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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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1answer
3k views

NEC code requirements for exterior outlet

Are there any code requirements with regard to the position of an electrical receptacle on an exterior wall? Such as distance above the ground, distance from a corner, distance down from a roof ...
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1answer
549 views

Are there any NEC restrictions for wiring 220v and 110v sockets on the same dual pole breaker?

I am working on an electrical upgrade for my garage. Some equipment I have requires 20A 220V power. Other equipment only needs 15A or 20A 110V. I would like to run in from a single circuit protected ...
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1answer
828 views

Do NEC receptacle spacing rules apply to solid (half-wall) banisters

I have a solid banister over my stairs. If it counts as a wall per NEC, then it needs an outlet. I can't find the reference in NEC defining a wall. Anybody know if this counts?
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1answer
873 views

Use 60Amp disconnect as a pass-through to another disconnect

We would like to add a second air-conditioning unit. The original 60 Amp disconnect is grounded via EMT to the panel. The existing EMT will meet code requirements for both conduit fill and derating ...
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2answers
1k views

NEC code regarding grounding and conductor pass through

I am adding a mini split system to my house which currently has a smaller air-conditioning condenser in place. In brief, the house is very old so we opted for a ductless mini-split over trying to ...
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2answers
101 views

How should a GFCI be installed according to the NEC?

I am taking a National Electric Code safety class as part of an electrical maintenance certificate course. On one of my quizzes, it asks me to explain how a GFCI is to be installed and tested. I've ...
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1answer
644 views

Is there any way to do an Ufer (concrete-encased) ground with a monolithic slab that has a vapor barrier?

If I understand correctly, when using a monolithic slab (where the footers and slab are poured as one piece), the vapor barrier is installed under the slab and the footers. The NEC does not consider ...
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2answers
103 views

How is the minimum conductor size (of some type) for a certain run determined?

I have a 200A service in a garage. I would like to run cable from this to a 100A service in a house. I would also like to run from this to a separate 50A service in the house which will supply ...
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1answer
123 views

BX cable in plaster by sink

I am re-plastering a wall in my kitchen after removing some damaged plaster. I am burying the electrical in BX cabling before plastering as allowed by NEC. However, NEC does say BX is not allowed in ...
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1answer
250 views

Does the lighting fixture size change the number of allowed wires in a junction box?

In am working on a 1920s era home. The electrical system in the house has been updated several times in a very hodge-podge way. Originally the house had conduit in the attic going from light ...
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1answer
264 views

Does the NEC permit brazing for connections to ground electrodes?

I need to connect several copper-clad ground rods together with AWG 6 solid copper wire for lightning protection, and as part of the electrical service grounding. I also need to connect some 2.5" ...
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1answer
208 views

How can we move a subpanel without replacing the supply cable?

We recently installed a subpanel, installed it ourselves and had it inspected. Now, as part of the ongoing renovation of the house, we have decided we need to move the panel over 22 inches. The 6 awg ...
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3answers
306 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
539 views

Is a divided wireway or auxiliary gutter considered one wireway/gutter or two for derate purposes?

A common accessory with auxiliary gutters or wireways is a divider that extends the length of the gutter/wireway and creates two wiring compartments instead of one. This is more commonly used to ...
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1answer
98 views

Code compliance of running EMT on exterior of exposed chimney inside

I am working on a 1920s era home with an exposed brick chimney inside. The chimney is not connected to a fireplace but is used to vent the water heater and furnace in the basement. I am currently ...
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2answers
253 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
119 views

Can a UL 1953 listed power distribution block be deployed in a panelboard cabinet?

So, one of the things I want to do if I ever get a chance to have a house wired to my specifications is have each room have its own lighting homerun to the panel, but multiplex these homeruns onto a ...
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1answer
135 views

Can an electrical subpanel be directly mounted to a hvac supply plenum?

Can an electrical sub panel be directly mounted to an HVAC supply plenum. I usually see and have installed the disconnect or sub panel to the actual equipment on a wall near by or used some sort of ...
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1answer
356 views

Single Neutral for Several Smart Switches

I have some (seemingly common, but specifically unanswered) concerns about providing a neutral wire to smart switches that are in a single multi-gang box (4-6 switches on different circuits). I am ...
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1answer
6k views

Do I need AFCI protection on new lighting circuits or just for outlets?

I am in the process of re-wiring a 100 year old house. I want to make sure everything is done to the new NEC codes. I need to know if arc fault protection is required on lighting circuits or just ...
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5answers
109 views

Flexible cabling for wiring

Article 400.12 forbids the usage of flexible cords for fixed wiring, but what makes an NM-B cable made out of stranded 14ga THHN non-flexible? EDIT: Terms 'cord' and 'cable' are used interchangeably ...
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3answers
4k views

What does “No Other Outlets” mean for a kitchen 20A branch circuit?

I'm trying to wire my kitchen up to code, which means (based on the outlet spacing rules) I need 6 counter-top outlets. How many branch circuits do I need? When the NEC talks about the 2 "appliance" ...
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1answer
211 views

How do I power fluorescent lights hanging from a drop ceiling?

Our basement has a high ceiling, and somebody fancied it up with a drop ceiling. The lighting is the common 4' 2-lamp fluorescent shop lights that are cord-and-plug connected, and hung from the ...
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2answers
734 views

Possible wiring configurations for isolated dishwasher location (satisfying 2014 NEC)

The key wiring requirements in the 2014 NEC seem to assume dishwasher placement in a cabinet space adjacent to the kitchen sink. For example, the placement of the GFCI receptacle, for use with a cord-...
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2answers
73 views

Does always-on safety lighting need a switch or other requirement?

