Boom!!!!

[Scott Baer]

Well, my 2 week old Steel City 3hp table saw scared the heck out of me today when it decided to blow up! It blew the collection hose off and sparks and oil were spewing from every oraface. Looks like the capacitor connected to the outside of the motor exploded. I was cutting through some 12/4 purpleheart, but it wasn't having any problems getting through it. Anyone have any clue as to what the heck happened? I never had this happen before.

Thanx

[glenn bradley]

Pretty impressive huh? Those folks who haven't been in the room when a decent size cap blows are missing something (like the need for a clean pair of shorts). The only reasons I know of are: bad cap or damaged cap. Maybe some folks who went further with electronics than I did will chime in. Either way, call SCTW CS.

[Randy Klein]

Electricity depends upon the smoke inside the components. I can prove it: When you let the smoke out, it stops working. I've done it a few times in the lab. The big ones go boom.

[Ken Fitzgerald]

Sounds like the cap went bad...shorted.....then the smoke and the boom. Cleaning up the mess from an exploded cap can be a reall pain!

[Matt Meiser]

I had a computer case open in the IT lab at my last job when a small one blew on the motherboard. Scared me pretty good, but the guy who was on the other side of the room about had to go home to change his pants. Can't imagine what a big one would be like. We couldn't get the smoke back in either...

[Scott Baer]

come to think of it... I am glad the sparks didn't ignite the DC dust.

[Peter Quinn]

I'd be asking for a new TS PRONTO!! Quite a mess inside a new machine. Possibly they'll throw in a frsh pair of shorts too?

[David DeCristoforo]

Finally... some excitement around here on an otherwise quiet Sunday! I am also very glad that your "collateral damage" was limited to underwear which is easily replaced. SC will surely cover the machine. Bad cap... it happens. Who can say why exactly. I had an event similar to Matt's when a PC power supply blew.... POW! Scared the crap outta me.

YM

[Alan Tolchinsky]

I guess that's why they have those sturdy covers over them. Sorry about your mishap and hope the mess is taken care of soon. I'm thinking of keeping a change of underwear in the shop now. ;)

[Mike Cutler]

Electricity depends upon the smoke inside the components. I can prove it: When you let the smoke out, it stops working. I've done it a few times in the lab. The big ones go boom.

Ahh yes, the old smoke theory. It's sort of like the light bulb theory.
Most folks think light bulbs give off light. Not true! They suck up darkness. That's why they have to replaced every so often... They're full.:rolleyes:,;)

Scott, yep you blew the starting cap. SC should replace the cap and or the motor.
Watch out for the oil, which is interesting by the way that you got oil. It can contain some unhealthful ingredients. Use some rubber gloves when cleaning up the residue.

[Tom Cowie]

Hi Scott

sorry to here about the machine. Probably a bad capacitor like the others have said. Anything man made can and will eventually fail. This didn't happen to me but this is the kind of stuff I work with. Thought you might like seeing the outcome of when something really goes wrong With electricity.
http://de.truveo.com/Exploding-Transformer/id/389743834

Tom :eek::eek:

[David DeCristoforo]

"Thought you might like seeing the outcome of when something really goes wrong..."

VERY COOL Tom! One of those pole mounted transformers exploded in my neighborhood once (years ago) and I gotta tell you, everyone was out in the street. I got to meet neighbors I had not even seen until then....

YM

[Randy Klein]

http://de.truveo.com/Exploding-Transformer/id/389743834

Tom :eek::eek:

Notice all the smoke that got out. There's no way that's working again:D

[David DeCristoforo]

"Notice all the smoke that got out. There's no way that's working again..."

My wife wants to know why I'm laughing but I can't stop laughing long enough to tell her....

YM

[Tom Cowie]

Notice all the smoke that got out. There's no way that's working again:D


My stomach hurts from laughing Randy, but your right it no work no more!!:D

Tom

[Jim O'Dell]

WHOA!! BABY! That was a show. I remember an ice storm back in '69, I think. Woke up about 2 in the morning. You could hear the transformers blowing on the lines, getting closer and closer. The explosions were about 5 seconds or so apart. Must have heard 12 or so in our area. Needless to say, we were without electricity for over a week. Lucky for us, my grandparents house had 3 fireplaces and we were able to cook and keep warm. Grandparents were fortuanate...they were visiting their daughter in Colorado! :D Jim.

[J. Z. Guest]

Well, sorry to hear about your saw. 12/4 purpleheart is nothing to sneeze at. Were you cutting it just to play with your new saw, perchance?

I don't think it was an overload problem. I think the capacitor got hit and the dielectric medium didn't hold up. That means a short either diretly across the line or through a motor winding.

When you get it fixed, I assume by replacing the cap, pay close attention to make sure the saw works as well or better than it did before. If the motor winding was damanged you might be in for more trouble.

