Author Topic: Capacitor Help  (Read 3519 times)

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Offline burnettmTopic starter

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Capacitor Help
« on: December 02, 2013, 05:05:35 pm »
Never mind, we figured it out below. I overlooked a period on a marking.

I am refurbishing a old KitchenAid 3-C Mixer which I think was manufactured some time in the 1950s. Upon disassembling it I found a capacitor connected to the motor. Knowing that these things sometimes go bad with time I decided to measure its capacitance. My equipment is rather cheap, all I have to measure capacitance is a (presumably Chinese) Velleman DVM890 multimeter.

The capacitor is marked 109 MFD however the multimeter only measures up to 20 uF. I decided to try it anyways and it measured 160 nF. Is it safe to assume this capacitor has gone bad? Or did it give a false reading because the meter is incapable of going that high?

If it is bad, does anyone know where I can find a replacement? I checked Mouser, they only had 1 similar part but it is far too large, an cylindrical aluminum electrolytic measuring 1.8 inches in diameter by 3.4 inches tall, the Mouser part was 539-PSU10835A. The old capacitor is rectangular measuring 1 inch by 1 inch by 0.4 inches. I am not sure if used the right search, I selected 105 - 115 uF for the capacitance and 220/230/250/275 VAC for the voltage.

The capacitor is marked:
MC-968-E
109 MFD
220 VAC
GAS
CORNELL-DUBILIER

Thanks!


« Last Edit: December 02, 2013, 07:09:17 pm by burnettm »
 

Offline KJDS

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Re: Capacitor Help
« Reply #1 on: December 02, 2013, 05:31:58 pm »
Have a look for motor start capacitor or motor run capacitor.

The value of these really isn't critical, just find something that will fit and it's likely to work.

Offline madires

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Re: Capacitor Help
« Reply #2 on: December 02, 2013, 06:20:52 pm »
Based on the shape and size I'd assume it's a filter cap, a film capacitor. A motor start or run cap would be just about a few µF (<10). 109MFD stikes me odd.
« Last Edit: December 02, 2013, 06:24:51 pm by madires »
 

Offline olsenn

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Re: Capacitor Help
« Reply #3 on: December 02, 2013, 06:24:10 pm »
I'm assuming the "109 MFD" marking means 1nF, and 220VAC would be the intended (or max) voltage to put across it.
 

Offline madires

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Re: Capacitor Help
« Reply #4 on: December 02, 2013, 06:32:39 pm »
I'm assuming the "109 MFD" marking means 1nF, and 220VAC would be the intended (or max) voltage to put across it.

AFAIK old caps are marked with MFD (microfarads = µF) or MMFD (micromicrofarads = pF). But 109 MFD would mean 10^9 µF since 109µF doesn't make much sense either  :-//
 

Offline fluxcapacitor

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Re: Capacitor Help
« Reply #5 on: December 02, 2013, 06:40:25 pm »
Heres a discussion on antique radio forum, talking about the same/similar capacitor, also from an old mixer .

http://www.antiqueradios.com/forums/viewtopic.php?f=2&t=219721&view=previous
 

Offline burnettmTopic starter

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Re: Capacitor Help
« Reply #6 on: December 02, 2013, 07:00:22 pm »
fluxcapacitor, thanks a lot! Apparently I overlooked the period which is rather important when determining the value. I guess it is still good then.
« Last Edit: December 02, 2013, 07:06:12 pm by burnettm »
 

Offline madires

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Re: Capacitor Help
« Reply #7 on: December 02, 2013, 07:00:45 pm »
Ok, so it seems to be .109MFD. 109nF?
 

Offline burnettmTopic starter

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Re: Capacitor Help
« Reply #8 on: December 02, 2013, 07:07:20 pm »
Yes. It is marked .109 MFD, which should be 109nF. I'm guessing a combination of the tolerances on the capacitor, the leads coming out of it, and the cheap meter is why it is reading 160nF.
 


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