The 1999 National Electrical Code may stimulate sales of some new electrical products for electrical distributors. The first part of a continuing series.

It's important that electrical distributors know which changes in the 1999 National Electrical Code will affect the products that their customers buy. As a result of these changes, electrical distributors will see increased demand for ground-fault circuit interruption (GFI) equipment, the introduction of a new product called an arc-fault circuit interrupter (AFCI), a call for boxes listed for the support of ceiling fans and heavy lighting fixtures, and products to support suspended framing systems.

As in the past, Electrical Wholesaling's coverage of changes in the N.E. Code will be based on a series of articles published in EC&M magazine, EW's sister publication. This series of articles, written by Fred Hartwell, noted N.E. Code expert and senior editor of EC&M, will appear in EW over the next few months. To gain a more in-depth understanding of the changes in the 1999 N.E. Code, get your hands on a copy of it, or on one of the books now on the market that interpret these changes.

Sec. 200-6. We will see a new identification on grounded conductors: three continuous white stripes.

The testing laboratories will decide just how wide these stripes need to be, or what percentage of the conductor circumference needs to be white. Hereafter, this section will be the only source for rules on grounded conductor identification. Similar provisions in Art. 210 and Art. 310 are deleted.

Sec. 200-7(c)(1). Now your customers can only reidentify a white wire, for use as an ungrounded conductor, when it's part of a cable assembly.

The panel decided that if you're dealing with a raceway, then there just isn't any good reason why you shouldn't pull in a conductor with properly colored insulation.

Sec. 200-7(c)(2). Your customers now have to reidentify the white wire in a cable assembly when you're using it as the supply run to the switch, as part of a switch leg.

One of the oldest topics for beginning apprentices is how to run switch legs with cables. As long as the white wire went to the switch, then the black wire came back from the switch. This put the appropriate color contrast at the outlet. There would be one white wire loose from the supply circuit, and one black wire from the switch. This has been so ingrained in all installers for so long that the N.E. Code never asked them to reidentify that white wire going to the switch, even though it wasn't grounded. However, the panel reacted to an instance where an unqualified person didn't realize that white wire was hot.

Sec. 210-11(c)(3) Ex. This new exception allows your customers to serve other equipment in a bathroom on a 20A bathroom receptacle circuit, provided it's the only bathroom served.

Background: This is a trade-offs between adding some load to a receptacle circuit in exchange for removing the possibility that other bathroom receptacles might be on the same circuit. Many shower ventilating fans come with a listing restriction calling for GFCI protection if installed in that area. The old N.E. Code required either a GFCI circuit breaker for these loads, or supply by a GFCI receptacle in an unusual location, such as the next bedroom, or if there was room in the box, a "master-trip" type GFCI without receptacle slots. In the face of those possibilities, the new exception looks pretty good.

Sec. 210-12. The Code defines, for the first time, the "arc-fault circuit-interrupter" (AFCI), a device that can recognize the electronic characteristics of an arcing fault in progress and then open the circuit. The AFCI concept makes its appearance, but the actual requirement only applies to dwelling unit bedroom circuits, and not until Jan. 1, 2002.

Background: The new devices are circuit breakers with electronic circuitry capable of recognizing the chaotic waveforms characteristic of electrical arcing. The devices are calibrated internally to trip, based on the likely ignition energy being released in the arc. The fault current levels, which produce secondary ignition of adjacent combustible materials, are reflected in the new UL standard.

As presently projected, an AFCI must clear a 5A arc in no more than one second, and clear a 30A arc in no more than 0.11 seconds. For higher level arcing faults, UL expects to use a test protocol that approximates someone cutting an energized cord with a pair of dikes, or a sharp edge of metallic furniture doing the same thing. The idea is to approximate a fault that isn't bolted but that does have a conductive surface in contact with the circuit conductors. In these cases, where the arc might be over 100A, the device must open within eight half-cycles of fault initiation. The reason for the half-cycle parameter is because these arcs may sputter, and come and go. Therefore the arc may not last a full four cycles all at the same time, and yet it could do comparable damage by the end of the eighth half cycle.

One of the most difficult aspects of the new technology is coming up with a device that knows the difference between an arc from normal operations, such as unplugging a cord or opening a switch, and a destructive arc. In short, the devices cannot nuisance trip. The manufacturers involved with the proposals believe they have solved this problem. There is even a device that will allow your customers to find hidden fault locations with a cheap AM radio.