Did it trip a breaker when it happened?

[Greg Muller]

Yosh-
unreal! I was reading this thread and when I got to your wife asking what's so funny, I starting cracking up also...

then my wife asked what was so funny...

I'm dyin' over here...


Greg

[Karl Brogger]

I was lucky enough to see a transformer get hit by lightning and explode from probably 150yards away! That was fricken awesome!

[Dennis Peacock]

Most folks think light bulbs give off light. Not true! They suck up darkness. That's why they have to replaced every so often... They're full.:rolleyes:,;)

Scott, yep you blew the starting cap. SC should replace the cap and or the motor.
Watch out for the oil, which is interesting by the way that you got oil. It can contain some unhealthful ingredients. Use some rubber gloves when cleaning up the residue.

Now Mike...that's a very interesting way to think about light bulbs. I'll have to go and see if I can experience that happening. :)

I also agree with Mike on this cap expolsion Scott. Sorry it happened, but as Mike mentioned...protect your skin when cleaning up the residue. It can be "unhealthy" for ya.

[Scott Baer]

Well, sorry to hear about your saw. 12/4 purpleheart is nothing to sneeze at. Were you cutting it just to play with your new saw, perchance?

I don't think it was an overload problem. I think the capacitor got hit and the dielectric medium didn't hold up. That means a short either diretly across the line or through a motor winding.

When you get it fixed, I assume by replacing the cap, pay close attention to make sure the saw works as well or better than it did before. If the motor winding was damanged you might be in for more trouble.

Did it trip a breaker when it happened?


Jeremy, breaker didn't blow. In fact, saw continued running. Luckily we were just about through the purpleheart. I am a bit concerned that it is somethin more than just the cap, though.

We weren't really playin around. My friend and I came across some 45 year old material that park benches were made out of in Pittsburgh (who in their right mind would make park benches out of purpleheart!) We were in the process of cleaning it up, gettin it ready to use in some projects. I will say, however, after 45 years in the weather. it was as if we just cut the tree down; not one sign of wear.

[David Pearson]

I was in one of the few high rise buildings in Lafayette, IN, about 10 years ago in a wind storm and saw a piece of corrugated tin land on a bank of transformers. It was quite a show!

[Ken Fitzgerald]

Scott.....Electolytic capacitors are generally used as the starting capacitors in motors and have a liquid like paste in them. I can't imagine what else in the motor would have "oil" in it.

I spent a couple of weeks cleaning the inside of a cabinet once.....it housed weather monitoring electonics equipment at a air traffic control center. Lightning struck out on the runway and traveled by the wires connecting the monitoring equipment in the weather-guessers office. It caused every electrolytic capacitor in the chassis to explode. Nasty stuff....very caustic.....tough to remove.

[Scott Baer]

SC tech tells me there is no easy way to check the motor as it is w/ out taking it to a motor fix-it place. Evidently there are two caps. A start and a run. They are sending me a new run capacitor.

Does anyone know if, in fact, you can't test the motor? At least test to see if there is a short in the windings. I would hate to have to clean all that up again. (let alone the risk and the downtime involved if the cap blows again.)

[CPeter James]

That sounds like a cheap out on the part of SC. A two week old saw should get a better response that that. You have to fix it yourself and all they are going to do is send a $5 capacitor for you to try?(try?) You have to clean up the mess, you have to be a electric motor technician, you have to be exposed to who knows what (PCBs?)? What does they woodworker who is not a mechanic do? At the very least they should have a whole new motor on the way and a local technician to install it.

What if you are injured or exposed to PCBs? Are they going to be responsible?

I am disappointed in their response to your problem.

CPeter

[Mike Spanbauer]

CPeter, that was my response as well. Yes, parts do sometimes go bad early on... it can happen, but to respond in that matter when the material that needs to be cleaned is caustic and a pain on top?

Scott, the material from inside the cap that blew everywhere is the dielectric. It is quite possible (and likely) a very nasty substance. It can eat paint and therefore, will go through the protective coating inside your saw. I don't mean to alarm you, but it'll cause rust very shortly if you're in an area with any amount of humidity.

I would call back SC CS and ask them to look up their MSDS on the capacitor on that saw. I can assure you once the tech realizes what is inside it, they might take on a more active role in addressing your saws issue.

sorry to hear about your new toy going boom, I'm certain it was rather enlightening... glad yuo were able to keep your wits about you and finish the cut without incident.

mike

[Scott Baer]

I called the manufacturer of the motor (Leeson). They tell me that the material in the capacitor is non-corrosive and non-hazardous... but who really knows. I got it on my hands while cleaning it up (prior to the understanding that it could be hazardous) and now you all have me worried that I'm gonna get cancer from it.

