capacitor on motor smashed!!

pjf134

pjf134

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Someone gave me a 1 HP motor with a cap hanging on by 2 wires, been like that for years, no problem until I put it on my lathe. I made my shim for the 1/2 HP motor and noticed the motor on the countershaft smashed it when I adjusted the tension bar I guess. It still runs good after I pieced it together for now. I did make a holder for it (TOO LATE I GUESS), BUT WOULD LIKE TO GET IT RIGHT. Where would I find numbers on it? Maybe just glue the plastic back together and put the holder on. It maybe has a different cap on it than original, just don't know, since I got it that way. It's a 1 HP , 1725 RPM, duel voltage single phase. It's still on the lathe for now, I am wiring the 1/2 HP motor and switch and plan on doing the switch soon, just trying to figure out where to mount my switch.
Paul
 
If it is a metal cased capacitor, the value will be stamped or embossed on the shell. If it is a bakelite cased capacitor, the markings are usually ink stamped on the outside. mark any wires you remove and note any markings, like number, letters, or symbols like triangles, squares or circles near the terminals.
 
Tony,
Thanks, I will check tomorrow, it is bakelite, just not sure if it is original though.
Paul
 
If it has been running ok, the values were probably fine, original or not. Look for XXX mfd for the value, and XXX volts for the rating. Could be up to 450 volt, guessing 125 mfd. Best to get exactly what was there, value and ratings. Ratings can be safely raised, but not so much on the value. Don't go below the voltage rating.
 
Tony,
I can only get some numbers from the cap, printing is wore off, see pic. C70-30 Start cap- 26225---
Paul

DCP_0436.jpg

DCP_0436.jpg
 
Last edited by a moderator:
[quote author=pjf134 link=topic=1587.msg9237#msg9237 date=1302152128]
Someone gave me a 1 HP motor with a cap hanging on by 2 wires, been like that for years, no problem until I put it on my lathe. I made my shim for the 1/2 HP motor and noticed the motor on the countershaft smashed it when I adjusted the tension bar I guess. It still runs good after I pieced it together for now. I did make a holder for it (TOO LATE I GUESS), BUT WOULD LIKE TO GET IT RIGHT. Where would I find numbers on it? Maybe just glue the plastic back together and put the holder on. It maybe has a different cap on it than original, just don't know, since I got it that way. It's a 1 HP , 1725 RPM, duel voltage single phase. It's still on the lathe for now, I am wiring the 1/2 HP motor and switch and plan on doing the switch soon, just trying to figure out where to mount my switch.
Paul
[/quote]

Here is a simple home test for approximate capacitance values using a light bulb and an AC voltmerer.

http://toad.net/~jsmeenen/capacitor.html

By the look of your capacitor, it's probably a Packard brand. They have flooded the market in the past ten years. Made in China, of course, but perfectly good. I would guess that you could use a 100-150 µf start cap at 250 volts for a 1 hp motor, assuming it will fit.


Happy Trails. :)
 
[quote author=pjf134 link=topic=1587.msg9276#msg9276 date=1302202903]
Tony,
I can only get some numbers from the cap, printing is wore off, see pic. C70-30 Start cap- 26225---
Paul
[/quote]

Paul

Looks like a 70 - 80 uF Starting Cap.

Most common for a replacement would be 72-88 uF. 125V should be ok, but if you err to 250V will not hurt. Any motor repair shop like myself and many others will have these in stock, I know I do.

If you have other caps floating around, you could try one. Too low and the motor will not start. Anything over that value and it just excess, that does not do anything, but preferably you should be within +/- 10% of the rated value.

Walter
 
I'll concur with Walter. 72-88 mfd @125 volts would be a good candidate, although I'd probably go 250 or even 370 on the voltage rating. Pretty common. Motor shops everywhere should have them, and here we even have a You Fix It show that caters to the DIYer, and they sell motor caps all the time.
 
I must have missed that he is operating this motor on 120VAC.
 
No Zig, he never said. That is an important consideration, and one reason I recommended a 250 or 370 volt cap.
 
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