or distributing electric power to customers. In those situations, the same general concerns would apply but the criteria used as a basis for acceptance would be those adopted by the utility and are likely to be based on the National Electrical Safety Code (NESC).

One additional consideration is the system life after initial inspection and approval. Typically, once a certificate of occupancy is issued the electrical inspector’s role with a building or facility is completed unless there is an addition, repair, renovation, etc., associated with the building or its systems or system components. Where existing and previously inspected and approved batteries are replaced, renewed, rehabilitated, etc., an electrical permit and subsequent review of the construction documents and inspection of the work may be necessary. For grid-side systems, this review would likely be addressed by the system owner (the utility). For customer-side systems, the notification of pending work on the system should occur through a permit application by the building owner, facility manager or electrical contractor.

ES system performance

Beyond the specific health and life safety aspects associated with an energy storage system is the performance of a system with respect to its intended function (i.e., peak shaving, frequency regulation, renewables smoothing). The availability of uniform, reliable, consistent and comparable information on system performance fosters market acceptance of such systems and eliminates the need for potential customers of such systems to develop their own separate criteria. Some performance information, such as system capacity and rating, is relevant to electrical inspectors, even if minimum performance thresholds are not within the scope of the electrical inspector’s function based on adopted codes and standards.

To address the lack of uniform, consistent and singularly acceptable criteria for measuring and expressing energy storage system performance, the US DOE’s Office of Electricity Delivery and Energy Reliability (OE) Energy Storage Systems Program, through the support of PNNL and Sandia National Laboratories (SNL), fostered an industry wide collaboration to develop a protocol for measuring and expressing the performance characteristics for energy storage systems. The protocol was published in late 2012 and currently provides criteria for all-electric systems intended for either peak shaving or frequency regulation applications. For those applications, the protocol addresses the definition of the system boundaries, what measurements are to be taken, the duty cycle to be applied to the system, and the methods for determining and reporting system performance from the resultant operational data. Both applications are evaluated as to capacity, round trip energy efficiency, response time and duty cycle round trip efficiency. The frequency regulation application also is evaluated for ramp rate and reference signal tracking.

Most recently a user’s group applied the protocol to a number of system installations and based on their experiences further refinements were suggested to the protocol. Those suggestions are being communicated to both US and International standards developers who are using the protocol as a basis for more traditional standards on system performance. In addition, work is concluding on enhancements to the protocol to cover applications of systems for microgrids and frequency smoothing of renewable energy systems. The core format of the protocol and the process for its development and enhancement serves as a foundation for future standards development and deployment, which in turn assists the industry at large. More importantly this model for criteria development and availability of underlying supporting documentation fosters the more timely availability of specific criteria in standards and codes that electrical inspectors can use in assessing and approving new technology.

What’s next?

The market drivers discussed above will continue to provide an opportunity for and encourage technology development and deployment. This statement holds true no matter the time frame in which it is considered. Just as a market driver for energy storage in the late 1800s might have been "we need to store the electricity we generate during the day to light the lights at night” and the business opportunity associated with artificial lighting at that time, storage technology has evolved since then, is evolving now, and will continue to evolve in the future.

For electrical inspectors some things will remain the same, others will change – more likely they will be new. What will remain the same is the physics associated with electricity. While what is "inside the box” may change and necessitate different considerations, the connections to that box, the associated controls, and what is flowing through the wires and conduit to/from the box will not fundamentally change. Beyond that, as evidenced by some of the storage technologies noted above, there may be an increased need to coordinate with those involved in building, fire, plumbing and mechanical code enforcement to address the integration of the system with the remainder of the built environment in, on, or around buildings. Clearly if the system is of a particular size and/or type those responsible for zoning may also need to become involved with respect to setbacks and emergency vehicle access.

As the technology evolves it will be incumbent for the storage industry to engage all stakeholders, including those involved in electrical and related code development, adoption and enforcement. Concurrently it is appropriate for those same stakeholders to proactively become more engaged with the storage industry at the individual level or through associations and organizations such as IAEI. This article is an example of that outreach.

Beyond the technical, there is also the non-technical or administrative environment. The clear distinction between what is and is not covered by the utility is changing. This will impact who is responsible for the adoption and enforcement of codes, standards and other criteria to govern system installation, commissioning and use. Training, licensing of electrical contractors, and a number of other issues will also have to evolve to keep pace with and to facilitate the acceptance of storage technology.

Electrical inspectors – now more than ever– play an important role in addressing our energy, environmental and economic challenges by fostering the acceptance of energy storage technology. The key overriding factor is to ensure the safety of not only the public at large but of those who are intimately involved with such systems in a thorough and timely manner. The infrastructure that has been in place to ensure that safety and foster new technology acceptance can and will, with your help and dedication, grow and evolve to address new technology; in this case, electrical storage systems.

Bibliography

1DOE/EPRI 2013 Electricity Storage Handbook in Collaboration with NRECA, SAND2013-5131, July 2013 (www.sandia.gov/ess)

2Power Systems of the Future: The Case for Energy Storage, Distributed Generation, and Microgrids, IEEE Smart Grid, November 2012 (www.smartgridresearch.org)

3Protocol for Measuring and Expressing the Performance of Energy Storage Systems, November 2012, PNNL-22010 (www.pnl.gov/main/publications/external/technical_reports/PNNL-22010.pdf)

About Pacific Northwest National Laboratory

Pacific Northwest National Laboratory, located in southeastern Washington State, is a U.S. Department of Energy Office of Science laboratory that solves complex problems in energy, national security, and the environment, and advances scientific frontiers in the chemical, biological, materials, environmental, and computational sciences. The Laboratory employs about 4,400 staff members, has an annual budget of about $1 billion, and has been managed by Ohio-based Battelle since 1965.

Tags:  Featured  November-December 2013 

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Tamper-Resistant Receptacles

Posted By Thomas A. Domitrovich, Wednesday, November 13, 2013

In the last edition of this column, we reviewed the incredible receptacle and the standards requirements around these products. Well, I left out one important piece of the puzzle: the tamper-resistant receptacle (TRR). These devices deserve to be put on a pedestal, so to speak as they work every day to protect our future — those little bundles of joy who at times become intrigued by those tiny slots in walls that seem to demand the insertion of paper clips or just about any other object that may seem to fit. Tamper-resistant receptacles are a direct response to statistics of children who tried to do just that and ended up in the hospital.

Just as with any new requirement in our industry, many people question new technology and resist adoption of these types of requirements. The fact is that many new code changes are supported by statistics and data at their core; the TRR requirements are no different. This is why the TRR requirements have fared so well in those jurisdictions adopting the National Electrical Code (NEC). The data behind the requirements for these devices include U. S. Consumer Product Safety Commission (CPSC) data over a 10-year period that found more than 24,000 children under 10 years of age were treated in emergency rooms for receptacle-related incidents, and more than 10% of those children suffered severe shock and burns. An average of seven children a day suffered from some type of injury from electrical receptacles. Eighty-nine percent (89%) of those injured were under six years of age. Fifty percent (50%) of those injured were toddlers. It was very interesting to learn that the vast majority of these incidents occur in the home where, more than likely, children are under adult supervision.

These devices may be relatively new to residential structures but, the fact is, they have been around for decades; mandated in hospital pediatric wards since NEC 1981 as part of Section 517-90(b) "Pediatric Locations.” The language in this section required, "Fifteen- or 20-ampere, 125-volt receptacles intended to supply areas designated by the governing body of the health care facility as pediatric wards and/or rooms shall be tamperproof. For the purposes of this section, a tamperproof receptacle is a receptacle which by its construction, or with the use of an attached accessory, limits improper access to its energized contacts.” Over time, this section has changed including the removal of the "tamperproof” terminology. These devices are resistant to tampering, not impervious to the act.

It was NEC 2008, as a part of Section 406.11, that introduced these devices as requirements for new and renovated dwelling units. As with every code change and it seems like every new safety provision, some resist local adoption of these types of new requirements. Even in light of opposition, the adoption of this provision has progressed quite well from state to state with approximately four states amending their requirement.

It’s All about the Shutters

The main goal of a TRR is to provide a level of protection to help prevent a child from inserting an object into one of the blade openings of the receptacle. When you look at the face of a TRR, you will notice that the two blade openings have what appears to be a barrier. The round hole, the one that received the grounding pin of the plug, does not have a shutter. Touching or inserting an object into the round hole of a properly wired device is not advised, but because it is the ground reference point should not result in harm to the inserter, more than likely a very curious child. In a NEMA 5-15, 15-A 125-V device the two slots that have barriers are, of course, the hot and neutral (grounded) parts. The object of the design is to ensure that the act of probing with an object, let’s say a bobby pin, safety pin or other similar object, in any single slot does not successfully let it penetrate to the energized components internal to the device.

