Hot answers tagged

11

Yes, this is a good idea, but a few details. No more than four cables per conduit, unless you're willing to upsize ALL the cables to the next larger size. That is 310.15(B)(3)(a). The conduit needs to be fairly large, because the cables are oval. Each oval cable is treated like a single wire of the wide dimension (because they twist). They can't fill the ...


8

Yes, when doing in-bench or in-cabinet work like that, I am very comfortable with EMT, provided it is anchored properly and not used as a hanger for other things.


8

I don't know if the exact match you're looking for exists, but you can get decora inserts (for the type of plate in your picture) that fit one, two, or three keystones. It'll be plastic rather than metal, but the plastic will match the keystones while the metal matches the box.


8

Yes, you can run NM/Romex cable through conduit. This is generally used to protect the cable in exposed areas. As long as the conduit is designed for electrical work, it should be fine. Sorry, you can't use Spa hose (but I've seen it tried) They sell special bell ends for PVC conduit that ensure that the cable does not get cut or damaged by the end of ...


8

Not sure where you got the idea that you need THWN-2, only. All you need is the W. TWN, THWN, RHW, XHW, XHHW, etc. are all perfectly fine, because they have the W that means they are waterproof, that means they can go in outdoor conduit. Most THHN is also THWN and MTW (multiply rated.) If you are in a situation where the wire temperature may be extreme you ...


8

THWN is rated for wet locations As Ecnerwal discusses. The issue is thermal The difference is at the top of Table 310.15(B)(16). THWN is allowed 75 degree C running temperature. THWN-2 is allowed 90 degrees C. THHN also is allowed 90 C Southwire is making a disclaimer: they are saying they don’t guarantee #14-10 will be THWN-2. What’s on their mind is a ...


7

Conduit fill The 110 NM terminates first 14-2 NM cable is 0.36" across in the wide dimension. Whenever a flat cable is used in a conduit, it must be treated the same as a round wire of the wide dimension. Three such cables just fit in 1" sched 40 PVC. The first 220 NM terminates shortly after. It is 0.75" conduit in the area with 2 NM cables. Two ...


7

Yes, you can extend the box in the back of the wall with a Raco 665.


7

stick a rope though there that's reaches more than twice the distance, tie each end to an anchor point. when you need to run a cable pull the rope's slack to you side then tie the cable to the middle of the rope, then go to the other side and pull the rope until you get to the cable untie the cable and leave the rope for next time.


7

That line from the power company pole to your weatherhead is called the service drop. The service drop is always energized. There's no breaker or switch up on the pole. To de-energize a service drop, they have to come with a boom truck and go up there and detach each hot from the poletop splice. So yes, the power company must be involved - that can't be ...


6

Cable in conduit Say what? It's never prohibited to run a wire in a conduit. What's prohibited is running wires in too-darned-small conduit, which is a problem of the cheap. Well, in fairness, it's easy to mis-guess with cable, because a flat cable needs the same space as a round cable of the wide dimension. (because they twist). For instance, with 1 ...


6

Your choice of 1-1-1-3 Aluminum is adequate. Most Level 2 car EVSEs only draw 30-32A continuous. A few years ago I dropped 2 gage Cu from my panel to my car charger spot. It was way overkill for my 32A ChargePoint, but just a couple years later and we have 40A and 60A EVSEs available. I could put two Tesla Wall Connectors on that wire and only need to ...


6

Get a cover plate with a knockout and a 90 degree connector to your NMT. That should get you started. If doing it for myself I'd use PVC conduit and an entrance ell, but that's just personal preference.


6

EMT is definitely an awesome way to do it. I do 99% of my work in EMT. However, you have to follow a few rules. One of them is "No more than four" circuits. If your service is 120V/240V split-phase it's that simple. However if you're in 3-phase land (120/208V), then the rule is "No More Than Three" if you have two or more 120/208 ...


5

Depending on how fancy you want to get, you either go Surface conduit such as Legrand Wiremold. This uses a low-profile "Surface conduit starter box" only 1" high, and allows you to retain a receptacle (or switch!) in the old location. The surface conduit then attaches to the surface, with a tight corner bend at the ceiling, and it remains conformal to ...


5

Use a Raco 665 or 187 over the receptacle location, then any type of connector out of the top of the box, and you still have the required access to the wires in the box.


