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.
370
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Cabling electric cable (AWG 8) through roof of garage; NEC code?
I'm going to run shrouded 8/3 (240V) from the main box on the house through the air to the garage in order to feed an EVOCHARGE 32A EVSE. Ideally I will come through the roof (flat-roof garage) at a ...
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How should this UL-listed boiler cutoff switch maintain Class 1 separation?
The Guard Dog RB-122E Low Water Cutoff is UL listed, it requires 120V AC and is capable of switching 24VAC on the control side of a boiler.
It is a self-contained metal enclosure with knockouts for ...
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splice ground wires together in conduit bodies
Is it against code to crimp(Bond) ground wires together inside conduit bodies or to extend the ground. a city inspector(Bronx) stated it was not up to code and I'm unable to find any information on ...
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2020 NEC: Proper installation of PVC Conduit for Data Cables
I am installing a media enclosure in an under-stairway closet on my first floor. I plan on running Schedule 40 PVC conduit between the enclosure and the crawlspace directly below, as well as between ...
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Does NEC 2023 prohibit the modification of a light fixture's mounting system?
I have a bathroom in which the light on the wall is offset from the center of the vanity by about 6 inches.
To avoid having to remove all of the wallpaper that is still in good shape, I bought a ...
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Relevant NPFA 70 sections for consideration when sizing a deep well pump
Previously I had little experience with well pumps, but after moving into a home with a failed pump in an area where a shallow pump is at 500', I'm beginning to learn a lot. Recently a pump servicing ...
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How can circuits be prioritized depending on real time demand?
I have a 125a service that’s part of a multifamily setup. I have been told by a licensed electrician contractor that upgrading my service to 200a would likely require $10k+ due to also needing to ...
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NEC gurus: What does condition 2 mean in the exception to subsection 250.32(B)(1), to not run an equipment ground in a feeder to an out building?
I'm trying to understand the exception in the NEC, subsection 250.32(B)(1), which gives permission to use the grounded conductor as the ground fault current path. Apparently, in earlier code cycles ...
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What are the code requirements for outdoor plumbing and electrical surface-level conduits?
I'm planning to re-design my yard, and I'm looking to decouple the dependencies between contractors.
I am planning to add some outdoor appliances (e.g. hot tub, sauna) which would require adding new ...
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Rules for cutting additional holes in an exterior panel body
I am looking to see if the NEC has any guidance on where you can cut a hole into your outdoor electrical panel. (To add a cable clamp). The existing pre-marked knockouts are either used or require ...
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Installing a subpanel with a service entry cable feed-through a Powerwall subpanel
Based on this post on installing an EV charger, I decided to research installing a sub-panel next to an existing surface mounted indoor sub (Square D HOM2040L125PRB), which is used for Powerwall ...
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Can I add an outlet to a sink disposal circuit for a TV?
I want to add an outlet for a TV in the living room. In the same stud bay on the other side of the wall in the kitchen is the switch for the disposal. The disposal circuit (20A) also feeds the ...
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Above ground (outdoor) UF-B cable and Conduit
We have a UF-B (12/2) cable run in PVC conduit above ground from panel onto a wall on a side of the house up to a point (fence comes then).
Then the conduit goes underground and 90-degree and emerges ...
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1 gang box fill capacity/size for receptacal and two 12/2 Romex & pigtales
I am installing a receptacle in a confined space inside some custom cabinetry, so I need to use the smallest (with respect to depth) box I can that still meets code. This is a remodel so the wire ...
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Metal clad cable: are there any useful residential applications?
MC cable is touted as a secure one. But when I look closely at its possible uses inside a residence (according to NEC code), I can see none. In all protected areas (like inside the walls), NM cable ...
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How do I wire to NEC code my detached garage?
I have read some of the NEC code but I am no professional. I am planning to run a 100amp sub panel in my detached garage with no more than 80' of wire, most likely URD 1/0 or so, from my main breaker ...
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Do I really need to run so many parallel EMTs?
