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In the making of the 1999 Code, thirty-nine proposals to Article 517 were accepted in one form or another. The code making panel itself generated twenty-two proposals. The majority of these proposals were to change the exceptions to positive language. Outlined below are some of the major changes that were adopted in this article.

Section 517-3 Definitions—Emergency System. In the first sentence, the wording “except as amended by Article 517” was added. This change will take precedence over other articles in the Code. In the past there has been a lot of confusion with authority having jurisdiction (AHJ) using the language in Article 700 to enforce sizing the standby generator for connected load, and this change, hopefully, will eliminate the confusion.

Section 517-3(a) Exception No. 3. The wording, “and switches located outside of the patient vicinity” was added to the exception because of some confusion, and the panel’s intent was that redundant grounding of the switch yokes was to be required only in the patient vicinity.

Section 517-18(c) Exception. The word “Exception” has been deleted, and the word “listed” was added before “tamper.” Also, the last sentence about a tamper resistant receptacle has been deleted. There are no such test requirements from any third party testing laboratories to evaluate covers or plates to ensure that they will be resistant tampering.

A number of widely distributed books on the 1996 Code mislead installers and inspectors into selecting noncompliant products. The 1996 Analysis of the National Electrical Code published by the IAEI (the authoritative spokesman to the enforcement profession) shows a conventional hooded cover leading readers to believe that such covers might be acceptable.

Section 517-18(a) Exception No. 3. This new exception was added to emphasize that a general patient bed location that is served from two separate transfer switches on the emergency system is not required to have a circuit from the normal operating system.

Section 517-30(c)(3) Exception No. 5. The word “listed” has been added to “prefabricated medical headwalls;” and “listed office furnishing” has been added to the exception. This will make it clear that all prefabricated medical headwalls and office furnishings will have to be listed before flexible metal raceways and cable assemblies can be installed in them. Also, this should clear up some confusion that seemed to exist in allowing flexible metal raceways and cable assemblies to be connected to office furnishings as they are not considered prefabricated medical headwalls.

Section 517-33(c). This new section has been added: “(c) Receptacle Identification. The receptacles or the faceplates for receptacles supplied by the critical branch shall have a distinctive color or making so as to be readily recognizable.” This change has been brought about because many jurisdictions do not recognize, or enforce, or acknowledge the identical provisions in NFPA 99, 12-3.3.2.

Section 517.160(a)(5). A new sentence has been added to read, “Where isolated circuit conductors supply 125-volt single-phase, 15- and 20-ampere receptacles, the orange conductor(s) shall be connected to terminal(s) on the receptacles that are identified in accordance with Section 200-10(b) for connection to the grounded circuit conductor.” There seems to be some confusion as to the method of connecting isolated circuit conductors to receptacle terminal(s) for the proper polarity. This provision should now make it very clear where the orange conductor of an isolated circuit should be connected. This change was taken from the Canadian Electrical Code, Rule 24-204(2)(d).

Jim Schmer, chief electrical inspector for Boise City Building Department since 1983, began his career as a journeyman electrician in 1970, and started working with the Boise City Building Department in 1978. He is past president of the Idaho Chapter of the IAEI and past president of the Northwestern Section. He is a member of the Idaho Chapter executive board and was elected to the IAEI international board last year. He has represented IAEI on code making panel 17 for three code cycles.

Major changes done by Panel 4 for the 1999 NEC on Articles 225, Outside Feeders and Branch Circuits, and Article 230, Services

by Junior Owings

Article 225 has now been divided into three parts. Part A—General, Part B—More Than One Building or Other Structure, and Part C—Over 600 Volts.

Several reasons brought this change about. After panel four reviewed the comments to the ROP Section 225-8, the panel considered how best to address the various comments and still maintain the integrity of this section and Article 225.

With more and more installations over 600 volts now owned by the customer, and under the authority of the NEC and not the serving utility, there appeared to be a much greater need for provisions in Article 225 to cover installations over 600 volts. This was further augmented by the fact the provisions formerly found in Article 710, Over 600 Volts Nominal, were being deleted and had to be moved into other respective articles.

After a considerable amount of discussion between panel members, the panel determined the best way to address the comments was to form a subcommittee and divided the article into various parts, taking into consideration the various comments along with existing section requirements. The comments were then reviewed and needed changes placed into the respective part and section.

