Motor Electrical

[Popeye]

I just brought an old Ryobi 16" scroll saw out of retirement..... cleaned up the rust, etc etc. Started fine... cool.....
Left it running while I turned to pick something up... turned back and had smoke coming from the switch cover.... capacitor was leaking goo and smoking. External to the motor, wired into the motor with wire nuts. Is something like this available from someplace other than Ryobi, like a motor shop or Radio Shack etc??? Pat

[crokett]

Run a search on capacitor here:

http://www.mcmaster.com/

[Popeye]

Run a search on capacitor here:

http://www.mcmaster.com/

Thanks Davey, but nothing that came close to matching in size. Of course there are no numbers on the thing to speak of, just SH Cap. 8 MFD, 250V AC.

[JR]

That definitely sounds like a failed capacitor. 8 MFD means eight millifarads, which is the electrical "size" of the cap.

Yes, any local motor repair shop should be able to hook you up quickly.

JR

[BobSch]

That definitely sounds like a failed capacitor. 8 MFD means eight millifarads, which is the electrical "size" of the cap.

Yes, any local motor repair shop should be able to hook you up quickly.

JR

MFD is microfarads. Might confuse the boys at the motor shop if you asked for an 8 millifarad cap.

BTW — the 250 volt rating is what you want, even though the motor runs on 120.

[JR]

MFD is microfarads. Might confuse the boys at the motor shop if you asked for an 8 millifarad cap.

Hmm, I'd have thought uf would be microfarad. These are pretty big caps, so I assumed milli was correct. It's been a long time since my AC theory days, though, so I could easily be wrong.

JR

[BobSch]

Hmm, I'd have thought uf would be microfarad. These are pretty big caps, so I assumed milli was correct. It's been a long time since my AC theory days, though, so I could easily be wrong.

JR

You may be right, but I've never seen a cap lables in millifarads. Micro (uf) and micro-micro (uuf) are the only ratings I've seen.

Maybe the best idea is for Pat to disconnect the cap and take it along to the shop and let them figure it out. Just remember to make a drawing of which wire goes where!

[vaking]

8 MFD seems harder to find, 4MFD is easy. Buy 2 and connect together.
Here is the link:
http://secure.data-comm.com/RB/Detail.bok?no=80419
These are 370 Volts, which guarantees that at 115V they will have no problems.

[LCHIEN]

Hmm, I'd have thought uf would be microfarad. These are pretty big caps, so I assumed milli was correct. It's been a long time since my AC theory days, though, so I could easily be wrong.

JR

It's gotta be microfarads. 8 millifarads at 120V or more would be the size of the whole saw or more.

Its not uncommon to use MFD for microfarads.

[Popeye]

Got it. Took the old one to a motor shop in Jacksonville and they fixed me up. 8MFD I guess isn't something US manufactures use. 7.5 is the std here. Also the new capacitor doesn't look like the little thing that was on the saw. Rewind shop assured me this 7.7MFD 250V will work fine. Just has to be mounted alittle different. Don't have time to get to it hooked up today, maybe Sunday. Thanks for the help. Pat

[heartwood]

Hey there Popeye! You said it was an older unit, just out of curiosity, was the motor & capacitor mfgd. by ryobi, or another mfgr. ?