NEC gives max number of conductors for certain EMT conduit. For example, it’s 16x12AWG for a 3/4” conduit.
Now it turns out this is really not the limiting factor at all. It is de-rating.
Suppose I ...
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Do I need to separate my main and gas grounding conductors?
I have a garage with the electrical meter and gas meter on one side, and the water and grounding rods on the other side.
I understand that the meter needs to be bonded to the water pipe and grounding ...
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Temp rating and insulation type of old nm sheathed cable
A family vacation home that we had someone build back in 1965 has a 200 amp service panel. A few of the breakers in my opinion are oddly sized for the loads that're on those dedicated ckts.
The hot ...
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What is the correct way to wire a Relay In Box (or similar relay) that has low-voltage signal wires bundled with 120V wires?
It is my understanding that low-voltage wires can share a double-gang box with 120V wires, as long as they are isolated from each other by a permanent divider. I was looking at getting this relay to ...
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EMT fill capacity and derates mixing 14ga & 12ga
I have an existing 1/2" EMT conduit that has three switch runners, a hot for an unswitched outlet, a neutral and ground, for a total of six wires in 14ga THHN, all for the same 15 amp circuit.
I ...
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Is it OK to bond an electrical box with 14ga wire if it also contains 12ga wire?
I have an AC unit on a dedicated 20A, 240V circuit running with 12ga THHN wires in 1/2 PVC conduit.
In the middle of the conduit I have a metal waterproof convenience receptacle wired on a separate ...
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Hanging NM cables from floor joists in crawlspace
What is the best and/or code-compliant way to run NM cables on the underside of floor joists in a crawl space?
Background. My wiring, done as a retrofit in the 1970s, has a set of runs (five #12/2's ...
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Can I cover a junction box on an unused circuit with an oven in a cabinet?
We're installing a cabinet with a double oven over where an outlet used to be. We've capped off the wires and will install a plate over them, but is that good enough if we put the cabinet in front of ...
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Is running low-voltage DC wire (for LED) between outdoor PVC trim (post wrap) and the wooden post permitted by the national electrical code?
The proposed specific application involves running 16AWG wire (lamp cord) for a 12VDC LED light fixture that will draw a maximum of 2.25 amps, beneath PVC trim in a routed channel with cross-section ...
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How and when must I satisfy NEC 2020 requirements for outdoor disconnect?
Context:
I'll start with some context. As a single-family homeowner intending to replace an interior main panel with a 200A panel under permit, I am interpreting the National Electric Code (NEC) 2020 ...
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Does the NEC allow a sub panel to be powered by a generator and an automatic transfer switch?
I plan to install a sub panel next to my main panel. Mainly because as I do electrical upgrades, I'm accumulating more circuit breakers. Since I need one anyway, I'd like to be able to power it with a ...
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Can I extend feeder wires to my main panel inside the panel?
Per NEC, am I allowed to extend the meter-to-main-panel wires (hot, hot, neutral) inside the main panel using split bolt connectors? The wires could be a bit short for the new replacement panel.
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Backfeeding a main breaker panel
Is the following allowed by NEC?
• A main breaker panel is used as a main panel in a house.
• The hot wires from the meter go to a breaker at an arbitrary branch location on the panel thereby ...
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Can I use a 125A panel with a breaker and wiring sized for 90A?
I have a detached garage. I would like to run power to it and have a 400 amp service on my house. I already have a bunch of 2-2-2-4 aluminum ser wire, which I know is only good for 90 amps.
I have ...
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Extending wiring - can I redesignate neutral as ground?
I have 10/3 NM-B wire I am extending with 8awg THHN blk, red, grn. For the green, should I attach to the bare copper or insulated white and redesignate it as green? Since both are grounded at the CB ...
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How to protect non-metallic cable entering a sub panel
I have this sub panel I'm considering replacing. What do I do with the exposed Romex to pass inspection? Some kind of cable trough maybe?
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Rewiring combined light/receptacle circuit in basement
I am considering upgrading a basement circuit as illustrated to allow the two lights (L1 and L2) to be controlled by a switch (SW) while keeping the outlet O always hot. The current version has no ...
