Switching 230VAC with Cerbo GX

Hi there!

I’‘ve installed a full Victron setup in my camper conversion including a Cerbo GX. Now I would like to use the two relay outputs to do the following, mainly to reduce the numbers of manual switches installed in the camper:

  • Relay 1: Switching a 230V/550W Boiler manually on/off through the Touch 50
  • Relay 2: Switching a 12V/100W water pump manually on/off through the Touch 50

Both relays will be controlling another, larger relay that will actually be switching the load. I’ve heard and read plenty of stories of people frying the relay output on the Cerbo GX and since my knowledge in this regard is limited, I’m asking for your input.

Can I use this relay: TRU COMPONENTS Halbleiterrelais TC-12705356 (DC to AC) to switch the 230V boiler? In the data sheet a max reverse voltage of -6VDC is listed, is this a problem for the Cerbo? This relay will only be turned on for maybe 1 hour a day when I want the boiler to heat up.

To keep the installation neat, I would like to use a similar relay to switch the 12V water pump: TRU COMPONENTS Halbleiterrelais TC-12705368 (DC to DC). The same reverse voltage is listed here. This relay will most likely be turned on most of the time while traveling, and turned off when the camper is in storage.

Both relays seem to have installed a freewheeling diode but it is on the output end, not the control end connected to the Cerbo.

Can I use these relays? Do I have to install a freewheeling diode in the control sircuit as well? Do you recommend another relay for simple installation?

Thank you for your help and kind regards from Switzerland,

Lars

These look suitable. The Cerbo will not generate a reverse voltage - the relay contacts are “volt free” This means that an external supply is also needed, but this can be any voltage up to the max - 32V in the case of this relay.