Jeremy,
This is an issue we've seen quite a bit at our store here in Nashville. When Mytee designed those air movers, they overlooked a potential issue down the road. Fortunately, the problem is rather easy to fix.
When you open up the air mover on the motor guard and cap side, you'll see a wire running to the start capacitor with a rubber wire connector on the end. The way Mytee designed the unit has that connector rubbing right up again the metal place of the housing, and over time it eventually rubs through the connector and causes it to trip the breaker. If you replace that wire connector and bend it 90 degrees so it doesn't make contact with the metal plate, you should be fine.
If you have any questions, or this doesn't make sense, give me a call at (800) 711-4716 and I'll run you through it.
Thanks,
Matt Stein