Insertion is permitted when both slots receive a blade at the same time. In a typical mechanism, inserting a plug compresses a spring, simultaneously opening both shutters. While insertion of an object in any single shutter will not open the device such that the shutter slides out of the way. This sophisticated approach to the shutters ensures that curious George does not successfully hit "pay dirt” and end up in the emergency room. Because these devices have a very important goal and are a bit more complex than the standard receptacle, the UL standard for receptacles was modified to include new requirements. Additional tests for the TRR are included in UL 498, "Standard for Safety Attachment Plugs and Receptacles.”

A Standards Perspective

So let’s peek under the hood and look at the standard requirements behind the products that entered the receptacle world of heavily used and often abused electrical devices.

UL defines this device as "A receptacle which by its construction is intended to limit improper access to its energized contacts in accordance with the National Electrical Code, ANSI/NFPA-70.” In true form for UL 498, "Standard for Safety Attachment Plugs and Receptacles,” tamper-resistant receptacles are subjected to performance requirements that go above and beyond those performance requirements for standard receptacles. The following performance criteria are additional items to those discussed in the last edition of this column.

1. Probe Test: This test starts fresh with twelve untested devices. A probe of specific dimensions, similar to that of a paper clip, is applied to each of the receptacle’s slot openings, at a force of 8 ounces. The test attempts to bypass the tamper-resistance mechanism by manipulation in the slots in any orientation. An indicator is wired to the probe and the wiring terminal of the outlet slot being tested to announce if contact is made. In addition, these devices are subjected to another set of probes for a period of 5 seconds at a force of 10 lbs., looking for a way to bypass the tamper-resistance mechanism.

2. Impact Test: This test uses six of the twelve devices used in the previous test and subjects them to either a ball-pendulum impact or a vertical-ball impact test which strikes the receptacle face or tamper-resistance mechanism or other. The test is trying to determine the ability of the tamper-resistant mechanism to withstand an impact and continue to function. The receptacle cannot crack and the tamper-resistant functionality cannot be compromised. The sphere used is 2 inches in diameter and weighs in at 1.18 lbs. For the pendulum test, the sphere is suspended by a cord and swung like a pendulum. It is dropped 51 inches and the impact is of a 5.0 ft-lb force. In the vertical impact test, the sphere drops from a height of 51 inches and impacts the center of each receptacle.

3. Mechanical Endurance Test: This test uses six devices that previously were subjected to the above probe test. In this test, a machine continuously inserts and withdraws — 5,000 times — an attachment plug having secured solid brass blades. The machine controls the velocity of the withdrawal and insertion; the blades, contacts and tamper-resistant mechanisms must not be adjusted, lubricated, or conditioned in any way before or during this test. After this test, these devices are tested again to ensure attachment plugs can be mated; probes cannot compromise the tamper-resistance ability, and it can perform for the dielectric voltage withstand test.

4. Dielectric Voltage Withstand Test: A TRR must withstand without breakdown, for a period of one minute, the application of a 60 Hz voltage of 1000 V plus twice the rated voltage rating of the receptacle. The devices used again are those previously used in the above tests.

As can be seen here, these devices are given no relief from a standards perspective; they must perform when called to do so.

 

This is an internal view of how both shutters must be acted upon to permit the blades of the plug to be inserted.

Field Performance

A question that often graces code adoption hearings and other similar venues is the question of insertion force. Inevitably, you hear about concerns of someone having difficulties inserting a plug into the receptacle. The presence of shutters and the lack of familiarity will understandably generate these types of concerns. As shown above, these receptacles do not undergo any additional testing beyond the standard receptacle with regard to insertion forces. If you recall from our last article on the receptacle, insertion force is covered as part of section 117.8 of the standard. This section performs conditioning on the receptacle and requires that the standard blade, which the Standard calls a "gauge,” assembled without the grounding pin and with the line blades without holes, be inserted into each outlet of the receptacle. The insertion forces are measured and must meet specified criteria. As per this requirement, forces must not exceed 40 lbf required to seat a standard gauge against the receptacle face. Again, this is the same requirement for a standard receptacle.

Insertion of plugs in the case of TRRs is physically achieved in the same manner as that for standard receptacles. There is no getting around the fact that some additional frictional forces are present when inserting plugs into these receptacles; the shutters do provide some additional resistance during the processes of insertion. The additional forces are not significant. Problems may arise, though, due to application issues due to various situations contributable to the misuse or abuse of these products. One good example of arguably a less obvious abuse is drywall sanding. There have been reported cases where receptacles present during the process of sanding by drywall finishers have experienced plugging of their shutters. These devices are no different from many other electrical devices and care should be taken during construction. Another example of where insertion may be impacted includes those times when plug blades have been bent and so abused that they are barely recognizable as plug blades. A standard receptacle can be quite forgiving for the insertion of these abused objects. A TRR is much less forgiving than the standard receptacle. Hand tools such as drills and similar are infamous for this in venues where I have personally been involved. Irons, hair dryers, and we cannot leave out the vacuum sweeper, are also guilty offenders. I have had to take pliers to a plug or two to enable its insertion into a standard receptacle as well as the TRR. Another very abusive habit for plugs is the rapid yank to remove from an angle instead of walking up and removing it in the correct manner. Sometimes we are our own worst enemies. There are always opportunities to explain the correct way to remove plugs from receptacles and outlet strips and to demonstrate the proper use of these types of devices. There have also been reports of new plugs that are very sharp at the tip of the blades and catch on the shutter, digging into the shutter’s plastic, making it difficult to insert. Those burrs may be the result of a manufacturing process issue or for other post manufacture reasons, but are easily enough dealt with all the same.

Industry References and Resources

The industry has some very helpful resources for additional information on the tamper-resistant receptacle. The National Electrical Manufacturers Association (NEMA) has put together a web site resource to answer all of your questions and to give you enough information to ask additional ones. This resource can be found at www.childoutletsafety.org.

As always, keep safety at the top of your list and ensure you and those around you live to see another day.


Read more by Thomas A. Domitrovich

Tags:  Featured  November-December 2013 

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Make Safety a Tradition

Posted By ESFI, Wednesday, November 13, 2013
The fifteen days from December 22 through January 5 are the most dangerous of the year in terms of home Christmas tree structure fires, according to NFPA. Defective holiday lights and line voltage cause approximately 160 home structure fires; Christmas trees account for an additional 230 fires each year. Together, fires beginning with holiday lighting or Christmas trees result in an average of 13 civilian deaths, 34 civilian injuries, and $26.3 million in direct property damage per year.

Electrical Safety Foundation International (ESFI) has prepared a toolkit of holiday safety tips to help counteract these statistics in local communities. A summary of these tips follow.

Pre-Holiday Tips

Test all smoke alarms. Replace the batteries or smoke alarm if the alarm is not working properly.

Inspect all electrical decorations and replace any strands that have broken lights, frayed wires, or insulation breaks.

Do not connect more than three strands of holiday lights, unless you are using LEDs.

Outdoor lights and decorations should be plugged into ground-fault circuit interrupters (GFCIs). If the circuits are not protected by GFCIs, purchase a portable outdoor GFCI where electrical supplies are sold. No specific knowledge or equipment are required to operate a portable GFCI.

Check product labels or packaging to determine whether a product is intended for indoor or outdoor use.

Do not overload circuits. Do not place cords under furniture or rugs.

Give a three-foot buffer from any decorations and an open flame (candles, fireplace, etc.).

Purchasing Tips

General

Check the labels of electrical equipment! Buy equipment only if the label indicated is has undergone independent testing by a nationally recognized testing laboratory, such as Underwriters Laboratories (UL), Intertek (ETL), or Canadian Standards Association (CSA).

  • Buy from trusted retailers to avoid the risk of purchasing counterfeit products.
  • Buy decorations according to their intended use: indoors or outdoors.
  • Send warranty and product registrations forms to manufacturers in order to receive any product recalls promptly.

Natural and Artificial Trees

In natural trees look for the following:

1) well-hydrated with vibrant green needles;

2) needles hard to pluck and don’t break easily from the branches;

3) trunk sticky with sap. Place in a tree stand with plenty of water to keep the tree hydrated and to reduce the risk of fire.

In artificial trees, choose one that is tested and labeled as fire-resistant.

Lights: LEDs vs. Incandescent

Incandescent lights burn more brightly than LEDs.

