posted on 7/23/2007
This is a continuation of same subject from 2-3 weeks ago, but the history on that seems to be unobtainable now on this web site. There were actually two issues, one was a faulty relay (relay power to blower, not the time delay relay.....which didn't have to do with the hi temp non-operation) and the other turned out to be an intermittent thermal protection device in the motor. Although the thermal protection in the motor is spec'd at 40 deg C (100 F) and the temp reached a max around 90 F, this device was cutting off the motor when the temp was high, but OK during the eve's when temps were about 15-20 deg cooler (temps in the attic where motor was located for the blower system). After a couple of weeks, the thermal protect broke down completely and motor would not come on in the cool ambient.
Solution: replace the motor as the thermal protection is internal to the motor, not serviceable but by the mfr..
Note: Grainger is an excellent source for motors, relays, transformers, etc. and if a problem, talk to their 800 tech assistance and they will find you an equal part. Have the part # that is on the part, not just the system model # or system part #. Get their catalog, a huge one, source for mucho parts.
Also, be sure you know the proper oiling amount, and when to oil, ref. a motor: You can kill a motor by overoiling each time, or too often. Some only want a couple drops, some 10 and some 20 drops...usually noted on the motor label, when in doubt, call the mfr. or distributor but if distributor, be sure they are reading from the spec, not "well usually a couple drops, don't overoil" type of advice. Regards, Steve