EC&M tips: Arc-fault detection does not replace other aspects of circuit protection. Short circuits from essentially bolted conditions must still be cleared instantaneously. Long-term overloads must still be cleared on an inverse-time basis, with greater overloads clearing more rapidly. Although the arc-fault detection mechanism will be inside a typical molded-case circuit breaker, its sensing mechanism is strictly in addition to the conventional components.

AFCI protection doesn't substitute for GFCI or GFPE protection, either. These devices are residual current devices: They measure the total current in a circuit, going to the load and returning from the load. If the vectorial summation of all currents does not equal zero, these devices detect the amount of that residual current and trip above a predetermined point.

AFCI protection does not duplicate any of these functions, although a manufacturer may well marry some of them within the same device. An AFCI detects and clears arcing faults whether line-to-line, or line-to-neutral, or line-to-ground. In spite of outward similarities, don't confuse an AFCI circuit breaker and a GFCI circuit breaker.

Multi-wire circuit functionality. Two-pole AFCI devices trip similarly to two-pole GFCI devices, by including the shared neutral in its sensing mechanism and then tripping as a two-pole device only. So, although you can protect a multi-wire branch circuit with these devices, when one side trips, both circuits open. These devices don't have single-circuit functionality (that is, a two-pole device with independently-movable handles). Although this can't be done with a GFCI breaker, it could be done (with an additional sensor) with AFCI devices. However, at press time, at least one major manufacturer has said it has no intention of producing a two-pole device with multi-circuit functionality, and no other manufacturer has announced any plans to accommodate this feature. To the extent AFCI circuit (as opposed to outlet) protection, becomes mandatory, it may well mean the end of multiwire circuit functionality.

Sec. 210-52(c)(5), and Ex. Countertop receptacles need to go above, and no more than 18 in. above, the counter, except for construction designed for handicapped people. The exception for islands and peninsulas now only applies to flat countertops with no vertical breaks, such as backsplashes, etc., and with no cabinetry, etc., within 18 in. above, that you could put a receptacle in.

This result is a decent compromise between those who want no possibility of toddlers pulling hot appliances on top of them by yanking on cords, and those who routinely design these spaces. Relatively few consumers are willing to tolerate tombstone outlets in their kitchen designs. In the end there will be plenty of receptacles in the kitchen above wall-positioned counters that toddlers can't reach. The parent is the one to decide when the peninsula receptacle is safe to use, and not the N.E. Code Committee. The changes also close a loophole in the prior N.E. Code, that arguably allowed any receptacle below a wall-positioned countertop to qualify as not being over 18 in. above that counter.

Sec. 210-70(a)(2). Outside lights now need only "provide illumination" for outdoor entrances and exits, which include remote floodlights. In addition, the lighting only needs to be provided for grade-level access points.

The prior wording used the preposition "at," suggesting the lighting outlet had to be adjacent to the doorway, which was never intended. Also, entry lighting for such areas as a second floor deck with no grade level access is strictly a design issue.

Art. 225, Part B. All secondary building and structure disconnecting requirements have been relocated into this new part of the article, except medium-voltage rules that go in a new Part C. The number of supply circuits to second or subsequent buildings, or structures supplied from another, is subject to limitations similar to the number-of-services limitations.

Sec. 225-30(d). Allowance included for multiple circuits as diverse sources of supply if used for "different uses" such as multiple control points for lighting.

This avoids what could be routine, and harmless, violations of the principal rule. For example, a detached garage could have a power circuit to some receptacle outlets and some three-way switch loops that may allow the owner to turn on the light at the outside of the garage door from the house, or to turn on the outside light at the house after getting out of the car in the garage.

Sec. 225-31. You need to supply a building or structure disconnecting means for circuits that merely pass through such a structure en route to supply another building or structure.

This is an important clarification. Energized conductors are energized conductors. They present equivalent risk whether or not they terminate within that particular building. However, the next section gives a way out.

Sec. 225-30(e). Additional supplies to multiple buildings are now also permitted for all occupancies with "documented safe switching procedures."

The concept of "safe switching procedures" has been around since the 1984 N.E. Code, but only for large multibuilding industrial complexes, and never for additional supplies- only for remote switching. A documented safe switching procedure means whatever the authority having jurisdiction (AHJ) says it means, and from jurisdiction to jurisdiction. The word "minimum" is a theoretical minimum, and isn't dependent on standard sized device ratings. Suppose you have a calculated load of 237A. You still install 237A minimum conductors, subject to allowances elsewhere in the Code for continuous loads, etc. The fact that the switch might be 400A with 250A fuses, because those are standard sizes, doesn't mean you have to cable to the 400A switch size.