Prior to dividing Article 225 in parts, the article did not contain any provisions for installations over 600 volts. Also Article 710 contained only a limited number of provisions for outside feeders and branch circuits.

As a result of dividing Article 225 into various parts, some renumbering also had to take place.

You will find many of the provisions found in Part H of Article 230, which could apply to outside feeders and branch circuits, are also now included in the new Part C of Article 225.

The panel is aware there may be additional provisions which need to be incorporated into the new Part C. With the creation of the new part, the door is now open for the submission of new proposals for consideration for the next code cycle.

Some of the additional changes which occurred in Article 225 are: Section 225-31 is new and requires all feeders and branch circuits which pass through a building to serve another building, shall have a disconnecting means nearest the point of entry into the building through which they pass.

In the 1996 NEC, Section 225-8(b) made reference to Section 230-71 “maximum number of disconnects” this provision has been incorporated into the new language of Section 225-33. Additionally the reference to Section 230-72 “grouping of disconnects” has now been incorporated into the new language of Section 225-34 and access to occupants. Section 230-72(c) has identical language placed in Section 225-35.

The majority of changes which occurred in Article 230 consisted of language revisions to further clarify the intent of the section.

There are several new provisions which may be of interest. In addition to the vertical distances required by Section 230-9, for service drop cables, a new horizontal distance of 3 feet now shall also be maintained from the items found in this provision, such as decks, platforms, etc.

A new change occurred in Section 230-46 which now allows splicing of service entrance conductors providing splices are made in accordance with 110-14, 300-5(e), 300-13, 300-15 and made in approved enclosures of proper size using approved splicing devices.

Section 230-205(c) also was revised and it now permits multi-building industrial installations under single management, to have the service disconnecting means electrically operated and controlled from a readily accessible location by a remote control device.

Junior L. Owings, semi-retired, teaches continuing education classes for the state of Oregon and performs electrical field inspections for local jurisdictions. He served as chief electrical inspector for the state until 1998. He is an Oregon-certified A-level electrical inspector and currently holds an active Oregon general supervisor license and a Washington general journeyman license. He is an alternate international board member for the IAEI, past president of the Oregon Chapter, and currently is secretary/treasurer of the chapter. He has served as an alternate member of NFPA code-making panel 4 for the last three code editions. He is a past member of Underwriters Testing Laboratories Electrical Safety Council. He has been an active IAEI member since 1979.

Article 600 in the 1999 NEC

by Tom Trainor

It is now fair to say that the complete rewrite of Article 600 in the 1996 NEC was very successful. This statement is based on a collection of experiences since the rewrite. There are a fewer code questions at sign seminars. This indicates that the article is easier to read and understand. The questions that are raised are generally about grounding or wiring methods. The number of proposals submitted for the 1999 NEC were considerably less than those submitted for the 1996. Most dealt with grounding, wiring methods and sign products. This indicates, again, that the bulk of the requirements are clear and understandable. The ongoing issues revolve mainly around the different sign products and how they can be use din the field. This is partly a testing and listed issue and partly a code issue. This closer look at Article 600 is intended to provide some insight into the issues addressed by the panel and to explain the basis of some of the changes accepted in the 1999 NEC.

First, as with all panels, a conscientious effort was made to rewrite exceptions into positive code language. The panel was very successful in this effort. Only three exceptions remain in Article 600. Two are in Section 600-6 and one is in Section 600-8. These are true exceptions which allow something different from the basic requirement contained in the section, and the panel felt that it was appropriate to maintain them as exceptions.

The changes to Section 600-4 are of the “good news, bad news” type. The good news is that the requirements for markings have been rewritten to be easier to understand. The bad news is that the requirement for markings to be “visible after installation” has been deleted. This was a sign industry proposal based solely on aesthetics which, in my opinion, should not have been accepted by the panel. However, in the code making process, these things do happen and if field experience proves it to be a problem, there will be proposals to change it for the 2002 NEC. Theoretically, this would allow the sign manufacturer’s label to be placed on the back of a wall sign so that you could only verify that the sign was listed before it was installed. In practice, the proponents may have won the battle and lost the war. Some inspections typically occur after the sign is installed. Most inspectors are going to want to see the UL label at that time. Manufacturers know that and are unlikely to place their labels so that they can not be seen. Contractors are unlikely to install signs with hidden labels after they have had to remove a sign to demonstrate that it is really listed. So this is a change that could have a major impact but probably will not.

