Ceiling Fans

[esox39]

I have a situation. I have 2 non reversing industrial ceiling fans. 1 speed controller operates both. 120V .70 amps. Fan A is 40 feet from the speed controller. Fan B is 55 feet from the controller. Both are mounted on 10' ceiling. When we turn on the fans, Fan A spins dramatically faster than Fan B. The manufacturer sends a new fan. We replace Fan A with the new one. Same results. We replace Fan B with the one we took down and again, same results. Wiring is in conduit, with switch leg conductors for general lighting. We re pulled conductors to be sure of proper wiring and no crossed neutrals. Same results. Does anyone have any insight as to why 2 fans 15 feet from each other run at 2 different speeds? Thanks for all the help.
Ron

 

[Dennis Alwon]

Okay I am going to suggest the obvious. Is there a speed control on the fans themselves also. Don't shoot me just a suggestion.

 

[480sparky]

Coriolis effect?

I'm with Dennis.... there's a switch on the fans.

 

[eds]

Are the fans and controller compatable, the industrial fans that I have installed had no speed switch and

 

[growler]

Are the fans and controller compatable.

I would think that if he were to post the make and model number of the fans and controller there may be something to be found on the spec. sheets or installation instructions.

If all else fails, read the instructions.

 

[esox39]

There is no speed control switch on the fans. I will get the make and model # tomorrow and post it if that helps.

 

[Dennis Alwon]

What happens if the speed controller is taken out and direct wired? I bet it works fine. If this is the case then I would guess the speed controller is not made for that fan or for two fans.

 

[GeorgeB]

If I understand that old fan A spins more slowly when in the fan B position, I would guess at a flow block on the fan A position. If it cannot couple to the air, it will spin faster. In your 3rd case, 2 identical, faster running fans installed and not at similar speeds, that'd be my guess.

 

[Nium]

What happens when the general lighting, with circuits in shared conduit, are shut off? Fans continue to run at same speed? If you can't turn off lights then turn off fans and take amp measurements of lighting circuits to see if there's a change. Are the fans and lighting on the same phase?

 

[cal1947]

retired

retired

have you disconected the fan that is turning faster and see if the slow one will go up to speed ,could be that the controller is not rated to carry both fans

 

[esox39]

The controller is rated to carry more that one fan but the problem was I needed 1 controller for each fan because the controller I needed has a speed tweak screw that I can use to adjust the speed to get the 2 fans going the same speed. Thanks for the help!!

 

[Belton]

??

??

The controller is rated to carry more that one fan but the problem was I needed 1 controller for each fan because the controller I needed has a speed tweak screw that I can use to adjust the speed to get the 2 fans going the same speed. Thanks for the help!!

It sounds like you are saying - you split the original controller into 2 controllers (same voltage as original) and now you have 2 switch legs, same circuit. Now you make the fan speeds equal by altering the speed of the other? Something still does not seem right.