Posted By ESFI,
Wednesday, November 13, 2013
| Comments (0)
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.
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.).
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.
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 email@example.com or (703) 841-3229.
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.
Read more by ESFI
Posted By Joseph Wages, Jr.,
Wednesday, November 06, 2013
| Comments (0)
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
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
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
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:
(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
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
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.
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.
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
UL Standard 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
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.
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
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.
Posted By David Clements,
Wednesday, November 06, 2013
| Comments (0)
We managed to survive the
recession without increasing
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
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
We are reassessing and
updating our organizational
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.
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
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
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.
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
Posted By Erica Schroeder,
Thursday, October 31, 2013
| Comments (0)
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
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.
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.”
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.
to process a huge volume of permits,” said Boris Sursky, Roof Plans Processor
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
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
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
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.
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
Online Training instructs users in reliable field inspection practices and
endorses efficient permit processes for residential PV installations.
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
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
"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.
Posted By Underwriters Laboratories,
Monday, September 16, 2013
| Comments (0)
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?
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.
Is there a PDF download available of the 2013 UL White Book?
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.
Read more by UL
UL Question Corner
Posted By Hugh Hoagland,
Monday, September 16, 2013
| Comments (0)
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.
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
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.
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
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.
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.
Hand Protection -- Occupational Health & Safety,
http://ohsonline.com/articles/list/ht-hand-protection.aspx (accessed August 21,
This article was
published in the August 2013 issue of Occupational Health & Safety magazine.
©1105 Media Inc. Reprinted by permission from 1105 Media.
Posted By Steve Foran,
Monday, September 16, 2013
| Comments (0)
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.
Read more by Steve Foran
Posted By Ark Tsisserev,
Monday, September 16, 2013
| Comments (0)
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.
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 126.96.36.199. and 188.8.131.52. 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 184.108.40.206.), 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 220.127.116.11. and 18.104.22.168. 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 22.214.171.124.(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:
"126.96.36.199. 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 188.8.131.52., 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 184.108.40.206.,
d) fans required for venting by Article 220.127.116.11., and
e) fans required by Clause 18.104.22.168.(1)(c) and Article 22.214.171.124. 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.
Article 126.96.36.199. of the NBCC mandates protection of conductors against exposure to fire as follows:
"188.8.131.52.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 184.108.40.206. serving
i) fire alarms,
ii) emergency lighting, or
iii) emergency equipment within the scope of Articles 220.127.116.11. to 18.104.22.168.,
b) emergency conductors serving fire pumps required to be installed under Article 22.214.171.124., and
c) electrical conductors serving mechanical systems serving
i) areas of refuge identified in Clause 126.96.36.199.(1)(b), or
ii) contained use areas identified in Clauses 188.8.131.52.(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 184.108.40.206.(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 220.127.116.11.(1)(c) of the NBCC], would be mandated by Z32 or by the correctional facilities guidelines.
Sentence 18.104.22.168.(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 22.214.171.124. to be provided with the emergency power. Sentences 126.96.36.199.(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 188.8.131.52.(1) requires emergency power supply to be provided by an emergency generator for pressurization fans in vestibules serving interconnected floor spaces (see article 184.108.40.206.) in a high building, and for mechanical exhaust system – to remove air from an interconnected floor space (see Article 220.127.116.11.) in a high building, fire protection of conductors supplying this particular equipment does not appear to be listed by Article 18.104.22.168., 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 22.214.171.124. 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.
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 126.96.36.199.(2) of the NBCC (to control smoke in exit stairs below grade);
2. Pressurization/smoke control fans and dampers required in accordance with Article 188.8.131.52. 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 184.108.40.206. of the NBCC (as venting means to aid firefighters);
5. Pressurization/smoke control fans and dampers required in accordance with Article 220.127.116.11. of the NBCC (in vestibules serving an interconnected floor space in a high building);
6. Mechanical exhaust system required in accordance with Article 18.104.22.168. 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 22.214.171.124. 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 126.96.36.199. 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.
