Motor starting caqpacitor

[Touchwood]

Hi All,

Bought my old Grizzly dust collector in 1991. turned it on yesterday and it just hummed,then turned very slowly up to speed. The 2HP 240V motor would have been expensive to replace but I remembered a post about motors and capacitors a few weeks back. It should have measured open circuit on my multi-meter but it read a high resistance that slowly drifted down...suspicious. A trip to Grainger, a new capacitor and 12 bucks later and I'm back in business.

The experience and information sharing on NCWW is invaluable. Thanks one more time folks :eusa_danc

 

[Joe Scharle]

Those $12 motors are the best!

 

[sawman101]

I had a band saw that required pulling on the belt and flipping the switch to get it to run, but I sold it before I got around to fixing it. Didn't know where to go for a new capacitor; thanks Don, now I do no where to get them.

 

[KenOfCary]

Smile.amazon.com also sells starting capacitors.

 

[nn4jw]

I recently bought a start capacitor for my son's a/c at D&L Parts Co. on Reichard St. in Durham. They had a wall full of different start capacitors.

I also learned in the process that some start capacitors are designed such that the end with the terminals will puff out like a can of spoiled beans when they go bad so that the internal connections are broken. It's a sort of safety thing. So, if you see a capacitor where the end is expanded and puffed out it's a dead give away that it has truly gone bad.

 

[Pop Golden]

$12 ! ! ! I had a HVAC service guy charge me $300 for a capacitor. It was on the fan moter I think that's around 1/2 hp. I knew he was ripping me off I just didn't know how bad.

Pop :wmad:

 

[Willemjm]

My experience was funny and I kind of kicked my own butt for going about things the wrong way.

1.) Friend tells me his compressor just died. When he switches it on, nothing happens other than a high frequency sound. He wants to go spend $850 on a new compressor.

2.) I tell him to hang in, let me come look at it.

3.) Pack my multi meter and off to his house.

4.) Tell him to plug it in and what follows is a high pitched sound, nothing turns. Never heard that from an induction motor before. We disconnect power.

5.) First, mistake I make is to try and see if I can turn the motor by hand. Everything is closed with guards and after realizing removing the guards will be a relatively big job I abort.

6.) Second mistake I make is to measure both capacitors. One measures just over 400 micro Farads, the other close to 30. Both perfectly in specification.

7.) Third mistake I make is measuring the resistance of the motor windings, which also seems just fine.

8.) Getting back on track now we plug it back in and the high pitched noise returns.

9.) I measure the voltage at the terminals, which is the darn first thing I should have done!!!! There is no voltage, no power.

10.) He plugs the compressor into an outlet with a surge protector. The surge protector died and the high pitched sound we hear is an alarm to indicate a failed surge protector outlet. Plugged it into a normal outlet and all was good.

Have to admit, I felt pretty dumb after that, but at least we saved $850. I guess that is what happens when one no longer practices the trade every day.

 

[Frank Berry]

My experience was funny and I kind of kicked my own butt for going about things the wrong way.

1.) Friend tells me his compressor just died. When he switches it on, nothing happens other than a high frequency sound. He wants to go spend $850 on a new compressor.

2.) I tell him to hang in, let me come look at it.

3.) Pack my multi meter and off to his house.

4.) Tell him to plug it in and what follows is a high pitched sound, nothing turns. Never heard that from an induction motor before. We disconnect power.

5.) First, mistake I make is to try and see if I can turn the motor by hand. Everything is closed with guards and after realizing removing the guards will be a relatively big job I abort.

6.) Second mistake I make is to measure both capacitors. One measures just over 400 micro Farads, the other close to 30. Both perfectly in specification.

7.) Third mistake I make is measuring the resistance of the motor windings, which also seems just fine.

8.) Getting back on track now we plug it back in and the high pitched noise returns.

9.) I measure the voltage at the terminals, which is the darn first thing I should have done!!!! There is no voltage, no power.

10.) He plugs the compressor into an outlet with a surge protector. The surge protector died and the high pitched sound we hear is an alarm to indicate a failed surge protector outlet. Plugged it into a normal outlet and all was good.

Have to admit, I felt pretty dumb after that, but at least we saved $850. I guess that is what happens when one no longer practices the trade every day.

First rule of law is always check the supply voltage first. I too have over looked that one once and got my head handed to me for it! Never forgot it again.

 

[golfdad]

Same thing happened to mine this spring.

 

[Pop Golden]

For great fun & games play with electricity! Over the years I've had power do things would amaze even Nikola Tesla.

Pop

 

[kelLOGg]

$12 ! ! ! I had a HVAC service guy charge me $300 for a capacitor. It was on the fan moter I think that's around 1/2 hp. I knew he was ripping me off I just didn't know how bad.

Pop :wmad:

The identical thing happened to me.:BangHead: