motor run-capacitor testing and identification

[brotherscott]

Hi!

I'm trying to help my neighbor repair the circulating pump in his hot-tub. When I test the run capacitor with my multi-meter the needle goes up but doesn't come back down so I think it's shorted or something. Is that a correct assumption? Next question, where do I find a replacement for this guy? I don't know what 6,3 means. Is it 6 or 3 or 63 micro-farads? Can anyone help me please?



I hope my question is clear and I provided enough info. If not let me know.

Many thanks in advance!!!

Scott

 

[73's de Edd]

Sir brotherscott . . . . .


Mamma mia that’sa being’a Italian numbers’sa . . . . . how’sa you clazee Amellicans say:
6 decimal 3 microfarads at 450 volts

And it’s using polypropylene dielectric materiel , so it should be stable.

If you are wondering ? if its shorted . . . . . try this DYNAMIC testing:

Round up a common filament type incandescent lamp of 60 watts rating and some thing that it can screw into . be it . . a floor/table lamp, drop cord worklight or individual socket.

An AC cord, that has its two end leads bared for making wiring connections.

Then you need to temporary jury rig up a circuit such that 120VAC from the line cord comes into one prong of the lamp plug. The other prong of the lamp cord plug goes to the capacitor at one terminal and the other terminal of the capacitor goes to the wire left on the AC cord line.

That gives you a closed circuit of AC from a line cord coming in and passing thru a 60W lamp (when the lamps switch is turned on) and passing thru the capacitor and ending up at the other lead of the AC cord.

Then all is wired up and laid safely aside . . . . When you plug in the AC cord expect one of three responses.

• The lamp lights to full brilliance . . . .the capacitor is being shorted.
• The lamp lights about half brilliance . . . . . the cap is being about 6 ufd, just as is desired
• No light at all . . . the cap is open . . . or you miswired . . . . short across the cap to confirm if full brilliance, if so the cap IS open.

Le Capacitore . . . . .

http://www.actrol.com.au/Products/Electrical/Capacitors/Run/RE-450V-Run-Capacitors/

Thasssssit . . . . .

73’s de Edd

 

[Minder]

If you do get a replacement make sure it is a AC Motor Run type, also do NOT by any Chinese versions.
M.

 

[duke37]

Some motor capacitors have a high value resistor buit in to discharge the capacitor when exitation is removed. This could be measured with a meter. Looks as though it is shorted.

6,3 is used in some countries for 6.3

 

[brotherscott]

Hey Folks,

I setup the experiment 73’s de Edd suggested and the light did not turn on. I checked my wiring and I believe I had everything setup correctly. The light worked normally when the cap was not in line and the only difference was I used a 40W bulb instead of a 60W bulb (those old bulbs are hard to find around the house now).

Three questions now:

1. Did my 40W bulb mess up the experiment?
2. Does anyone know of a place in the US where I can buy a replacement capacitor?
3. I'm still a little unclear on the voltage. I see the 450V at the bottom so I'm almost 100% on board with the diagnosis that I need a 450V cap; however, there are also three other voltages listed toward the top. Why don't those apply and how do I know I don't need to get something that will go up to 500V, which is the highest voltage listed?

Thank you for your continued interest and help!!!

Scott

 

[Minder]

I usually buy CDE N.A. made.
I assume this is a 120vac pump so 400/400v should be ample, do you have any motor rewinders in your area, or motor suppliers?
That could be a first place to try.
DMF series from Digikey also.
Mouser sells CDE.
M.

 

[brotherscott]

Thanks Minder. It's actually a 230vac pump. Digikey seems to be a very comprehensive website! I must be horrible at this because I can't figure out how to filter my search correctly to pull up the correct part. I am looking for a film capacitor correct?

EDIT: I found this one: https://www.digikey.com/product-detail/en/kemet/C276CC34800AA0J/399-13855-ND/6558683
Does it look correct?

Below is a pic from the box on top of the pump.

-cheers

Scott

 

[Minder]

Here you go.
https://www.digikey.ca/product-detail/en/kemet/C878AF24600AA1J/399-13884-ND/6558712
It is slightly more on the Can site.
M.

 

[brotherscott]

Here you go.
https://www.digikey.ca/product-detail/en/kemet/C878AF24600AA1J/399-13884-ND/6558712
It is slightly more on the Can site.
M.

Wow, I'm getting extremely close here. I'm really glad I found you guys!

One more question: Does the .3 micro farads make a difference? The one you found is a 6 and the one I found is an 8: https://www.digikey.com/product-detail/en/kemet/C276CC34800AA0J/399-13855-ND/6558683

The original was 6.3. The research I've done said to go bigger but not too much. Maybe 8 is too much and the .3 doesn't make a difference, which is why you recommended the one you did.

Thank you for helping out. Sorry to bother

Scott

 

[Minder]

6 or 6.3 is close enough not to make that much difference.
We are not dealing with precise equipment here.
M.

 

[brotherscott]

Thank you!