That was strange.
My power went out in a storm for several hours, so I decided to make use of the battery backup unit I bought for the home theater, and run my fan off of it for a while. I ran it for about 20 minutes until I noticed it was cool enough to turn it off.
Later, when power was restored, I plugged fan back into regular wall receptacle and nothing. Fan wouldn't run. Checked wall outlet and it had power. Seems odd that running a fan on battery backup power would burn out the motor.
Ordered a new fan from Amazon.
