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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4
votes
1answer
184 views

Can I paint a load center cover?

I would like to paint the cover and door of my flush mount load center to match the wall color more closely. The manufacturer does offer a white in addition to the standard grey cover, but it is hard ...
0
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1answer
40 views

In conduit with 75C wire, can I use #14 wire for 20A circuits?

I note that with 8 AWG wire... in NM-B (Romex) cable I can only get 40A: I am required to pull from the 60 degree C column of Table 310.15(B)(16). However, in conduit, with 75C wire (THHN) and ...
1
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0answers
58 views

1 generator + multiple ATSes: how can I install this to Code without unobtanium?

I want to supply standby power to both units in a separately metered duplex from a single permanently installed generator. The cheapest way to do this is a pair of bog-standard ATSes and a smallish ...
2
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0answers
46 views

How do I connect surface wireway to a breaker box?

I am running Legrand/Wiremold 4000 series for a garage shop. The instructions for the panel connector (4086A) consist of a tiny picture that implies all I need to do is cut a large square hole in my ...
7
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3answers
2k views

Any way to meet code with 40.7% or 40.44% conduit fill?

I’m running conduit along the walls in my shop (in a commercial warehouse) to provide power to some machines and additional outlets. The service is 3 phase, 208 V, 100 A. One of the machines requires ...
3
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3answers
465 views

Does this violate electrical code? (UF run plugged into GFCI to use smart outlet)

I built a deck on the back of my house last year and installed a new breaker and a handful of outdoor electrical outlets. I wanted one outdoor outlet to be switchable via a smart outlet, but my smart ...
1
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1answer
79 views

Oven wiring - needing to add a ground, can I retrofit?

I'm dealing with a 1970-built home and the oven has 6-3 without ground running to the oven. 2 hots and the neutral. Got a new oven coming in and want to make sure it's wired right. I could run new ...
8
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4answers
2k views

Why are 120 V general receptacle circuits limited to 20 A?

The NFPA-70 (National Electrical Code) prohibits the use of breakers larger than 20 A for general receptacles. But I have my doubts. A 20 A breaker on a 120 V circuit with appropriately sized wires ...
1
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0answers
37 views

Dedicated 240v 30A Circuit Switched for A/C and NEMA 14-30 [duplicate]

I have a dedicated 240 volt circuit that's hard wired into my air conditioning unit. The circuit has a 30 amp breaker at the main box and another 30 amp breaker on the wall next to my air conditioner....
1
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2answers
82 views

IBT and whole house transfer switch

The inter-system bonding termination (IBT) is where other services like telephone and cable TV get their ground bonds from the house's grounding electrode system (ground rods). 2014 NEC (NJ) 250.94 ...
1
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1answer
36 views

Stacking 'Main lug' load centers for garage

I am aware of most NEC codes and am actually asking if this is allowed, There really shouldn't be any reason..I also fully understand keeping my netural and ground seperate and how the bus bars are ...
1
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2answers
111 views

Why don't we just use combination AFCI/GFCI breakers for every circuit in a home?

With pretty much every circuit in a home needing one of the two types of protection (AFCI or GFCI), why don't all new homes have combination breakers installed just to be safe? Would it hurt anything ...
1
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2answers
64 views

Romex exiting junction box just below 8 feet

I am installing new outlets by drilling up from the garage between the wall cavity and fishing romex up. As seen in the picture: I had my first inspection and the inspector called out that the ...
1
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3answers
84 views

Extremely low suspended ceilings? (NEC)

Here are the key points: Condo in NYC with concrete ceilings Recessed lighting "Exactly" The ceiling is to be dropped by only 2-1/2" The light in mind is a 1-1/4 LED light (Extremely low profile) Ex: ...
0
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2answers
229 views

Running a low-voltage audio cable through a wall; with or without conduit?

I'm running wire for a 70V audio system and there is a barrier wall in the way of my run. I was wondering if it is legal as far as NFPA 70 / NEC goes if I just poke a hole in the wall (non-insulated ...
3
votes
1answer
153 views

Derating 6 current-carrying conductors?

