electricalperson
Senior Member
- Location
- massachusetts
The question states:
The motor feeder conductor size for 3 15 hp 208v 3 phase motors, 3 3 HP 208v 1 phase motors and 3 1 HP, 120v 1 phase motors will be_____
A 2/0 awg, B 3/0 AWG, C 4/0 AWG, D 250 MCM
15 HP = Largest motor load. 46.2 x 1.25 = 57.75
(46.2 x 1.25) + 46.2 + 46.2 + 18.7 + 18.7 + 18.7 + 16 + 16 +16 = 254.25
250 MCM is rated for 255 amps
my answer was D but the example in the books answer is C
i think the book is wrong since i have the answer key right infront of me and they only added in 1 1 HP motor.
The motor feeder conductor size for 3 15 hp 208v 3 phase motors, 3 3 HP 208v 1 phase motors and 3 1 HP, 120v 1 phase motors will be_____
A 2/0 awg, B 3/0 AWG, C 4/0 AWG, D 250 MCM
15 HP = Largest motor load. 46.2 x 1.25 = 57.75
(46.2 x 1.25) + 46.2 + 46.2 + 18.7 + 18.7 + 18.7 + 16 + 16 +16 = 254.25
250 MCM is rated for 255 amps
my answer was D but the example in the books answer is C
i think the book is wrong since i have the answer key right infront of me and they only added in 1 1 HP motor.