Pentair WhisperFlo (WFE-3) 3/4HP Pump - Have to manually turn to get started / HOT!

[SirBrowning]

I have a Pentair Whisperflo WFE-3 3/4HP Pump that seems to no longer turn on by itself. I will come in when it should be running, check on it, and I can smell a very hot smell, if I touch the pump the housing is hot enough to burn me. I then have to cut the breaker, come by, and get a wrench to manually turn the nut on the end. Once I do that and I turn it back on it runs without issue. I checked the capacitor with a volt meter and it seems to be registering that it is okay.

There also seems to be some major corrosion in the middle of it that just flakes away like powder. It is a 230V pump.

Any ideas?

 

[mas985]

Sounds like bad motor bearings.

You can replace the bearings, the motor or the entire pump.

 

[SirBrowning]

Sounds like bad motor bearings.

You can replace the bearings, the motor or the entire pump.

What does a kit typically cost to do that? And if one is going to dissemble to that point is it worth replacing other parts in a type of rebuild kit?

How difficult is this and are there any tutorials that go into detail?

And with the significant corrosion, is it worth rebuilding?

Thanks for the suggestion!

 

[Schadenfreude]

If it is getting hot enough to burn you without tripping the breaker, I would disconnect it from power immediately. Sounds like a potential hazard to me.

 

[mas985]

You might be better off going with a new motor and it might be a good time to go with a two speed motor to save on energy costs. Here are two speed replacements depending on the voltage:

B2980-230v
B2981-115v

You will also need a Whisperflo Go-Kit

There are many videos on YouTube to show you how to do it.

whisperflo motor replacement - YouTube

 

[max2k]

I have a Pentair Whisperflo WFE-3 3/4HP Pump that seems to no longer turn on by itself. I will come in when it should be running, check on it, and I can smell a very hot smell, if I touch the pump the housing is hot enough to burn me. I then have to cut the breaker, come by, and get a wrench to manually turn the nut on the end. Once I do that and I turn it back on it runs without issue. I checked the capacitor with a volt meter and it seems to be registering that it is okay.

There also seems to be some major corrosion in the middle of it that just flakes away like powder. It is a 230V pump.

Any ideas?

if the rotor turns freely and pump doesn't make unusual noise when running then it's most likely capacitor. I'm not sure how did you exactly check it with voltmeter but if you just checked the voltage on the capacitor then you didn't check it at all. If you removed it from the pump, discharged and then checked with multimeter in Ohmmeter mode even then you often get incorrect results as multimeter uses very small current to measure resistance. I'd simply try to buy one and replace 'blindly', they're not that expensive. I'd turn it off for now or you can lose the motor due to overheat.

 

[mas985]

come by, and get a wrench to manually turn the nut on the end. Once I do that and I turn it back on it runs without issue.

The OP would not be able to do that if it were a bad capacitor.

 

[max2k]

The OP would not be able to do that if it were a bad capacitor.

he would if it is not fully bad- recently there was a thread around here where pump did exactly that and new capacitor cured it.

 

[SirBrowning]

Any suggestions on where to buy the capacitor as it seems to be around $45, which is quite a bit more expensive than I was thinking.

 

[mas985]

he would if it is not fully bad- recently there was a thread around here where pump did exactly that and new capacitor cured it.

Capacitors fail as shorts or opens. Even low capacitance will still start a pump motor. If it is a loose terminal, you can wiggle the wire to see if it fixes the problem.


SirBrowning,

Once you loosen the motor shaft, can you repeatedly turn on and off the motor?

Is the motor loud when running?

 

[max2k]

Any suggestions on where to buy the capacitor as it seems to be around $45, which is quite a bit more expensive than I was thinking.

any capacitor designated to be used with motors and for the same voltage/capacitance would do, AC/fridge/etc. Try to look on this site for possible sources.

- - - Updated - - -

Capacitors fail as shorts or opens. Even low capacitance will still start a pump motor. ...

