Greenhouse project :D wiring electric motor PLEASE help, my project continued.

Im having trouble with a 3/4 hp century motor, it keeps shutting off after 20-30 minutes, the thermal shutdown kicks in because the motor gets very hot. Its on a 15 amp circuit dedicated, doesnt trip my breaker or the gfi weatherproof. Im hoping maybe me not being a motor specialist I wired it wrong. Thank you in advance for any help given. Its mounted to a greenhouse exhuast fan 30" with an aluminum shutter it has to blow open aswell as turn the fan.

Since it works until the thermal cuts out, the first thing I would attempt to test is how hot it is when the thermal fuse cuts out. If that seems like it is in spec, then the motor you have is likely undersized. Given Watts = Amps X Volts, the maximum amount of wattage you theoretically have available: 15 X 120 = 1,800 watts. Realistically, though, you have a bit less. Your motor is rated at 6.8 amps, so 6.8 X 120 = 816 watts. Which means you are leaving some wattage 'on the table' and could up-size your motor significantly without popping the breaker.

Another thing you might look at is thermal properties around the motor: eg. is the motor set in a place where the sun is directly beating on the motor case? That could cause it overheat as well.

Thank you for your reply first of all, all night running around the internet looking for answers. I recieved an email from a "mark" at century, "note motor comes shipped for 230 volt and must be changed to run 115v. this is a diagram for a 1hp motor but the 3/4 hp motor has to be changed the same way by moving the white wire to clip 1 and the blue wire to clip 3." I had asked them for "a diagram for dummies" lol, being an electrician, thats kinda frustrating to find out how little I know about electric motors. Century 3/4 hp electric motor wire diagram for 115v. My assumption was what you stated Bluesky, to much load turning the fan and blowing open shutters, tomorrow ill wire it up correctly and see.