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NEC Question about laundry area 210.52(f)
210.52(f) states a 20 amp circuit must be in the laundry area.
What is defined as the laundry area?
My washer and dryer are in my undivided, unfinished basement. Is my entire basement considered the ...
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Exposed Electrical Cabling Inside Cabinet
I have standard, unshielded 12-2 romex run through some studs that comes out of the wall and will go into a cabinet. The intention of this cable is to power a dishwasher (on the other side of the ...
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Generator Inlet Box Location per electrical code
I'm installing an inlet box for a generator on my property. My transfer switch and main circuit panel are indoors, in my basement utility room. There are numerous other utilities that all enter my ...
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32 amp charger on a 60 amp breaker
I installed a hardwired 32 amp EV car charger using a 60 amp breaker with 4 awg copper wire. The electrical inspector failed me, concerned that the 32 amp charger should be on a 40 amp breaker. ...
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NEC 250.148(b) vs. Luminaire Grounding
I'm always trying to learn more and improve my methods for home wiring.
Most examples I see regarding 250.148(b) simply illustrate use of a pigtail and wire nut.
(B) Equipment Grounding Conductor ...
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Can I safely run nm-b below 8' exposed perpendicularly between stud cavities in an unfinished garage?
My Siemens flush mount combo electrical panel is installed to the exterior of my garage. The garage isn't finished (open studs) and eventually I'd like to close it up with drywall (but not for this).
...
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Power Requirements for an Added Oven
Existing condition is one oven off a 40 amp, 120/240 V dedicated circuit. We are looking to replace both the existing oven and also add a new 120/240 V speed oven as well. So the new wall ovens would ...
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Putting a non GFCI downstream from a GFCI
I have an outlet next to my sink in a kitchen remodel. There is another outlet downstream that is located behind the refrigerator where the fridge will be plugged in. I know the outlet next to the ...
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USA rules for relocating a bedroom light switch
After carefully considering and measuring the layout of two proposed recessed medicine cabinets over my bathroom vanity, I've discovered that the spec homebuilder carefully considered how they might ...
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GFCI / AFCI Breaker Protecting Old 2-wire Setup With Regular 3-prong (non-GFCI) outlets?
I have read through a lot of discussions on GFCI protection for old 2-wire circuits that don't have a ground wire; most discuss installing a GFCI outlet when replacing an original 2-prong outlet, and ...
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Reference to NEC spec on dryer breakers
I just moved into a newly constructed house and have found several 240 breakers to be of the incorrect amperage.
The breaker for the dryer is 25 Amps but everything I've read says that the NEC ...
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Splitting Service conductors to reach remote building
I am hoping ThreePhaseEel can chime in!
I am looking far ahead and planning the electrical for a home I am building. From left to right I have an electrical pole - 100ft then a garage - then another ...
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Main panel grounding modification (two grounds in box to single ground wire)
My old house’s main panel has two ground wires, one leading to pipes, another to a grounding rod. Because the bottom is the only easily-accessible side for new circuits, and because most of the ...
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110.15 High-Leg Marking
In the 2020 Edition of the National Electric Code, in Section 110.15, titled High-Leg Marking, it states,
...only the conductor or busbar having the higher phase voltage to ground shall be durably ...
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Do conduit nipples have to be straight?
Reading the 2018 NEC, near as I can tell, a conduit nipple from an electrical panel to a junction box doesn't need to be straight, only 24" or less in length. Is that right?
My house is old and ...
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Service Entrance Wire To Drop Splice - 200AMP
I am replacing the old service drop wire from 4AWG to 4/0, as the panel has been upgraded for 200A service.
The service has been shut off at the pole, and I was able to remove the old service drop ...
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If I have a 120V and a 240V single circuit (each) to an outbuilding, do they need disconnects?
NEC 2017 question.
There are lots of detached garages out there that have single 120V circuits run from the house. This powers receptacles and lighting. It does not have a disconnect switch inside ...
