Multi RS 3phase set-up AC disconnect: 'Multi-Phase Issue'

DIY
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1

Hi all,

I have a 3x MultiRS (v1.28) with a Cerbo mk2 GX (v3.71) and victron’s VM 3phase grid meter.

Over the past few days, I have had the following sequence of events happen 4 times:

  • While under (normal) load, the relays click and the systems suddenly states to be ‘disconnected’ from the AC_in for a split second.
  • After 40 seconds the relay tests happen and everything turns back on.
  • After the units turn on, phase 1 and 2 are back to normal while phase 3 remains ‘off’ for a bit. The L3 unit shows no error code, relay is closed and shows a correct AC_in grid connection, yet does not deliver / pull energy to the AC_in according to the DESS schedule.
  • After max. 15 minutes, it’s triggered to go back to production. I believe this coincides with the 15 minute schedule of DESS somehow.
  • When this issue happens, The Multi RS settings –> Grid –> NS protection log also shows “Multi-Phase Issue”.
  • I have a hunch this issue started with the 3.70/3.71 install on the GX, but not 100% sure.

To illustrate how this looks (issue at ~18:35):

Screenshot 2026-03-20 at 19-29-27 Gulikers - VRM Portal
Screenshot 2026-03-20 at 19-29-27 Gulikers - VRM Portal4098×1860 323 KB

The questions I have:

  1. Anyone else experience something like this or have any documentation what “Multi-Phase Issue” in NS protection log means?
  2. Is there any way I can pull a more detailed log than the very (very) limited logging on VRM and the NS protection log?
  3. Any suggestions for troubleshooting?

Appreciate the help in advance

cheers

2

Hi @Matsuda

This is a known issue in firmware 1.28, and we are testing a fix for it now in 1.29 beta.

This beta is not yet public, so I will send you a private message with a link.

1 Like
3

Hey @guystewart, really appreciate the prompt reply and solution.

Have a great weekend!

4

You’re welcome.

We would appreciate if you could report back if it resolves or not.

5

I’ll report back in a few days. Issue was intermittent with a frequency of about ~once per day, I’ll monitor it.

Or is there any way that I can manually ‘trigger’ the issue? Since I’m unaware of what is the underlying reason, I’m not sure how to test the condition :slight_smile:

6

This is the line item in the (pre)release notes

Changes applying to the Multi RS in 3 phase configurations -
Improve phase rotation detection, preventing spurious disconnects on 3 phase system, this was visible as “Multi phase issue” in the disconnect log.

There was an additional note that due to this bug fix they are prioritising a fast release from beta to production.

I don’t have any more info on how you could force reproduce it unfortunately. Best case success, and you don’t see it again.

1 Like
7

@guystewart so far so good, everything runs perfectly for 2-3 days without fault. Thanks again.

8

Hi @Matsuda

1.29 is now released as normal.

9

Installed it this morning, so far everything working like a charm.

Cheers

1 Like
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