  • LEDs last up to 20 times longer than incandescent lights.
  • LEDs generate less heat, which translates to greater energy-efficiency.
  • LEDs are made of epoxy lenses, not glass, and are much more durable.
  • LEDs are initially more expensive, but recover cost through energy savings.

Lighting Safety Tips

When planning and implementing the lighting design, follow these safety tips to reduce the risk of property damage, injury or death.

  • When hanging lights outdoors, you should use a wooden or fiberglass ladder to avoid residual shock.
  • Turn off all indoor and outdoor holiday lighting before leaving the house or going to bed.
  • Never drape anything over a light bulb or lampshade.
  • Avoid using candles when possible. Consider using battery-operated candles instead.
  • If you must use candles, place them three feet away from combustible material and in areas where they will not be overturned.
  • Never leave an open flame unattended; extinguish it before you leave the room.

Cord Safety Tips

When using an extension cord, select a cord that is long enough to meet your needs. Never attempt to extend the length of a cord by connecting it to another cord.

  • Check that all electrical items, including extension cords, are certified by a nationally recognized independent testing lab, such as Underwriters Laboratories (UL), Intertek (ETL), or Canadian Standards Association (CSA).
  • Extension cords are for temporary use only.
  • Extension cord placement: 1) not in high traffic areas or under carpets, rugs, or furniture; 2) not at sharp angles or in pinched positions; 3) never stapled to wall or baseboard; 4) never run through walls or ceilings.
  • Extension cords usage: 1) never remove the third prong to make a three-prong plug fit a two-prong outlet. 2) Insert plugs fully so that no part of the prongs is exposed when the extension cord is in use. 3) Make sure cords are rated properly for their intended use: indoor or outdoor. 4) Make sure cords meet or exceed the power needs of the item being energized.

Space Heater Safety Tips

Space heaters are one of the leading causes of home fire deaths, responsible for an estimated 412 in 2010, according to a report by NFPA. In addition, it is estimated that heating equipment was involved in 57,100 reported U.S. home structure fires resulting in 1.062 civilian injuries and over $477.7 million in direct property damage.

The leading factors contributing to ignition in home heating equipment fires were failure to clean the device, the heat source being too close to combustibles, and mechanical failure or malfunction of the equipment. Proper installation, use, and maintenance will reduce the risk of property loss, injury, or death resulting from the use of heating equipment.

Gas-fueled heating devices pose additional danger, as they are the primary heating source responsible for non-fire carbon monoxide poisonings. Carbon monoxide is odorless, invisible, and potentially deadly. Test carbon monoxide and smoke alarms each month to keep the family safe and before using additional heating equipment.

All heaters need space. Keep things that can burn at least three feet away from heating equipment.

Plug portable space heaters directly into an outlet; do not use an extension cord.

Vent all fuel-burning equipment to the outside to avoid carbon monoxide poisoning. Also, remove snow or fallen leaves from around the outlet to the outside to ensure proper venting of the exhaust.

Childproofing Tips

Holiday celebrations also present additional safety hazards for children. If you have not already done so, install tamper-resistant receptacles (TRRs) or use safety covers on all unused electrical outlets, including those on extension cords. TRRs include a built-in shutter system that prevents foreign objects from being inserted. When equal pressure is applied simultaneously to both sides, the receptacle cover plates open, allowing a standard plug to make contact with the receptacle contact points. Without this synchronized pressure, the cover plates remain closed, preventing the insertion of foreign objects.

Avoid putting Christmas tree lights, ornaments, metal hooks, and other small, "mouth-sized” decorations near the floor or on lower limbs of the tree where young children may reach them. Avoid using sharp or breakable decorations within reach of children. Never allow children to play with lights, electrical decorations, or cords.

Avoid toys with small, detachable pieces that can present choking hazards. Avoid also gifts that require small button batteries; these pose choking risk if children are able to open the battery covers.

Watch children closely in the kitchen. They must be supervised at all times when an electric or gas stove is within reach. Actually, keep them at least three feet away from all cooking and heating equipment. Never hold a child while cooking or removing hot food from the microwave, oven or stove.

Wrapping Up the Season

Holiday decorations are for temporary use. Leaving electrical decorations up for extended periods leaves wires unnecessarily exposed to the elements, which can decrease the product’s shelf life and increase the risk of electrical hazards.

Always unplug decorations by using the gripping area. Pulling on the cord could damage the wire and present a shock or fire hazard. Inspect the wiring and discard any cracked, frayed, or that appear to have damaged wire insulation. Label, box, and store indoor decorations separate from outdoor decorations. Remember to store all electrical decorations in a dry area that is not accessible to children or pets.

Natural Christmas trees continue to dry out, making them increasingly flammable. Check with your local community to find a recycling program through which to dispose of your tree early in the New Year.

For more information on how to wrap up the holidays safely and on other electrical safety resources for use throughout the year, visit www.esfi.org or contact them at info@esfi.org or (703) 841-3229.

References

Electrical Safety Foundation International (EFSI), Make Safety a Tradition community outreach kit. Available from www.holidaysafety.org.


CEO David Clements represents IAEI on the ESFi board of directors.

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Holiday Lighting Requirements and the NEC

Posted By Joseph Wages, Jr., Wednesday, November 06, 2013

I was in a very nice restaurant the other evening, and I noticed something while pondering the electrical code that got me to thinking: Those are really cool "Christmas Lights” they have strung all around the restaurant. It made me think of the holiday season. The only problem was it was July! 

Holiday lighting has existed for centuries. Early lighting consisted of bringing in an evergreen tree and adorning it with candles. It did not take long for an open flame and a drying out tree to produce unfavorable results.

With the development and use of electricity came the desire to make things safer. Out went the unsafe candles and in came the strands of holiday lighting. Early versions of holiday lighting were seen annually during the Christian celebrations of the birth of Jesus. Millions of homes were decorated with various forms of holiday lighting strands and ornaments. Children were mesmerized by the beautiful lights and with the hopes that Santa would be visiting soon.

 

Photo 1. Cool icy treats available from this holiday lights ship.  Photos by J. Wages, Jr.

Who can forget the movie Christmas Vacation and Clark Griswold’s obsession with having the brightest house on the block? Clark Griswold’s installation had electrical inspectors cringing all over the world, but the local utility was happily benefiting from the use of more electricity.

Unfortunately, there are people that take things a little too far. The NEC addresses holiday lighting in Article 410 and Article 590 and limits the use of this product. We will also be referencing UL standards in this article.

 

Photo 2. Can you find the opossum in the sea of lights? This photo demonstrates that not all holiday lighting is temporary; some is left in place year-round.  Photo by J. Wages, Jr. 
 

One of the requirements is that holiday lighting shall be listed. Another one limits the installation and use to 90 days as seen below for your review:

410.160 Listing of Decorative Lighting. Decorative lighting and similar accessories used for holiday lighting and similar purposes, in accordance with 590.3(B), shall be listed. (2011 NEC)

590.3 Time Constraints.

(B) 90 Days. Temporary electric power and lighting installations shall be permitted for a period not to exceed 90 days for holiday decorative lighting and similar purposes. (2011 NEC)

590.5 also contains lighting requirements for holiday lighting.

A Little History

A wise man asked me a series of questions concerning these installations. Since I did not know all the answers, I visited our library to find a few more answers.

From my research results, requirements for these installations first appeared in the 1971 NEC. At that time, these requirements were located in a new article, entitled "Temporary Wiring,” and were found in Chapter 3, Article 305. Code-Making Panel 6 made the proposal in hopes of generating enough comments to establish an adequate section for temporary wiring in the NEC. The panel vote was unanimous for this new article.

The language was similar to that now located in Article 590. The language in 305-1(b) stated that temporary electrical power and lighting installations may be used for a period not to exceed 90 days for Christmas decorative lighting, carnivals, and similar purposes, and for experimental and development work. It is interesting that the word "Christmas” was specifically mentioned at that time.

The 1999 NEC was the last edition to contain Article 305. For the 2002 NEC, Article 305 was deleted and Article 527 became the location for finding a new term holiday lighting; but this article was to be short-lived. In the 2005 NEC, Article 527 vanished, and Temporary Wiring Installations was moved to Article 590 where it remains today.

 

Photo 3.  Old-fashioned Christmas lights. Courtesy of David Dini, Underwriters Laboratories

It is interesting to ponder another question. We often see trees within parks adorned with holiday lighting. Is this permitted by the NEC? Let’s visit 590.4 (J) in the 2011 NEC concerning support. The language here reads:

590.4 General

(J) Support. Cable assemblies and flexible cords and cables shall be supported in place at intervals that ensure that they will be protected from physical damage. Support shall be in the form of staples, cable ties, straps, or similar type fittings installed so as not to cause damage.

