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New motor keeps cutting off

PostPosted: Mon Nov 05, 2012 4:59 pm
by lwparchive
The pump motor ( ¾ HP ) is replacing an old A.O smith ½ HP, - identical in all respect except for the HP rating - but it seems that the thermal cut-off switch is engaging often.
My wiring is for 230 volts and since the max amps on this new pump ( 10.5 A ) is lower than my old pump ( 11.5 A ) I believe my current power wiring AWG size is correct and should not be changed.

-What could be the problem? ( Pump is in a well ventilated area )
-Please confirm AWG wiring size

Thank you !

Eric D

Re: New motor keeps cutting off

PostPosted: Fri Nov 30, 2012 4:36 pm
by dlamp67
Replacing your 1/2HP motor with a 3/4HP motor should not have caused any heat issues. If anything, the pump would probably be more efficient. There may be an issue with the motor "dragging" due to faulty bearings? I don't know without having the pump here at our shop and on our test bench. Could there be something in the pump housing causing this problem? Again, the pump would have to be taken apart to determine. Could it be a faulty motor. You may want to call our office so that we can go through the entire application and see we can determine where the problem may be.

You should not have had to change the wire size, Unfortunately, we normally will not recommend wire sizes.

Re: New motor keeps cutting off

PostPosted: Wed Jul 17, 2013 8:59 am
by dlamp67
Thank you. The forum is in its beginning stages. Hopefully, we will attracted other professionals to join in the conversations.