One of the major changes to Article 600 is in Section 600-7 dealing with grounding. The basic requirement, which is unchanged, is that all signs and the metal parts of outline lighting systems have to be grounded. However, this section goes on to deal with two specific wiring methods for secondary conductors, the small metal parts of signs, the metal parts of buildings and the minimum size and type of conductor to be used for the purpose. It is important to read this section slowly and carefully. While each of the individual requirements is fairly clear, overall the section is one long, run together paragraph. There will undoubtedly be proposals for the 2002 NEC  to break this section into numbered subsections imply to make it easier to read.

  The other potentially confusing issue is an apparent inconsistency in the terms used in the section. Although the section heading is Grounding, the terms grounding and grounded are only used in the first sentence (the basic requirement) and the last sentence, which deals with the metal parts of buildings. All of the other requirements in this section use the terms bonding or bonding conductor. In point of fact, the use of these terms is generally consistent with the changes in Article 250. Section 250-2 now makes two things clear. Grounding is a connection to earth intended to provide protection from lightning and high voltage. Bonding is the interconnection of metal parts that creates a fault current path from electrical equipment to the service neutral to assure that overcurrent devices will work under fault conditions.

The use of the term bonding reflects the panel’s understanding that the important issue with signs is to bond the metal parts together and to the transformer secondary “neutral.” Since the transformer secondary is, in effect, a separately derived system, both grounding and bonding conductors return to the common terminal on the transformer. This provides a fault current path from the sign to the transformer that assures that the secondary ground fault device will function properly. In this case, it is better not to get hung up on grounding versus bonding, but to focus on creating an effective fault current path.

There are two new requirement sin Section 600-7 dealing with the spacing of nonmetallic conduit from grounded or bonded parts. These represent an effort to deal with the effects of the electro-magnetic lines of force created by the flow of current in the secondary conductors. Every conductor carrying current generates a magnetic field which surrounds the conductor. When the conductor is run in metallic conduit, the lines of force tend to all compress into the conduit surrounding the conductor because metal offers less resistance to magnetic flux than air. Although the magnetic lines of force are now more concentrated, they are still more or less symmetrical around the conductor. This keeps the stress on the conductor more or less equal all around the conductor.

However, when a current carrying conductor is run in nonmetallic conduit and a bonding conductor is run along the conduit, the magnetic lines compress into the bonding conductor on that side of the conductor and remain expanded on all other sides. This compressed magnetic field goes from zero to maximum and back to zero with every alternation of the current flow. The stresses on the conductor from the compressed magnetic field on the one side are much higher than those on the other sides and the ongoing “unbalanced stress” causes deterioration of the conductor insulation.

The intent of the new requirements is to provide spacing between the secondary conductor and the bonding conductor so that this unbalanced stress condition is not created. This same requirement was added in Section 600-32(a) to require spacing between secondary conductors in nonmetallic conduit and all bonded or grounded parts. The panel understands that this is simply one step in the ongoing effort to reduce GTO failures in neon installations. The panel has indicated to UL that the standard for GTO Cable should be reviewed to determine if the present construction and testing of GTO is adequate for its use in neon secondary circuits. IAEI has also raised this issue with UL through the IAEI/UL Technical Advisory Panel. The concern is that conductors use din the secondary circuits of neon signs are subject to “unbalanced stresses” in normal and typical installations and should be capable of withstanding those stresses without relying on special and unrealistic installation restrictions. There is some indication that UL will be revisiting this standard.

One of the smallest changes in the 1996 NEC created a large stir in the industry. This was an increase in the minimum size of the bonding conductor from No. 14 CU to No. 12 CU. The feeling was that there was no documentation to substantiate a need for the change and that No. 14 CU had served effectively for many years. The panel received this input in many proposals and took action in Section 600-7 to return the minimum size bonding conductor to No. 14 CU.

The prohibition on using the metal parts of a building as a grounded conductor or as an equipment grounding conductor already existed in Section 600-32(a) but was intentionally repeated in 600-7 because it is a grounding requirement which was often overlooked because of its location in the section on Wiring Methods.

The changes in Sections 600-9 and 600-23(a) are editorial, but there is a new requirement in Section 600-23(f) that is significant. There is a requirement that transformers and power supplies be marked to indicate that they have secondary fault protection. This should help to eliminate the confusion in identifying transformers and power supplies that meet the requirements of Section 600-23(b).

