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.

Filter by
Sorted by
Tagged with
0
votes
1answer
59 views

Wiring in conduit - TH? Color coding? Grounding?

Installing tankless water heater - 18kW, requires 2 x 40A circuits. I have a lot of 8ga Black TW wire AND 3/4” conduit. Is TW still legal ( I have some THHN, but want to use up the TW where I can)? ...
0
votes
1answer
51 views

How do you verify a good ground connection when using EMT conduit as the ground?

When using metallic conduit as the ground wire, how do you confirm that the conduit provides a solid end-to-end connection? If using an ohm meter, how would you set it up and how many ohms are ...
11
votes
2answers
4k views

Can I legally add an outlet with 2 screws when the previous outlet was passthough with 4 screws?

My existing wiring has 2 black and 2 white and a ground. One pair is obviously source. The 2nd pair passes to the next outlet. The current outlet has 4 screws: black on one side and white on the other....
5
votes
2answers
1k views

How should I mount conduit to my wood-laped siding?

I was thinking about using superstrut to hang conduit on the side of the house, but hangers would be easier because siding is wood-lapped so it is not a flush surface. I'm open to other options as ...
1
vote
1answer
72 views

New outlets installed with wires for switch control, but tabs left intact

Before moving into our house recently I had inquired about a pair of switches in the living room that seemingly did nothing. The seller said that they were for a couple of the outlets in the living ...
4
votes
2answers
2k views

Will this electric panel pass NC inspection?

Will this electrical panel pass inspection? I know there is a 3 foot clearance requirement but not sure if it's an issue here. This is a replacement panel in an old house that previously had an ...
4
votes
1answer
770 views

Can I run my three-way travelers in a 14/2 without a neutral in the cable?

I have a surplus of 14/2 and a little bit of 14/3, and this project is price-sensitive, so I drew up this plan to make use of what I have on hand. It minimizes the length of 14/3 needed because that's ...
0
votes
3answers
115 views

can I use UF B cable to wire a dryer?

Can UFB cable be used for wiring my dryer? Normally I'd just run some NM able, but I found a good deal on 8 AWG UF B and wonder if this is code compliant (NEC 17) or not....or maybe there is another ...
4
votes
2answers
520 views

Should I repair or replace floor joists with holes in poor locations?

I have seen some questions that are close, but different, and don't seem to answer my question. I'm in a late 1950s home and the previous owner drilled a bunch of holes in the joists in the basement ...
3
votes
2answers
98 views

Romex/NM Clamp For PVC Sch80 Conduit?

During the last inspection visit, I was told that the pvc sch80 conduits I have needed to have some sort of fastening/clamp to secure the cable at the top of the sch80 pipe. Even though I had ...
2
votes
1answer
78 views

Are smoke/CO detectors required to be interconnected with wire?

I am planning on hardwiring 6 combination smoke/CO detectors on various levels of the house (2nd flr, 1st flr, basement) using 12/2 wire branching off from permitted sources (standalone 20a outlets). ...
0
votes
3answers
89 views

14ga Wire Out Of 20amp/12ga Circuit (outlet) To Power Smoke Detector

During some renovations I have opened up enough wall for the inspector to note that smoke/CO detectors need to be hardwired throughout the house. It is much more convenient to power them using the ...
2
votes
3answers
481 views

Is it against NEC code to use 12/2 gauge wire for receptacles and 14/3 light fixtures in California?

I've been searching for answers but most of the questions involve using two separate gauges for the same circuit. I'm in the process of upgrading to a 200 amp service and I changed out all the ...
1
vote
1answer
87 views

Ceiling Receptacle and ziptied NM cable - NEC 2017

Two questions: At a recent stop-over, a professional electrician mentioned that outlets/receptacles that are mounted in the ceiling (pointing down) are not permissible by code. The reason being that ...
6
votes
2answers
1k views

Does electrical code allow NEMA 14-60R receptacles in residential settings?

I know that NEMA 14-60 plugs and receptacles exist, but they seem really rare. I've come across a few random online forums where people say that this is because they're not allowed by code, since any ...
2
votes
3answers
93 views

SE cable indoors, thermal rating: 60C or 75C?

This is a Code question about Article 338, expect lots of Code cites. Any answer or challenge to answer MUST be well supported with Code cites, committee notes etc. The allowed temperature of a ...
1
vote
2answers
91 views

AFCI - worth installing and not just GFCI?

