/diy/ - Do It Yourself

>>2596369
Don't use this for ampacity and wire size for any installation covered by the NEC.

>>2562731
>If you run 14 ga. Through an attic or other hot area you have to derate it, and it can no longer handle even 15 A.
Not necessarily. The ampacity table for a copper 14 AWG 90 C conductor is 25 A. That's the number you start with before the derating for ambient temperature and conduit fill. For residential applications, NM-B is fine in the attic because it's 90 C conductors derated to 60 C. That attic temperature is already baked in the 15 A maximum overcurrent protection for 14 AWG.

>>2558748
If that's the reason, the circuit is most certainly undersized. Code requires 10 AWG for 30 A circuits. While 12 AWG with a 90 C rating can run 30 A, that's purely for the conduit fill and temperature derating calculations.

>>2465440
well what do you need? if the dryer is electric, its either a 3 prong or a 4 prong, which either requires 2 conductors and a ground, or 3 conductors and a ground. either way, you arent getting away from the fact that electric dryers usually require 30+ amp. look at an ampacity chart. if the wires are 14 gauge, theyre only rated for 15 amps. if they are 12 gauge, they are only rated for 20 amps. if you got a gas dryer, you could just run a 120v nema 5-15, but then you gotta run gas to the dryer.
>breaker box is a floor down and a ways away, I’d rather not run new line the whole way as there’s solid concrete floors, walls and ceilings.
run conduit on the outside of the building, or run MC on the surface indoors would probably be the easiest if you dont mind it looking ghetto.

>>2034586
>Look it up in NEC 310, you didn’t say if your 60A run is going to be copper or alum. If copper, then a 6ga wire can handle 65A. It needs to be 4 wire.
Not if it is NM-B.

>>2024722
NM-B is a 90 C conductor running in at 60 C. He might cook of the PVC outer jacket, but the conductors themselves should be fine. 14 AWG is good for 25 amps and 12 AWG is good for 30 amps; however, the code restricts you to 15 and 20 amps respectively. It really helps when you are running THHN in conduit for fill and maximum number of current carrying conductors calculations.