Need advice on pump motor

gustafson

Well-known member
Jul 20, 2015
89
Houston, TX
#1
I have an AO Smith Centurion B855 2HP motor driving my Pentair pump. A couple of days ago, the pump stopped working. When I switch it on, there is a straining sound for 5-10 seconds after which it trips out. I am able to turn the shaft. I tried replacing the 30 mfd run capacitor to no avail, and cannot remove the back cover to check if there is a start capacitor, and whether it is faulty. Anything else I should be checking?

Also, if this calls for a new motor, what is the best way to get an affordable motor, and what should I budget? Thanks!


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gustafson

Well-known member
Jul 20, 2015
89
Houston, TX
#4
Check for proper voltage at motor, if correct pull motor assembly from pump housing and remove diffuser cover, then try motor.Pentair / Purex Whisperflo Parts - INYOPools.com
OK, so I didn't get around to checking the voltage yet (don't have a multimeter), but did open up the pump and can confirm that the shaft is turning (based on the impeller) before it trips off after 5-10 seconds. After a while, there is a clicking sound, after which the motor can be started up again for another 5-10 seconds. After the second cycle, the motor body feels warm to the touch.

It seems like the motor may be shutting off due to premature overheating?

Is there anything else I can do to salvage the situation?


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ckk81

LifeTime Supporter
Jan 1, 2015
235
Kalamazoo MI
#5
OK, so I didn't get around to checking the voltage yet (don't have a multimeter), but did open up the pump and can confirm that the shaft is turning (based on the impeller) before it trips off after 5-10 seconds. After a while, there is a clicking sound, after which the motor can be started up again for another 5-10 seconds. After the second cycle, the motor body feels warm to the touch.

It seems like the motor may be shutting off due to premature overheating?

Is there anything else I can do to salvage the situation?


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Any idea how old the motor is?
 

ckk81

LifeTime Supporter
Jan 1, 2015
235
Kalamazoo MI
#7
The capacitor has a date of Jan 2010, so I'm thinking at least 7 years old.
I bet it's getting the correct voltage, but you really should make sure that it is correct with a multimeter -you can get one pretty cheap.

That said I'd probably just replace the motor, looks like about $210 from Inyo or the like.
 

gustafson

Well-known member
Jul 20, 2015
89
Houston, TX
#8
I bet it's getting the correct voltage, but you really should make sure that it is correct with a multimeter -you can get one pretty cheap.

That said I'd probably just replace the motor, looks like about $210 from Inyo or the like.
Great, thank you for the advice! Might as well check if it's a voltage issue, I'd hate to find that out after installing a new motor. What's the recourse if it's not getting the correct voltage?


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gustafson

Well-known member
Jul 20, 2015
89
Houston, TX
#10
Probably a short in the windings causing it to heat up and trip. Likely time for a new motor.
Thank you, that seems to be the consensus.

So I went to Leslie's and they tried to sell me a variable speed Jacuzzi-brand pump for $1500. Is there a cheaper alternative for upgrading from the single speed B855 to save on electricity costs?


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kadavis

TFP Guide
In The Industry
Apr 5, 2015
1,439
tucson, arizona
#14
Depending on how many jets your running the Superflo 1.5 probably wouldn't do the job, I'm not familiar with the Jacuzzi model. If your pump is a Whisperflo model you would definitely be better off with the Intelliflo VS
 

gustafson

Well-known member
Jul 20, 2015
89
Houston, TX
#15
Depending on how many jets your running the Superflo 1.5 probably wouldn't do the job, I'm not familiar with the Jacuzzi model. If your pump is a Whisperflo model you would definitely be better off with the Intelliflo VS
Looks like I have a Pentair Challenger 2HP pump. Any idea which motor would suit that? Would it make sense to swap out the pump as well with a new pump + motor bundle? I was hoping to keep my expense under $300 by replacing the motor myself. Am guessing I will need to factor in install costs if I go the pump + motor route.


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gustafson

Well-known member
Jul 20, 2015
89
Houston, TX
#16
I bet it's getting the correct voltage, but you really should make sure that it is correct with a multimeter -you can get one pretty cheap.

That said I'd probably just replace the motor, looks like about $210 from Inyo or the like.
You were right, line voltage was 245, and pump when running is at 230. So no issues with the voltage.



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gustafson

Well-known member
Jul 20, 2015
89
Houston, TX
#18
Pentair Challenger Full Rate Motor - INYOPools.com
if you just want to replace motor and keep around 300.00. They also have two speed motors w/timers. Your motor the B855 is a uprated motor and is the same total hp as a 1.5 full rated motor
That is extremely helpful, thanks a ton! Could I continue to use the existing Challenger pump and impeller that are rated for 2HP with a full-rated 1.5 HP motor? I'm almost thinking if I can switch to a 1.5 HP full-rated, I could consider even a pump+motor set, either dual-speed or variable speed, and the savings from 2/2.5HP models appears substantial.


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gustafson

Well-known member
Jul 20, 2015
89
Houston, TX
#20
I have a neighbor that has a used Magnetek B985 2HP dual speed that he's willing to let go for under $100. It's attached to a pump with a similar bracket as mine but different line sizes (2" inlet and 1.5" outlet, compared to 2.5" inlet and 2" outlet on mine).

I'm thinking I can salvage and use the B985. I realize I need to get a high-low switch at some point, but is it possible to use it until then? If so, is the default speed the high speed or low speed? Any guidance on this will be appreciated.

Also, in this scenario, assuming I connect the B985 to my Challenger, would I need to replace the shaft seal? I know it is recommended for new motors, but was wondering if that applies in this situation.


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