5

NM doesn't belong here! Since you're putting conduit down, you do not want to try to stuff that NM cable down your conduit, for multiple reasons. First and foremost, a buried conduit is a wet location, as per NEC 300.5(B): (B) Wet Locations. The interior of enclosures or raceways installed underground shall be considered to be a wet location. ...


5

That stuff is called Unistrut. Comes in a variety of configurations. Keep in mind the normal way to attach to it is put special clips with springs that latch into those tucked-in grooves. They're not just for strength. When you see stupid pricing on the Internet, that's the "I don't want to sell it" price, or to be more precise, the "I don't want to ...


5

Conduit is still your friend Even though running rigid EMT back to the main panel from the basement junction box is basically impractical with all those other cables in the way, it is still possible to stay in conduit all the way back to the panel. How? Flexible conduit, that's how! In particular, instead of running a cable (or cables) back to the panel, ...


5

Elevating the conduit 7/8” or more off the roof surface will be more effective than painting but yes white is the least heat absorbing color. Why 7/8” elevation? That is what code requires or a temperature adder is used when derating the wire; with 7/8” elevation, the adder is not required. This is located in section 310.15(A)(3)(c), "Raceways and Cables ...


5

NM-B ("Romex" is a brand name...) in conduit is a pain. Conduit fill calculations treat "oval" cables like a round cable of the largest dimension, so if you need more than one you need HUGE conduit. So, use a junction box in the attic to transition from NM-B to THHN in conduit, which makes life MUCH easier. Properly attached rigid conduits (which can be a ...


5

I have no idea what you're looking at, but no, the NEC does not demand a pipe that fat for a 200A feeder I have absolutely nary a clue what sources you are looking at, but according to Chapter 9, Table 5A of the 2017 NEC, a 4/0 Al XHHW-2 compact stranded conductor takes up 176.3mm2 of fill. Multiplying that by four, which is quite conservative as you will ...


5

Filling uncharted waters While the use of innerducts (conduits inside conduit, basically) is not completely unheardof (NEC 800.110(A)(3) permits purpose-built innerducts for communications work, which is where they are usually found, and the Code is silent otherwise about "nesting" Chapter 3 conduit types within each other), the problem with any ...


5

If you have a double pole breaker or 2 handle tied breakers you can run a normal neutral it is called a multiwire branch circuit. Are you going to need arc fault or GFCI protection in the room? If so I would run a second neutral and keep the breakers separate. GFCI’s don’t always play well with multiwire branch circuits. They can still be used but there is ...


5

To add to what Ed wrote, the neutrals must be clearly marked as to which neutral is with which circuit. Noting that it is THHN individual wires within conduit, you are not allowed to re-mark a white conductor to be a hot. Therefore any marks on white wires are NOT remarking to hot, but simple markings. You can also just bundle the pairs of wires. Take care ...


5

I assume you are in the USA for this answer. 120 volt circuits are not considered “low voltage”. Low voltage means 60 volts (I believe) or lower. 120 volts and 240 volts are the same voltage class and it is perfectly fine to run both of them in the same conduit. Besides, in the USA, 240 volt circuits are simply two legs of 120 volts in opposite phase. While ...


4

The subpanel is the way to go. But make it big! That is our #1 thing on panels - you want lots of spaces. Spaces are cheap, regrets because your panel is full are expensive. And that is a dinky little panel downstairs, you're not going to get much out of it, and I bet you're already double-stuffing that! Of course you want a small "box size", but that ...


4

Don't replace metal pipe with PVC "just because it's what everyone uses today". Metal pipe is superior in every way. And may also provide a valid earthing path. You should not use cable in conduit. You should use individual wires which are rated for pulling through conduit. For instance, North America uses THHN, which has a nylon outer coating to make ...


4

If you don't object to having a junction box cover below your new light fixture, consider leaving the original box right where it is. Install the new box above it, and connect the two boxes with a short conduit nipple in a pair of knockouts that line up (or if there's a bit more space than shown, use an offset nipple if that helps to line things up.) Wire ...


4

Conduit provides expandability One of the banes of amateur chefs that we have seen over and over again on this site is having too much kitchen equipment and not enough juice available to make good use of it. The Code-minimum of two 20A small appliance circuits is good for well, about two kitchen appliances, give or take one depending on how they are mapped ...


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