i have two 480 3 phase motors, the first is a 10HP (14FLA)and the second is a 30HP (40FLA) these two are to be fed from individual circuit breakers at a main lug panel and a fusible disconnect supplies the incoming power. how do you properly calculate for the correct size time delay fuses at the disconnect.

How about 430.63, which would, in your case put you at 430.62?
40A x 175% = 70A
70A + 14A = 84A
84A + the lighting and appliance load on the panel = Time Delay Fuse size?

[This message has been edited by Redsy (edited 04-05-2005).]