ceiling fan 3 way switch

Use your voltmeter to measure on the motor side of the switch, in all its states. If you don't see 120VAC, then the switch is bad.

JM

thanks. Three speeds plus off, so 4 position switch. Each of the four positions has 120vac on one or more of the motor side of switch. Two of the four positions have the same output leads high. That's with just the red connected to the switch. The red comes from the white wire thru the directional two position switch. However when I re-connect the black to the switch then neither of the other two leads from the switch are high. Also there is no voltage between the red and black while connected to the switch, and the motor is humming, but not turning. When I disconnect the black and red from the switch then I get 120 between them.

Sounds like bad motor to me.

What should be going on there is that, depending on which of the 3 "ON" positions is selected by the switch, a different set of motor windings is selected. Rather than add resistance to the circuit, & generate heat like with a DC motor, different windings give different speeds. That's why I asked about the voltages between the switch & motor. If the switch was bad, there would be no voltage between switch & motor. Also, it's possible that 1 or more speed might still work. The humming motor, not turning, isn't good.

JM

I would suspect the capacator. Cheap, $2 to $5 if you have an electrical supply dealer nearby. Dave

I just cut and touched some switch wires and I got the fan to spin. So, I think I can hardwire for single speed. Your thoughts?

Be clear about this. The extra windings add series inductance which drops the effective motor voltage and hence the speed. This works like resistance or capacitance but it is easier and cheaper to do, although series capacitance now has come into favor.

...

Sounds like 1 or more of the windings are shorted. If single-speed is OK with you, wire it up as it works.

JM

Right. My point was that there isn't some sort of variable-voltage speed control in front of the motor.

JM

I am trying to fugure out how this fan worked and I am lost. The four wire switch had red power and the black common both connected to it. Why?

Also the other two connections on the switch went to the two caps. The other side of the caps were connected and went to the fan. Does that make sence?

----- Original Message ----- From: "Paul Mars" Newsgroups: sci.electronics.basics Sent: Wednesday, October 25, 2006 1:00 AM Subject: Re: ceiling fan 3 way switch

Additionally, in several positions of the switch, the red and black wire terminals are connected together inside the switch. I know that makes no sense and it would trip a circuit breaker, but the breaker does not trip.

wire

sense?

Disconnect the switch from the fan and the caps completely and then use an ohm meter to probe its connections. I think you're being fooled by the motor windings.

Did that.

wire

no

trip.

the

I'd suspect the switch is a single pole triple throw but there are other possibilities such as this diagram shows:

mine is not spst. mine has both power wires connecting to it. Then the two remaining switch connections join and feed the motor. I still do not understand this.

What I am saying is two wires in and one out.