Vegetation shall not be used for support of overhead spans of branch circuits or feeders.

However, we find an exception to this main rule, which states:

590.4 General

(J) Support.

Exception. For holiday lighting in accordance with 590.3(B), where the conductors or cables are arranged with strain relief devices, tension take-up devices, or other approved means to avoid damage from the movement of the live vegetation, trees shall be permitted to be used for support of overhead spans of branch-circuit conductors or cables.

Articles 225 and 230 still prohibit feeders and services from being supported by vegetation. By exception in Article 590, branch-circuit conductors and cables are allowed to be supported by vegetation and trees if appropriate strain relief devices and/or take-up devices are used.

Unintended Consequences

Unfortunately, needless loss of life and property result from the use of these products. Every year there are news reports of families losing their homes or loved ones due to careless use of holiday lighting. Placement of these products on once live trees that have a tendency to dry out has resulted in many fires. Improper use of extension cords is another contributing factor. Again, revisiting the movie Christmas Vacation helps drive home this point. In this scene, a family member who is a careless smoker ignites the tree at their Christmas celebration.

Interestingly, nationally recognized testing laboratories such as Underwriters Laboratories conduct investigations on the flammability of some of these products. This author was fortunate enough to be able to witness one of these tests. The tests were conducted with two Christmas trees. One had a fire rating and the other did not. It does not take long for a once beautifully adorned tree to become a raging tower of inferno. Viewing this testing procedure drove home for me the simple point that things like this could become truly dangerous if not treated properly.

UL Standard 588

UL 588 addresses the use of Seasonal and Holiday Decorative Products. This standard was developed due to testing of these various seasonal and holiday products. The UL 588 document is included for your review:

Seasonal and Holiday Decorative Products

UL 588

1 Scope

1.1 These requirements cover temporary-use, seasonal decorative-lighting products and accessories with a maximum input voltage rating of 120 V to be used in accordance with the National Electrical Code, ANSI/NFPA 70. Temporary-use is considered to be a period of installation and use not exceeding 90 days.

1.2 These requirements cover factory-assembled seasonal lighting strings with push-in, midget-screw, or miniature-screw lampholders connected in series for across-the-line use or with candelabra- or intermediate-screw lampholders connected in parallel for direct-connection use. These requirements also cover factory-assembled seasonal decorative outfits such as wreaths, stars, light sculptures, crosses, candles or candle sets without lamp shades, products in the shape of, or in resemblance to, a Christmas tree not exceeding 30 inches (762 mm) in height as measured from the top of the tree to the bottom of the base of the tree and provided with simulated branches and needles, products in the shape of, or in resemblance to, a wreath not exceeding 48 inches (1219 mm) in outer diameter and provided with simulated branches and needles, blow-molded figures or objects, animated figures, tree tops, controllers, tree stands, and motorized decorative displays. These requirements cover products which are portable and not permanently connected to a power source.

1.3 These requirements additionally cover ornaments which are provided with an adapter for connection to a push-in lampholder and are intended to replace a push-in lamp in a series-connected decorative-lighting string or decorative outfit.

1.4 These requirements do not cover strings employing lampholders larger than intermediate-screw, non-seasonal lighting, non-seasonal products, permanently connected products, non-decorative lighting intended for illumination only, cord sets, or temporary power taps. These requirements also do not cover nightlights which are covered under the Standard for Direct Plug-In Nightlights, UL 1786, or flexible lighting products that are not part of a decorative outfit which are covered under the Standard for Flexible Lighting Products, UL 2388.

1.6 These requirements do not cover portable electric lamps intended for general illumination with a seasonal decoration and a typical lamp shade construction open at the top and bottom, which are covered under the Standard for Portable Electric Luminaires, UL 153.

One can also find useful information within the 2013 UL White book. See Categories DGVT, DGWU, DGXU, DGXO, DGXW and DGZZ. Category DGVT does not cover nonseasonal lighting, nonseasonal products, permanently connected products, nondecorative lighting intended for general illumination only, cord sets (extension cords) or relocatable power taps.

UL 588 has language at 1.6 to clarify that a Portable Lamp (intended for general illumination) is not covered under UL 588, even if it has a seasonal theme. An example would be a portable lamp with a lampshade and a Santa Claus on its stand. This would still be covered under UL 153, the Standard for Portable Lamps.

 

Photo 4. Christmas lighting to the extreme. 

UL 153, states at 1.4 that these requirements do not cover Christmas trees and decorative lighting outfits, electric candles and candelabras without lampshades, or portable luminaires with a seasonal decoration and a lampshade of other than the open top and bottom construction. It directs us to the Standard for Seasonal and Holiday Decorative Products, UL 588.

In Conclusion

The holidays are a time for celebration with family and loved ones. The anticipation of Santa and his reindeer is broadcast annually by many weather stations throughout the country. Technological advances have allowed us to track Santa with great detail and success, but holiday lighting has a purpose and a time frame for use. It is fun and enjoyable, but all good things must come to an end. For the safety of the user, this lighting has been deemed as temporary and has a 90-day limit of use.

 

Photo 5. UL testing procedures help assure safety with these products.

Take a look around and see how much of this lighting is being used on a non-temporary basis. There may be a need for manufacturers to produce a similar item that can be tested and listed for year-round use. A review of fire statistics might suggest that this product could be safely used more than the Code currently allows. It is evident that demand exists for such items. The Code may need to look further at these installations and offer additional guidance.

Some homes and businesses elect to leave these lights installed yearly so as not to have to put them up and take them back down. Even though these items are not energized for a vast amount of the year, is this acceptable and in line with the intended use of this product? Let’s take a few moments to think about the consequences of this situation. It is never our intent for someone to get hurt. This is not the season for something that is unavoidable to take place. Happy Holidays to all and please celebrate safely!

References

National Electrical Code, 1999, 2002, 2005, 2011

Copyright © Underwriters Laboratories Inc. Standard for Seasonal and Holiday Decorative Products, UL 588, 18th edition, 2000

Copyright © Underwriters Laboratories Inc. Standard for Portable Electrical Luminaires, UL153, 12th edition, 2002

Copyright © Underwriters Laboratories Inc. Guide Information for Electrical Equipment , White Book, 2013. Categories DGVT, DGWU, DGXU, DGXO, DGXW and DGZZ.

Tags:  Featured  holiday lighting  November-December 2013 

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Staying Relevant

Posted By David Clements, Wednesday, November 06, 2013

We managed to survive the recession without increasing membership dues.

Looking back, we managed to survive the recession that started back in 2007 by making tough operational changes over the past three years; and, unlike many organizations, we did this without increasing membership dues. In fact, membership dues have remained the same since January 2009. However, reliance on an improved economy or good luck is not an appropriate action for us at this time. Now, we need to stay current and grow the association, to provide our members the best value for their membership, and to invest in our future.

We retained member confidence in IAEI’s excellent value.

In my "Point in Time” July- August issue, I indicated that it does not matter how I, or the Board of Directors, perceive IAEI; what counts is how you as members, the public, and the electrical industry view us. To understand your viewpoint, we sent out a survey to our members, and we had an excellent response. I want to thank those who took the time to complete the survey as the results provided us with valuable information. Overall, we are pleased with the results and the feedback we received. The survey pointed out several areas where improvements are needed. The survey indicated 87% of our members felt membership in IAEI was of excellent value; however, it also pointed out that we need to do a better job in providing training at the local Chapter and Division levels. We were surprised that many members were not aware of the benefits offered with membership.

So we heard your concerns and feedback, and we have identified several key areas on which we will focus over the next year.

We are increasing the number of local meetings and quality training programs.

First, we will be identifying which of our Chapters and Divisions are not currently offering training or holding meetings. Then we will work with those groups to ensure they hold regular meetings, and we will provide them the support they need to offer quality training programs. Second, we will be looking at better ways to communicate the benefits of membership.

We are reassessing and updating our organizational structure.

During this year’s Executive Committee meeting, the Executive approved the hiring of a consultant to complete an organizational assessment. This resulted from a recommendation made during last November’s board meeting whereby it was noted that our current By-Laws are outdated and are restricting us from growing the association. The findings and recommendations of this assessment will be presented to the Board of Directors during this year’s November Board meeting.

We are re-establishing the IAEI brand.

