Overly hot pool pump motor

[JamesW]

If you shut off power at the breaker, you can remove the pump basket and reach in the hole to see if the impeller is spinning freely.

Or, you can check from the back to rotate the shaft.

The impeller should have the part number stamped on it. Look for evidence of damage due to scraping.

Based on the power draw, I think that it is probably a binding impeller or an oversized impeller.

 

[Dfranc80]

I pulled the motor out from the pump and checked that the impeller spun freely. The part # is SP3010-C as suspected, see attached. Did not see any signs of scraping.
With regards to Randrx2; I reduced flow on the supply side and noticed a small drop in amperage on the motor. Down to 9a from 9.3a.
If I were to reduce impeller size and encounter the same problem I have to believe it’s the thermocouple of the motor. Then I figure a replacement motor or pump is my best bet.

 

[JamesW]

When you measured the voltage at the pump, was the pump on or off?

Measure the voltage line to line while the pump is on.

 

[JamesW]

If I were to reduce impeller size and encounter the same problem I have to believe it’s the thermocouple of the motor.

What is the thermocouple of the motor?

 

[Dfranc80]

Voltage reading while pump running is 246v line to line.

Thermocouple is basically a temperature sensor within the motor casing that will cut power of the motor gets too hot to prevent a fire.

 

[JamesW]

Ok, I'm not sure why it's using an excessive amount of current.

I would switch to a SPX3007C or SPX3005C impeller or maybe go to a variable speed pump if you want to do that.

 

[Dfranc80]

My mistake, motors have overload protection. Baseboard heaters have thermocouples/thermal cut-offs.
Anyway thanks for the help, I hope to pay it forward in the future. I am evaluating switching to a VSP, my fear is having the same issue although I don’t see how it would remain. Am I just being paranoid?

 

[mas985]

Is the motor noisy at all? Could be issue with the motor. It there is a problem with the motor, an impeller change may not solve the problem.

 

[jimmythegreek]

A VS works differently you wouldnt be running it at max speed it will stay much cooler and less draw on meter. They do have their issues at times lots of electronics on the drive boards but that's the future of pumps. Some states are making it illegal to install a single speed anymore.

 

[Dfranc80]

Is the motor noisy at all? Could be issue with the motor. It there is a problem with the motor, an impeller change may not solve the problem.

The motor isn’t noisier than what it is supposed to be. My worry is if I change impeller and save 1-2amps, will the motor still be almost as hot and only turn back on once the thermal protection has cooled off. In other words I’d still be stuck with the same problem and know that it IS the motor. This thinking leads me towards going with a VS.

 

[JamesW]

Try running the motor with no load to see what the amp draw is.

If the amp draw is low, I would try a SPX3005C impeller.

Or, maybe just get a variable speed pump if that's what you want to do.