Smoking 3 speed fan control

[michaelthomas]

So I have 2 wood stoves that I watch vigilantly for fire danger and I turn on my ceiling fan and smoke started coming out of the fan switch on the wall. I took the control out and it had started to melt inside. A few days ago the ceiling fan started to make a little more "motor" type sound when it was running. Do you think this is a switch problem or a fan problem? Switch looked like a real cheap one. Fan is an 8 year old home depot special, installed by the previous owner. Unfortunately he was an electrical engineer...he built computer chips...and had no business wiring his own house! Some of the stuff that we have come across is down right scary. Anyway what is your best guess? Switches are cheaper than fans...start there?

 

[jebatty]

Replace the switch and see what happens. If you are able, with an AC volt-ammeter you can check current draw on all three fan speeds; I doubt that it should be more than a couple of amps at most, but if you can find the rating plate on the fan, that will tell you the same info. My guess is that the fan is OK, else would have blown the circuit breaker, and the switch is bad.

 

[michaelthomas]

I installed a new 3 speed switch and the fan is still making a loud electric buzz sound when it turns. Both forward and reverse. I guess I need to look at the fan?

 

[Redox]

I'm wagering that the motor is probably bad, but check the run capacitor first before you get out the shotgun. Most ceiling fans have a small capacitor in the junction box with the fan switch. If it open circuits, the fan will pull high current and may buzz. It may also not start turning unless you spin it by hand. The best way to check it is with a meter that reads capacitance, but not everyone has one of these. If you use a regular ohmmeter set to high resistance (<10K) you will see a momentary low resistance when you connect the meter, then increasing resistance until it looks like it is open as it charges. Short it out before you check it just to make sure it doesn't have a charge on it; it could blow your meter or zap you if it is charged. It should discharge through the motor winding when you shut it off, but short it anyway before touching it. If in doubt, change it. It couldn't be more than a few dollars.

See if you can get a clamp on ammeter on the thing while it is running. It shouldn't be pulling more than an amp or so. If it is, and the cap checks out, then the motor probably has shorted windings. FWIW, you got about six more years out of yours than I got out of my last HD fan. You might want to check out the Hunter fans. Even their cheap imported ones have a "limited lifetime" warranty and are smoother and quieter than just about anything else out there. The cast iron "Originals" are built like tanks and will outlast both of us, but are pricy. Good luck and let us know how you make out.

Pook: what is that thing in your avatar? It looks like a spawn of Chucky doll...

Chris

 

[michaelthomas]

Why didn't this smoking occurance trip my breaker? That kind of scares me?

 

[jebatty]

Even if your motor or capacitor are bad, the switch was smoking, so I would also replace the switch.

As to not blowing the circuit breaker, take a bead on this: 240v, 200A , underground cable. Gopher chewed into the insulation and the cable, shorting to ground, blew up underground. About 5' of cable was vaporized and glassified. The circuit breaker did not trip.

 

[Redox]

Whenever you let the smoke out of something electrical. you should replace it! Most household circuits are fused at 15 amps and the little triac in the speed control is only rated at 3 to 6 amps. It will usually blow the triac open long before you trip the breaker. Hopefully, it is installed in a metal box to contain the damage. Don't lose a lot of sleep over it, just find the real cause of the problem and fix it. Electronics don't usually fail unless something else causes a problem. Amp the motor out and replace it if it is bad.

Chris

 

[raybonz]

Even if your motor or capacitor are bad, the switch was smoking, so I would also replace the switch.

As to not blowing the circuit breaker, take a bead on this: 240v, 200A , underground cable. Gopher chewed into the insulation and the cable, shorting to ground, blew up underground. About 5' of cable was vaporized and glassified. The circuit breaker did not trip.

Jim it sounds like your service feeder was shorting before the main breaker.. A breaker will only sense current that passes through it not before it..

Ray

 

[jebatty]

Boy, you sure would think so, but not this time. My main breaker is on the pole - 240v & 200a; splits 3 ways: 100a to house, 100a to barn, and 200a to machine shop. The machine shop feed is the one that blew, without blowing the main.

 

[raybonz]

Boy, you sure would think so, but not this time. My main breaker is on the pole - 240v & 200a; splits 3 ways: 100a to house, 100a to barn, and 200a to machine shop. The machine shop feed is the one that blew, without blowing the main.

Sounds like a defective breaker.. FPE (Federal Pacific) breakers were notorious for not working.. Do you know if it was a FPE breaker? Once I observed an FPE 20 amp breaker draw 35 amps for 5 straight minutes and NOT trip lol.. They no longer make service equipment as far as I know.. Have no idea how they got UL approval.. We joked that FPE stood for F'n Poor Equipment lmao


Ray

 

[jebatty]

Will take a look - thanks. Is there any safe way to test these?

 

[Redox]

Will take a look - thanks. Is there any safe way to test these?

They can be tested, but it is probably cheaper and easier to replace it if there is a question. The FPE breakers that were causing the problem were the little ones with the orange handles and were popular about 40-50 years ago. Our electricians called them as "house burners" Their panels also didn't have a main breaker in many cases. Not sure if the problem extended to their larger sizes, but I have seen and heard of too many instances where they should have tripped, but didn't. Put them high up on the list of must replace items if you find them.

Jim: maybe the varmint was only pulling 190 amps?

Chris

 

[begreen]

Jim: maybe the varmint was only pulling 190 amps?

Chris

Yeah, don't you just hate those low amperage gophers! They screw up the whole works.

 

[Redox]

Jim: maybe the varmint was only pulling 190 amps?

Chris

Yeah, don't you just hate those low amperage gophers! They screw up the whole works.

Energy Star rated, no less!

Chris

 

[raybonz]

Will take a look - thanks. Is there any safe way to test these?

Jim my advice is if in doubt throw it out.. To test a circuit breaker you practically need to destroy it.. UL tests Interrupting rating and normal trip ratings. Interrupting rating could be 22,000 amps and that means the breaker must be able to trip at that amperage.. This is a Cutler Hammer link that mentions interrupting rating: http://www.eaton.com/EatonCom/Marke...m?ssSourceNodeId=3483&ssSourceSiteId=EatonCom .

They mention both 10kAIC and 22kAIC ratings meaning 10,000 and 22,000 amps interrupting capacity..

Better safe than sorry so toss it out if any doubts..

Ray

 

[seige101]

So I have 2 wood stoves that I watch vigilantly for fire danger and I turn on my ceiling fan and smoke started coming out of the fan switch on the wall. I took the control out and it had started to melt inside. A few days ago the ceiling fan started to make a little more "motor" type sound when it was running. Do you think this is a switch problem or a fan problem? Switch looked like a real cheap one. Fan is an 8 year old home depot special, installed by the previous owner. Unfortunately he was an electrical engineer...he built computer chips...and had no business wiring his own house! Some of the stuff that we have come across is down right scary. Anyway what is your best guess? Switches are cheaper than fans...start there?

It's probabally a $50 home depot fan, better off to just replace it, along with the speed controller switch. The bearings could be bad due to an improperly balanced fan or as others have said the capacitor could be bad. However make sure the speed selector switch on the fan itself is in the high position when using a speed switch on the wall!

Tim