No volt contacts ??

[daddy33]

Hey all, can anybody here explain to me what exactly a no volt contact is and how you wire to them as I am coming across them a lot on pcb's either for fire panel shut down or for other control reasons but have no idea as usually I only wire mains across say d.p. switches, spurs, lighting switches etc...

Sorry for my stupid question but I haven't a clue on this stuff..:confused:

[VRVIII]

I take it you are referring to volt free contacts; doesn’t the name say it all?
You need to supply voltage to the common terminal, when contact closes voltage will be applied normally open terminal. Obviously this will be vice versa with a normally closed contact.

[chemi-cool]

Sorry for my stupid question but I haven't a clue on this stuff..:confused:

Not knowing is not being stupid.
Not asking is.

Read here:
http://www.control.com/thread/1026171624

[Brian_UK]

The description means that the relay contacts have no voltage feed from the relay or mounting at all.

The fire panel (eg) will switch a 'no volt' relay when in alarm mode and you can link your HVAC control circuit through the relay. Your voltage may be from 12vdc up to 230vac depending on the control circuit itself.

The important thing is that the fire panel has not directly connected with your HVAC panel.