On 07/27/2015 7:06 PM, Deane Williams wrote:
I set up a thermostat in my garage that comes on at 80 degrees F. and sends a 6 VDC battery voltage to control a 120 VAC solid state relay which powers up the vent fan. The fans always quit within 2 months to a year with no obvious defects. These are inexpensive 20 inch box fans with induction motors. I have tried several brands and styles of fans. The latest was a Home Depot unit that only lasted 2 months.
Does anyone know of a reason why I can't run an induction motor from a SS relay? What is killing the fans? I have taken two apart and there is no smoke smell, no visible damage and if there is a capacitor it tests OK.
Thanks for any ideas. I am going to switch over to a mechanical relay.

Dean


Have you had any other fans of the same make/model running on just
115VAC to see if they run any longer? They could be just cheap fans
whose oil dries up.

Hard to see where a SS AC Relay could hurt an induction motor if the
motor isn't overheating.

Does the fan still spin? Is there continuity in the winding?

John :-#)#

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