Wiring for Emerson Electric motor

Thread Starter


Joined Jun 29, 2017
I am trying to wire an old Emerson Electic whole house fan motor for 120v. The part number is KS73CXS1-139. The wiring compartment has 5 wires, 4 black and 1 gray. the wires have no markings. The terminals are labeled T1,2,3, and T4. There was no connection to T1, one black wire to 2, two black wires to 3, and one black and one gray to T4. I think this motor was wired for 240v, but the wiring was very scary. it appears that is was hooked up to two 120v circuits.


Joined Nov 4, 2013
It may be of the same configuration as a dual voltage transformer where t1 and t3 are one winding and t2 and t4 are the other.

For 230 - 240 VAC power L1 feeds to t1, T2 and T3 are tied together and L2 goes to T4.
For 115-120 VAC operation L1 would go to both T1 and T2 and L2 would go to T3 and T4.

The odd grey wire may be the chassis ground being in a few odd wiring color code schemes grey was an alternate to the now standard green, yellow or light blue.

Just a guess at this point though.