Large Printer

[babool]

I hooked up a large Printer pulling 52a, ran #6 thhn wire to feed this and put it on a 70a breaker as a 60a is only rated for 48a. The maintenance facilities representative is arguing this should be #4 wire. The 75c column allows 65a for #6 but next OC device available is a 70a breaker. I thought there was an allowance for next size up on equipment with motors but can't seem to find it. Am I wrong here?

 

[infinity]

#6 is rated at 65 amps at 75°C. Next size up rule is 70 amp OCPD. IMO since the unit is non-continuous the circuit OCPD could be 60 amps.

 

[augie47]

Being <100A there is a small chance, depeding on the printer termination rating, that you would need to use 60°C rating but even then your #6 is 55 amps, greater than the load.