Read more by Ark Tsisserev
Posted By Jeff Greef,
Monday, September 16, 2013
| Comments (1)
Most residential electrical services are not
designed to accept two sources of power, but they are often utilized for the purpose
of connecting PV systems in addition to utility power. NEC Article 705
provides accommodation for such connections, but sometimes these accommodations
cannot be used without replacing the service enclosure, or adding a distribution
panel, or making a supply-side connection, all of which entail additional cost.
Occasionally installers get "creative” by tapping directly into feeder
conductors coming off the service to a subpanel in the house. Article 705 is
silent on this specific method, and controversy exists as to whether it is a
compliant method at all. Jurisdictions must decide for themselves whether this
is compliant; and if they do allow it, examiners and inspectors must be aware
of how such an installation triggers the provisions of Article 705 which are
meant to prevent the overloading of conductors or busbars. This article
explores the specific issues encountered in such an installation.
For a broader treatment of NEC 705.12(D)
regarding requirements for making load-side connections for PV systems, see the
papers and articles on the subject written by John Wiles of the Institute for
Energy and the Environment at New Mexico State University. Those articles are
referred to at the end of this one. Mr. Wiles has written extensively on the
fundamental intent of 705.12(D). The focus of this article is how 705.12(D) comes
into play only in the case of a load-side tap. This specific issue brings the
fundamental intent of this code section to bear and so requires a brush up on
the basics of these provisions. See John Wiles’ article in the January-February
issue of IAEI magazine, "Unraveling the Mysterious 705.12(D) Load Side
PV Connections,” which demonstrates the basic intent of these provisions as
they pertain to connections at a load center bus bar with a breaker. Mr. Wiles’
article does not address the issue of tapping into feeders; however, the same
principles that come into play at bus bars with breakers also apply with
feeders and taps.
When a PV system is connected to a load center by a
breaker, the problem that can occur is overloading the busbars (see figure 1).
For example, if the main disconnect and
busbars are rated at 200 amps, and the PV system is capable of producing 40
amps, it is then possible to pull 240 amps off the busbars via feeders and
branch circuits, if the users of the system connect enough equipment simultaneously. Section 705.12(D)(2) requires that the "sum
of the ampere ratings of overcurrent devices in circuits supplying power to a
busbar or conductor shall not exceed 120 percent of the rating of the busbar or
conductor.” So, 240 amps are allowed onto busbars rated at 200 amps. But,
705.12(D)(7) requires that PV breakers be located at the opposite end of the
busbar from the utility feed. Figure 1 shows why. If the PV 40-amp breaker is
located adjacent to the utility feed, the sum of amperage on the busbars
immediately after that breaker can be 240 amps, too high for the metal of the
busbar. But, if the breaker is located at the opposite end, this cannot occur,
since power is fed from two different directions. As we will see, a similar scenario can exist
when tapping into feeders with a PV system.
Figure 1. PV load side connection at breaker complaint and non-compliant breaker locations
Tapping into Feeders
Figure 2 shows conductors from a PV inverter
connected to the system by tapping into feeder conductors coming off a breaker
in the service panel. The figure shows a service that has very few breaker
slots, only enough for feeders to a subpanel and several others for loads such
as AC and range. On such a panel, if all slots are taken, the installer cannot
add a breaker to connect the PV. The connection could be made with a breaker at
the subpanel (if all rules are followed), but routing conduit to a subpanel
inside the house is often difficult. A line side connection could be made at
this service panel, but this entails installation of an additional service
disconnect and could violate the terms of listing of the meter enclosure, which
was designed to handle only utility power. A separate subpanel could be
installed adjacent to the service, but this is expensive. Tapping directly into
the feeders is easy, but is it safe and compliant?
Figure 2. Load side PV tap overloaded feeders and busbars
Is This a Tap?
NEC 240.2 defines a tap conductor as "…a
conductor, other than a service conductor, that has overcurrent protection
ahead of its point of supply that exceeds the value permitted for similar
conductors that are protected as described elsewhere in 240.4.” In figure 2,
the overcurrent protection for the feeders exceeds the value permitted for the
PV conductors spliced onto the feeders, but one could argue that those feeders
are not the point of supply for the PV conductors, so that these conductors are
not "taps” at all. However, in the event of fault current between the splice
and inverter, the feeders will supply fault current to the spliced PV
conductors, and the only overcurrent protection to clear this fault is the
feeder OCPD. For this reason the PV conductors qualify as tap conductors, even
though in normal operation they will put current onto the feeders rather than
pull current off of them. If such an installation is allowed by the AHJ, the
tap rules of 240.21(B) must be followed.