I wish it was always that simple Capacitor would need to be able to conduct enough current to turn the shaft. Since the motor here is 3/4 HP if capacitor develops internal resistance in series you won't be able to detect it with multimeter but it will prevent motor from running.

here's the thread I was referring to- http://www.troublefreepool.com/threads/37135-pool-pump-makes-humming-noise-and-does-not-pump/page2 msg #31 and later but the rest is interesting too

 

[mas985]

There are resistant start motors as well which don't use a start capacitor. You only need a small phase shift in the starter winding to start an induction motor. So it doesn't take much. Also, the starter winding doesn't carry much current. The main winding carries most of the current. The starter winding is only needed to provide a small phase shift in the winding to get the rotor to turn in the correct direction.

However, I don't see how that post applies here. First, there are like five posts in the one thread but in each case, the OP stated when he turned on the motor, it just hummed and did not start. That is typical of a failed capacitor. And if you turn the shaft while energized, then yes it will spin up. But if you stop the motor and try to start it again, it will just hum again unlike this situation where once the shaft was freed, the motor started on it's own after being turned off. That is typical of frozen bearings.

 

[max2k]

There are resistant start motors as well which don't use a start capacitor. You only need a small phase shift in the starter winding to start an induction motor. So it doesn't take much. Also, the starter winding doesn't carry much current. The main winding carries most of the current. The starter winding is only needed to provide a small phase shift in the winding to get the rotor to turn in the correct direction.

However, I don't see how that post applies here. First, there are like five posts in the one thread but in each case, the OP stated when he turned on the motor, it just hummed and did not start. That is typical of a failed capacitor. And if you turn the shaft while energized, then yes it will spin up. But if you stop the motor and try to start it again, it will just hum again unlike this situation where once the shaft was freed, the motor started on it's own after being turned off. That is typical of frozen bearings.

It's up to OP to decide- if the shaft spins freely without 'sticking' then I'd say it's a capacitor. If it needs to be 'freed' first to start then I don't think it falls under 'spinning freely' category and I'd agree something is up with the bearings.

 

[SirBrowning]

Capacitors fail as shorts or opens. Even low capacitance will still start a pump motor. If it is a loose terminal, you can wiggle the wire to see if it fixes the problem.


SirBrowning,

Once you loosen the motor shaft, can you repeatedly turn on and off the motor?

Is the motor loud when running?

When I turn the shaft it seems a little hard to turn and make a little noise. Once it is turned, and the motor cools down it seems to kick on without issue after a few turns. While it is running it sounds quiet and normal.

Any ideas???

 

[mas985]

Still confused:

So are you manually turning the shaft while the power is applied and the shaft starts to turn on it's own?

OR

Are you turning the shaft before the power is applied after which you turn on the motor and it starts to run by itself?

The order of things makes a difference as to the cause. The first is usually a capacitor issue while the second is normally a bearing issue.

 

[SirBrowning]

Still confused:

So are you manually turning the shaft while the power is applied and the shaft starts to turn on it's own?

OR

Are you turning the shaft before the power is applied after which you turn on the motor and it starts to run by itself?

The order of things makes a difference as to the cause. The first is usually a capacitor issue while the second is normally a bearing issue.

So today I went out and checked it out. I put a new capacitor on it, it is not the exact one, but the power ratings are the same, and it would still only Hum/Buzz when power was applied. I would shut it off, turn it a bunch, then turn the breaker back on and try to start it and it would still not work, just hum/buzz. So right now I can't get it to kick on at all.

I even tried turning it while it was powered on and humming / buzzing and when I turned it the tone of the humming would change to something that sounded like a slight rattle sound, but it would not start.

It gets hot extremely quickly and the thermal protection kicks on I'm assuming and the power is cut off.

So what could it be? it doesn't start no matter which technique I use, and I put a new capacitor on it, although it is not the exact one, it is actually larger, but has the same power ratings. If it was the capacitor it would have started when I turned it while it was humming / buzzing I assume, so I am wondering, could something be jammed / stuck in the motor?

 

[mas985]

If the ufd rating is not the same, the capacitor may not work. But I don't think it matters. The bearings are probably shot. You need a new motor.

 

[JamesW]

Looks like there has been something dripping on the motor. I suspect that that has contributed to the motor’s demise. The drip should be fixed before installing the new motor.