The Executive Board also agreed that we needed to re-establish IAEI’s brand. The board recognized that our brand is fragmented, and that we must take steps to realign the brand to be viewed as one organization. This means we need to establish IAEI’s brand as a cohesive unit following its mission statement and objectives, and to develop a marketing outreach protocol (templates, logo usage, collateral, messaging, etc.) This will not happen overnight; it is expected to take upward to 18 months or more. We will start by identifying gaps, and we will be working with staff and the Sections, Chapters, and Divisions, and providing them with necessary tools.

We are expanding digital options and becoming interactive.

IAEI magazine has been available in print and in blog format to members for some time. However, it was offered as a beta test in an interactive environment for the past six months. This was available to members at no additional cost and could be accessed from any personal device such as an iPad. We are currently refining the inconsistencies that were found during this initial test. A new interactive will be officially launched in the near future. The new version will be more efficient and engaging. We are also currently piloting the Analysis 2014 book in an E-reader format.

We are updating publications on a tighter schedule.

Our publications are being updated and revised to the current 2014 NEC. Analysis 2014 is currently available. Soares Book on Grounding and Bonding will be available by the first of the year. Hazardous Locations, Photovoltaic Power Systems, the Study Guide books and Ferm’s FastFinder are being updated to the 2014 NEC.

I am excited as to the accomplishments of the past three years and about the direction the Board of Directors is taking to grow and move IAEI to the next level. I commend the work the Sections, Chapters and Divisions are doing to support our members and our mission. Most importantly, I want to thank you, the members, for supporting the IAEI and our mission to promote electrical safety.

We are fund-raising for new facilities to enable growth and outreach.

IAEI Capital Campaign is in progress. I want to thank all those that have donated. We have reached 25% of our goal of two million. We have a way to go.

These funds will be used to help in purchasing a new building complete with modern training rooms for local and remote training; resource library; publication and education work areas to expand production of IAEI products; offices and work areas for staff as well as visiting IAEI members; and electronics infrastructure for internal and expanded external capabilities.

Your donation is a gift for the future. A gift that keeps the public safe by promoting electrical safety through membership, education, and advocacy. A gift that will help future generations of electrical professionals understand the importance of practicing safe installation and staying current with the Code. This association belongs to you, so I encourage you to invest in its future. Donations can be made online at IAEI.org.

Follow Dave on Twitter @DavidEClements

Tags:  Editorial  November-December 2013 

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Easy Does It: The Benefits of a Simplified Solar Permitting Process

Posted By Erica Schroeder, Thursday, October 31, 2013

These days many municipalities and other authorities having jurisdiction (AHJs) are facing tight budgets and staff shortages. At the same time, many AHJs are experiencing dramatic increases in rooftop solar permit applications. Simplifying the solar permitting process is a prime way that AHJs can save time and money, while still promoting economic development in their communities.

According to IREC, nearly 85,000 homes installed solar photovoltaic (PV) systems in 2012, representing 529 MW and a 61 percent increase over 2011. These numbers are only going up. On the sunny island of Oahu, Hawaii alone, the Department of Planning and Permitting issued an impressive 16,715 solar PV permits in 2012, according to the Honolulu Civil Beat. This was a dramatic increase over the fewer than 4,000 permits the Department issued in 2011.

At the same time, residential PV prices fell 27 percent to $5.04 per Watt in 2012. In the first quarter of 2013, they dropped below $5.00 per Watt. Decreasing prices, along with various state, federal and local policies promoting solar, will continue to drive the rapid growth of the solar market.

The growing popularity of solar has direct and immediate impacts on the workload of permitting staff. As a result, simplifying building and electrical permitting processes will likely become increasingly important to more AHJs. Many AHJs have already taken steps to modify their permitting processes to allow them to review and issue solar permits more efficiently.

"It was really beneficial just to lay out the process,” said Kristin Sullivan, the Solar Program Coordinator for the City of Philadelphia, Pennsylvania, referring to the City’s Guidebook for Solar Photovoltaic Projects in Philadelphia. "It helped installers to have a clear understanding of the process and its timelines. It also helped our Licenses and Inspections department interact more easily with applicants. L&I employees could utilize the checklists and documents to help them quickly approve a permit, deny a permit, or ask for more information. This helped the process move forward more smoothly for everyone.”

"We accept applications in many forms, including those based on California State guidelines, local International Code Council Tri-Chapter Uniform Code Committee, and the Solar ABCs forms,” said Don Hughes, Senior Building Inspector in the County of Santa Clara’s Department of Planning and Development. "When the applications are properly completed, all of the required information for a successful expedited plan review is provided. That saves time for both the applicant and the County.”

While an influx of solar permit applications may drive these modifications, AHJs have often been able to implement changes that improve the process for all permit applications, not just for solar.

"We have to process a huge volume of permits,” said Boris Sursky, Roof Plans Processor for

Miami-Dade County. "Our e-permitting Concurrent Plans Processing system allows us to manage this volume efficiently. It saves on travel time for contractors and saves everyone from dealing with lots of paper. It also allows our staff to do multiple simultaneous reviews, which speeds things up significantly.”

Expediting the solar permit review process

AHJs around the United States have found that they can offer expedited permit review for the majority of residential PV installations in their jurisdictions while still protecting public health and safety. Some AHJs provide fast-track treatment for systems that meet certain specified criteria, approving permits over-the-counter or within a few days. Templates for such quick review already exist, such as the Expedited Permit Process for PV Systems by Bill Brooks, published by the Solar America Board for Codes and Standards (Solar ABCs).

"Our over-the-counter process allows us to easily scale up and down depending on the number of applications we receive, which depends on the varying levels of incentives available for solar,” said Jessica Scott, the Solar Program Coordinator for the City and County of Denver, Colorado, a certified Solar Friendly Community. "With our streamlined process, we were able to process 800 solar permits over the course of two months when incentives were high.”

Other AHJs have taken different approaches to speeding up their process. Some AHJs offer expedited treatment for systems that fall within pre-approved templates, as in the City of Honolulu’s Materials and Methods Approval (MMA) process. Others process permits from pre-approved installers more quickly, such as those with a certain number of successful installations under their belts.

Speaking about the various permitting process improvements that the City of Santa Clara, California, has undertaken over the years, Sheila Lee, a City Building Official, said, "anytime we have adopted a streamlining effort, we have seen significant benefits in reduced staff time as well as time for the installers. For example, while the permit process used to require review by three members of our staff, the entire process can now be done by just one plan checker in our offices.”

Improving the inspection process

Inspection is when the rubber meets the road for the approval of a solar installation. While undeniably important to ensuring safety, inspections can also be time-consuming for AHJ staff—especially when the installer is not adequately prepared.

To make sure that the process goes smoothly, AHJs have come up with various improvements.

Miami-Dade County has an especially robust online system to deal with all County inspections. "I see this system as a win-win for contractors and our inspectors,” said Boris Sursky. "It makes the process more efficient for everyone and helps us stay accountable internally. For example, because a contractor can easily cancel a scheduled inspection online up until 8:00 am on the day of the inspection, an inspector doesn’t waste any time going to a site that isn’t ready, and the installer doesn’t fail the inspection and have to pay a re-inspection fee.”

Other AHJs offer checklists and other guidance materials to installers in an effort to help them prepare for the inspection so the inspector does not have to waste time when she or he arrives on site. This sort of guidance can be useful for installers, and it can also double as an internal resource to make sure inspectors understand and apply requirements consistently.

Many AHJs have also determined that they can ensure that a solar system has been installed safely with just one inspection. For AHJs interested in encouraging their inspectors to move to one inspection or to learn more about PV installations, there are a number of resources available, including Photovoltaic Online Training for Code Officials. PV Online Training instructs users in reliable field inspection practices and endorses efficient permit processes for residential PV installations.

Coordinating regionally

Consistent technical and procedural requirements—regionally, statewide, or even nationally—can offer significant efficiency benefits for both AHJs and the solar industry. AHJs within a state or region can look to their neighbors for examples of successful change rather than wasting valuable resources reinventing the wheel.

When consistent forms and processes are in place, it does not just make installers’ lives easier. As installers across the region become familiar with a more standardized set of requirements, they ask fewer questions, submit fewer faulty applications and are better prepared for inspections—all of which save time and resources for AHJs.

The East Bay Green Corridor’s Rapid PV Process is a recent example of a successful regional collaboration to improve the permitting processes by nine California cities east of the San Francisco Bay. "Our participating cities’ commitment to consistent requirements and fast turnaround times should lead to greater satisfaction among contractors and homeowners, and more complete and accurate application packages to the AHJs,” said Carla Din, who served as Director of the East Bay Green Corridor during the development of the Rapid PV Process. "We believe this will result in a greater number of installations and overall benefit to the local economy.”

