[major]

Does anyone know what a GE 2CM77 motor looks like? I believe that is what I have in this car I picked up. I tried googling lots of different ways but cannot find a picture of one and there are no numbers on this motor to help identify it. There is 4Awg on the E-, C+, with a small 10Awg on A+. It runs just fine this way but if there is another way to do it, I'm interested.

From the terminal block, it looks like an old aircraft starter-generator. They were made by several companies to maybe the same spec. I've seen a number of conversions using them, mostly from 20-30 years ago. You'd likely have better luck searching for the Jack & Heintz version. There's been a few related discussions on this board. They're pretty rugged.

major

 

[major]

The numbers on it are all GE numbers and it has new brushes and assemblies. All I'm trying to do is get a different motor controller for it, a new lithium battery pack, and clean it up. As this appears to be a sepex motor I need to know if this thing is wired up correctly or not.

Yes. Wiring and control is tricky. I believe it is a compensated shunt wound generator. But was used for cranking aircraft engines so able to put out high torque as a motor. I think there is internal schematic for the J&H version somewhere on the interweb and GE might be same. Not sure but I think Westinghouse also made a version.

Thanks Brian. Correction made.

major

 

[major]

Thanks guys. I agree, it does look to be complicated but I did find the original builder here! http://www.evalbum.com/204
I still need a diagram to hook this up so I'll check my local motor shop here in town and see what they say.

You might try the EVDL. It was a long time ago but I recall helping a guy named Michael in Texas or OK get his J&H wired up correctly. There's others on that list who've used those genneys. Maybe a guy named Lee Hart will chime in. He knows his way around those. I think he is also a member here.

major

 

[major]

Thanks Major. I'll keep sleuthing around and see what I find. I got through some of the EVDL and found that one of the coils needs 28VDC to make it work. Currently, the motor is running on a DC PWM motor controller, it just has very little torque to get going. If I could just get an internal diagram for this I'd know what to do.

Yeah, that's the problem Texas Michael had. Running a shunt motor on voltage control starts it out with a very weak field meaning low flux meaning low torque. Solution was/is to separately excite the shunt field with about 30V. IIRC requires an internal wire relocation. Also because it compensated (compound) you need to get the series winding polarity correct.

major