question

dylan-hyslop avatar image
dylan-hyslop asked

Victron MP2 Tripping earth leakage on Mains fail & recovery

Good day,

I have recently installed an MP2 5000 into a home that had a 3 phase db board.

Have essentially just taken L1 and run it through the inverter and then back to the original DB Board. So everything on L1 is backed up and L2,L3 is not.

Please note that this db board has an RCD per phase. ( we have kept the original one in place, we just went to the inverter along the way.

SO just to clarify the setup:

{Mains 3 phase 63A Breaker} => 40A Input Breaker => Victron MP2 => 40A output Breaker => Back to original RCD => (Plugs and lights on L1)

(There is no Upstream RCD)

Now I have an issue that when I trip the mains breaker, L1 RCD trips immediatly.

But strangely If I then go and put it back up, it will continue to work fine. (so this is a major issue as it basically removes the point of having a UPS backup).

Then secondly, after I have put the RCD back up, and I turn the mains breaker back on. After a few seconds (when the MP2 enables ACIN) the RCD trips again?

What I don't get is why would it trip only when it switches? after it has switched it seems fine?

This does not quite make sense to me.


<Further Playing AROUND>

  • I have noticed that if I turn all the breakers OFF, on L1 and do the same test the RCD does not trip.
  • I have noticed that if I leave just 3 of the light breakers up, it does not trip.
Multiplus-IIinstallation
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2 Answers
JohnC avatar image
JohnC answered ·

Hi @Dylan Hyslop

You don't mention the Multi's onboard Ground Relay, so may not be aware of it. Some discussion of it here.. https://community.victronenergy.com/questions/35325/ground-relay-setting-on-or-off.html

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seb71 avatar image
seb71 answered ·

I have noticed that if I leave just 3 of the light breakers up, it does not trip.

That RCD did not trip before adding the Multiplus? It sounds like there is a problem on one circuit.

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