>"So, relay or any other switching device is not suitable."
>
>It is not possible without some sort of switch.
>See my original answer!

I am not sure for such statement. I see it's possible,
just could be as non-approved action.
Andy, could you explain me please, what whould be happen,
if my ring generator is blowing their exchange equipment
instead of their generator. I am not going to forvard them
~220V, but it looks like they are protected even from this
voltage.

Thanks,
Oleg