what size wire for a 250 amp load, 480 volt 3 phase a/c
Model: plant parts washer
What size breaker are using on this circuit?
I assume you are using copper wire in metal conduit.
300 AMP BREAKER, FUSE AT 400 AMP DISC BY 250 FUSES
The load is 250A and you are using 250A fuses? Or is the actual load less. This makes a difference on the size wire you can use. It might save you some money.
TOTAL LOAD THEY TELL ME IS 250 MAX COULD BE LESS AT TIMES AS THERE ARE 3 MOTORS FOR PART CLEANEING IN THE UNITS THAT ARE STEAM FOR CLEANING
Ok then you have to size for the max amperage.
For this install you need to use 250mcm copper wire with THHN insulation. You will need to use a #4 copper ground wire.
If you need more help please ask here.
23 yrs as an electrician, self employed contractor, municipal inspector