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2

We don’t calculate conduit fill based on lookup tables. We calculate it based on the actual size of the wires, or in the case of an oval cable, the swept area as it twists (like a circle of the large dimension). We total up the effective cross-section area of the wires, and then, compare that to the actual cross-section area of the pipe in question - and ...


3

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 ...


2

For most applications you would use wire in household installations, you don't need the THWN-2. The 90C rating is pointless for anything other than when you need to de-rate wire for having a lot of conductors in a single conduit. Most residential products have terminals rated for 60 or 75C anyway, so you still end up sizing the wire for that anyway, meaning ...


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 ...


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 ...


1

Your setup seems very well thought-out. You’ve done your homework and gotten 99% of it correct IMO. 12 or 14 AWG THHN/THWN-2 wire (white, black, green) or 14/2 UF-B (which I already have, but may not have enough of) Cost difference in UF 12 vs 14 is enough to care about. Cost difference in THHN 12 vs 14 is not significant. UF in conduit is usually a bad ...


1

1" conduit is fine, but it needs to be conduit Your plan to use 1" PVC conduit is alright, but it needs to be conduit, not plumbing pipe, with an expansion joint at both the ground-end and at the shed-end to control for ground motion. You'll want to use prefabricated sweeps for the underground bends, with a LB for the aboveground direction change ...


2

"Direct burial" means that the cable is rated to be in direct contact with the ground and keep the ground water away from the wires inside. It does not mean that it is only to be used in direct contact with dirt. Feel free to wire your whole house with direct burial cable if you'd like, just be prepared to pay through the nose for it. (Just be sure ...


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.


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, 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 ...


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