"On the day we held our press conference announcing Denver as a Solar Friendly Community, our phone was ringing off the hook,” said Jessica Scott. "Other cities wanted to know how we did it because they want to be able to encourage solar in their jurisdictions, too. Clean tech is the fastest growing job sector in Colorado.”

IREC and The Vote Solar Initiative have identified nine Solar Permitting Best Practices, which offer AHJs ideas on how to simplify their permitting processes. Together, IREC and Vote Solar offer a wealth of other resources for AHJs considering permitting reform. Visit IREC’s web site (www.irecusa.org/regulatory-reform/permitting) and Vote Solar’s Project Permit (projectpermit.org) for more information.

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If the nylon on THHN is scuffed, is the insulation damaged?

Posted By Underwriters Laboratories, Monday, September 16, 2013

Question

In the process of pulling THHN conductors through raceway we encountered some scuffing and scraping of the outer nylon conductor covering at the final fitting. The engineer says we ruined the conductor and wants it replaced. Does damage to the nylon covering constitute damage to the conductor insulation?

Answer

A Type THHN wire is comprised of three basic parts, the conductor, PVC insulation, and a nylon jacket. Each part has a specific use. Damage to the nylon jacket only, does not constitute damage to the insulation. The nylon jacket does provide mechanical protection to the insulation during and after installation and also provides gasoline and oil resistance for the wire. The question concerning replacement of the damaged wire can only be answered by visually examining the wire to understand the extent of the damage; and if the PVC insulation is damaged, or if the conductor is exposed to gas and oil, then replacing the wire may be necessary.

UL certifies (Lists) THHN conductors under the product category Thermoplastic- Insulated Conductors (ZLGR), located on page 491 of the 2013 UL White Book and can also be found in UL’s Online Certification Directory at www.ul.com/database and enter ZLGR at the category code search field.

THHN conductors that are certified (Listed) under (ZLGR) are evaluated for compliance with the Standard for Safety for Thermoplastic-Insulated Wires and Cables, UL 83. UL 83 requires THHN conductors to be provided with a nylon jacket extruded tightly over the insulation with a minimum thickness of 4 mils for 14-10 AWG conductors and thicker for larger conductors.


Question

Is there a PDF download available of the 2013 UL White Book?

Answer

Yes, the 2013 version has been improved and is more user friendly and intuitive providing linked navigation embedded into the document for ease of use and with an internet connection, direct access to Code-complaint UL Certified products. The Linked version of the 2013 UL White Book PDF is now posted at www.ul.com/whitebook just click on the banner on the right side of the page.

What does a "linked version” mean? The Table of Contents (TOC) and the Indexes of the UL Product Categories Correlated to the 2008 and 2011 NEC are all linked so that if you click on any TOC entry; or the page number or the category code in the NEC Indexes, it will link you to that page in the file/book. In addition, each of the product category titles in the book (that are not main product categories without any certifications) will link to all the UL Certifications for the product category in the UL Online Certification Directory at www.ul.com/database. This will provide you the proper categories for each code section and then the certifications for those categories, giving the user direct access to code-compliant products.

The links in the pdf will also work on iPads and iPhones by opening and using the file in Drop Box. If you save it directly to your Apple device outside of Drop Box, the links will not work and it will be a regular pdf file. The links in the pdf do not work on Android devices, even if opening in Drop Box. It will just be a regular pdf.

Drop Box is a free application that allows you to share files between all your devices and can be downloaded for free at www.dropbox.com.


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Gloves, Arc Flash, and the New ASTM Test Method

Posted By Hugh Hoagland, Monday, September 16, 2013

The 90-year-old technology of using rubber gloves for shock and leather gloves for protection of the rubber soon could be turned on its head by innovation.

For years, we have heard the question, "What about gloves in arc flash?” The reason this question wasn’t answered sooner is complicated, but the standard is now available. ASTM F2675-13, Test Method For Determining Arc Ratings of Hand Protective Products Developed and Used for Electrical Arc Flash Protection, is an ASTM International standard with an approval date of June 1, 2013, that was expected to be published by ASTM International within the month of July. Testing is progressing already, with more than 25 types of gloves tested in the past few years, now having a specific standard to target.

Photo 1

Gloves meeting this standard may not be designed for shock. Only ASTM D120-compliant gloves are currently approved for use for protection from shock, but some ASTM D120 gloves, all of which are made of rubber, have been tested by this method and could begin to be labeled as such in the near future for the information of the end user. The method, however, really was designed for protection from arc flash only, thus the title.

ASTM D120 gloves on the market today are made only of rubber and are primarily for shock protection, though historically, they have been covered with an ASTM F696 leather protector glove and provide excellent arc-flash protection. The rubber gloves, however, can ignite in arc flash, so a small contingent of the ASTM F18 committee wanted them excluded from the required testing to avoid a possible legal requirement that could not be met. However, rubber gloves that have been tested have shown a strong performance in this arc test method, and certain additives could make them even more flame-resistant in the future. Research is ongoing, but some suppliers plan to label their D120 gloves with F2675 arc ratings and ignition values. Check to see if your supplier has data. Different colors will have different results; and the results, to date, have varied between suppliers even with the same colors because the colors are formulated with different additives to achieve the color.

 

Photo 2.  Rubber gloves with leather protectors are quite protective from arc flashes.  New technologies might make them more flexible and offer a better grip.

 

Photo 3.  A new leather protector has patented "grip strips” developed by a Canadian lineman. It also has a 40 cal/cm² arc rating

Advantages for End Users and Manufacturers

So if this standard is for arc-flash gloves that might not meet ASTM D120 for shock, what good are they? The gloves are useful for arc flash as work gloves. If your hazard assessment for an electrical task includes a shock hazard, ASTM D120 gloves are still your only option, with or without a leather protector (see OSHA, NFPA 70E, and ASTM F496 requirements for protector gloves).

Uses for arc flash gloves include the following:

1. "Heavy duty leather gloves” for arc-flash protection (NFPA 70E-2012, Standard for Electrical Safety in the Workplace, required these for several jobs without shock hazards). But because there was no arc flash test method for gloves, the committee had to make the gloves of a certain thickness. Now, the gloves could be made thinner and still meet minimum protection for the hazard.

2. To replace "heavy duty leather work gloves” when they are inadequate for other multiple threats. Non-leather gloves are being worn in more workplaces today. Non-leather specialty gloves that grip when wet or oily can be engineered to make the gloves more task-specific and ergonomically designed. Now, these gloves also can be arc-rated so that a machine operator who is operating a disconnect will have no need to change gloves when the tables are used for arc-flash hazard assessment but needs a cut-resistant para-aramid.

3. The NFPA 70E Table 130.7(C)(15)(a) Hazard/Risk Category Classifications and Use of Rubber Insulating Gloves and Insulated and Insulating Hand Tools-Alternating Current Equipment and 130.7(C)(15)(b) for DC Equipment require "arc-rated gloves” or D120 gloves with F696 leather protectors for certain tasks. Now, there will be "arc-rated gloves” for the non-shock hazard tasks that have arc flash potential.

4. The additional option the ASTM F18 committee is working on now is to allow OSHA-required (1910.137) "protector gloves” to be something other than leather. The 90-year-old technology of using rubber gloves for shock and leather gloves for protection of the rubber soon could be turned on its head by innovation because the cut standards, puncture standards, and now arc-flash standards for gloves are in place to specify new options to protect workers from shock and arc flash while making gloves lighter, thinner, and giving a better grip.

A new glove on the market from Canada is an ASTM F696 leather glove with a patented added polymer strip on part of the palm, making the leather protector glove have improved grip when oily or wet. This was developed by a lineman in Canada and tested for arc flash last year. It is a potential game changer for protectors. Watch for other innovative designs in protectors soon, now that a performance based test method is available.

Because OSHA mentions "protector gloves” in the standards but doesn’t call them "leather” (though F696 is listed in the standard as acceptable), it is possible we could see knit "protector gloves” being adopted for low voltage within the year. What other options could we see with test methods to test for real product performance? Could we have other improvements in safety equipment for arc flash? Testing has been driving innovation for several years, so expect change for the better.

 

Photo 4: Traditional leather protectors provide puncture, cut and arc flash protection but with this new standard the bar may be raised to allow materials other than leather to be protector gloves with better cut, puncture and even better arc protection in a thinner package.  The possibility is now there.

Selection Considerations

Caution: When selecting gloves for arc flash exposures, two considerations must be followed:

1. Assess the hazard for shock first. If shock hazards exist, use an ASTM D120 rubber insulating glove under the arc flash protector glove and properly match the length of the rubber to be the proper length for the protector gloves. Most companies choose ASTM D696 leather protectors. Additionally, the protector must be shorter than the rubber glove by a distance set in ASTM F496.

