[Bill Mosley]

My harbor breeze celing fan is not working. All of parts of the fan (switch, reverse switch, etc.) all check out fine. This fan/motor has 3 caps in cased in a black sealed box. The values of the three caps are 3.5, 4 and another 4uf cap. The cap lists a +/- 5% tolerance and I measure 3.25, 3.65, and 3.7 respectively which is just outside of 5%. I don't feel the cap is bad but I don't find anything else wrong. The fan will not spin in any position, do not hear a hum; motor spins freely and I have verified power is getting to the motor. This fan has a light kit that does work. Any ideas?

[KISS]

Usually these go in Elect & lighting. Bad tolerance is usually a sign of a bad cap. You need to measure ESR to have a good test.

Here are some diagrams of fans: Ceiling Fand wiring Diagrams

www.ceiilingfanparts.com has parts.

On the above site, note just how many switches there are.

The reverse switch needs to be inspected.

[Bill Mosley]

Esr?

[Bill Mosley]

Effective series resistance, wouldn't I need a special meter to test this? Checking resistance with a fluke 189 won't tell me anything will it, even if I have a new cap to compare it to?

[KISS]

Nope. I would doubt that all 3 caps failed at the same time.

ESR is like, you put the CAP in a circuit and apply a low amplitude sine wave and measure I and V across the capacitor. That value needs to be low.

I don't susspect them. With a weak cap, you can sometimes spin the blades and it will keep running. It just is unable to start.

[Bill Mosley]

Any idea what the problem might be? I feel as though I have ruled out either switch, the cap, connection issue, or power problem. That pretty much on leaves the motor which has no visible problems.

[KISS]

The reversing switch is what I would suspect.

If it's moved when the fan is running, bad things happen.

You have 3 caps and I'm not sure how that integrates in except the speed switch selects cmbinations of capacitors.

You basically have two windings, sometimes there are taps. Continuity will identify problems there.

With 2 caps, they essentially selct the two in parallel for the highest speed and then the lowest cap and then the middle value. Speed switches generally select combinations of the caps unless it's a design that uses taps on the motor winding.

You'll note that the reversing switch essentially reverses a winding. It's a DPDT switch with the ends crossed. Esesntially a polarity reverser when used for DC. That's why only 4 wires are used. They are either connected straight through or crossed.

I still suspect that.

Disconnect te cap.

Test the motor winding - ohms.

Remove the lamps and put ohmeter on power leads. Check for motor continuity through the swich positions. One should be infinate.

[Bill Mosley]

I tested the reverse switch and it is fine, I will ohm the motor windings. Thanks for your help, will let you know

[Bill Mosley]

One winding is 98 ohms and the other is infinite. It should not be infinite should it?

[KISS]

Nope. Might have to take things further apart.

[Bill Mosley]

It appears that one winding is shot but wouldn't it run with the reverse switch in the other position if all switches and cap are good? Might be better off replacing fan, at this point I already have a few hours into troubleshooting and with a new fan for $100 or so I think I might stop wasting time. I found a 10x135mm motor for $35 but the fan is 8 years old so the cap is probably close to failing also. Thanks for your help

[Bill Mosley]

Would the fan run in the opposite direction if the switches and cap is good? One winding for each direction right? Thanks again for your help