senrab avatar image
senrab asked

MPPT RS 450/100 Programmable Relay Status Always Closed


I have just had two MPPT 450/100 (Firmware version v1.10) solar charges installed in my residential hybrid/solar system. They are synchronised via the CAN bus and the programmable relay of one is wired via the N.O. contact to a Selectronic SP Pro to signal it to go to Float.

The moment the MPPT is powered up the relay closes even though it's not in Float. I changed the configuration of the relay to Always Off but that makes no difference (to either MPPT).

This issue was raised on this forum back in Jul 19 2021 and answered by Victron as follows:
"This should be fixed in the 1.04 firmware version that is shipped with VictronConnect v5.42 or later."

My MPPTs are at v1.10 and still have a problem. Has this ever been resolved?



MPPT SmartSolarRelay
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
tslewis99 avatar image
tslewis99 answered ·

I am having a similar issue with firmware version 1.11

I have 15 separate installs using this MPPT and other than this unit all others appear to work properly. Before I RMA this unit I want to see if anyone has any ideas.

I am triggering the relay based on "Panel voltage high"

Panel high voltage 165.0V

Clear panel high voltage 145.0V

Once the unit hits 165v the relay closes but never opens when voltage drops below 145v.

  • If I set the relay to always off it still does not open.
  • If I cold reboot the complete system including opening the PV disconnect the relay closes as soon as the unit reboots.
  • If I force a manual firmware update from v1.11 to v1.11 the relay opens and remains open until it is triggered again by "Panel voltage high". After it is triggered it remains closed no matter what I do unless I again update the firmware.

Any suggestions?


@Simon Ytterbom

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources

Additional resources still need to be added for this topic