[randas]

I've got a kitchen exhaust system I could use a hand with.
We got two exhaust fans and a makeup air unit to replace the air that's removed from the building. When the switch is thrown in the kitchen the MUA needs to start, and then two minutes later the exhaust fans need to start.
Air prove switch in the MUA must verify operation. I've got a on delay timer for the two minute delay.
Problem is if the MUA fails the exhaust fans need to drop out as well.
Additionally if ither exhaust fan fails we need the MUA to shut down as well. ( have air prove switches in the exhaust fans).
When the switch is shut off everything is shut down immediatially.

I'm close but I got a race between my exf prove switches and my holding contacts.

 

[randas]

I think I got a race between my two cr contacts

 

[Jlarson]

I probably would have paralleled a second timed contact from another TDR around the check switches.

 

[randas]

I could have sworn their was a way to do it with one timer. Been driving me nuts