Motor operated dampers

[snadeau]

I am trying to control one motor operated damper from two separate exhaust fans on two separate circuits. These dampers need to operate so that they actuate when either or both fans are running. How can I do this. The dampers are 120 volt.

 

[ptonsparky]

Have the damper control the fan(s). Many have an aux switch for the purpose. Use a simple toggle to open the damper. When damper reaches full open have it pull in the starters for the fans.

 

[ptonsparky]

Duplicate

 

[masterinbama]

Control the damper with relays energized by the fan circuits.

 

[Smart $]

Control the damper with relays energized by the fan circuits.

...or auxiliary contacts if the fans operate through motor starters.

Lack of details force us to speculate :huh:

 

[fmtjfw]

If you can group the circuit breakers that feed the two circuits and add a handle tie, then you can use two S2 switches (DPST) with fan A controlled by Sa left side, fan B controlled by Sb left side. Sa and Sb right sides to be paralleled and used to control the damper.

 

[ptonsparky]

If you can group the circuit breakers that feed the two circuits and add a handle tie, then you can use two S2 switches (DPST) with fan A controlled by Sa left side, fan B controlled by Sb left side. Sa and Sb right sides to be paralleled and used to control the damper.

Use a current sensing switch and loop one leg of each fan through it. Have the switch control the Damper.

Or we could really make some bucks on this project by adding a PLC, HMI, and maybe control via your smart phone.