wiring a dpdt limit switch to shut off a fan when my swing-out door opens


Thread Starter

Ron Brown

I would like to wire a Square D 9007C heavy duty limit switch in a hazardous area to control a fan inside a hazardous container. It should shut down when the door opens. It also has a open/close control station to be mounted outside the container. How can I wire this?

Zacharia, Tomy

I am assuming that all parts (Fans, limit switches, control stations) are certified for the "hazards" in question and wiring will be done as per certification requirements. Wire the fan in series with NO contact (The contact is open when door is open). You need to wire an "open/close" control station.. I assume that this is a fan start/stop switch. Wire it the usual way. The start contact wired in parallel and stop contact in series.

Tomy Zacharia


Thank you for replying to my post. I'm sorry, but I think I neglected to say that the start/stop station has to override the limit switch when the door is closed and the fan is running. I'm using a 2 circuit contact block, 2 n.o. and 2 n.c. 9007 C type snap action limit switch from SquareD. How would I wire that?