Delta band saw motor started smoking, then switched popped and smoked...

[brianp]

I've got a Delta ShopMaster bandsaw that I've had for years and don't use very often. I was cutting some plywood today and noticed a burning smell and some smoke coming from the motor. I turned it off, let it cool down, started it again for a few minutes and it seemed fine, then there was a loud, electric pop, lots of smoke came out from the switch, so I turned it off. I unscrewed the switch, looked inside and didn't see anything burned, hot, etc. so I put the switch back in, tried turning it on again and it made noise like it was trying to run, but didn't move. I was able to move the belt manually, but the engine didn't turn. Is this saw dead? Does it sound like this is something I can troubleshoot and fix? Thanks!

[knuttle]

Some years ago my table saw motor died. I took it into the small motor repair shop and they disassembled it. It was an older capacitor start motor and there was wood chip in a switch inside of the motor. Since the switch could not close it cut off the capacitor that was necessary to turn the motor over.

He showed me how to disassemble the motor to clean that area if I ever had the problem again. Also as I am cleaning up the saw at the end of a project vacuum out the ports on each side of the motor. I also periodically oil the motor bearings.

If the winding in the motor are intact it probably can be fixed, so if you can not find the problem I would recommend taking it to a shop before discarding it.

[Sonny]

I'd first suspect loose wiring at the motor end of the switch's wiring. Probably need to replace the switch and its wiring to the motor end.

To me, that popping sound was caused by wires touching, somewhere, not the motor itself.

Sonny

[krw]

The capacitor may have simply failed (catastrophically). Replace that first. It shouldn't be that difficult.

[Dr. Deb]

Unless you are confident soldering components in the motor, follow Keith's advice and take it to a place that rewinds motors and let them trouble shoo t it for you. It is a lot simpler and could be less expensive than probing around in an area you are not comfortable with.

[Scott Lurndal]

It's a $100 bandsaw with a cheap little 1/3hp motor. Probably cost more to take it in for troubleshooting than to simply replace the saw.

[brianp]

replying to krw, brianp wrote: Thanks to everyone for the replies!! I opened the switch housing and found the blown capacitor!! Hopefully I can just replace that and save $160. However, I started looking around for it and can't find a replacement anywhere that looks like it will fit into the same spot in the saw...anyone have any ideas??

[brianp]

replying to brianp, brianp wrote: ...actually...I think I may have found it! $20 with shipping:

[DerbyDad03]

What about this:

You can also 20UF caps with higher voltage ratings (e.g. 450V) that will work just fine. Typically, you want to at least double the expected voltage.

[J. Clarke]

You don't give the dimensions.

Google "20 microfarad rectangular run capacitor" and see if you get anything that is close. Note that in general you can substitute a capacitor with a higher voltage rating for one with a lower.

[DerbyDad03]

As opposed to the $3.99 ebay link I offered?

or 12.50 on Amazon?

Your choice...

[Markem]

Digikey might be a source

[DerbyDad03]

Probably is a source, but site doesn't seem very easy to search.

Search for CBB61 and you get "We weren't able to find any results based on your search entry."

Search for 20uF, and you get 16,605 results categorized by component type, which you then need to drill down into. You really need to know what you are looking for, like what *type* of capacitor (Tantalum, Aluminum, Ceramic, etc.) before you can get very far.

On the other hand, search Amazon or ebay for *either* CBB61 or 20uF, and you'll find an exact match for *both*.

Just 2 examples...

[Markem]

Agree with the searching on Digikey, if you know what you want not that much of a problem. More for a electronics person who knows what they want.

[dpb]

Locally, the best source in town is the HVAC parts guys -- they've got most all motor capacitors for small single-phase motors. The motor shop folks have the big stuff mostly; don't get many small motors.

[brianp]

replying to J. Clarke, brianp wrote: Thanks! The opening is pretty tight, about 1 3/4" across...and that was the long part of the old one, about 1 1/2" wide and deep. I can get exact measurements but I think the one I got will fit. Thanks!

[krw]

Exactly. It's the best electronics search tool for engineers. The rest of the industry search tools aren't even close. I probably order from them a couple of times a month (just got an >$1,000 order but haven't been able to open it - locked out due to a WuFlu exposure in building). If it's not at Digikey, in my desk, or a manufacturer's sample, the possibility of a design-in is about nil.