[Mike Spanbauer]

If you spoke w/ Leeson and they weren't concerned that would ease my mind a little bit (vs. a support agent @ SC that is). I would still ask for the MSDS on the material in the Cap though. They DO have it and considering it exploded on you, I would be concerned enough to get my hands on it to ensure there is nothing in there to worry about (in any quantity that is).

mike

[Rod Sheridan]

Hi Scott, the days of using PCB's as the dielectric of capacitors ended decades ago.

The run capacitor has current flowing through it whenever the motor is running, and it sounds like you had a defective capacitor.

Capacitor explosions are exciting, I've had to replace bus bars in equipment that suddenly are pretzel shaped instead of straight.

Hopefully your new capacitor is just fine.

Regards, Rod.

[Matt Meiser]

Uh....PCB's (http://en.wikipedia.org/wiki/Polychlorinated_biphenyl) were banned in the 70's. I highly doubt a 2 week old table saw has PCB's in the capacitors. Then again toothpaste has been found with antifreeze and toys with lead.

Anyway, I'd rather change out a capacitor than a motor at least to start. Any you've got 4 years and 50 weeks of warranty left to find out if there was any damage to the motor.

[Alan Schaffter]

The problem might not have been the capacitor at all!

Most of those motors have a centrifugal switch mechanism (at the end of the motor housing) - once the motor gets up to a certain RPM, the centrifugal switch disconnects the start capacitor from the start windings (and connects the run capacitor if equipped?). If that switch failed to operate, then it could possibly cause the capacitor to fail. Bad contacts on that switch can also cause the motor to start slow or not start at all.

[David DeCristoforo]

"I got it on my hands while cleaning it up ... now you all have me worried that I'm gonna get cancer from it."

Not to worry. You won't get the cancer for a long time. But seriously, sending you a capacitor to "self install" seems a bit 'weenie", esp considering that a motor short could have caused the issue. Considering that this machine is only two weeks old, I would be inclined to ask for at least a new motor.

YM

[CPeter James]

A motor made in the USA would not have PCBs, but one coming from Cina...who knows? I did not know that the motor was a Leeson. Do check the MSDS on it.

CPeter

[Eric Haycraft]

That's a crappy deal. They should really replace the whole motor. One of the caps on my Dewalt died within a few weeks of ownership (although in a much less dramatic manner than yours...thankfully) and they swapped out the whole motor.

[Mark Springer]

I work with electric motors and generator parts. I wouldnt worry to much about that grease. I have been covered in it before without damage other than what I already had. Its messy and hard to clean up but "shouldnt" be a health issue. Getting the MSDS info from the manufacturer isnt a bad idea though.

I do have to chime in here and say that there is no way I would tolerate not getting a replacement unit. I understand first hand that sometimes parts are just bad from the manufacturer and things happen but the unit is only two weeks old. There is no way of knowing what other damage is lurking in that case that might not show itself until after the warranty has expired.

[Scott Baer]

Well, at least they are overnighting the cap.

I can feel my cells mutating as we speak.

[Hank Knight]

I you'll forgive the OT diversion, Scott's post reminds me of a funny experience I had in the Army in the 1960s. I was all of 22 or 23 years old and a brand new 2Lt commanding a fire control platoon in a Nike Hercules missile battery. I had a Tech seargent working for me named Jordan. In his 60s, he was the "old man" in the outfit and had been working with radar since the early days of WWII. He was great at fixing stuff with chewing gum and hairpins. One afternoon Sgt. Jordan was up to his armpits in the 10,000 volt power supply for a high power acquisition radar when suddenly there was a bright flash and a very loud BOOM! He was knocked back about 30 feet and landed on his rear end. I ran over to him thinking he was surely fried to a crisp, but he merely picked himself up shook his head and said, "Wow! That tingles!" I still laugh when I think of it, and since that day I have had a great respect for old timers.

[Josiah Bartlett]

I blew a start capacitor in my outdoor A/C unit a couple of years ago. It spewed the oily stuff all over as well, and it doesn't seem to have caused any apparent damage. I wiped it out and then hosed it down with water, and it would have rusted by now if it was going to.

Motor shops and HVAC distributors stock those capacitors if you are in a hurry.

They tend to fail either in early service or under eventual heavy vibration or overvoltage.

[Reed Wells]

Wait a minute, I want to go back to Mike's lightbulb theory. I didn't believe it at first, but I went out to the shop and turned a desk lamp on ( 60 watt ). Plenty of light, right? Smack with hammer and sure enough it let every bit of the darkness out. Now I need the flashlight to find the tweezers to get this stupid light bulb out of my fingers.

[Scott Baer]

For anyone who might own a saw with a Leeson motor... no need to worry about your capacitor spewing oil all over your shop. According to their MSDS sheet, it contains no PCBs :). Furthermore, it is not caustic, so I don't have to worry as if Sigourney Weaver playing around in my cabinet.

[Scott Baer]

Reply from Leeson...

Hi Scott!