Sec. 225-32. Now you can use the provisions of Sec. 230-6 to establish leeway in locating a structure disconnecting means location, even in cases where service entrance conductors aren't involved.

This is a very logical extension of the Sec. 230-6 concept, and it should be extremely useful.

Sec. 225-32 Ex. 1. The remote disconnecting means allowance, formerly only for large-capacity industrial occupancies with "documented safe switching procedures" now extends to all occupancies with such procedures.

Refer to the discussion of Sec. 225-30(e). This change resulted from a defensible proposal to broaden the exception to include institutional occupancies. The idea was that many of these environments, including college campuses, have equally qualified electrical staff, and yet didn't qualify as industrial. The panel expanded this almost beyond recognition, however. This is another one you'll need to discuss with the local authority.

Sec. 230-42(b). The minimum-size rules for ungrounded service-entrance conductors are deleted in favor of a reference to long-standing similar requirements in Sec. 230-79. This may affect the type of distribution equipment and wire and cable that your customers buy.

This raises the minimum size of service conductors to a single-family house to 100A. It also lowers the size limit on single-circuit applications to No. 14 and for two-circuit applications to No. 10 (from No. 8).

Instead of having a parallel set of requirements as in the past, the panel went with a cross reference to Sec. 230-79, but the results are sometimes surprising, unsubstantiated, and perhaps unintended. For example, the minimum size on a single circuit was always No. 12. However, Sec. 230-79(a) sets the minimum disconnecting means for such circuits at 15A, which would allow a No. 14 for the first time. Similarly, the two-circuit installation used to be No. 8 minimum; now the rule goes over to the 30A disconnect size, which allows for a No. 10 instead. The former exception allowing a No. 8 for general use on limited demand situations by special permission has been deleted outright.

The one substantive change in Sec. 230-79 concerns single family homes, and its provisions would be reflected here as well. Now we can say good-bye to that journeyman's examination question, "when can a single-family home have a 60A service?" because the answer is never; the minimum size is 100A. The old rule that allowed 60A services if the initial load was below 10kVA with six or fewer branch circuits is a virtual dead letter. This is because with separate laundry and bathroom receptacle circuits, and with a minimum of two small-appliance branch circuits, any house with more than one lighting circuit couldn't use the allowance anyway.

EC&M tip: Don't jump to conclusions when you look at the exact phrasing of the rule calling for an ampacity not less than "the minimum rating of the disconnecting means." The word "minimum" is a theoretical minimum, and isn't dependent on standard-sized device ratings. Suppose you have a calculated load of 237A. You still install 237A minimum conductors, subject to allowances elsewhere in the Code for continuous loads, etc. The fact that the switch might be 400A with 250A fuses, because those are standards sizes, doesn't mean you have to cable to the 400A switch size.

Sec. 230-46. Service entrance conductors can now be spliced with clamped or bolted connections. The connections need to be in an enclosure, or underground using listed underground splice kits.

This section used to state an outright prohibition followed by six exceptions with no end in sight. The panel decided there really wasn't any reason to micromanage the subject, and converted to a general allowance instead.

Sec. 230-50(a). You need to protect service entrance cables by raceway or other approved means if, and only if, they are subject to physical damage. The former list of areas that inspection authorities frequently took to be areas where liability to physical damage was to be presumed, has been deleted.

Sec. 300-4(b)(1). The protective grommets for Type NM cable run through metal studs must cover the entire perimeter of the opening.

Years ago, inspectors used to come to meetings with pasteboard boxes full of Type NM cable shavings collected from construction sites where the cables had been abraded during installation on the unprotected upper edges of slots with V-shaped grommets. Although that isn't the problem it used to be, it is still a periodic issue. For example the cable box may hang while you're running the cable through the holes, and depending on the direction of tension, the cable may be stretched upward to where it runs over the upper edge of the slot. Sometimes a cable loop pulls out and catches on the unprotected upper edges as well.

This change addresses the problem. With a little work, two V-shaped grommets, one up and one down, cover an entire rectangular opening.

Sec. 300-11(a). Now you can put wiring methods back on suspended ceiling support wires, but only sometimes. The wires normally need to be in addition to those that are part of the ceiling design, they need to be secured at both ends, and in the case of a fire-rated ceiling assembly, you need to provide a means, such as color or tagging so the inspector can tell which support wires you added.

