125 Amp Sub Panel Wire Size

The calculator allows entry of a voltage drop but caution should be used when doing so to make sure you are calculating the wire sizes in accordance with nec article 210 19 fpn no.

125 amp sub panel wire size. The wire size according to codehas to be up sized to 125. If you have a 125 amp breaker you need 125 amp wire. The wire size chart below shows allowable ampacities of insulated conductors rated up to and including 2000 volts 60 c through 90 c 140 f through 194 f not more than three current carrying conductors in raceway cable or earth directly buried based on ambient air temperature of 30 c 86 f.

I w e 70000 240 291 67 amps. 500mcm copperwire with an insulation factor of 75 and 90 degrees c is rated at380 and 395 amps respectively. Since this is a single phase dwelling service you can use 2 awg copper or 1 0 aluminum for a 125 amp service or main feeder.

See the table here. You need to use the 75 column since no one makes a 90 breaker just yet. I m going to make an assumption that you want to add a sub panel for a garage or workshop you will be burying the cable in pvc conduit at least.

The wire size according to code has to be up sized to 125. I assume i need to run 4 wires 2 hot 1 neutral and 1. 291 67 x 125 364 6.

To calculate the wire size you would have to find the amperage. I will be installing a 100amp breaker in my main panel. I understand i could use a 125 amp breaker but i do not need the additional amperage.