I'm having a hard time understanding 310.15(B)(2)(a). Here's the boat I'm in: I hooking up a tankless water heater that calls for 3 40 amp breakers (it's a 24 kw Ecosmart). So I put in a sub panel in ...
0
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3answers
84 views

Is “14 AWG” NM-B allowed by the newest NEC for new residential construction?

Is "14 AWG" NM-B allowed by the newest NEC for new residential construction? My concern is what the NEC says concerning 14 AWG NM-B for new residential construction. I have been told that the "NEC ...
2
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2answers
769 views

Can I wire a doorbell transformer in-wall this way?

My current under-powered doorbell transformer is in a very awkward location (old home, etc.) and in a location where several old wires are cable-nutted together and I would rather not replace it there....
1
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1answer
198 views

What does NEC require for strapping down conduit and wire here?

Below is a picture of the current conduit and wire setup for my new underground service into my house with generator automatic transfer switch and manual transfer switch to allow me to switch to an ...
1
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1answer
41 views

Do I need to upgrade other circuits if I only plan to change one?

(San Francisco, California) I plan to run a new dedicated circuit for a kitchen appliance, and to get up to code also move the bathroom to its dedicated circuit as well. This is an old house. The ...
0
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1answer
35 views

can an indoor Transfer Switch be used on the other side of the wall as an outdoor service entrance and main panel?

Can an indoor Transfer Switch be used on the other side of the wall as an outdoor service entrance and main panel? The concept is: The outdoor service entrance is wired through the wall to the SE ...
0
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1answer
85 views

Electrical outlet clearance from a hot water panel radiator

What is the clearance of an electrical outlet from a hot water panel radiator? So facing the wall with a window and having a panel radiator down below hanged/fixed on the wall, how far away left and ...
1
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1answer
54 views

Homeowners Electric Permit - Mongomery County, Maryland, USA [closed]

Our county allows homeowners to test to acquire permits for "rough wiring" and "heavy-ups" (https://www.montgomerycountymd.gov/DPS/Process/combuild/homeowner-electrical.html). I did electronics/...
3
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2answers
939 views

Can I run #14 armored cable behind baseboards?

Residential basement remodel problem: Replacing old, ungrounded wiring. Problem is cinder block walls. Inside, the exterior walls have rigid insulation and one layer of 1 x 3 furring strips ...
0
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2answers
65 views

NEC (United States)

Is there a website where I can access the complete and most recently updated version of the United States NEC for free?
4
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2answers
187 views

Can I add USB outlets to bath/hall lighting circuit box (not GFCI)?

My bathroom, inside near door, has a 2-gang box, containing 2 light switches, powering combination ceiling light and fan. This box is fed by hallway lighting circuit, and the work box is not covered ...
1
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2answers
828 views

Main Breaker Panel or Main Lug Panel for Sub-panel in Attached-Detached Garage

I am installing a ~100-amp sub-panel in my "attached-detached" garage (an "attached-detached" garage is a detached garage that shares a continuous roof with the home). The sub-panel will be fed by my ...
1
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1answer
46 views

Intersystem grounding bus ran out of terminals; now what?

My intersystem grounding terminal bus is out of available terminals, and I have two additional communication wires to ground to it. Does NEC allow supplementary bus bars? NEC 250.94 seems to imply no, ...
1
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2answers
71 views

Operational Electrical Panel in an unfinished building — safe? Sane? Legal?

Is it realistic to have an operational and functioning load center panel (with power supplied only to temporary outlets mounted near the panel), fed by an offgrid solar system, in a half-built ...
3
votes
2answers
827 views

Is it OK to have a light that can only be controlled via automation?

I am retrofitting the main light in a room to be controlled by a home automation system, in this case, I'm using z-wave, but for purposes of this question, it could be any digital protocol. I would ...
1
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0answers
46 views

Approved weatherproof way of connecting SER into panel

I have a knockout in an outdoor electrical panel that is above the uninsulated portion of the panel. I need to run 4/0 SER wire into the panel. According to NEC 312.2, I need a wet listed fitting when ...
1
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2answers
96 views

THHN to NM-B wiring, Transition from External Piping Conduit to in wall junction box

I am working on a project, In my own home, Permanently installing a Faux Fireplace, Shiplap, and some iron pipe shelves. The shelves are going to have built in lighting in the form of Edision Bulbs at ...
10
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1answer
5k views

Is this wiring safe and is it according to code?

