How crucial is it to match the right capacitor to the right condenser fan motor? If you have the wrong capacitor, can this cause the motor to stop after running for a while, say 20 or 40 minutes? It would start up again, but would allways stop. The specs for the motor are: Emerson E-line, model no KA55HXPAK-7253, H/P 1/8, 208-230 V, RPM 825, HZ 60, AMP 1.0 PH, single phase? and a 5/440V 50/60Hz capacitor was fitted by the service people.
The motor would overheat and shut down after running for about 20 minutes. The problem is now fixed, after we had to buy a new motor, (and fan), after which this capacitor caused the same problem, after which we fitted the capacitor suggested by the retailer (turned out to be the wrong one, causing the same problem), after which we bought the capacitor that was CLEARLY indicated on the box of the new motor (after 5 days of troubleshooting! ).
I need to know whether I have good cause to take the capacitor back to the service people and ask for a refund. I feel I should get a refund on the entire service call, seeing as they did not ever check the specs of the motor before putting in the new capacitor. I am starting to think it was all planned, to have the wrong capacitor causing the motor to shut down so that they could potentially get more money out of me (they wanted to charge me 375 dollars for a new motor which I declined because we eventually bought and fitted it ourselves for about 120 dollars. (maybe this is just being paranoid but this is how I feel!)
Thanks to anyone who might reply.

Matching the capacitor to the motor is essential, and should be replaced when motor is replaced , you can try to get a refund but you will have the burden of proof on you . Good luck. Mike

I have a South Bend lathe from 1941 with a GE motor model 5KC73AB244 and I need to replace the start capacitor on the motor. The capacitor has no information on it. How do I go about finding the correct capacitor rating? The motor is 1ph 3/4 hp 110V 60cy 10.8A 1725 rpm reversible motor

Go to or take it to granger or another electrical supply, they might help

This depends on the type of motor....generally speaking 5ufx370v for 1/4 hp...7.5ufx370v for 1/3 hp....10ufx440v for 1/2 hp. You can usually tell if the capacitor is properly sized by checking the amp draw under load, it should be roughly 3/4 of the rated max...You can also check operating temperature after the motor has run under load for say 20 min or so...Rule of thumb, if it's too hot to hold your hand on, then you got a problem, either the bearing is bad, the cap is too small, or bad, or a winding is shorted