2. Assess the arc flash hazard from a realistic distance from the hazard. Most arc flash calculations are for a working distance of 18–36 inches. The hands may well be closer, and this should be considered in the hazard assessment.

Could arc flash crossover, multi-threat gloves for cut, chemical, and arc flash protection be something to consider to update your safety program? Stay tuned as these glove choices increase in the near future.


Hugh Hoagland is senior managing partner of e-Hazard.com, a leading provider of arc flash and electrical safety training, and senior consultant at ArcWear.com, the leading testing company for arc rated materials and PPE.

Reference: Hand Protection -- Occupational Health & Safety, http://ohsonline.com/articles/list/ht-hand-protection.aspx (accessed August 21, 2013).

This article was published in the August 2013 issue of Occupational Health & Safety magazine. ©1105 Media Inc. Reprinted by permission from 1105 Media.

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The Missing Link to Excellent Service

Posted By Steve Foran, Monday, September 16, 2013
Over the last few weeks I have been on the receiving end of unprecedented levels of customer service — at both extremes of the spectrum. The four quick incidents that follow all happened during a weekend away with some old friends.

First, being asked what we wanted for dinner in a restaurant as the waitress was swallowing food herself, and then she was eating pie at the register as we paid our bills. Second, at another meal one of my mates was patted on the back and told, "Finish it off,” instead of asked, "How is your meal?” The fact that he ate less than half of what was on his plate should have been a signal.

On a positive note, for the third incident we had a corner store owner almost do back flips to serve up a bag of ice and two ice cream cones. She was pleasant, talkative, and interested in us. She made us want to come back. And to wrap it up, when we asked the concierge at the resort to point us to our cabins, she explained very politely why she does not point and gestured using four fingers and an open hand. We felt like we learned a universal truth.

In each of these cases, what would prompt someone to act that way?

There are many reasons we could presuppose, all of which are superficial. For the mediocre servers, maybe their boss does not care, or they do not understand the importance of their job, or they do not have the proper training. I do not know.

As for the great servers, perhaps we caught them on a good day, or they are jazzed up about helping others, or they have an incentive to provide great service. Again, I am not sure why.

Regardless, there is one underlying reason that explains the difference between excellent service and mediocre service. The root cause rests in how the server thinks about his or her work.

For people who provide excellent service, they care. They care about the work they do and the customers they serve. For the people who provide mediocre service, quite simply they do not care.

Who knows why these individuals cared or not, but fortunately there is a cure for not caring. There is a feeling, that when elicited, is guaranteed to help people care more. It is the missing link to caring, as well as to excellent service and happy people. It is simple and it will transform someone who does not care into someone who cares.

The missing link is gratitude and you can help someone experience it by asking the question, "What are you grateful for about your work?”

Be patient and listen. Resist the temptation to tell them what they should be grateful for. If they continue having difficulty in finding something to be grateful for, then share what you are grateful for. Be open and honest. Then ask them the question again.

Once someone is genuinely grateful, they cannot help but care. They will seek out solutions to the superficial reasons like lack of training. As a result, they will be happier and the customers they serve will be happier too. Remember, this is not a "bucket list” question. It is a question that must be asked over and over again so that caring and excellent service do not become flavors of the month.

There is one caveat. If you want this technique to work with others, first you must be genuinely grateful and you must care. So make sure you have a good sense of what you are grateful for concerning what you do and those you serve. If someone senses that you are not genuine in how you express your gratitude or your care, the question just might backfire on you.


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Protection of Electrical Conductors Against Exposure to Fire: What, Why and How

Posted By Ark Tsisserev, Monday, September 16, 2013
The subject of fire protection of electrical conductors appears to create some confusion in the industry, and this article attempts to clarify provisions of the National Building Code of Canada (NBCC 2010) in this regard.

Background

Subsection 3.2.7. of the NBCC mandates emergency power for specific systems and equipment that must continue to function in the event that a regular power to these systems and equipment is interrupted.

These specific systems and equipment are defined in Section 46 of the CE Code as "Life safety systems” as follows: "Life safety systems — emergency lighting and fire alarm systems that are required to be provided with an emergency power supply from batteries, generators, or a combination thereof, and electrical equipment for building services such as fire pumps, elevators, smoke-venting fans, smoke control fans, and dampers that are required to be provided with an emergency power supply by an emergency generator in conformance with the National Building Code of Canada.”

Articles 3.2.7.4. and 3.2.7.8. of the NBCC state that for emergency lighting and for fire alarm systems (including voice communication where voice communication is required to be provided as a part of a fire alarm system by Article 3.2.6.8.), such emergency power source could be represented by batteries or generators. These NBCC articles further specify a minimum period of time during which such power supply sources must automatically supply the connected loads. This minimum required period varies from 5 minutes for a building allowed by the NBCC to be equipped with a single zone fire alarm system up to 2 hours, where such systems and equipment are installed in a high building.

 

 Photo 1.  Building exhaust fan system

Although Articles 3.2.7.4. and 3.2.7.8. of the NBCC allow an option of using batteries or emergency generators as the emergency power supply source for emergency lighting and fire alarm systems, Sentence 3.2.7.9.(1) of the NBCC specifically mandates use of an emergency generator capable to operate under a full load for not less than 2 hours as an emergency power supply source for a very particular life safety equipment as follows:

"3.2.7.9. Emergency Power for Building Services

(1) An emergency power supply capable of operating under a full load for not less than 2 h shall be provided by an emergency generator for

a) every elevator serving storeys above the first storey in a building that is more than 36 m high measured between grade and the floor level of the top storey and every elevator for firefighters in conformance with Sentence (2),

b) water supply for firefighting in conformance with Article 3.2.5.7., if the supply is dependent on electrical power supplied to the building,

c) fans and other electrical equipment that are installed to maintain the air quality specified in Article 3.2.6.2.,

d) fans required for venting by Article 3.2.6.6., and

e) fans required by Clause 3.2.8.5.(1)(c) and Article 3.2.8.8. in buildings within the scope of Subsection 3.2.6”.

The NBCC also mandates protection of certain electrical conductors supplying power to the equipment that is identified as part of "Life safety systems” (i.e., of conductors that supply power to the equipment required to be provided by the NBCC with the emergency power supply) and protection of certain electrical conductors supplying power to the equipment that is not specifically identified as part of "Life safety system.

Thus, the subject of protection of conductors against exposure to fire has generated some confusion in respect to the following:

1. Conductors supplying what equipment should be protected? (i.e., does the NBCC requirement include conductors supplying power to mechanical exhaust systems — to remove air from interconnected floor spaces, conductors supplying power to lifts for disabled persons in low and high buildings, conductors supplying every elevator in a high building, conductors supplying a make-up or exhaust air handling systems in low and high buildings, etc.?)

2. What is the extent of the required fire protection of conductors? (i.e., are these conductors required to be protected from the normal or emergency supply, to the equipment being served or to the last distribution panel supplying such equipment, to the devices of a fire alarm system located on a floor, etc.?)

3. What are the means to provide protection of conductors against exposure to fire (i.e., are these conductors required to be enclosed in a shaft enclosure of at least 2 h fire resistance construction, or to be provided with a minimum cover over the raceway of at least 100 mm in concrete, floor slabs or walls that form part of fire separations, or to be circuit integrity cables that conform to the ULC S139 circuit integrity test and that are marked "CIR ULC S139 2 h” in addition to a certification monogram?).

4. Whether such fire protection of conductors is, in fact, required for 1 h or for 2 h?

The following discussion and conclusion on this subject intends to clarify this subject.

Discussion

Article 3.2.7.10. of the NBCC mandates protection of conductors against exposure to fire as follows:

"3.2.7.10.Protection of Electrical Conductors

1) The protection of electrical and emergency conductors referred to in Clauses (a) to (c) shall conform to the requirements stated in Sentences (2) to (8):

a) electrical conductors located within buildings identified in Article 3.2.6.1. serving

i) fire alarms,

ii) emergency lighting, or

iii) emergency equipment within the scope of Articles 3.2.6.2. to 3.2.6.8.,

b) emergency conductors serving fire pumps required to be installed under Article 3.2.5.18., and

c) electrical conductors serving mechanical systems serving

i) areas of refuge identified in Clause 3.3.3.6.(1)(b), or

ii) contained use areas identified in Clauses 3.3.3.7.(4)(a) and (b).

