Pool Pump Capacitor?

[Dirtboy6]

I am thinking my capacitor may be bad on my Pentair Dynamo. I cut on the pump and hear a humming noise. I took the pump off and the impeller is spinning just fine. Looking for some suggestions and maybe a video how to replace a capacitor for Dynamo pumps. Also how do you open get into the inside of the pump?

Thanks

[BigTallGuy]

Electric pumps and motors are not my area of expertise, but If I understand capacitors correctly, they are used to jump start the motor from a stop, because it take a bigger jolt of electricity to start a motor, especially with a load on it. Once the motor is running, it settles down and runs on a lower amperage. Sooooo, If your motor starts, I'm not sure you have a bad capacitor. My very limited experience says capacitors either work or they don't. I have seen (heard) motor capacitors hum very loud, but they won't start the motor.

Does your motor "Drag" and take a few extra seconds to finally come up to speed, or does it start right up?

Hope this helps. BTG

[mas985]

The capacitor in an induction motor is used to shift the starter winding current by 90 degrees so the motor will spin up from a dead stop. Without a capacitor or if it is bad, the motor will just sit there and hum. To replace it, you can remove the back cover but I wouldn't suggest doing this unless you are familiar with working on motors and electricity.

[BigTallGuy]

Thanks Mark, After thinking about this overnight, I came to realize that the windings in the motor makes the Humming noise not the capacitor, and your post verified that for me.

I think it is time for Dirtboy6 to take this motor in for a check up. It is probably doing what my last pump motor did, which is drawing way more amps than it should. I ended up buying a new pump and motor.

Rick

[Lip Out]

I am an Electrician. I came home one day and turned my motor on. It was making the same noise. I took out my voltage tester and I wasn't getting the correct voltage off the capacitor. I took it down to the pool shop and they just told me I needed another $400 motor. I wasn't able to do that again (would have been my second one in a year), so I took the capacitor out and went down to the electronic warehouse. $30 later it was fixed. It would be worth a shot just to try it. Also, if your motor is or is able to draw more amps then it should, I would take a look at the breaker that is supplying the circuits.

Chris

[kevreh]

Chris;

Couple questions.... how do you know what the correct voltage should be off the capacitor? And whats the proper (or good enough) way to discharge the capacitor. I heard short it with a screwdriver (!) or use a voltmeter. I assume I would set the voltmeter to read AC?

TIA
Kevin

[mas985]

I would not test the capacitor on a live circuit. Here is a much safer way to test a motor capacitor:

http://www.ehow.com/how_6185394_test...ultimeter.html

[kevreh]

Good link, thanks.