Can a Tap Connect PV?
Section 705.12(D)(1) states that the connection
from an inverter must be made "at a
dedicated circuit breaker or fusible disconnecting means.” Figure 2 shows the
tap conductors originating from a 60-amp fused disconnect. Is the connection of
the PV system to the other system made at the tap splice itself, or is it made
at the 60-amp disconnect? Opinions seem to vary on this point. Some consider
that the tap conductors from the splice to the disconnect are part of the other
system, so that the two systems are connected at the disconnect. Others
consider that the tap conductors are part of the PV system, so that the two
systems are connected at the splice. Taking the latter position, the connection
is not compliant because it is not made at a breaker or fusible disconnect, but
rather at a splice. Taking the former, it is compliant since the connection is
at a fused disconnect. Since the code is silent on this issue, each AHJ must
decide this point for himself. The remainder of this article presumes that the
tap connection is judged compliant if it leads to a breaker or fusible
disconnect as in figure 2.
Overloading the Feeders
Figure 2 shows the PV system spliced into the
feeder conductors somewhere along their length. The feeders are protected by a
100-amp breaker. Let us say for sake of discussion that the feeders themselves
and the busbars on the subpanel are rated at 100 amps each, and that the PV
system is capable of putting 30 amps onto the feeders in sunlight. When few or
no loads are being pulled off the subpanel during daylight, the current from
the PV system will backfeed toward the utility. When more than 30 amps are
pulled from the subpanel in daylight, the 30 amps from the PV will go to the
subpanel and the utility will make up the difference. If the building users
connect enough equipment during daylight, they can conceivably pull a total of
130 amps through the subpanel before the 100-amp feeder breaker trips or the
30-amp PV breaker trips.
Let’s say the
users are pulling 130 amps and no breaker trips. The section of the feeders
from the 100-amp feeder breaker to the splice is carrying 100 amps, its maximum
rating. The PV tap conductors from the 30-amp disconnect to the splice are
carrying 30 amps, for which they are rated. But the section of feeders from the
PV splice to the subpanel busbars is carrying 130 amps. As well, the tops of
the busbars themselves, before any breakers take loads off the busbars, are
carrying 130 amps. In this case, both the feeders from the splice and the busbars
are well beyond their ratings and can overheat, distort, burn insulation, etc.,
with no breaker tripping to protect the circuit.
If the PV system were smaller and its breakers were
at 20 amps, the feeders from the splice and the busbar tops would carry 120
amps, which is 120 percent of their rating, and therefore compliant with
705.12(D)(2), the 120 percent rule. However, this installation still violates
the intent, if not exactly the wording, of 705.12(D)(7) which requires that the
connection in a panelboard be made at the opposite end of the busbars from the primary power source. But in this case, we
are dealing with a connection at feeders as well as at a panelboard. Since the
provision regards only a connection at a panelboard, it is debatable whether it
applies to feeders. But still the intent of the provision is clear — the
connections must be made in a way that avoids overloading any given section of
busbar or conductor. In both the 30-amp and 20-amp PV scenarios described
above, such serious overloading is possible because the tap does not connect at
the opposite end from the primary feed. It is added to the primary feed, so
that the sum of amperages enters the feeders mid-way, and the panel from only
one end, in these cases overloading both feeders and busbars.
Size Down the Feeder Breaker
Let us say
that the installer suggests sizing down the breaker for the feeders from 100
amps to 70 amps (in the 30-amp PV scenario). In this case, it will no longer be
possible to pull more than 100 amps through any section of conductor or busbar.
However, this assumes that 30 amps are always available from the PV system
which, of course, they are not when sunlight is not on the PV array panels. At
night the maximum that can be pulled through the subpanel is the 70 amps. If
load calculations for the building show that 70 amps is enough, this is a quick
fix for an otherwise non-compliant situation. If load calculations are over 70
amps, there is a risk of nuisance tripping at the feeder breaker; but the absence
of a working calculation should prevent the installation at all.
