SMC Discussion Areas

Trouble-Shooting => Refrigeration => Topic started by: on July 09, 2002, 12:58:37 pm



Title: Compressor motor wiring
Post by: on July 09, 2002, 12:58:37 pm
Does anyone know where I might find a wiring diagram for the compressor motor on my Gullwing?  The motor is a Westinghouse 1/4 hp. 1725 RPM  60 cyc. 110V   3.8 amp.
The power cord and the wiring from the thermostat to the motor are both melted and have broken away from the motor connections.

Also, can anyone provide some insight on overhauling the actual compressor unit (cleaning, lubrication, common parts that should be replaced during a rebuild)?
Thanks,
Bryan


Title: Compressor motor wiring
Post by: johnieG on July 10, 2002, 03:39:04 pm
have you got a picture of the terminal side of the compressor?


Title: Compressor motor wiring
Post by: johnieG on July 10, 2002, 08:18:08 pm
This is a westinghouse compressor is it simular to yours?


Title: Compressor motor wiring
Post by: on July 10, 2002, 08:52:11 pm
Thanks, JohnieG.  Here it is.



Title: Compressor motor wiring
Post by: johnieG on July 11, 2002, 08:04:00 pm
OK can you back the camera up and give me a angled side shot, and is there a start cap on the side of the motor?


Title: Compressor motor wiring
Post by: on July 11, 2002, 10:33:31 pm
Not sure what you mean by start cap.  The start button is on the thermostat unit.
Here's a better photo.


Title: Compressor motor wiring
Post by: johnieG on July 12, 2002, 08:12:42 am
Working on memory here...so bear with me I'm attaching a generic drawing of a mechanical compressor layout, please note that not all of the components may be present on all systems. (I've only seen the gut's of a gullwing once, and don't recall if there's a evaporator assembly & fan in the soda cabinet, or if like an Ideal slider, the evap. coils are part of the side wall of the cabinet) hope this help you in sorting out you wiring, you might have to call Eric at Global Compressors and ask if he's worked on one of these puppy's, any one in the peanut gallery worked on one lately? ???


Title: Compressor motor wiring
Post by: Jim on July 12, 2002, 02:20:50 pm
Bryan,

Can you see a model number anywhere on the Westinghouse unit?
Secondly, in the photo, I can see three terminals, two are bright and clean meaning they where in use. The third may not have been used and looks to be like a ground, is this correct?

I have old Westinghouse frigeration material that I could post but I want to get the closest version of refrigeration unit to ensure proper wiring!

Lastly, is this picture of the compressor? If so, have you cut the freon lines to remove the unit...?

Johnie, excellent diagram!


Title: Compressor motor wiring
Post by: on July 12, 2002, 03:19:25 pm
Jim,
Here is the info on the belt driven compressor unit:
Refridgerator Unit Part No. 64346
Model A1 4FH
1/2# freon charge

and the info on the electric motor:
Westinghouse 1/4 hp
1725 RPM  60 cyc.
110V   3.8 amp
40 deg. C, hours (Continuous)
Serial# FK    Style 956628A  Open

"Secondly, in the photo, I can see three terminals, two are bright and clean meaning they where in use. The third may not have been used and looks to be like a ground, is this correct?"
There were some connectors with wire remnants attached to all 3 terminals, but the power cord and thermostat/start unit weren't connected.

"Lastly, is this picture of the compressor? If so, have you cut the freon lines to remove the unit...?"
The photo is of the motor/fan only.  The compressor freon lines haven't been cut, the cold line was connected to the cooler with a compression fitting.


Title: Compressor motor wiring
Post by: Jim on July 12, 2002, 06:29:18 pm
Bryan,

Unfortunately, I don't have any info on this type of refrigeration system...
Looking more indepth at JohnieG's diagram and it seems to be accurate.

Essentially, the thermostat is controlling the electic motor that runs the compressor and condensor fan. The evaporator fan should run al the time. The only confusing part may be whether or not you have a start relay... Do you know if the unit has one? It will look like a little box with three or possibly four terminals on it.


Title: Compressor motor wiring
Post by: on July 20, 2002, 10:10:03 pm
Is polarity an issue when hooking up the electric motor (I didn't think it mattered with A/C)?  I'm worried that the compressor will cycle backwards if I wire things wrong.  The diagram JohnieG posted doesn't show specific terminal conections and there are 3 terminals on my motor (as shown in my previous posts).


Title: Compressor motor wiring
Post by: Jim on July 21, 2002, 01:28:32 pm
As long as you're brave enough to play with electricity, I would bench test the motor first. In this case, the motor could be connected either way and it will rotate in its intended direction. From your previous picture, I see two posts that are shiney; I would start with those two.

Get an old extension cord and cut of the female end leaving the cord and the male end. Strip back approximately 1/4" of bare wire and twist it so there a re no frayed ends that could accidentally touch another part of the motor during a test!

Make sure the motor is secure to the bench somehow... If the motor is still in the mounting bracket, screw it down.

Plug in the custom extension cord making sure the ends are seperated and touch them to the two shiney teminal posts. The motor in all practicalities should spin since these are the two terminals utilized prior to disassembly...

As for the third terminal, it may be an internal ground wire... I'm not really sure, but the picture looks as though it wasn't connected or used because it's still very dirty...


Title: Compressor motor wiring
Post by: on July 21, 2002, 02:46:45 pm
Jim,

The third terminal was used (it had the remnants of a connector attached).  I believe it may be where one of the wires from the thermostat/start unit hooks in.  Thanks for the suggestions on the makeshift power cord, I'll post any findings.  I guess if you guys never hear from me again, you'll know that things didn't work out too well   :laugh:


Title: Compressor motor wiring
Post by: on August 16, 2002, 12:51:07 pm
Update:  The compressor motor wiring is fixed, I'm alive and our house is still standing.  My wife always gets nervous when I play with electrical wiring, maybe it's because of that time she walked into the garage just as sparks started flying out of the pinball machine I was working on.  Apparently I had unplugged the wrong pin  :D .  Any way, a big thanks to JohnieG and Jim for providing information and technical advice.  Now if I can just find the phone number of that A/C repairman who said he could re-charge my system.  Hope he dosen't have any R-12 laying around, it might be bad for the environment  :;): .