hi
im new to the forum can anyone explain what and how volt free contats work? I have a elliwell controller which can run a compresser or defost heaters or fans some are 240volt some are 24volt supply but are swicthing components that are mains voltage

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Hi,
I think "Volt Free Contacts" is just another way of saying "Dry Contacts" i.e. relay contacts.

Regards
Roy

 

It is a set of open switch contacts that are opened and closed by the controller.  You supply the voltage and the load. (within the switches ratings, of course)

Bill

 

It's a basic interface method.

The phrase is commonly used to refer to a set of contacts in one device which are made available to another system. (Because they may not be compatible, it's important that there's no voltage involved. The contacts don't DO anything, they just operate. The other system decides what to do with them.)

For example, if one system goes into some critical state, it may close a set of contacts so that a signal is passed to another system. (Think of a machine shutting down when it "hears" the fire alarm, or alternatively a fire alarm being triggered by a critical state in some sensor.) There may be a more general technical meaning but in the UK this is what I've understood as the common usage.