A 45 KW motor (440Vac, 3Ø, 60Hz, IFL=73.2 A) is having a contactor (for star & delta) rated at 22KW @ 440Vac and 1-set-of-14 mm2 THHN. (See attached picture).
Clearly the contactor & the wires are undersized, which leads to the conductors being heavily hot during continuous operation.
I think that wire must be at least 22 mm2 or 30 mm2 and the contactor must definitely be replaced.
However, since the circuit breaker is 150AT, should I use a much bigger wire size (say 50 or 60 mm2)? Since the CB is 150AT, I am thinking of using a wire size that matches that ampacity. Also, if this will be the case, I need to change the main feeder.
What do you think?
Clearly the contactor & the wires are undersized, which leads to the conductors being heavily hot during continuous operation.
I think that wire must be at least 22 mm2 or 30 mm2 and the contactor must definitely be replaced.
However, since the circuit breaker is 150AT, should I use a much bigger wire size (say 50 or 60 mm2)? Since the CB is 150AT, I am thinking of using a wire size that matches that ampacity. Also, if this will be the case, I need to change the main feeder.
What do you think?