Ceiling fan runs slow on highest setting

[mylomine]

So I have three identical ceiling fans in my home. Two of them run on a single normal wall switch and seem to operate as expected. The ceiling fan in the master bedroom however does not. This is the second fan I bought for this room because the first fan operated slow as well which leaves me to believe it's not the fan that is causing the problem. There are two wall switches in this room. One of them is a lighted switch so that you can see it in the dark when the switch is in the off position. What could be causing this fan to run considerably slower than the other two? Could there be a wiring issue? Everything I research on the web points to a faulty capacitor but that wouldn't explain two fans doing the exact same thing? Ideas?

Thanks,

super hot in phoenix summers, josh

[DonL]

Hello mylomine,

Maybe your fan motor is connected in series with another circuit, rather than in parallel.

I think that you are correct about it not being the cap, unless they had a bad batch of caps.

I would measure the voltage at the fan motor an see if it is getting 120V.

I would think that if the fan had lights also, then they would be dim also.

I have also seen bad light switches, that arc inside, but you can normally hear them arcing. (making bad connection)

Good Luck with your project

Have a Great day.

DonL

[mylomine]

Hi DonL and first off, thanks for replying.

The lights don't appear to be dim and seem to be operating normally.

Is there a way to check the voltage without completely taking the fan down?

Now I have heard one of the switches make a sparking noise once in awhile. Is this what you are referring to as arching? Would that mean I should replace it or start there first?

There are two switches that control this light/fan. They are either both on or both off no matter what position the switch is in. Does this have anything to do with the series vs. parallel thing you were talking about?

I really appreciate your response and have a great day as well.

Josh

[DonL]

Hello Josh,

I would suspect one of the switches. If there is any resistance in one of the switches then the voltage would be low. You might try
turning one switch on and the other off, If it is a two way switch circuit, you can test it that way also.

Normally you can remove the light fixture and measure it there. Or remove a light bulb and carefully measure the voltage
in the lamp socket, should be the same voltage that the fan motor is getting. I prefer a screw in outlet adapter that screws
in to the light socket, It make measuring much safer. Especially when the fan may be moving the light socket.

You could also measure the voltage at the wall switch itself.

DonL

P.S. You might have a normal operating Fan , and just the distance from the ceiling to the blades can effect fan speed. You can sometime test by reversing the motor and see if it runs faster. If it is a high efficiency fan, it don't take much to slow the speed down, even blades out of balance can change the fan speed.

[ActionDave]

Could be a wiring problem.
You did not mention if you tried yanking the pull chain on the fan that controls the speed.

[jwelectric]

Switch the switch that controls the light for the one that controls the fan to see if it is a problem between the switch and the fan motor.

Did you keep the fan and light separate in the ceiling box?

[mylomine]

I have tried all three speeds on the fan by pulling the chain. I would say that when the fan in my room is on high it is comparable with low to medium with the other two identical fans in other rooms.

[mylomine]

It's not two separate switches that control the light vs. the fan. There is a one switch on the north wall that gives all power to the fan and light. There is also one switch on the south wall that controls all power to the fan. If I turn on the power to the fan with the north switch then I can turn the power off by switching the the south switch (not sure if this makes sense)

I have not had a chance to test any voltage yet as I am waiting to find some time. I am planning on doing some testing today after work.

[hj]

Having two single pole switches in series like that, which seems to be what you are describing, is unusual, and although that should NOT be causing the symptoms you describe, I have the feeling that it is actually the cause for some reason which you have not told us, and probably do not know yourself.

[mylomine]

Having two single pole switches in series like that, which seems to be what you are describing, is unusual, and although that should NOT be causing the symptoms you describe, I have the feeling that it is actually the cause for some reason which you have not told us, and probably do not know yourself.

Would you suggest that I disable one of the switches and then see if the problem persists?

[DonL]

Hello Josh.

You said that all the fans were Identical. Did You buy all of them at the same time ?

Are your switches single pole double throw, or single pole single throw ?

I think that may help, For you to get your answers that you need. Too help you better.

If you did hear noise coming from one of the switches, I would check that one first.

Normally where it is humid there can be switch problems.(Should not be a problem where You live)
Also a smoking environment is hard on switches.

It pays to get good replacement switches. And know the type that you have and how they are wired.

Just be careful, playing with electricity.

Have a Great Day.

DonL

[mylomine]

I did buy all three fans at the same time. However the original fan in my room was doing the same thing so I returned it and replaced it with an identical fan which proceeded to have the same issues which led me to believe the fan was not the culprit.

As for the SPST or SPDT, I'm not sure about his one. I don't have enough electrical knowledge to answer this. From the brief research I have done, I'm guessing they are SPST. Do you know of a easy way to figure this out or an electrical for dummies type of site I may peruse?

Hello Josh.

You said that all the fans were Identical. Did You buy all of them at the same time ?

Are your switches single pole double throw, or single pole single throw ?

I think that may help, For you to get your answers that you need. Too help you better.

If you did hear noise coming from one of the switches, I would check that one first.

Normally where it is humid there can be switch problems.(Should not be a problem where You live)
Also a smoking environment is hard on switches.

It pays to get good replacement switches. And know the type that you have and how they are wired.

Just be careful, playing with electricity.

Have a Great Day.

DonL

[DonL]

Hello Josh,

Well you must have had some knowledge of wiring, when you installed the fans.

A SPST will normally have two (2) Screw connections on the sides of the switch. And should have a ground wire.

A SPDT will normally have three (3) Screw connections on the sides of the switch. (should have a ground also.)

Grounds may go to the box if it is metal or go to the switch metal. (Green Screw)

The number of wires that are connected, depends on the wiring in the house.

Sometimes circuits are connected together, as to save wire and building cost. (You may have more wires, connecting other circuits)
You can turn off the breaker for the fan and see the circuits that it affects.

If you do decide to DIY make a drawing of how it is connected, and the kind of switch it is.

Turn the power off before taking the switch out. Normally you can tell the type of switch without removing it.

Wish I could be more help, but the type of switch make a big difference, and how many wires that are connected to it.


The reason I asked about the fans, is because I have seen Manufactures Run out of parts, and use a substitute.
A lot of those fans use a 2 MFD 250 Volt AC Run Cap. I thought they could have substituted it, when it was made.
The workers, do make mistakes, when they assemble things. (They work for Food , that's all they want or need)

You might want to compare the wiring and color codes, and cap value for the one that works, to make sure the motor is wired correctly
and the run cap is the same.


Good Luck, Don't give up. But don't get shocked.


DonL

[jwelectric]

bypass all switched and use the breaker to turn it on. If it still runs slow then it is either wired wrong in the fan or fan box or there is something wrong with the fan.

If the light and fan are both controled from the same switch and the light is doing as it is supposed to do then I would think it was the fan.

[mylomine]

Update: I bypassed all switches and the fan is still running slow. The fan is getting 120V. Sounds like the fan is wired incorrectly up above. I will take the fan down next weekend and check the wiring up there. Thanks for all the help everyone.

Josh