There are two major changes in Section 600-32(a). The one regarding spacing from bonded or grounded parts was previously noted. The second deletes electrical nonmetallic tubing as an acceptable wiring method for secondary circuit conductors. This was the final result of an intensive panel discussion of proposals which would have prohibited all nonmetallic wiring methods for this use. The concern expressed by the proposer was that nonmetallic wiring methods will not contain arcing and sparking which occur when the secondary cable fails. The panel’s ultimate conclusion  was that wiring methods are only intended to protect secondary conductors from physical damage and that the concern over arcing was addressed by the requirement for secondary fault protection. The panel also noted that cable failures caused by normal electrical characteristics such as electro-magnetic stress, corona and capacitive inductance should be addressed through the testing and listing process. In other words, GTO cable should be constructed so that it is capable of withstanding these stresses, which are a normal part of the neon secondary circuit. The panel supported the deletion of ENT because they felt that its flexibility would make it very difficult to maintain the required spacing between it and the bonding conductor.

Section 600-32(e) was amended to note that no spacing is required between GTO cable and the metal conduit or tubing in which it is installed. This was simply a clarification, as the previous wording could have been interpreted to require a 3 ½" conduit for a single GTO cable which would have to be suspended in the middle of the conduit to maintain the 1 ½" clearance.

Section 600-32(j) was amended to clarify that the length restrictions on secondary conductors are measured “from a high voltage terminal of a transformer” to the first neon tube. The grounded terminal on the transformer is not considered to be a high voltage terminal and there is no length restriction on the secondary conductors returning from the neon tubing to the transformer.

Section 600-42(g) was added after extensive debate and discussion regarding the various types of nonmetallic electrode enclosures currently being used. There was a significant effort to prohibit all nonmetallic electrode enclosures, primarily because they are not capable of containing arcing and sparking which occurs with poor connections or when neon tube age and the connection is subjected to excessive heat. In fact, the panel accepted a proposal that would have required a significantly higher grade of nonmetallic material to be used in these devices. That proposal was amended at the annual meeting and the requirement for enclosures to be listed was added. This was to address the concern that a receptacle was not an enclosure and that the listing requirement for receptacles might not cover enclosures. The panel comment on this issue clearly states that the safety standard for nonmetallic enclosures needs to be revised so that listed products will withstand the stresses and damage normally encountered in neon sign installations.

 Thomas E. Trainor, past IAEI international president, is the manager of inspection services for the city of San Diego and has 35 years of service with the city. Tom represents IAEI as a principal member on CMP-18 and is a member of NFPA and the UL Electrical Council.

A Neutral to Every Switch

by Anthony Montuori

Should the Code require installers to bring the grounded conductor of a switched branch circuit to every switch location? It is probably that this question may end up as a major focus of CMP-9 discussions at the January meetings for the 2002 NEC.  The following considerations are presented for review.

CMP-9 had a 1999 NEC proposal from a major manufacturer of a electronic controls for lighting and other residential and commercial loads. Clearly one of the major markets for this equipment involves retrofits for energy conservation, including such items as occupancy sensors. If you remove a simple snap switch and replace it with one of these controls, how does the control have 120 V (or 277 V) available to power its brains? The manufacturer, citing increased usage of these products, thought the NEC should require the grounded circuit conductor to be available.

There was another issue as well. Some electronic controls do not require the grounded conductor. Instead, they use the equipment grounding conductor as a return path. Present product standards allow for this on a limited basis, up to 500 microamperes. This presents, at best, a startle hazard to someone working on a fixture with the control showing “off.” There have been reports of personnel falling off ladders after contacting supposedly dead luminaries. If a grounded conductor will start being routinely run to switch points, product standard could prohibit this practice.

The final consideration directly involves enforcement. The panel had a surprising degree (although not unanimous) of consensus on the proposition that these controls were being connected to equipment grounding conductors wherever convenient, whether or not this comported with listing instructions.

