Episode #125 of the Stack Overflow podcast is here. We talk Tilde Club and mechanical keyboards. Listen now

New answers tagged

3

First, a ground wire and neutral is mandatory for this setup. You cannot set up groundless, and you cannot "bootleg ground" off neutral as once was legal for dryers. This is extra important because if a neutral wire has a problem, it will electrify the grounds - and that'll shock and drown people in the hot tub. If the hot tub already requires a 30A ...


7

Don't reuse old nuts, or ones of indeterminate origin. Some wire-nuts are single-use; using them destroys their gripping power. Wire-nut technology has moved in leaps and bounds in the last 10-20 years, and the newer nuts are much better. Aim to use nuts near the middle of their working range Not at their extremes. Black is not a new code, it's a ...


7

Here is a catalog from Thomas & Betts, the makers of Marrette connectors. Pages 14-15 cover the black high-temperature wire nuts including the Model 33. The graph on Page 15 shows limits of "Min. 1 #18 + 1 #14 Max. 4 #14", so four 14AWG wires is exactly at the manufacturer's limit. There's also a detailed table at the end of the document (Model 33 is ...


2

Feeling the heat While your conduit can physically fit all those wires, sure, there is a problem with your plan still, and that's the amount of heat stuffing 16 current-carrying conductors into a conduit throws off. In fact, due to the inability of the conduit to dissipate that much heat, the NEC limits your 10 12AWG wires to carrying a mere 15A per wire ...


6

You don't need a wired ground in EMT conduit between metal boxes. Your calc is fine, but you forgot the other calc. So many wires, so close, will make too much heat. And that's settled here. You have 16 conductors so a 50% derate. You derate off the thermal max for the wire you are using (for THHN, that's 90C column in table 310.15B16). Blah blah,...


3

The answer to your question is "quite critical": Grounds must be green, yellow/green or bare. Neutrals must be white or gray. All others are hot. Binding stranded wire to a screw terminal is tricky. Not impossible but tricky. I like to "super-twist it" by gripping the wire in a hole intended to shear off bolts, which keeps it circular. You have to ...


Top 50 recent answers are included