speedaire by dayton runs slow then eventually stops

by julius
(fort valley,ga)

model # 3z784, 2hp, phase(1)
stage (1)
ROT -- ccw
dayton electric motor -- 9k4578 -- capacitor start duty
2hp 3450rpm
115/230v - 60hz single phase

the compressor runs slow then eventually stops(about 20sec)
- oil level on line
- new belt, pressure switch

______________________
Bill says...

Julius, if the motor is fine, and lugging or running slowly, then it's likely that you're not getting enough voltage to it. A too long extension cord, too many other appliances pulling power from the same circuit... and so on.

If the power supply is good, then it's time to get the motor load tested.

Cheers,

Bill