With such low-power LED lights available, I've been setting up some of my lighting to simply be on all the time, 24x7, e.g. 1 of 6 downlights or 1 out of 4 LED "tube"s in a troffer. Usually I just ...
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2answers
168 views

Is it legal to torque-seal terminal screws on electrical equipment?

Torque seal is a lacquer-like product used in critical applications after a screw is tightened to provide a visual indication if the screw comes loose. Considering that a terminal screw on an ...
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2answers
101 views

NEC 2016 AFCI question

I am currently dealing with a little confusion regarding arc fault protection and how it would be enforced by 2016 NEC code. I'm not a licensed electrician, I'm doing an apprenticeship and the guy ...
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1answer
98 views

How can one make a connection where flexibility is necessary despite the connection being exposed to physical damage?

It seems that it is common practice in HVAC-land to use a LFNC whip to connect air conditioner condensing units to the house wiring. However, as statueuphemism rightly points out, it is eminently ...
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1answer
333 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-...
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4answers
2k views

Over-the-range Microwave on small-appliance branch circuit

Either there is conflicting information or a lack of when it comes to this question. Is it allowed in NEC code to permit an over-the-range microwave to run off of one of the small-appliance branch ...
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1answer
391 views

Can a washing machine closet be located adjacent to an electric panel?

We want to relocate a washer/dryer into a closet that shares a wall with the house's electrical panel (which is in the kitchen). Any code violations here or considerations?
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2answers
256 views

Does replacing an electrical junction box require the wiring to be brought up to code?

I live in Sparks, Nevada and the 2011 National Electrical Code applies to me. I am installing a new bathroom fan on a separate circuit from the existing bathroom circuit. I want to change the ...
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4answers
2k views

Is it legal to add a jumper wire to a conductor that is too short in a junction box?

I live in Sparks, Nevada, and the 2011 National Electrical Code applies to me. My work will be inspected when complete. I am replacing a switch and have found that someone before me (accidentally?) ...
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1answer
274 views

What are the requirements for supporting non-metallic cable through a finished wall?

I know this basic question has been answered before by reference to 334.30(B), but there's an aspect I don't understand. Does 334.30(B) allow unsupported installation if 334.30(b)(1) OR 334.30(b)(2) ...
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1answer
102 views

Can a single set of conductors feed utilization equipment *and* a subpanel simultaneously under the NEC?

So, let us assume we have a set of conductors (hot/neutral/ground) going off to some piece of utilization equipment. Can I also run a set of conductors of appropriate ampacity off this circuit to a ...
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1answer
315 views

If a breaker is GFCI/AFCI protected, does the NEC still require garage and exterior outlets to be GFCI protected?

I am looking into upgrading the cabling from very old clothed 14-3 wire to 14-3 MC wire and the outlets in my garage and I understand they must be GFCI protected; however, can I simply replace the ...
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1answer
66 views

Hooking up additional outlets & lights to a central vac circuit?

My unfinished basement has a central vac on its own 20A circuit. The central vac is plugged into a 15A duplex outlet (not hardwired). I want to finish my basement and build a closet around the vac ...
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1answer
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 ...
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2answers
492 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 ...
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1answer
86 views

What's the Actual Code for Receptacles Below Counters in Peninsulas

I'm installing a kitchen that'll have a peninsula and I'm wondering about section 210.52(c)(5) where it says that "...receptacles mounted below a countertop must not be located where the countertop ...
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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 ...
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1answer
12k 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 ...
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1answer
149 views

Is it NEC-compliant to place a GFCI or AFCI receptacle or deadfront device in a location not readily reachable?

NEC 240.24 requires overcurrent devices (fuses/breakers, incl. AFCI/GFCI/DFCI breakers) to be placed so that their operating means is no more than 6'7" off the ground under most circumstances, and ...
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1answer
491 views

Should switch cover plates be installed before final inspection?

For final inspection should I put the switch/outlet cover plates on? It's a minor pain because we still have to tape, sand and paint. We are in Portland Oregon. This is in a bedroom, not a kitchen or ...
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1answer
369 views

15A circuit allowed to supply multiple general purpose receptacles?

For some reason I have it in my head that there is a section in the NEC which prevents the use of anything smaller than 20A circuits to supply multiple general purpose receptacles. While I know for ...
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2answers
520 views

Strain relief for cable into metal box - clamp ok?

I am having trouble fining a strain relief clamp to cover the hole into a metal canister (the canister for a heating unit). Is it ok to use an NM cable clamp - the kind you use around the hole going ...
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1answer
634 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 ...
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3answers
485 views

Semi-flush mounting a surface mount (NEMA 3R) panel

This is a new one for me. The owner needs a new main panel in a wet location but wants the box inset in the wall. I cannot find a reason not to do it, other than it will be a bit harder to wire. The ...
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1answer
245 views

electrical work: create “future boxes” - is this to NEC code?

I would like to run cable for an in-wall heater but not actually connect to the heater right now, I just want to get the cable run and connected to the sub-panel (along with all the other cables that ...
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1answer
431 views

Is it a violation of NEC code to install a receptacle horizontally and 3/4" from face of a stud?

A wall has been framed out to mount a touch screen computer monitor. Once the 1/4" drywall is installed, the monitor will be placed into this cavity and plugged into said receptacle. Question Does ...