HVAC Tech Question

[dustoffer]

I have a blower motor out of a central air system that I use in my shop for an exhaust fan to pull the dust/hot air out. I has developed a problem after 5-6 years of flawless performance. I turn it on, any speed, and it spins up to RPM, and 5-10 seconds later it quits. Let it rest 10-15 minutes and repeat, with same result.

One fellow told me it was a bad thermistor (?). Is it a reasonably priced fix or should I look for another fan?

[ballgame]

PM jreyna920 he might be able to help ya.

[deer99hunter]

Fields are shorting out in the winding causing excessive heat, which will cause the motor to shut down.

Do you have either the side or front partially blocked ? "Squirrel cage" blower assemblies work off of static pressure. If you don't have one of the openings partially blocked then the motor can't develop enough airflow. Without enough airflow ( over time ) the motor overheats and causes winding failure


But what do I know, I've only been an A/C man for 25 years

[dustoffer]

Yep--got one side 2/3rds blocked-