Background: As in the prior code, you need to know the fundamental differences between a suspended ceiling that is an integral part of a fire-rated floor-ceiling or roof-ceiling assembly, which are comparatively unusual, and the far more common nonfire-rated assemblies. Some ceilings are designed with a thinner slab than one that would establish the required fire separation on its own. In this case, the suspended ceiling is an integral part of the overall fire rating. Qualified testing laboratories have evaluated many such designs, using specified ceiling panel materials. Invariably, the designs specify, in precise detail, exactly how many support wires must be used, how thick they must be, how and where they must be attached, how fixtures are to be supported, how air ducts must be constructed and run, etc.

In making these tests, the testing laboratories do not assume any additional weight loads on these support wires, nor do they (or could they) evaluate how such a ceiling might deform under fire conditions with such loading. In these cases, the wiring methods must be supported securely and independently of the support wires.The only exception allows for the possibility someone might rerun a ceiling assembly test with specified wiring attached to specified supports. Because the rated designs specify the support wire locations, both electrical and building inspectors must be able to know which support wires are in addition to the essential elements of the ceiling construction.

In the case of nonfire-rated applications, you have to add wires to those required for ceiling support, but you don't have to identify them in any particular way. If the ceiling manufacturer chooses to recognize wiring on his specified ceiling support protocol, an exception allows you to use that recognition and avoid having to put up additional wires. The likelihood of that happening is very slim.

Sec. 250-50(a)(2) [250-81(a)]. Supplemental ground rods and other made electrodes of the pipe or plate type have to meet the resistance requirements of made electrodes generally, as covered in Sec. 250-56 [250-84].

This has the effect of requiring an additional rod or pipe electrode in those instances where the ground resistance of the first electrode exceeds 25 ohms.

Background: Some are suggesting since Sec. 250-56 allows for water pipes to augment a deficient made electrode, the water pipe plus the single electrode are enough. There are two problems with this. Basically, you're saying the electrode needing to be supplemented is capable of being a supplement, which is a needless repetition.

The second, far more important reason is that argument overlooks the reason for the rule in the first place. As long as the water pipe is in place, the ground rod is a mouse helping to carry the burden of an elephant. Its only function is to serve as the principal electrode if the metal water pipe is ever replaced with plastic. In that sense, a better term for it would be a reserve electrode.

The intent of this change is absolutely clear: the made electrode system installed under this section must fully qualify as an electrode system with the metal water pipe removed.

Sec. 305-6(a). The construction site GFCI requirements have been extended to 30A 125V receptacles.

The cord set allowance for portable GFCI protection now includes devices that don't include cords, such as self-contained GFCI units. These devices must be identified for portable use.

The requirement for identification as suitable for portable use means that the device has what most people refer to as open neutral protection. That is, if the grounded conductor opens for any reason, a relay drops out and the device deenergizes the load. Otherwise, an interrupted grounded conductor would cause the device to lose its brains and fail in its closed position.

Sec. 310-8(d). Conductors exposed to direct sunlight, including drip loops, must be listed for or marked as being sunlight resistant.

EC&M tip: Although everyone understands the value of this change for extended outdoor runs, such as single conductors in outdoor cable tray or cable bus, or open wiring on insulators, the lack of an exception for drip loops has the potential to create some very serious mischief. Although Type SE cable conductors go through some sunlight resistance testing, most building wire doesn't. It remains to be seen whether the major wire manufacturers are going to get their building wire reformulated and routinely tested for sunlight resistance. To the extent this is enforced, it may well raise hob with any raceway service entrance not located on the north side of a building.

Although many large black conductors would probably pass easily, for small services using No. 6 or smaller wire, the entire grounded conductor must be white. White wire can be made sunlight resistant, but it's expensive to do so. Meanwhile, no loss experience was ever cited in rejecting numerous public comments that sought an exception for drip loops. Be sure to sort this one out with the local authority, at least until you know what kind of conductor ratings will be locally available.

Sec. 336-5(a), item 1. Now you can use Type NM cable in single-family and two-family housing of any height or number of stories, but multifamily and other uses remain subject to the 3-story limitation.

Over the years there have been exceptions for basement conversions, attic conversions, etc. Now the three-story limitation simply disappears, along with those exceptions, for one-family and two-family dwellings.

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