How worthwhile is it to install dual-function CAFCI / GFCI outlets rather than going with ones that are just GFCI? Is it a significant increase in safety factor?
1
vote
0answers
28 views

312.6 interpretation when entering from the back of panel

312.6 lists (A) and (B) tables, for when NOT enterting oposite and entering on opposite wall of the box. How is the entering through the back wall interpretted? Technically it would be "NOT ...
2
votes
3answers
345 views

Can I splice NM-B cable in the ceiling? [duplicate]

I am moving my bathroom exhaust fan from its current location to 2 feet farther, over the shower cabin. I need to extend existing wire for this. I can't fish new wire because existing wire has been ...
0
votes
1answer
48 views

200A 240V Electric Panel Clearance

I am installing an electric panel. NEC 110.26A providing for 30" x 36" x 6'6" is met EXCEPT for the main water supply line which will runs against the wall and underneath it at floor ...
0
votes
0answers
64 views

Low-voltage LED light strip through wall to outlet - Allowed?

I am installing some cabinets in my basement media room. I'd like to use a Philips Hue Lightstrip for accent lighting. The other side of the wall on which the cabinets are mounted is unfinished - it's ...
2
votes
3answers
246 views

Two 14/2 cables for a Ceiling Fan with Two Separates Switches for the Light and Fan

Is this wiring scheme a code violation for showing two 14/2 cables controlling a ceiling fan with separate switches for the light and the fan a code violation? We are remodeling and added ceiling fans ...
5
votes
1answer
180 views

Outlet for built-in Microwave has 120v/20A (USA) breaker... what amperage receptacle is required?

Currently I'm not able to pull the built-in microwave out to examine the outlet, so am leaning on the expertise here. It is a duplex outlet and the connected breaker is 20A, constructed around 2005. I'...
0
votes
1answer
78 views

Do I need to do anything other than wire grommets to protect electrical wiring in a 2 1/2 inch steel stud?

I'm used to making sure electrical wire is setback 1 1/4 inch from the face of a wood stud, but what are the requirements (US NEC) for 2 1/2 inch steel studs? They appear to come punched out for wires ...
3
votes
2answers
128 views

Why would an inspection company flag two NM 12 gauge wires going through the same joist hole?

How many cables are you allowed to run through a single hole in a wooden floor joist? We have a question and good answers for the NEC guidelines. Why would an inspection company flag this and note ...
0
votes
0answers
35 views

Installing power for irrigation controller in conduit?

I have a property where the irrigation controller is mounted on an exterior wall-its power cable is plugged into a wet in use GFCI outlet. Beyond the outlet, the power cable hangs off the wall and is ...
0
votes
2answers
101 views

Can I extend 20 amp garage outlet? Or can I only move it?

In attached garage there is a receptacle with a single 20 amp outlet (marked as "Freezer" in a breaker panel). It is in inconvenient location. The idea is to extend this circuit to an area ...
0
votes
1answer
133 views

What are the NEC rules for holes in a wooden top plate?

What are the NEC rules for holes in a wooden wall top plate? Specifically, how far apart do the holes need to be and what is the max diameter of a hole? In NEC 300-4 I found "...holes shall be ...
2
votes
1answer
235 views

Single Ground Wire Run Under Floor Joists

I'm in the process of finishing my basement and, aside from a ground wire that was run under the floor joists, I have a fairly clear path for drywalling the ceiling along the floor joists. I have ...
3
votes
1answer
38 views

Any code points, other references on using compression and set screw fittings on same EMT run?

This is more a commercial/industrial electrical question, but there's no Stack for that, so; Anyone ever been dinged by an inspector for this? I can't find anything in the 2017 or 2020 NEC, even went ...
1
vote
2answers
434 views

Height of gang boxes for entertainment center

Wall mounted televisions are supposed to be at a comfortable viewing height when sitting down, according to most television and wall mount manufacturers (standard -- 42"). Now I'm working on new ...
1
vote
1answer
92 views

Retain access to recessed electrical panel

I have an electrical panel that is surface mounted to a sheet of plywood in an unfinished section of my basement. I would like to finish that section. The panel is rated for either surface mount or ...
1
vote
1answer
102 views

Which NEC code sections deal with outdoor junction boxes?

We had a neighbor move our junction box that is in a utility easement over our neighbors property. When he moved it, he used up all of the slack in the box and he also buried it under 4' of soil. ...
1
vote
2answers
125 views

What does the NEC consider to be a kitchen?

