I have a surplus single phase induction motor that I pulled out of a treadmill the other day and am trying to figure out if it's good. The face plate says it's 3/4 hp, 1725 RPM, 115 Volts, 10.4 Amps, and 60 HZ. When I wire it to my 120V mains, it starts right up and seems to work great. When I measured the current draw with no load, it draws about 9.1 amps. I know these are not very efficient motors but I would have guessed half that just to keep it running. I don't see any start or run capacitors on this but it does have a centrifugal switch built in for starting. It clicks if you turn it by hand, is that normal for this type of motor?
So what should the idle current be for a motor this size and type? 9 amps? or is this drawing excessively?
Part of the reason I ask is because I obtained a much older (1978) 1/2 hp motor of the same type a while back and upon testing found that it's start winding was burnt out, requiring a hand spin to get it to run. It was rated for 8 amps and at Idle used 7.2 amps, and got pretty hot pretty quick I thought, so I deiced that it must be drawing excessively because of a shorted winding or something. So either they are both good or both bad... I don't know.
Thanks for your help,
Alan
So what should the idle current be for a motor this size and type? 9 amps? or is this drawing excessively?
Part of the reason I ask is because I obtained a much older (1978) 1/2 hp motor of the same type a while back and upon testing found that it's start winding was burnt out, requiring a hand spin to get it to run. It was rated for 8 amps and at Idle used 7.2 amps, and got pretty hot pretty quick I thought, so I deiced that it must be drawing excessively because of a shorted winding or something. So either they are both good or both bad... I don't know.
Thanks for your help,
Alan