Multifrid overload warning in ess

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steffenp asked Jan 22, '19

Multifrid overload warning in ess

Hi,

Today my MG 48/3000 running latest FW and latest ESS-assistant generated an overload warning as I pulled about 5 KW in my phase compentasted net parallel system (FW 2.22 on venus gx). From vrm log I can see it pushed about 2556W into grid at phase 1. It generated that much warnings, that it got suspended from email push notifications.

The question is, why does it actually generate so much power, that it could cause an overload warning by itself in ESS? With a cos phi of 0.8 it may be possible to throw a warning at 2400W=3KVA. This would be reasonable.

So is it ok, to ignore the warning until I get an alarm? Actually the warinings in the Multi are disabled, but the vrm portal seems to receive it anyway. I do not want to disable warnings in general but this is...

Do I need to be concerned in OL conditions, or will the multi shut down / go into passthrou, if something becomes critical? It should stay a little while with up to 6000VA consulting the datasheet.

Steffen

MultiPlus Quattro Inverter Charger ESS multigrid warnings

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Answer 1 · 2019-02-24T05:51:36Z

mvader (Victron Energy) answered · Feb 24, 2019 at 05:51 AM

Hi @SteffenP, I’m sorry that no one was able to answer your question any time sooner.

See this documentation for a possible cause of the overload:

https://www.victronenergy.com/live/ve.bus:grid-codes-and-loss-of-mains-detection

Otherwise, as long as it does not shut down there is mo need to worry about it.

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Answer 2 · 2019-02-24T10:30:02Z

Hi @mvader (Victron Energy Staff),

no there is for sure no external event causing this. There was no LOM, I have very stable grid conditions (never below 230V) and strong wiring to the MulitGrid. It actually looks really like a small overshoot caused by the Multi itself. Not much, and for sure not bigger than 5-10% wich is quite acceptable for PID controlled systems. But it seems to be enough to fire the warning.

The yellow one is a BLDC controlled air condition. The black is an ohmic load (stove) that activated a turbo heating mode (the peak). Blue is the Multi running at about 2500W which may be slightly more then 3KVA. I do not know about the power factor the Multi generates.

I am not concerned about it, really. So I turned of the warnings in the Multi in its setup menu in the venus gx and changed from warnings and alarms to alarms only. But VRM-Portal does report it anyway. So the only way is to disable all warnings in VRM-Portal. But this may disable all other warnings which I meight be interested in - also from other devices. So I received no warning as The multi switched to passthru lately because of some bus error.

Today I tried to reproduce the problem. By switching in the menu from „optimised without battery life“ to „optimized with battery life“ which currently has dynamic SOC of 75% (we definetly need to have a reset for this in menu) and back. SOC was at about 50% that time, and the Multi fireing its warning while switching back to full load (feeding in). You may see the little overshoot here... (blue)

Yesterday I updated to firmware 2.23 on the venus. The problem where you can not switch from menu panel to pages panel without restart seems to be back again...

Since last firmware of Multi (not latest today) and 2.22 venus, I am happy, to see, that the Multi will generate more power (before it was kind of limited by about 2200W). But as I am using ess (newest assisent), and pylontech batteries, I only can see 52.2V max at MPPT output of the solar charger. So actually in the Multi, there are values of 53.2V in the ESS assistent entered. DVCC is enabled. No other dc loads than the multi/venus gx. Batteries will only get about 95% SOC so. Is this correct and wanted behavior? I am a bit concerned if the batteries will trigger balancing with this lower voltage correctly...

Steffen

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