Volera Unica HE - voltage-free time switch

[bill12d]

I have just had a new Volera Unica HE combination bolier fitted. The timeclock i had previoulsy was 240v switched and I am told i need a voltage-free time switch.

I have purchased a 5A 240Vac DPDT miniature relay and have wired it to provide a voltage-free switch via the time clock.

So now to connect the voltage-free switch to the bolier. The manual is not clear, but it indicates I connect the switch to 2 connectors which currently are connected by a wire loop. This makes sense, but when I test the 2 connectors on the bolier they are carrying 240V.

My questions:
1. Why a volt free switch if it is to switch 240V?

2. Will the volt free side of the 5A 240Vac DPDT miniature relay handle switching 240v?

Many thanks

Bill

 

[Agile]

Oh dear!

The description "volt free" means that you should not put your own volts on either wire! Of course the boiler has to supply its voltage otherwise it will not know when it has been switched.

Without knowing the specifications of your relay how am I able to know? You say a "miniature" relay but whats that?

However if it says its rated at 5A 250 vac then it will handle the small signalling current from the boiler.

Its an expensive boiler to damage if you have got it wrong.

Tony

 

[Paul Barker]

Yes I just looked at the instructions and it is very unclear isn't it?

I suspect they are naming it volt free because they mean that you don't want to be using something that needs a neutral.

I don't see the value of your relay.

Which timeswitch are you wanting to integrate?

by the way what I normally do with vokera is use the integral mechanical clock or in case of unica you have to buy it, then I interupt one of the leeds from the switching connectors of the clock (two leeds are for switching two are mains line and mains neutral to power the timing mechanism) with a room thermostat. It doesn't matter which aslong as one is interupted.

 

[D_Hailsham]

I suspect they are naming it volt free because they mean that you don't want to be using something that needs a neutral.

Tony Agile is quite correct when he says

The description "volt free" means that you should not put your own volts on either wire! Of course the boiler has to supply its voltage otherwise it will not know when it has been switched.

Many mains operated time switches will provide a 240V to the output connections, e.g CH ON. If a boiler required volt-free switching this is no good; the switch must be a switch and nothing else. You will need two wires to the boiler so the switch can work. It's a bit like a 2-port zone valve. The micro switch is a volt-free switch as it is not automatically supplied with 240v from the same wire as the motor.

I don't see the value of your relay.

If the existing timeswitch does not have voltage free switching, the relay will provide this facility.