I am a finish carpenter who builds furniture in his spare time. After many years I am building my own shop just off the main house. I am installing a 125 amp sub panel and need to make sure I use the correct wire size, conduit size, and junction box. This will all be done in copper. The junction box is because I am feeding a second sub panel of the main. Thanks to all in advance.
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Replies
The 125a sub panel should be using three 1 gauge copper conductors with a 6 gauge grounding conductor (4 wires total)
Some AHJs might let you get away with #2 since 115 is not a standard size breaker.
I would run this in 2" PVC to make it an easy pull. You can squeeze it in 1.5" but if you are going very far you might have quite a tug.
Use a pretty good size junction box if this is going to have another big feeder in it. A 6x6 Carlon box is a reasonable fit because it gives you enough room to handle the #1s but bigger may be better.