Oversized Feeders and Busbars
consider the situation if both the feeders and the subpanel busbars are
oversized to begin with. In figure 3, the feeders are rated for 140 amps and
the subpanel busbars are rated at 200 amps, but the feeder breaker is 100 amps
and the calculated load is below 100 amps. Now the installer taps into the
feeders with 30 amps, and the users connect enough equipment to pull 130 amps
through the subpanel during daylight. Current in the feeders is below their
rating, and the panel is well below its capacity; but this still seems to
violate the provision in 705.12(D)(7) which tells us to locate the PV
connection at the opposite end. Or does it?
The text reads,
"Unless the panelboard is rated not less than the sum of the ampere ratings of
all overcurrent devices supplying it, a connection in a panelboard shall be
positioned at the opposite (load) end from the input feeder location… .” In
this case, the sum of the ampere ratings of the breakers is less than the
ratings of the subpanel busbars or the feeder conductors, so no possibility of
overload exists. This code provision is written to cover scenarios where
busbars are not oversized to begin with, where the addition of another power
source presents a possible overload problem. But the provision allows for
situations where equipment is oversized to begin with, which avoids the
possibility of overload so long as the total amperage fed into the busbars is
below the capacity of the equipment. The same principle applies to the feeder
conductors. Section 705.12(D)(7) is in place to prevent overheated equipment.
It is not necessary to locate the PV connection at the opposite end of the
busbars in this scenario because connecting it ahead or anywhere else cannot
cause an overload.
Figure 3. Load side PV tap oversized feeders and subpanel busbars
Tapped Feeders in a Gutter
shows an installation where three subpanels are fed off of tap conductors in a
gutter. Two possible locations are shown for tapping a PV system onto the main
feeders along with the taps for the subpanels. The same principles apply here
as in the above scenarios. If the PV system tie in occurs upstream of the taps
for the subpanels (PV tap location 1), the section of feeder between the PV tie
in and the first subpanel tap splice can theoretically have an amperage running
through it that is equal to the sum of the main disconnect breaker and the
amperage supplied by the PV system. If this total amperage is greater than 120
percent of the rating of the feeder, 705.12(D)(2) is violated. If it is within
120 percent, it is still necessary to locate the tap at the opposite (load) end
of the feeder, just as you would do with locating a breaker on a busbar, to
comply with 705.12(D)(7). PV tap location 2 shown in the figure is located
where its amperage cannot be added to the amperage coming from the main
disconnect on any given length of the feeder, avoiding overloading that
section. But if the main feeder is oversized to begin with, locating the PV tap
upstream of the subpanel taps is compliant so long as no section of conductor
(or busbar) is overloaded.
Figure 4. Load side PV tap in a gutter with feeder taps
Most residential service load centers are not
designed to accept secondary sources of power such as PV systems. Connecting to
these load centers can be easily done with a backfed circuit breaker, within
certain parameters. But installers are
faced with connecting to a wide range of load center configurations, where
sometimes such a breaker cannot be installed. Sometimes a load-side tap is the
option of choice. Such a connection raises various code issues which inspectors
and installers must be aware of. The basic principles of installation laid down
in the code for use in connecting with circuit breakers also apply when
installing a load-side tap. Thorough understanding of the principles behind the
provisions is essential to ensure safe, effective installations of PV
connections with load-side taps.
John Wiles articles at New Mexico State University
can be found at:
Solar Ready Residential Service Panel
The photo shows a Siemens "solar
ready” service panel which is produced as a response to the need for easier
connections with PV systems.
This panel design constitutes a
line-side tap. A separate set of busbars, rated at 60 amps, is supplied for
connecting to an inverter with a set of breakers. That set of busbars is
connected directly to the load side of the meter socket before the main
disconnect, bypassing the main busbars altogether. This also bypasses all the difficulties
involved with load-side connections.
Since the line-side tap
connection is integral with the equipment and a part of its listing, it avoids
the problem of violating the listing of a panel by connecting a line-side tap
where the equipment is not approved for such use. But it will be a long time
before significant numbers of such panels are installed; and, meanwhile, the
majority of PV installations will be done on older service panels that were not
designed for the use.