A single 12-3 cable was run to a double switch to control individual lights. The white is used as a hot, is this wiring correct/per NEC code?
2
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1answer
61 views

2 meters for 1 structure

We are currently building an addition to our house. It was a duplex before (one part stick built, other part mobile home, they were connected by a common entryway). We moved the mobile home away and ...
1
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1answer
57 views

Can a single cable type do the following

Running from a new 200amp main interior in the attached garage, out a 150 amp breaker into 4/0 cable (4/0-4/0-4/0-2/0 assumed). The cable will travel about 30 feet inside through raceways and EMT (...
1
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1answer
123 views

are tamper resistant receptacles required when rewiring an old house

rewiring an old house due to having knob and tube wiring. it it code to have all receptacles tamper resistant? Does the NEC require hard wired smoke and carbon monoxide detectors? Are "in-use" ...
0
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1answer
64 views

is AFCI required for 220v CA residential?

As I understand it CA now requires AFCI protection for practically all residential outlets. I'm setting up my theater room and it calls for a 50A 220V NEMA 6-50 outlet for the subwoofer I want but I'...
3
votes
2answers
484 views

Relabeling 6-AWG Wire

I'm pulling 2 hots, 1 neutral and 1 ground through conduit to a subpanel and I was wondering if it's possible to use the same color wire and just relabel the endings. I was thinking of using 6 AWG ...
0
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1answer
429 views

PVC conduit into PVC box: Can I make it watertight when using a threaded fitting? Are sealing locknuts allowed?

I have some 2" PVC conduit coming out of the ground and into a PVC box where it enters with a terminal adapter and held in place with a locknut. I intended to use a sealing locknut to keep the box ...
0
votes
1answer
239 views

is there an outlet box mounted overcurrent protection device?

I am adding some additional outlets and outside lights to my garage. The existing outlets are on 12 gauge wiring, so presumably a 20 amp circuit (I did not check this - did not have my reading ...
2
votes
3answers
2k views

Can I add a non-GFCI receptacle in the garage for a freezer?

It seems that GFCI-protected receptacles are required in all areas of the garage (even on the ceiling, where the garage door opener plugs in). Can I install a non-protected (15A) receptacle ...
8
votes
4answers
700 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 ...
1
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1answer
160 views

Questions regarding my plan for new 50A circuit (with pictures)

Overview Pictures/diagrams at the end. I will pull permits and would like to do this correctly. I will be disconnecting an unused 40A circuit and replacing it with a new 50A circuit to my garage for ...
1
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2answers
340 views

Is NEC code for non-metallic cable applicable now that I've installed an attic ladder?

Just installed an attic ladder. I've read this: What is the proper 'per code' method for running nonmetallic sheathed cable above a ceiling in the attic? So my attic is now "accessible" and ...
2
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3answers
10k views

How to connect grounding wire to gas pipe for 2017 NEC 250.104(B)

I'm trying to interpret and apply the 2017 NEC bonding requirements from 250.104(B) to my existing home gas line. I've read this related question to determine I should use #6 AWG wire, but I'm unsure ...
1
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3answers
396 views

Is a Garage considered a 'Dwelling' for standalone electric service?

I just wrapped up adding new overhead 100 amp service for my parent's garage outside Chicago. My Mom is a retired ceramics teacher and wanted a 30A two phase kiln and/or welder in there and the ...
2
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2answers
182 views

Move grounds to subpanel when I moved 8 single pole breakers to same subpanel?

When I move 8 breakers from main panel to a subpanel (a few feet away) can I simply move the hot and neutral only to subpanel? The 8 breakers are grounded in the main panel already. A 100 amp breaker ...
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 ...
1
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1answer
846 views

interpretation of conduit vs raceway wet location vs outdoor vs NM NM-B

eventual question: for a sealed PVC conduit external to house, does that qualify as a wet or damp location preventing use of non metallic (NM or NM-B) indoor type wire? And does underground feeder (...
1
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2answers
1k views

OK to bundle wires together with colored electrical tape?

I have 3 bundles of 3 12AWG THHN wires each, black-white-green (red tape) black-white-green (blue tape) black-white-green (black tape) these 3 bundles come out of the load center and into 1/2 EMT. ...