I understand that the NEC requires GFCI outlets in kitchens. But how does it define a kitchen? If a room has a wet bar, that's not a kitchen, right? What if we add some more appliances (maybe a stove ...
1
vote
0answers
27 views

Code regarding exterior disconnects, outlets and fixtures

What are the code requirements for wiring to outdoor disconnects, outlets and outdoor lighting fixtures? I've usually just ran the type NM cable directly to the box. It seems difficult to transition ...
9
votes
2answers
1k views

Can I run stripped Romex/NM through conduit?

If I have NM cable running into a junction box, can I strip the sheath of the NM cable starting inside the junction box and run the conductors without a sheath through conduit that is connected to the ...
0
votes
1answer
86 views

Plastic screw from inside outlet box to stud

So I went to Lowe’s to see Their selection of double outlet boxes and came across old construction and new. The new construction had nails on the outside. So I thought hey I’ll try it since I can ...
2
votes
2answers
136 views

Why do pigtails not count towards box volume capacity

I would like to know why pigtails are not included in the volume count for outlet receptacle boxes. I recently upgraded to a two way outlet and had a total of four 14/2 wires coming into the box and ...
6
votes
3answers
1k views

Are GFCI outlets allowed on new circuit installations?

A comment thread on GFCI outlet on 2-wire ungrounded question led to a discussion of whether GFCI is better/worse or even permitted at point-of-use (GFCI/receptacle) instead of GFCI/breakers in the ...
2
votes
3answers
84 views

Calculating subpanel breaker size

I'm building out a shop (within the same building as the main panel) and I'm considering adding a sub panel to make running circuits easier, and to make any future expansion easier. I'm unsure how to ...
1
vote
2answers
151 views

Can I run cable across the gap between floor joists?

I've been working on wiring my shop in my unfinished basement (sub-panel installed by a licensed electrician) and I've come across a question I haven't been able to find an easy answer to. There are ...
2
votes
2answers
285 views

What are the options for putting cabinets in front of receptacles?

I'll be putting some base cabinets in my townhouse (northern Virginia), on an existing wall with several electrical receptacles. The receptacles are near the floor, as this is not a kitchen, and would ...
0
votes
1answer
279 views

Smoke detector wiring - black wire in 3 wire appears to be damaged. Can I use power from AFCI circuit to power but use red wire to interconnect?

I have ~10 smoke alarms (one per bedroom, one per hall). Somehow the last one isn't working. The green light didn't go on. I've done some troubleshooting - swapped the connectors and swapped the ...
1
vote
3answers
245 views

Nearly all basement lights dependent on switch at top of stairs

I went to a house this evening for a showing and encountered a situation involving the basement lighting that I'm almost certain violates at least one part of the NEC. The house was built in 2000. The ...
2
votes
1answer
49 views

Calculate box volume needed with light

I think I know the calculation for this gang box, but I want to double check. Specifically, does the light count as a "yoke"? This is a 15A circuit. Per my other question (Calculate ...
3
votes
2answers
1k views

Can PVC conduit be run through garage/house firewall?

The wall between my garage and the rest of my house (US) is the usual drywall-insulation-drywall wall framed out with 2x4 studs. Can I run 1.5" PVC conduit through that wall perpendicularly (e.g.,...
20
votes
3answers
5k views

Why does US Code not allow a 15A single receptacle on a 20A circuit?

Living in the UK, where we have a different system of mains wiring, my curiosity was piqued by Is it okay to install a 15A outlet on a 20A dedicated circuit for a dishwasher? and its answers. Although ...
1
vote
1answer
42 views

Replacement or retrofit listed smart switches

Most smart (WiFi remote) light switches available online say "neutral wire required". For example, this Gosund dimmer. In some older houses, this requirement for a neutral in the switch ...
1
vote
2answers
82 views

Recessed light wiring

I am planning to install recessed light in ceiling of my 2nd floor condominium. Here are some facts. There is truss framing (picture attached) in the ceiling, between my ceiling and the upstairs unit'...
0
votes
1answer
107 views

Can I tie grounded/white and ground/bare from a subpanel to any grounding bar in in the main panel?

Suppose I'm wiring a 100 A subpanel, which receives my two phase wires (black, red/black), my grounded/neutral wire (white), and my ground wire (bare) from the main panel. Since this is a subpanel, ...

1
2 3 4 5 6