On my third blower motor!

[thdbmn]

What are the main causes of blower motors to burn out? I have had a couple of a/c guys out here and none of them could give me an answer or fix the problem. The blower motor I have in there now just quit working one day with no smoking or burning smell (when the first one went out it was obvious) but when I took the motor out there are a few burn marks on the coil but it doesn't have that classic burn smell.

With the little bit of burn marks on the motor will I have to replace it? Is there anyway to test it? What about a bad capacitor? The unit is a Intertherm 1/3 hp 4 speed. Winter is coming fast and anything you guys can tell me would be awesome. Thank you!

[Robert]

Hi,


Did you replace the run capacitor with each motor replacement ?

You can ohm out the motor wires to see if windings are ok.

Have you or anyone checked the amp draw on the motors ?

What about the voltage ?

If furnace is old, how is the wiring conditions ?

Is it getting correct airflow ?

Is the a/c a-coil clean ?


New motor (correct one also) + new run cap with correct amp draw and voltage should work fine.


What is your furnace model number ?


Thanks,
Robert