What's it supposed to be pulling, amps-wise? Run capacitor OK? Start winding OK? Overload OK? Start relay dropping out correctly?
Walk in cooler, Tecumseh compressor AKA9442EXD, R-22.
Customer calls walk in cooler warm compressor hot. I check unit and find the potential relay contacts not opening and further inspection find the relay coil open. I go get new start components, install and the unit is doing the same thing, relay contacts not opening, compressor pulling 16 amps.
Potential relay was crossed to a Mars 19163 per the manufacture.
The comp will only run about 20 seconds before going out on the ext overload. What am I missing? Any help or suggestions appreciated.
Also customers says a day before the cooler had trouble they had a power surge.
What's it supposed to be pulling, amps-wise? Run capacitor OK? Start winding OK? Overload OK? Start relay dropping out correctly?
According to Tecumseh spec sheet RLA 4 amps, LRA 31.
Start relay was found to be bad, all start components were replaced including run cap.
C-S = 2.3
C-R = 1.9
R-S = 4.1
I've had bad start components right out of the box, I'd check the caps again to start off. Once the compressor is running pull one wire off the start cap and watch the amperage, all your doing by this is dropping out the start manually. I've also had maufacturers do a bad cross reference over the phone but highly unlikely.
I'l probably catch hell for telling you to risk life and limb by disconnecting power, loosen the spade terminal to the single wire spade connector to the start cap, apply power, let compressor start, usng a needle nose pull the loosened connector off the start cap and check amperage but what the hell.
js
I think you've found your problem, per the resistance readings you've given. This is another one of those rule of thumb issues that has a correct answer if you go to the mfg on a specific motor, but the issue is that your C-R and C-S are too close together. Looks as if you have a shorted winding.
Found my ROT: C-S is normally 3 to 6 times higher than C-R.
According to my Techumseh book.. AK9442E @ 77*F
S-C 9-12
checking potential relay or start components
I keep saying I want to make a rig with a momentary switch this could be used like a hard start to turn a compressor or check pot relay
Was there ever a final determination of what was wrong with the compressor or it's start components? Terminal readings didn't look right to me. Just curious
Thanks for the update. I don't deal with many compressor failures on ice merchandisers but when I do I try to understand why they failed and gain any knowledge from testing them. Thanks