480V. 3P. branch motor circuits

[BrentG]

I have a cal. question.
I have two motors, both cont. duty 480V. 3P.
They are fed from a fuse panel, which is fed from a fused disconnect. Both motors have there own branch circuits.
Anywhere in the calculations for the motors overload protection, cond. size, overcurrent protection do I have to use an additional 1.25% for the cont. duty?

Example motor #1 Fla 40amps.
would the overload and NTDF fuse protection be.
40x1.25=50 40x3.00=120

 

[augie47]

Re: 480V. 3P. branch motor circuits

Standard computations would probably be as follows:
motor branch circuit 125% of motor FLA (per 430.250)

short circuit protection (fuses) 175% FLA

overload on a 40 hp is normally part of the controller