The other day, I was changing a light bulb in an exhaust hood and noticed no air was moving through the hood. So, I went on the roof and, sure enough, the exhaust fan motor wasn't running.
This is a 3/4HP, 1725RMP, 208-230/460V, 1.25SF, 2.65A-2.66A/1.33A, 5/8" shaft, belt drive, no thermal protection motor wired for 460V. In the drop ceiling above the exhaust hood is a G. E. motor starter. When I checked the overload heaters, all three were open. So, thinking the motor was having starting issues, I inspected the motor and noticed nothing visually unusual with the motor, though I didn't take it out and open it up. I did isolate the motor leads and checked to see if it was grounded, but my meter showed no grounds on any of the three leads. I OHMed the windings and the resistance between the three windings was the same, 3.64OHMS.
Before I condemn the motor or burn up three new overload heaters, is there anything else I should be looking at more closely? By the way, the breaker was not tripped.