Searched the archives and did not find anything directly on this:
I have a facility designer that want to drive two exhaust fans possibly with a single VFD and then be able to cycle one of the fans off on a new application (this is due limited wall space for all the electrical disconnect, enclosures, etc. required). Separate motor protection will be required with klixons in the motor windings since the ambient can be up to 130 F. When they open, I was planning on shutting the drive down but could a contactor be installed just before each fan's motor to just take the overheated fan offline until it cools down? And since there will already be contactors there, can we cycle off a fan when there is too much exhaust with both fans running at minimum speed? If required, we could stop both the fans with the drive, open the contactor, and then restart only with one fan.
What are your thoughts/ concerns/ caveats.
I have a facility designer that want to drive two exhaust fans possibly with a single VFD and then be able to cycle one of the fans off on a new application (this is due limited wall space for all the electrical disconnect, enclosures, etc. required). Separate motor protection will be required with klixons in the motor windings since the ambient can be up to 130 F. When they open, I was planning on shutting the drive down but could a contactor be installed just before each fan's motor to just take the overheated fan offline until it cools down? And since there will already be contactors there, can we cycle off a fan when there is too much exhaust with both fans running at minimum speed? If required, we could stop both the fans with the drive, open the contactor, and then restart only with one fan.
What are your thoughts/ concerns/ caveats.