Industrial style 56" Fan- multiple fans w/ 1 speed control?

[sw_ross]

Im roughing in a shop building with 14' sidewalls. It will have 2 industrial style fans.
Ive installed these fans a bunch but it's been awhile and I don't think I've used one speed control for multiple fans?
Normally I get the fans and speed control from the supply house so I don't remember the brand name.

I'm thinking I should just run a switch leg from each fan to be safe and plan on a speed control for each fan.
I'll talk to the SH tomorrow morning about the situation, but will still probably run 2 switch legs to be safe.

Anyone have experience/opinions with 2 fans on one speed control?

 

[Besoeker3]

Im roughing in a shop building with 14' sidewalls. It will have 2 industrial style fans.
Ive installed these fans a bunch but it's been awhile and I don't think I've used one speed control for multiple fans?
Normally I get the fans and speed control from the supply house so I don't remember the brand name.

I'm thinking I should just run a switch leg from each fan to be safe and plan on a speed control for each fan.
I'll talk to the SH tomorrow morning about the situation, but will still probably run 2 switch legs to be safe.

Anyone have experience/opinions with 2 fans on one speed control?

I have put in variable speed drives running multiple motors. The last I recall was the roller tables in a steel mill I think we maybe had five VFDs and about 80 motors. Worked fine.

 

[kwired]

The fans have no issues with multiple units being on one controller, the key is to get a controller rated for the load. Many common ones marketed for ceiling fan use are only rated maybe 3 amps max - if you overload them it won't be a problem for the fan but will lose the controller. There are higher load rated controls out there. There are also controllers for other PSC motors (agricultural ventilation controllers can handle 15 or 20 amps of load and multiple motors sometimes) that will work just fine on these motors.

 

[hbiss]

From Bigassfans:

"Auxiliary wall-mounted digital keypad with touch controls and an LED display to control the fan’s direction, operation, speed and programming. In the unlikely event that there’s a problem, the wall controller is equipped with a simple diagnostic program to identify, troubleshoot and reprogram faults in the system. Communication between the fan’s variable speed drive (VFD) and wall controller is by a standard CAT5 (or higher) Ethernet cable, which comes standard with 150-ft of factory-assembled cable.An unlimited number of fans can be daisy chained together and operated at the same speeds."

So here, you would run power to the fans and CAT5 from fan to fan then back to the controller.

-Hal

 

[kwired]

From Bigassfans:

"Auxiliary wall-mounted digital keypad with touch controls and an LED display to control the fan’s direction, operation, speed and programming. In the unlikely event that there’s a problem, the wall controller is equipped with a simple diagnostic program to identify, troubleshoot and reprogram faults in the system. Communication between the fan’s variable speed drive (VFD) and wall controller is by a standard CAT5 (or higher) Ethernet cable, which comes standard with 150-ft of factory-assembled cable.An unlimited number of fans can be daisy chained together and operated at the same speeds."

So here, you would run power to the fans and CAT5 from fan to fan then back to the controller.

-Hal

That is likely more complex fan and control system than what OP is asking about. I installed a couple BA fans, they were three phase motors with VFD controller. I think OP has simple fractional HP (and likely under 1/8 HP) paddle fan with a 120 volt PSC motor. Most those called "industrial" don't have multi-value capacitor and switch to change taps to capacitor to change the speed, so we use a solid state controller that is much like a dimmer switch in design that shaves the current peaks as a method to limit torque produced, which ultimately results in being able to control speed.

 

[sw_ross]

That is likely more complex fan and control system than what OP is asking about. I installed a couple BA fans, they were three phase motors with VFD controller. I think OP has simple fractional HP (and likely under 1/8 HP) paddle fan with a 120 volt PSC motor. Most those called "industrial" don't have multi-value capacitor and switch to change taps to capacitor to change the speed, so we use a solid state controller that is much like a dimmer switch in design that shaves the current peaks as a method to limit torque produced, which ultimately results in being able to control speed.

Correct,these are simple paddle fans to circulate the heat in the shop since there's a 14 foot sidewall.
I'll talk to the supply house in the morning about the fan they supply being setup so that 2 or more fans can be operated by one speed control.
Thats how I'd like it to be set up rather than 2 speed controls.

I remember we had one install once where a 2-car garage had 2 fans. The HO wanted one speed control to operate both fans. He bought the big box store fans that come with a speed control. Initially we set it up using one speed control to operate both fans. The first fan in the string operated fine, but the second fan operated at about half speed compared to the first one. Probably a cheap speed control. I wasn't there so I'm not sure how the situation was resolved.

 

[kwired]

Correct,these are simple paddle fans to circulate the heat in the shop since there's a 14 foot sidewall.
I'll talk to the supply house in the morning about the fan they supply being setup so that 2 or more fans can be operated by one speed control.
Thats how I'd like it to be set up rather than 2 speed controls.

I remember we had one install once where a 2-car garage had 2 fans. The HO wanted one speed control to operate both fans. He bought the big box store fans that come with a speed control. Initially we set it up using one speed control to operate both fans. The first fan in the string operated fine, but the second fan operated at about half speed compared to the first one. Probably a cheap speed control. I wasn't there so I'm not sure how the situation was resolved.

If you have typical 3 speed with pull chain controlled fans, you must set them on same speed (preferably high) or you will get different performance out of them.

Also possible one fan had some other problem, eliminating the speed control temporarily they both should run close enough to same speed you won't be able to tell with naked eye.That speed control is sending the same voltage wave to both fans, anything else that might effect current is what is going to make them run at different speeds if everything else is identical. If you had really long branch circuit you might get enough VD to have some impact, but it would need to be awfully long.