Dust Collector Motor on Fire

[KingBubbaTruck]

So, Had a bit of a scare this weekend. Was cutting up some wood on the tablesaw, and had the dust collector hooked up to it (Delta 50-850 1.5 HP). Table saw is on one side of the garage, Dust Collector is way back in a corner on the other side.

Decided I needed a spring clamp to help in making a cut, which meant I had to go back over by the dust collector. As I start getting closer I notice a lot of smoke and a burning smell. Look at the dust collector and I see a bright orange flame! Turned off the DC, got the fire extinguisher and hit the motor a couple of times. (I've got 4 fire extinguishers stashed all around the shop, never really though I'd need one, but was very glad one was around when it was).

Basically, there's a hump on the motor, with something that looks like a capacitor that caught fire. What freaked me out was the motor just kept right on running while this thing was on fire!

Guess I'll have to get on the phone with delta to get a replacement part, because this part doesn't appear on the parts list. The starting capacitor is in the box with the switch. I'm not exactly sure what this thing does, but I did cut it off. After removing the bags, and blowing all the fire retardant out with compressed aire, I plugged it in to see what happens. Motor started right up and seemed to run normally, until the breaker tripped after about 3 seconds, so apparently, it does something to prevent the motor from using to much juice.

Great, something else to watch out for in the shop!

Guess I'm just saying, if you don't have fire extinguishers in your shop, it wouldn't hurt to go pick up a 2-pack at costco... Pretty cheap insurance...

 

[Jim15]

Glad you caught it in time.[:0][:0]

 

[JimGo]

Wow...good timing! Glad you're OK.

 

[Dario]

Good that you caught it before it got to the bag!!! [:0][:0][:0]

Good reminder too that we should keep our Fire Extinguisher always within reach...mine is in the kitchen [B)][V]...need to move it (and/or get more). [B)]

 

[ed4copies]

Glad the story has a happy ending, but I HAVE THAT DUST COLLECTOR!!!!!!

Time to take a closer look at it!!!

Thanks.

 

[KingBubbaTruck]

Yeah, I'm not sure what the heck happened. Didn't seem dust related or anything. and The motor still seems ok.

Might be worth popping the cover off that hump and doing a visual check, but I'd be very careful. Capacitors are a bit of a risky thing to play around with...

I'd really like to just replace the capacitor instead of the motor. If you do check it out, if you could post the part number, I'd be greatly obliged...

I've had mine for probably at least 7 years, I guess, can't really remember when I bought it, but it's always run like a champ, until now...

It's got me looking at all the motors I have in the shop...

 

[woodbutcher]

It is not a bad idea to replace capacitors after several yrs of service. If it is new from China it might be a good idea to replace them right out of the box.
Jim

 

[Firefyter-emt]

That is the "start capacitor" and is only "used" when the motor is spinning up to speed. As to why it caught on fire?? I dunno, It should be pretty clean inside there with little sawdust, but it may of started leaking... However, I don't believe what is in it is flamabable.. You can buy a new capacitor from McMaster Carr if you can still read the numbers on the cap. Should run about $5.00

As far as tripping the breaker, you may have to pull the motor apart and clean it and the shaft bearings. You may have a lot of gunk inside it. Also, dry powder is a little bit corosive so I suggest you or a motor shop look into properly cleaning the motor out.

 

[woodwish]

Wow, looks like you got lucky on that one. You woodworking guardian angel sent you for that clamp for a reason! I have two FE's in my shop but after reading this I may add two more, really cheap insurance. I don't think there is any danger in having too many of them within reach. []

 

[KingBubbaTruck]

Found the part on the delta site. It's odd that the image on the parts list doesn't show it, but it does have the capacitor listed (With just two .. and no number to match it up to, but having the part number helped).

From what I've been researching on this motor, it's a 'Capacitor Start, Capacitor Run' motor. This means that it uses one capacitor for starting, and one for running. The start capacitor is located in the switch box on the side of the motor, and the run capacitor is the hump on the outside.

Apparently, the run capacitor enegergizes the secondary windings and allows the motor to run a bit more efficiently (draws fewer amps when running). This explains why the motor could start and get up to speed ok without the 'run capacitor' when I was testing it, but tripped the breaker once it got up and running.

The start capacitor is the 200uf capacitor and the run is the 30uf capacitor.

I went ahead and ordered a replacement 30uf capacitor from the Delta website. (13 bucks, but cheaper than a motor). It's a TEFC (Totally Enclosed, Fan Cooled) motor, so the dust didn't really get in anywhere, but i went over it pretty good with the compressed air and wiped it off and cleaned it up. Looks like new..

One thing I did take to heart was that putting this thing in an remote corner where it's difficult to get at probably wasn't a good idea. I'll keep it in a more open location where if something does happen in the future, I'd be able to get to it all around with the extinguiser.

I'll probably even put it out on the driveway with a fire extinguisher next to it when I'm using it for a while till I trust it again...

 

[Firefyter-emt]

Good point.. I have a small section off my shop I was going to put this in. (think only access is from outside and the back of the shop. I thought it would be perfect as it is just the size for a DC and in the back RT corner of my shop (a perfect run) I think I have to re-think this idea a bit. (or at least look into a daisy chained fire alarm, Maybe a full halon system?) []

If you have a dual capacitor, that makes more sence..

 

[PenWorks]

Good to hear you got it in time.
That problem with the capacitor is not limited to your Delta. The one on my Jet went bad twice. The repair guy thinks my 220 line is dropping voltage in one or both legs, something you might want to check out.