wiring a pressure switch

[kjharry]

I would like to fit a differential pressure switch to a duct with a delivery fan in it to interrupt the electrical supply to an appliance in the event of the fan breaking down,there is a three core flex feeding the appliance and I assume I would have to re-route the supply through the pressure switch which has three terminals,but how would the wiring be done?,any one help?,thanks.

 

[Lectrician]

You would only be able to switch the live on the pressure switches I have fitted in commercial kitchens.

These are always wired to a contactor which controls the appliances.

In the case of a commercial kitchen it is best to use the control panels designed for the job. They force the kitchen operative to start both intake and extract fans before being able to open the gas valve. If any emergency stops are operated, or the firealarm sounded (if connected), then the fans stop and gas valve closes.

 

[Spark123]

What is the rating (voltage and current) of the pressure switch? Agree with Lectrician, these are normally used on the control side to run a relay or a contactor which controls the power circuit. How are you looking to connect the pressure switch, is the connection on the intake or output of the fan against atmosphere or across the fan? You say delivery fan so I take it you are using it to pressurise a room? Is there anything else in the ventilation i.e. filters?