2) Except as otherwise required by Sentence (3) and permitted by this Article, electrical conductors that are used in conjunction with systems identified in Sentence (1) shall

a) conform to ULC-S139, "Fire Test for Evaluation of Integrity of Electrical Cables,” including the hose stream application, to provide a circuit integrity rating of not less than 1 h, or

b) be located in a service space that is separated from the remainder of the building by a fire separation that has a fire-resistance rating not less than 1 h.

3) Electrical conductors identified in Clause (1)(c) shall

a) conform to ULC-S139, "Fire Test for Evaluation of Integrity of Electrical Cables,” including the hose stream application, to provide a circuit integrity rating of not less than 2 h, or

b) be located in a service space that is separated from the remainder of the building by a fire separation that has a fire-resistance rating not less than 2 h.

4) The service spaces referred to in Clauses (2)(b) and (3)(b) shall not contain any combustible materials other than the conductors being protected.

5) Except as stated in Sentences (7) and (9), the electrical conductors referred to in Sentence (1) are those that extend from the source of emergency power to

a) the equipment served, or

b) the distribution equipment supplying power to the equipment served, if both are in the same room (see Appendix A).

6) If a fire alarm transponder or annunciator in one fire compartment is connected to a central processing unit or another transponder or annunciator located in a different fire compartment, the electrical conductors connecting them shall be protected in accordance with Sentence (2).

7) Fire alarm system branch circuits within a storey that connect transponders and individual devices need not conform to Sentence (2). (See Appendix A.)

8) Except as permitted in Sentence (9), if a distribution panel supplies power to emergency lighting, the power supply conductors leading up to the distribution panel shall be protected in accordance with Sentence (2).

9)Conductors leading from a distribution panel referred to in Sentence (8) to emergency lighting units in the same storey need not conform to Sentence (2)”

 

As it could be seen from this NBCC requirement, except for the conductors supplying electrically connected fire pumps required to be installed in any building (and not just in a high building), onlythe conductors that:

(a) supply life safety systems required to be provided with the emergency power supply (regardless of the source), and

(b) are installed in a high building, must be protected against exposure to fire for a period of not less than 1 h.

It could be also seen from this NBCC requirement that in accordance with Sentence (1)(c) above, conductors supplying such equipment as fans providing air supply to the area of refuge compartments that contain operating rooms, ICUs, delivery rooms or recovery rooms in a hospital, or conductors supplying pressurization fans required only in unsprinklered contained use areas of a jail [i.e., equipment that is not specifically identified as being a part of a "Life safety system” by the CE Code and that is not specifically listed by Sentence 3.2.7.9.(1) as being required to be provided with the emergency power supply by an emergency generator] must be protected against exposure to fire for a period of not less than 2 h. It should be noted that the requirement for an emergency generator in this case [as specified by Sentence 3.2.7.10.(1)(c) of the NBCC], would be mandated by Z32 or by the correctional facilities guidelines.

Sentence 3.2.7.10.(5) states that conductors supplying various equipment comprising "Life safety systems” and the equipment listed in Sentence (1)(c) must be protected from the source of the emergency power supply (i.e. from batteries or emergency generator) up to the equipment being served. This Sentence clarifies that only conductors supplying elevators in a high building that is more than 36 m high measured between grade and the floor level of the top storey – must be protected against exposure to fire, as only elevators in a building higher than 36 m are required by Article 3.2.7.9. to be provided with the emergency power. Sentences 3.2.7.10.(7) and (9) further clarify that fire protection of conductors connecting fire alarm system devices within a floor or conductors supplying a unit equipment for emergency lighting or remote lamps within a floor – is not necessary, and only "riser” conductors connecting transponders of a fire alarm system with a CACF or a CPU, or riser conductors supplying distribution panels for emergency lighting between floors must be protected against exposure to fire. It should be noted that although Sentence 3.2.7.9.(1) requires emergency power supply to be provided by an emergency generator for pressurization fans in vestibules serving interconnected floor spaces (see article 3.2.8.5.) in a high building, and for mechanical exhaust system – to remove air from an interconnected floor space (see Article 3.2.8.8.) in a high building, fire protection of conductors supplying this particular equipment does not appear to be listed by Article 3.2.7.10., and perhaps this omission was made by the NBCC writers by accident.

Thus, it is strongly recommended to provide fire protection of conductors supplying pressurization fans for vestibules serving an interconnected floor spaces and conductors supplying mechanical exhaust fans from interconnected floor spaces when such interconnected floor spaces are located in a high building.

Finally, it could be also seen from Article 3.2.7.10. that protection of conductors against exposure to fire could be accomplished by placing these conductors in service spaces with fire separation of the appropriate fire resistance rating (and if this option is selected, it must be discussed with the architects), or by specifying a circuit integrity cable that conforms to the fire test specified in the ULC standard S139. It should be noted that use of such circuit integrity cables is mandated not only by the NBCC, but by the CE Code, ULC S524, and by C282. It should be also noted that Rule 46-204 of the CE Code mandates such fire protection of conductors between an emergency generator and other components of the emergency power supply systems (i.e., transfer switch) when such components of the emergency power supply system are located in separate, not adjoining each other fire rated service rooms.

Conclusion

Electrical conductors between an emergency generator and the following electrical equipment installed in a high building must be protected against exposure to fire for a period not less than 1 h:

1. Pressurization/smoke control fans and dampers required in accordance with Sentence 3.2.6.2.(2) of the NBCC (to control smoke in exit stairs below grade);

2. Pressurization/smoke control fans and dampers required in accordance with Article 3.2.6.3. of the NBCC (in vestibules between a high building and any other building);

3. Every elevator serving storeys above the first storey and that is installed in a high building that exceeds36 m in building height and every fire fighter elevator in a high building;

4. Every exhaust fan installed in a high building and that is used as a smoke venting fan in accordance withArticle 3.2.6.6. of the NBCC (as venting means to aid firefighters);

5. Pressurization/smoke control fans and dampers required in accordance with Article 3.2.8.5. of the NBCC (in vestibules serving an interconnected floor space in a high building);

6. Mechanical exhaust system required in accordance with Article 3.2.8.8. of the NBCC (to remove air from an interconnected space in a high building).

 

Electrical conductors between an emergency generator and the following electrical equipment must be protected against exposure to fire for a period not less than 2 h (regardless whether it is a high building or not):

1. Pressurization fan installed in an area of refuge constructed in a hospital in accordance with Article 3.3.3.6. of the NBCC (in fire compartments that contain operating rooms, delivery rooms or ICUs).

2. Pressurization fan installed in a contained use area in accordance with Article 3.3.3.7. of the NBCC (in unsprinklered buildings only).

Electrical conductors between an emergency generator and each electrically connected fire pump - must be protected against exposure to fire for a period not less than 1 h (regardless whether it is a high building or not): Note: communication conductors between the generator and the transfer switches are also required to be protected against exposure to fire.

 

Electrical conductors between an emergency power supply source (from batteries or an emergency generator) and the following equipment installed in a high building must be protected against exposure to fire for a period not less than 1 h:

1. Fire alarm system control units (except for the control units provided with integral emergency power supply by means of batteries);

2. Fire alarm system transponders or annunciators;

3. Fire alarm system CACF;

4. Distribution panels supplying emergency lighting feeders and circuits to the emergency lighting/remote lamps located on various floors.

Notes: (a) riser conductors between FAS equipment indicated in items 1 – 3 above are also required to be protected against exposure to fire;

(b) fire alarm system conductors within a storey that connect transponders with individual devices and branch circuit conductors between a distribution panel that supply emergency lighting units or remote lights located in the same storey do not have to be protected against exposure to fire;

(c) communication conductors between the fire alarm system transponders, control units and CACF installed in different fire compartments of a high building are also required to be protected against exposure to fire.

 

Conductors that are deemed to be protected against exposure to fire by conforming to the ULC S139 fire test are the conductors that are marked: Circuit Integrity Rating (letters "CIR” 2 h ULCS139)

Note: A typical MI cable or other available circuit integrity cable on the market (i.e., "Draka,” Lifeline,” etc.) with the above referenced marking on the cable outer jacket is deemed to be considered as being protected against exposure to fire for 2 h in accordance with Clause 6.1A of ULC S139. Note: Electrical designers and electrical contractors may choose means of protection of electrical conductors against exposure to fire by placing these conductors in service spaces with the fire resistance rating of at least 1 h, and when such means of fire protection are selected, these means must be coordinated with the architects and general contractors accordingly.

And as usual, local authorities with jurisdictional power for enforcing protection of electrical conductors against exposure to fire must be consulted during the design and installation stages.


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Tags:  Canadian Perspective  September-October 2013 

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