Pentair Motor overheating

[WarmFZI]

Reviving this old thread because I have the EXACT same issue. My 22 year old wisperflo suddenly started overheating the motor. I initially thought the year old bearings in the motor gave out so I just put in a new 1.5hp motor. From the beginning it didn't sound right and was running hot. I see the same amperage unloaded and loaded, and it will thermal trip after a little while. Second new motor does the same. I have a new impeller, diffuser and seal plate. The motor spins freely when completely assembled.

@RogueAg - did you ever get to the root cause of your problem?
TIA

 

[ajw22]

Welcome to TFP.

Put a clamp on ammeter on the electrical lines and see what the amps are.

Post pictures of the old motor data plate and new motor data plate.

Can you show the wiring compartment?

What part number impeller did you install?

 

[1poolman1]

Reviving this old thread because I have the EXACT same issue. My 22 year old wisperflo suddenly started overheating the motor. I initially thought the year old bearings in the motor gave out so I just put in a new 1.5hp motor. From the beginning it didn't sound right and was running hot. I see the same amperage unloaded and loaded, and it will thermal trip after a little while. Second new motor does the same. I have a new impeller, diffuser and seal plate. The motor spins freely when completely assembled.

@RogueAg - did you ever get to the root cause of your problem?
TIA

Did you put in a motor with a total horsepower of 1.65 or 2.25? Your 2hp Whisperflow with the OEM impeller requires the 2.25 if it is a single-speed.

 

[WarmFZI]

The problem started with the original (22yr old) 1.5hp motor overheating, with original impeller.
WhisperFlo is WFE-6 1.5Hp, SF 1.47

 

[1poolman1]

The problem started with the original (22yr old) 1.5hp motor overheating, with original impeller.
WhisperFlo is WFE-6 1.5Hp, SF 1.47

2.21 (rounded) total horsepower motor. New motor should have that or slightly higher total horsepower (label horsepower X service factor).

 

[WarmFZI]

New motor is 1.5Hp SF=1.1 One mystery down.
Now why is the original motor overheating, just old age? It spins freely (year old bearings).
I'll try it with all the new pump parts.
Thanks

 

[WarmFZI]

Welcome to TFP.

Put a clamp on ammeter on the electrical lines and see what the amps are.

Post pictures of the old motor data plate and new motor data plate.

Can you show the wiring compartment?

What part number impeller did you install?

Well that explains something - good to learn there are different impellers. I got the 073131, which probably isn't happy on a 1.5HP motor.

 

[JamesW]

Impeller......Total HP.

073126.........0.95
073127.........1.25
073128.........1.65
073129.........2.20
073130.........2.60
073131.........3.45

The total hp is the rated hp x the service factor.

 

[RogueAg]

Reviving this old thread because I have the EXACT same issue. My 22 year old wisperflo suddenly started overheating the motor. I initially thought the year old bearings in the motor gave out so I just put in a new 1.5hp motor. From the beginning it didn't sound right and was running hot. I see the same amperage unloaded and loaded, and it will thermal trip after a little while. Second new motor does the same. I have a new impeller, diffuser and seal plate. The motor spins freely when completely assembled.

@RogueAg - did you ever get to the root cause of your problem?
TIA

I see you've gotten some replies already.

The short answer is I never resolved it. Now my issue was a little different. The original pentair motor completely failed for me. After that, I tried 3 different motors, from two different manufacturers (including a direct Pentair replacement) and ran into the same issue repeatedly. Each new motor overheated, and did so quickly. Within a few minutes of startup. I never chased down the impeller issue as I did see about that being a possible cause, mostly because I was replacing with the exact same size motor each time. After as much work I put into it, I ultimately replaced the entire pump with a variable speed which I'm quite happy with. Probably was the better way for me to go anyway.

Sorry I can't help further. I'll be curious if a different impeller resolves your issue.

 

[JamesW]

The problem started with the original (22yr old) 1.5hp motor overheating, with original impeller.
WhisperFlo is WFE-6 1.5Hp, SF 1.47

The original impeller was a 073129.

I got the 073131, which probably isn't happy on a 1.5HP motor.

The 073131 impeller is not original; when did that get installed?

073129.........2.20
073130.........2.60
073131.........3.45

 

[WarmFZI]

The original impeller was a 073129.

The 073131 impeller is not original; when did that get installed?

073129.........2.20
073130.........2.60
073131.........3.45

View attachment 613890

I put the 131 on by mistake, before learning about all the different options.

 

[JamesW]

I got the 073131, which probably isn't happy on a 1.5HP motor.

The impeller does not care.

The motor is not happy being asked to drive a 3.45 HP Impeller.

Basically, you are asking the motor to work twice as hard as it is designed to work.