Brand new Pentair Superflo Pump humming but not turning...

chrisk500

Member
Apr 4, 2012
11
I just installed a new Pentair 2 HP Superflo dual speed pump. When I turn on the power, the pump hums but will not turn over and hums for about 10 seconds before the thermal overload trips. With the pump off, I can freely turn the motor from the back, but with power applied I can not turn it in either direction. I have filled the strainer basket with water.. I have tried tapping the motor housing with power applied, and I have verified there are 2 leads both with 115 VAC applied. I can't find any info on whether this pump has a start capacitor, but I believe the run capacitor is located on top.
Please help with troubleshooting. Kind of frustrating since this is a brand new pump.

Thank You.
 

benm2010

Well-known member
Mar 16, 2017
143
Fort Worth, Texas
All single phase motor's have to have a start capacitor, and that is often the culprit for situations like this, but if the pump is new (you said you just installed it so I'm assuming here) that would be odd. Have you tried spinning the motor and then immediately turning it on (it should go without saying to be very careful messing with a motor that is powered)? If that worked I would say it is definitely the capacitor. Hopefully someone with a little more pool pump knowledge will come along as the capacitor is the only thing I know much about.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,380
Pleasanton, CA
All single phase motor's have to have a start capacitor
PSC motors only have a run capacitor but it serves as a start capacitor as well. But I believe the SuperFlo has a PSC motor so it would only have a run capacitor and that could be bad although rare when new.
 

benm2010

Well-known member
Mar 16, 2017
143
Fort Worth, Texas
PSC motors only have a run capacitor but it serves as a start capacitor as well. But I believe the SuperFlo has a PSC motor so it would only have a run capacitor and that could be bad although rare when new.
Perhaps I should have said "all single phase motor's need a capacitor to start," as many motors run and start capacitor are the same, although there are a lot of motors with a start and run capacitor. Any time I've ever had a motor doing what was described it always ended up being the capacitor (not pool pump, think A/C, Microwave Fan, etc...). Here in Texas we blow lots of caps in the summer on our A/C units as they are rated at barely enough for the high temps here. Also, it can't be overstated when dealing with a capacitor (especially large ones) how important it is to discharge them FIRST as they have a nasty bite. If the pump is new Pentair customer service should take care of this.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,380
Pleasanton, CA
Some single phase motors do not have a capacitor. They are called resistive start as that is what provides the phase shift.
 

benm2010

Well-known member
Mar 16, 2017
143
Fort Worth, Texas
Some single phase motors do not have a capacitor. They are called resistive start as that is what provides the phase shift.
Interesting, either these were never mentioned in my motors class or I forgot about them (it's been almost 10 years so me forgetting is certainly possible). I stand corrected.
 

CJadamec

TFP Expert
Apr 29, 2016
2,253
Quaker Hill, CT
The first question I would ask is if the motor is wired correctly to the right voltage. If the pump is wired up to 110v and it needs 220v to run it will act like what was described as well.

Mas has reminded me of many things I have forgotten from my motors classes....
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
11,393
Bedford, TX
Please show us a pic of your input wires and where they are attached to the pump..

And a pic of the placard on the side of the pump..

Thanks,

Jim R.
 

gwegan

TFP Expert
Apr 19, 2013
2,769
Sacramento, CA
Its a brand new pump that you wired? Or was it wired by someone else?

Please post a picture of the wiring connection as you wired it and the faceplate of the pump. I am concerned its not wired correctly.
 

chrisk500

Member
Apr 4, 2012
11
So, I finally got around to looking at it again. I replaced the capacitor that is on top. Unfortunately did not solve the issue. I have verified each line going to the pump is 115 VAC by measuring the lines without them connected to the pump. The pump still moves freely by hand when not energized, but is very hard to move when energized and humming. Running out of things to check... I have attached the wiring diagram and wiring.
 

Attachments

JamesW

TFP Expert
Mar 2, 2011
13,325
Can you show the switch?

Are you trying to run high speed or low speed?

Are you getting 240 line to line?

You can try connecting the switched leg to high or low.

Also, the wiring really needs be be cleaner and more secure.

Why is one of the motor through bolts out?
 

chrisk500

Member
Apr 4, 2012
11
I have attached a copy of the switch. I also cleaned up the top line connection by crimping it to a connector to attach. I have ran in both high and low speed and no luck. The motor through bolts was removed for me to check the impeller, but I have replaced them all now.
I am getting 240 line to line.
 

Attachments

JamesW

TFP Expert
Mar 2, 2011
13,325
Try wiring one hot line to terminal 1 and one to terminal 2 to see if the pump will run in high speed. Remove the yellow wire from terminal 2.

If you're putting 240 directly to terminals 1 and 2 and the pump won't run, you probably have a bad pump and should file a warranty claim.

Also, you should not have removed the through bolts. Did you pull off the end part?
 

bsnobles

Member
Jun 4, 2013
17
Fuquay-Varina NC
Can anyone refer me to a post of this happening with an existing (previously working last season) system? Same pump. We opened the pool yesterday and when I went to backwash this morning the pump only hummed after turning it to backwash and switching it back on. Thank you!!!
 

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