Trying to choose best cable

[wabekanish]

I'm upgrading power to an outbuilding: from 20 amp, 120 volt to 90 amps, 240 volts. Have looked at several alternative cables. MHF seems best.

Trying to decide if I can use 2-2-4-6 MHF or if I need to go up to 2-2-2-4. Will do direct burial.

A load calculation on Kopperfields yields 79 amps (after adding 25%), which I'm rounding up to 90. NEC Table 310.16 says #2 AL for 90 amps.

The outbuilding will have a washer, dryer, lights and outlets, a workbench, and a hot water heater.

Done lots of wiring, etc., but no idea how to determine the proper size of the ground and neutral for 240 volt service.

 

[Dennis Alwon]

Please try diychatroom.com

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