Thanks for your inquiry!

The capacitors used in our electric motors do not contain any PCB's
what-so-ever.

If you would like, I can send you an MSDS sheet for your review.

If you have any questions or need any additional information, please let
me know.

[Wilbur Pan]

If you really want to have fun with blowing out capacitors, I've got two words for you.

Tube amps.

This starter capacitor business is for amateurs.

(Sprinkle these liberally throughout this post: ;);););););););) )

[Michael Wildt]

Anything in the 1F range makes for some nice welding ;-)

The small ones tend to smell bad when too much voltage is applied. Though they sound fun when 'lit'.

Michael

[Chris Cordina]

Thats why I am a contributer, all the things I have learned from reading these posts. I never knew electricity needed smoke to work or light bulbs soaked up dark. :D

[Scott Baer]

cap didn't fix. must have screwed somethin else up. new motor on the way. :(

[Hank Knight]

cap didn't fix. must have screwed somethin else up. new motor on the way. :(


BUMMER :(

Good luck with the fix.

[Michael Wildt]

he he

Ever been asked to change the fuse in a light bulb ?

Electricity sure is fun.

[Brian Backner]

On the other side ....

When I was in college, someone in my dorm found a VERY large capacitor - 125 farads (yes, 125 full farads) - it was the size of a 4 drawer legal filing cabinet and weighed over 1500 #.

We managed to get it up to our floor with a combination of ethanol and obscenity fueled enthusiasm. After looking at it for several weeks and deciding what to do with it, one of the EE majors built a "charging system" for it, hooked it up, and plugged it into a wall socket for a week!

We then drew straws to see who got to drop a steel bar across the terminals (isn't it amazing the suicidal stuff you manage to survive when you're young!).

Anyway, when shorted out, it vaporized the middle 4" of a length of 1" x 2" cold rolled steel and set the carpet ablaze with the resulting fireball! Somehow managed to put it out with just fire extinguishers. Had real fun explaining to the Dear of Student Affairs why 20 yds of carpet had to be replaced.

Still gives me chills to think about it.

Brian

[Matt Meiser]

Gotta wonder what those huge caps the car audio guys put in their trunks would do if they blew up?

[Scott Baer]

good point. i had a 1F in my boat. never thought about it.

[Dan Barr]

I'm an Air Force Radio Operator and every once in a while, I get a new airman under me.

I send them to the supply office and tell them to pick me up some frequency cleaner. :D "comes in the spray can like spray paint"

ciao,

dan

[David DeCristoforo]

"...pick me up some frequency cleaner..."

Is that anything like sending the "new guy" on a construction job down to the lumber yard to "pick up some toenails"?

YM

PS If you are ever driving down the freeway and see the trunk deck come flying off some lowrider...you will have a pretty good guess, at this point, what happened...

[Karl Brogger]

Gotta wonder what those huge caps the car audio guys put in their trunks would do if they blew up?

Some of those are 2 farad (sp?). That's pretty damn big for something that goes in a car.




We always used to send new green guys at a shop I worked at to go get the board stretcher. Somebody in the office had one guy trying to find the door to the basement because thats where the board stretcher was. There was no basement.

[Peter Quinn]

Last winter we had a small mouse problem...uh..the mice were small...the problem was large, After trying several more humane methods that offered marginal results my otherwise kind wife brought home the shocker; A small trap with a capacitor wired to a thin aluminum plate powered by a nine volt battery. Peanut butter on one end, entry door on the other, shock strip in the middle.

LOML says "here try this...I don't want to see any more mice in my cupboards!" BIG WARNING on the box..this thing will hurt you!

Mice step in...dust comes out! Learned two things...mice prefer peanut butter to cheese, and don't mess with a capacitor, even a tiny one.

[Bob Hallowell]

I'm an Air Force Radio Operator and every once in a while, I get a new airman under me.

I send them to the supply office and tell them to pick me up some frequency cleaner. :D "comes in the spray can like spray paint"

ciao,

dan

I used to be in the Air Force also as an back shop avation tech for the F-15. We used to send new Airman to go get a peice of Flight line.

Bob

[Dan Barr]

He he he he he, :)

ciao,

dan

[Gene O. Carpenter]

PCB's were banned from use by order of the US Govt in the late 70's early 80's , so you won't find anything mfgd since then that contains these PCB's BUT any motor with a cap can attached, oil cooled transformer or other items containing oil in a sealed container mfgd prior to 1980 I would be most wary of coming in contact with said oil.. Capella Oil is used in refrigeration equipment for lubricating purposes..
I cleaned that crap up quite often until the s__t hit the fan with "Love Canal" in NY and a couple other places and then when we had a cap open up we backed up and the Co called in professionals who had the knowledge and the equipment to clean it up and dispose of the waste properly..I'm 72 and no ill effects,,,,,,,yet!