What happened in the 1999 Cycle?
After unanimously rejecting the proposal, the panel got a number of comments, including an official one from NEMA, supporting a code change. What happened next is very rare, occurring at most one or two times in a code cycle. The panel voted, by majority affirmative, to require the grounded conductor at switch points. The vote at the meeting, as I recall, was 8-2 affirmative. Then, after re-circulation of comments in the voting, what started as 8-2 affirmative resulted in a 3-7 final result! Now, result reversals from votes not maintaining the required 2/3rds affirmative are common, but for a reversal to result in half the panel switching, and the final result to not even hold a majority, is remarkable. In addition to procedural concerns about taking such a major step following a flat rejection during the proposal stage, here are the major substantive issues raised in the re-circulation period:

1. Design vs. Safety. Clearly, if the Code is strictly enforced as written, there is no hazard. Nevertheless, some design deficiencies produce predictable routing violations of other code rules, to the point that these deficiencies cross the lien and become inherent safety issues. For example, Section 210-50(b) requires receptacle outlets wherever cord- and plug-connections are used. This applies in dwelling units just as anywhere else. Nevertheless, it is understood that not enforcing Section 210-52 can result in the misuse of extension cords, since dwelling owners will not rewire every time their furniture patterns change. In a certain sense, Section 210-52 is a design section, documented reasons, as providing a minimum level of safety. Has the industry reached that point here, or are these changes merely “designed to improve the market share of a certain style of switching device” (one panel member’s reaction)?

2. Paradoxical results. The extra conductor might have the effect of increasing violations of conductor fill limitations in boxes. In addition, it might be routinely terminated improperly, producing short circuits or downstream-grounded circuit connections to equipment grounding conductors, with attendant hazards and GFCI device malfunctions. In addition, the conductors might be improperly reused as an additional ungrounded circuit conductor for other purposes.

3. Product standards. One negative voter suggested revising product standards as an alternative. For example, any electronic control that uses the load as a circuit return could be prohibited from using the word “off,” and instead use “standby” or equivalent. For the benefit of unqualified personnel, the installation directions might also carry a bold-print explanation of how to distinguish between equipment grounding conductor and a grounded circuit conductor. For instance where the electronic circuitry exceeds the 500-microampere limits and requires a grounded conductor return, the instructions must then warn never to connect to an equipment grounding conductor. Following recent precedent on paddle fans, there might be a required label on the outside of the sales package saying, “Product requires grounded (white) conductor; switch box may need to be rewired. Consult a qualified electrician if in doubt.”

4. Enforcement. Has the industry really reached the point that connecting loads to equipment grounding conductors is routine? Are the installers really that incompetent? If so, what else needs to be changed in the NEC? It was alarming how easily that the then solid majority accepted the proposition that connecting these devices to equipment grounding conductors in lieu of bona-fide grounding circuit conductors is, indeed, commonplace if no grounded conductor has been brought the switch.

5. Where should a change apply electrically? If the Code is changed, how? The 1999 NEC proposed comments (which failed) would have applied to many cases where the grounded conductor would be absurdity. For example, it would apply to a 30-ampere snap switch controlling a 240-volt hot water tank. Now, such tanks often have electronic controls operated by utilities, but they operate line-to-line and a grounded conductor is still superfluous. The proposed rule also would have applied to all points of a 3-way and 4-way switch loop; would just one point be sufficient? What about snap switches on underground systems, such as exist in some mills?

6. What occupancies should be involved? Residential occupancies seem to have the most prevalence of unqualified work and inadequate inspection. On the other hand, there may be a political problem if homebuilders accuse the industry of gold plating the electrical design. There is a cost to this, since the extra conductor impacts box size and cable configurations. Now, look at the other occupancies. Industrial and commercial occupancies could more easily comply due to increased prevalence of raceway wiring methods, although Type MC cable use is steadily increasing. On the other hand, industrial and commercial occupancies seem to be the largest market for these devices.

Your input for the 2002 NEC is important
It is commonly understood that the present Code rules are adequate if they are followed. The panel needs to hear from industry members and from manufacturers and testing laboratories, particularly in two areas. First, we need objective reports covering the actual prevalence of noncompliance arranged by occupancy. We also need much more detail about the actual product standards, what devices are allowed to do, and what warning information must be included in the installation instructions.

Several panel members seem to think that CMP-9 appears very open minded at this point. Several members have commented that they genuinely have no idea how they are going to vote the next time around. They want to hear what we think. Although this column is usually about an existing code provision, considering this question is a fantastic and timely opportunity to get involved in shaping the next Code.

Anthony Montuori has been a member of both the Master Electricians Licensing Board and New York City Advisory Board since 1984. He was the New York Chapter chairman of IAEI, and a NFPA member. Tony is a past Kiwanis club president, and is on the Blue Ribbon Advisory Council of John Jay High School.

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