Questions tagged [nec]

For questions about the National Electrical Code, NFPA 70. Just about all US jurisdictions that have adopted an electrical code use the NEC, often with a handful of local or state level amendments.

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4k views

Do both legs in 220V have to be switched?

I posted this question but for some reason I can't get back into my account: Is it up to code to do a parallel circut with 220V? Is there a limit to number of splices? Most things I see with 220V ...
3
votes
1answer
3k views

When replacing non-grounding type receptacles is a GFCI receptacle required, or can any GFCI device be used?

Under the NEC (it was 210(7)(d)(3), but appears to have moved around some), it is permissible to replace an ungrounded receptacle with a GFCI receptacle, then wire further ungrounded or non-grounded (...
8
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4answers
694 views

How should ground wires be handled when updating switch loops in an older home?

I have a house built in the 1950’s with fabric covered NMC wiring still present in most circuits. Those original wires are all 12/2 with no ground. I am currently in the process of replacing some of ...
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3answers
25k views

How many lighting circuits are needed in the LED era…? (US - NEC)

This is in a two story, ~1000square foot per floor building. With the advent of affordable, decent (IMHO) LED fixtures (finally!) the entire lighting load for the structure looks to be 500W - 1000W at ...
5
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2answers
193 views

Can I use a ground rod as an equipment ground for a detached garage?

I'm in a bit of a dilemma. The house we bought has a detached garage supplied by 12/3 UF with ground. The previous owner/handyman set this up as a multiwire branch circuit (MWBC) with a twist: one ...
4
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1answer
13k views

Can Romex (NM-B) be run in conduit for more than 10 ft when starting from the breaker panel?

The answers to this question indicate that NM can be run in conduit: Can Romex (NM-B) be run through conduit? I was hoping to enclose 12-2 NM-B in EMT for about 20 feet from the breaker box up my ...
1
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1answer
370 views

Is it okay to use an LFNC whip to connect air conditioner where subject to physical damage?

I have seen many air conditioners at ground-level in multiple cities near me that are connected using liquid-tight non-flexible conduit (LFNC) whips. Example: http://www.southwire.com/products/whip-...
3
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2answers
5k views

NEC Definition of “Maintained Spacing” for Wire in Free Air

This seems like a simple question, but I cannot seem to find the answer in the 2008 NEC. There are references to "maintaining spacing" in many sections of the code such as the following: 310.15.B....
4
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1answer
1k views

NEC, use more extension boxes or an access panel?

What is the maximum number of extension boxes you can hang from a ceiling? This is ridiculous and I probably need one or two more to meet the new drywall ceiling. Are junction boxes permitted behind ...
3
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1answer
2k views

Can service entrance and branch circuit cables be commingled in an auxiliary gutter?

One of the major Code defects in my current house that I want to rectify at some point is the fact that the (only) panelboard is mounted too high up on the wall (the current panelboard's service ...
3
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1answer
2k views

Does the circuit providing a light at the electrical panel have to be ONLY for that light?

Does the circuit providing a light at the electrical panel have to be ONLY for that light? I'm fairly sure there specifically has to be a light at the panel, as well as a circuit with an accessible ...
2
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2answers
33k views

Is it okay to staple romex to a floor joist when running it perpendicular behind a finished basement ceiling?

Taking down my ceiling to run some wire to new outlets. The outlets are going in an area with an unfinished ceiling, so I know the romex there will need to be ran through the joists when going ...
2
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1answer
662 views

Replacing subpanel in detached building - yet another ground/neutral question

Here's the situation. I've added on to my detached shop/garage and need to upgrade the very small subpanel. The existing garage pre-dates the 2008 NEC by at least a decade, and is supplied by a 3 ...
2
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3answers
330 views

Properly installing a grounded subpanel for lightning protection

I'm installing a large antenna on the side of my house opposite the electrical service entrance. The antenna must be grounded, by nature of its design. For lightning protection, it's important that ...
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2answers
262 views

Can multiple panelboard interior/cabinet combos or loadcenters be chained together to form a single “logical panelboard”?

Background Both the houses I deal with (which are quite far apart btw) are in need of panelboard reworks: One still has the original fusebox, never mind that the main disconnect is basically at the ...
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2answers
1k views

Does the NEC limit the maximum size of junction boxes?

In this question, the OP has constructed a large junction box out of several extension boxes attached to a "regular" junction box: Is there any upper limit on the size of a junction box (either as-...
1
vote
2answers
511 views

Is it up to code to do a parallel circut with 220V? Is there a limit to number of splices?

State is Florida. I am wiring a continuous run non-submersible irrigation well pump. I am using a 30A breaker with #10 THHN in Sch 40 PVC conduit buried 18". I could have gone direct bury but I ...