Hi,
I have a 50hp 3 phase 460 volt (single voltage) 1/2 part winding motor with six leads. The control panel is set up with 2 starters. When starting the system, the first set of windings (1-2-3) is energized. After a small delay the second set is energized (7-8-9). This effectively creates a soft start setup.

My question is, What size should the six conductors be that go from the starters to the motor?. The motor is located about 40 feet away from the control panel. The motor nameplate shows 61 amps.


This was a setup that we bought used. It was previosly setup using #6 conductors for the six leads.

Joe,

The conductors on the secondary side of the motor controller can be selected based on 50% of the full load current of the motor. See 460.22D

#8 should do the trick

Tom

Joe,

Are you sure it is a "Part winding" starter and not a "Wye-Delta" starter?
I thought "part-winding" control was only suitable on the lower voltage of dual-voltage motors, where the windings are connected in parallel?

Yes,
It is a Lincoln Electric Motor. I also got some supporting information off their website.
Thanks for your help