Wire a Fibaro FGS-222 potential free

Need some confirmation…

I have a Fibaro FGS-222 that switches ON/OFF my central heating. The wire diagram - if only one relay is used - looks like this:

I have connected it like this:


where C.V. is the ON/OFF themostat input of my my central heating system. This allows the Fibaro to switch ON/OFF the heating and works fine. No connection is made between L and IN, so it operates potential free.

I would like to add the possibility to manually switch the relay, so use the S1in the first diagram. However, I see that it is connected to L (mains).

Is it correct that as long as no L is connected to the IN, I am still switching potential free?

Yes, 100% correct, I can confirm, having similar setup for my irrigation.

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@danone
Thanks for the confirmation!

Is it important what kind of switch is connected (as in 230v allowed?)

Yes, you must use a switch connected to 230V. But that does not affect the relay outputs which are totally separated from the high voltage.

Thanks for your help @danone!

I am not being very clear. Sorry about that…

What i meant was, does the switch have to meet certain standaards?
I have some of the:

but should I use one that is capable of 230v, like this one:

You should only use switch that is rated for 230V.

Which usually makes that the installation can be made only by certified electrician (may depend on country you live in)

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I would definitely check if the switch is rated for 230VAC.
Although the load is extremely low (like really low) if the switch is not rated 230V then it’s possible you get an electric shock.

Like this one HERE you can see it’s rated up to 250V. It looks similar with the one in your picture, thought. Check the spec of yours.

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