compressor crapped out

[kengineering]

Just installed a new condensing unit in a grab and go display merchandiser. Fired it up and at about 20 minutes, just as it was about to cycle off for the first time, the compressor dropped out. The control was still calling and it tried to start but now it was off on Overload. I installed a new start kit containing Potential relay, start cap and run cap. Then I started her back up. right at about the same time , 20 minutes, the same thing happened. Compressor stopped and wouldn't start back up. It's a 208-230 V unit the voltage checks out at 219V so thats not it. The charge is fine. any thoughts here? Ken

[Brian_UK]

What sort of temperature was the compressor running at and what were the running amps compared to FLA.

Was the Klixon open when the compressor stopped?

Was the pull down load too much for it or is the new unit the same size as the original?

[kengineering]

Thanks, Ambient temp 69*f , Compressor was running at 8.7 amps RLA on data plate states 9.2, This condensing unit is an exact replacement. There was no load as the case was empty. I do not know the answer to the Klixxon, being open. I don't know if I will be able to check tomorrow as I will be replacing this entire unit with a fresh one. ken

[lowcool]

it is possible that it may be locking up at a particular temperature,had a recon kelvy t82 that would nip up after 15 mins run time each time,3 times the thing was rebuilt it turned out the crankshaft was the only common part reused each time and the bludy thing was bent.first and last i have heard of one these cranks bending

[kengineering]

Another kit and all is fine. It has been online all day without a hitch. Here's what I have figured out. I can measure the capacitance of the run cap and the start cap, after removing the bleed resistor, with my meter. The run cap measured 24mfd, it's rated at 20. The start cap came in at 197mfd. it's rated at 185-230. So they are ok. I could not find what the resistance, ohms, for the relay coil is but I measured it at 10 ohms. I suppose I could go back to the job and pull the cover off the new one but...anyway 10 ohms for some reason seams low but thats just a guess. The windings are not grounded and have reasonable resistance although I don't know what they should be. With the exception of the relay coil at 10 ohms I really didn't find anything wrong with the components. Anything else I can check? Ken