House-service panels

Q
We label panels as general lighting, washer, dryer or furnace. Now an inspector wants them labeled room by room, including every outlet. I can't find this in the NEC or in the NFPA's residential 2000 one-two family dwelling book. Can you advise?

A
The requirement for labeling circuits in a panelboard was in 384-13 in the 1999 NEC. This requirement was removed from the relocated section 408.13 in the 2002 NEC and moved to 408.4. Section 408.4 is more general because it's in Part I of Article 408, so it also covers switchboards. Section 110.22 covers this requirement too, but it does not include the location requirement: “on the face or inside the panel door.”

“Identified as to purpose or use” is the subject of your inspector's interpretation. In my opinion, “washer” and “dryer” are adequate marking unless there are more than one of each. “General lighting” is not a useful label, however, as there are likely to be multiple devices with that marking. I think identification of the room or area is a reasonable expectation for things like “lights,” “receptacles” or “general lighting.”

Perhaps the worst label is one that says “outlets” because to a knowledgable person this says nothing at all as it could refer to lighting outlets, receptacle outlets or just about any appliance.
Noel Williams

Data-cabling upgrade

Q
We are doing some data wire replacement at one of our schools, and the electrical inspector has indicated we are to remove all existing cable for our raceways. Our thinking was we would leave the old cable in place in case something happened to the new cable. Then we could use the old cable again if needed. Is there any way around the removal of the old cable? The data codes are somewhat confusing.

A
You did not say how your data wiring is classified. Typically, such circuits are Class 2 circuits and are covered by Article 725. However, they may be reclassified as communications so that they are covered by Article 800, or they may be optical fiber cables as covered in Article 770. In any of these cases, a new rule in the 2002 NEC requires that certain abandoned cables be removed. Abandoned cables are defined in Sections 725.2, 770.2 and 800.2. Section 725.3(B), 770.3(A) and 800.52(B) all require that the “accessible portion” of abandoned cables be removed. According to the definition of “Accessible” in Article 100, it may seem that cables in raceways are accessible. However, the definition of “Concealed” in Article 100 states, “Wires in concealed raceways are considered concealed, even though they may become accessible by withdrawing them.” Raceways above dropped grid-type ceilings are not considered to be concealed, and are in fact considered to be exposed according to the definition of “Exposed” in Article 100.

The stated intent behind these changes was to remove the fire load presented by abandoned cables, and from that standpoint, abandoned cables installed in metallic raceways are not a problem. However, based on the rules and definitions mentioned above, cables in concealed raceways are not considered to be accessible, but cables in exposed raceways apparently are accessible and must be removed.

Note also that cables that are “identified for future use with a tag” are not considered to be abandoned, according to the definitions. Adding a bunch of tags is not the answer here, but if you really intend some cables for future use, they can be tagged and are not considered abandoned, and therefore not required to be removed. Finally, a number of other rules prohibit abandoned cables from being left in place without mention of whether or not they are accessible. You can find some of these references in 725.61(A), (B)(1) and (E); 770.53(A) and (B)(1); and 800.53(A) and (B)(1).

As you can see, there is some room for interpretation here, based on whether we are considering the intent behind the words, or just the words themselves. Literally, the words require that all abandoned cables be removed if they are in plenums, if they are open cables in vertical risers, if they are open cables in hollow spaces or anywhere else if they are accessible.
Noel Williams

Damp locations

Q
I have 11 ceiling fans to install in a covered canopy area. Per 99 NE5(a) all conduit systems in damp locations must be installed weathertight. Per 422-18 (A&B) all ceiling fans must be installed with boxes listed for such. What type of box meets both requirements?

A
Your covered canopy area is a damp location according to the definition of a damp location in Article 100. Section 370-15(a) (314.15 (A) in 2002) requires boxes in damp locations to be arranged to keep moisture from entering or accumulating in the boxes. Boxes are not required to be “weathertight” unless they are installed in wet locations. This section does not address the conduit system at all, but the rules for conduit are similar. For example, if EMT is used, the fittings are required to be raintight if installed in a wet location, but the requirement does not apply to damp locations. This rule is found in 348-10 (358.42 in 2002).

Section 422-18 (422.18 in 2002) does not require that special boxes be used with ceiling fans. It permits a specially-listed box to be used for fan support. An ordinary box (one not listed for fan support) may be used if the fan is supported independently of the outlet box. Fan support boxes are required to be supported from the structure, but the support for a fan can go directly to the structure.

Generally, fan support boxes may be used in damp locations if they are arranged to exclude water, as they would normally be on the underside of a canopy. There is no requirement that such a box also be listed for a wet location. Also, there is no requirement that a box listed for fan support be used with all ceiling fans. Such a listing is required only where the box is used to support a fan. Often, the construction of a building does not lend itself to the use of fan support boxes, and other structural support must be arranged. If a wet location box were required, the fan would also have to be listed for a wet location.
Noel Williams

Break points

Q
I am a continuing education teacher in the State of Washington. In studying the NEC 2002 Analysis of Change, the change to Table 220.36 Optional Method confuses me. I understand how to use the table, but the Summary of Change states that the table for new restaurants has been changed to reduce the break points from six to four. What break points are they talking about? Where does it show that in the new Code?

A
If you compare Table 220-36 from the 1999 NEC to Table 220.36 from the 2002 NEC, you'll notice that the new table has only four rows and the old table had six. The values in the first column are the “breakpoints” mentioned. They are actually four ranges of values, but I guess you could call either the low end of each range or the high end of each range a breakpoint. At any rate, the table is simplified, and the new values are apparently more in line with the study and research upon which the table is based.
Noel Williams

Pigtail lampholder

Q
Can a pigtail lamp holder be used as an Edison-base fuse holder in a lamp circuit? Or is it against the electrical Code to use a lampholder as a fuse block, even if it is wired parallel in a circuit?

A
According to Section 410.47, “Lampholders of the screw-shell type shall be installed for use as lampholders only.” Section 240.50(B) requires fuseholders for plug fuses to be marked with ampere ratings.

The UL White Book includes marking and listing information for both lampholders and fuseholders, and they are listed to different standards.

Although both may use an edison-base socket to accept a fuse or lamp, the devices are made for different purposes and are not intended to be interchangable.

One obvious difference is in typical ratings. Lampholders for edison-base lamps are usually marked for a maximum size lamp — typically 660W (about lamps) or less, while fuseholders for plug fuses are often marked with ratings up to 15A, 20A or 30A.
Noel Williams

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