With effective application of
existing code provisions, those panels can be safely utilized with PV while we
make the decades-long transition to equipment designed for the purpose. But 20
years from now, you’ll still see someone trying to do a line-side tap into a
rusty Zinsco 100-amp service at the meter socket, because there is no room for
more breakers and the owners would rather spend their cash on granite
countertops than a nice shiny new service panel.
Jeff Greef is a combination inspector with the City
of Cupertino in Silicon Valley, California.
Posted By Leslie Stoch,
Monday, September 16, 2013
| Comments (0)
The Canadian Electrical Code Part I is a voluntary standard for adoption and enforcement by Canada’s provinces and territories, with provincial and territorial amendments. We rely on the CEC to provide safety standards for installation of electrical wiring and equipment. Its stated purpose is preventing electrical fire and shock hazards. But not all of its requirements are between its covers. Sometimes, we must get into other publications to obtain more complete information. This article reviews some examples.
Rule 12-012 provides, in great detail, the CEC requirements for installing high and low voltage underground conductors and their allowable ampacities (Table 53). At the end of this lengthy rule we find Rule 12-012(13) which advises us, that when an installation falls outside the scope of this rule, we must go to the underground standard, CAN/CSA-C22.3 No. 7. Reference to that standard brings its applicable parts into the CEC.
Rule 36-300 and Table 51 provide minimum grounding conductor requirements for substations over 750 volts for minimum copper wire sizes based on the available short-circuit current and fault current duration. A footnote to Table 51 indicates that wire sizes have been calculated using the IEEE Guide for Safety in AC Substation Grounding, ANSI/IEEE Standard No. 80. Table 52 provides maximum step and touch voltages in and around substations for several types of earth. You will note that a footnote to this table once again specifies that its values have been calculated using ANSI/IEEE Standard No. 80.
Rules 36-304 and 36-306 stipulate that maximum substation ground resistance for stations over 7500 volts must be calculated, based on available fault current levels and earth resistivities. Appendix B identifies the CEA Research Report 249-D-541 as the approved method of working out substation grounding electrode design. That document in turn references ANSI/IEEE Standard No. 80, which contains all of the formulae necessary for controlling step and touch voltages and conformance to Table 52.
Rule 32-200 requires that fire pump conductors be protected against fire exposure and to provide continued operation in compliance with the National Building Code of Canada. The rule refers us to Appendix B which elaborates on the rule — when called upon, fire and life safety systems must continue to operate for at least one hour. Checking Appendix B, we note it makes reference to NFPA Standard No. 80 as a further source of information for installation of fire pump wiring.
Rule 36-108 and Table 31 list minimum horizontal spacings between overhead conductors on pole lines for voltages up to 69 kV. A Table 31 footnote shows that the table does not cover voltages over 69 kV and pole spans greater than 50 m. For that information, we are referred to the CSA overhead lines standard CAN/CSA-C22.3 No. 1.
Rule 36-110 and Table 32provides vertical clearances for live parts up to 230 kV for indoor and outdoor substations for areas accessible only to pedestrians and areas accessible to vehicles. The vertical outdoor clearances are based on location — whether the substation is in a light or heavy snow area of the province or territory. Appendix B tells us that this information should be obtained from the Meteorological Service of Canada, Environment Canada, or the Atlas of Canada published by Natural Resources Canada.
Rule 18-000is the scope paragraph of Section 18 – Hazardous Locations. This rule refers to Appendix B which displays a long list of documents affecting the design of hazardous locations containing explosive gas atmospheres, combustible dusts or ignitable fibres. Appendix B shows 3 tables listing the applicable reference publications:
Table A – Documents generally applicable to all classes of hazardous locations.
Table B – Documents applicable specifically to Class I hazardous locations.
Table C – Documents Applicable specifically to Class II hazardous locations.
As you already know, the Canadian Electrical Code does not stand alone. As with previous articles, you should always check with the electrical inspection authority in each province or territory for a more precise interpretation of any of the above.
Read more by Leslie Stoch