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werner567 avatar image
werner567 asked

Multiplus reboots after remote VE config

Good day,


I have a Multiplus ii 48/5000 230V, with a Cerbo GX and a 5Kw LFP battery running ESS.

I have recently upgraded the Multiplus firmware from V497 to V502 in an attempt to hope this will fix Eskom brown out issues when the grid is failiing.

After the update I've reconfigured the Multiplus using remote VEConfigure, and noted the multiplus reboots itself when the config file is uploaded, dropping everything on AC1.


This did not happen on the previous firmware version V497 and would update without any reboots.


Any advice on why this would happen?

Multiplus-IIVEConfigure 3
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nickdb avatar image
nickdb answered ·

Remote veconfigure will restart the inverter. Pretty much always has because it reloads the full config.

There is nothing in recent inverter firmware that will improve eskom’s grid issues.

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werner567 avatar image werner567 commented ·
this is interesting, as this never happened on V497. only after the recent upgrade.


While on the topic of Eskom as well, Do you perhaps have anything to try, when switching over from grid to battery my output voltage sometimes dips as low as 80V, sometimes its instant. When i try and simulate this by turning a breaker on and of this is perfect every single time with no dip what so ever. I think Eskom grid might be causing this.


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nickdb avatar image nickdb ♦♦ werner567 commented ·

Common issue usually battery related. You can try raise the ac cutoff limits but usually it is a battery with a pace bms: etower, hubble; bsl. What battery do you have and what spec?

Generally a 5kWh battery is way to small for a 5kVA inverter.

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werner567 avatar image werner567 nickdb ♦♦ commented ·

The multi is using the NRS 097 grid code standard, I am unable to change the ac cutoff limits.

I am using a bluenova bn52v-100-5.2k bp battery. This happens while AC out is running at a constant 200W load.

this happens at someone I know house as well using 2 x bluenova bn52v-100-5.2k bp batteries, and a 250/85 MPPT while pulling 50W from the grid & all the additional power from the DC bus. Switching 50W should not have an impact on the size.


At first I thought it was also a battery thing, but after I found somebody with the same issue and solar, they experience the same with a very small load on the AC IN

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nickdb avatar image nickdb ♦♦ werner567 commented ·
Its not about the load. The brownout causes a surge that such a small battery can’t cater for. Always resolved with another battery. The DCL of that battery is way beneath what the inverter can pull. VRM cannot show the transient, the sample limit is too big.
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werner567 avatar image werner567 nickdb ♦♦ commented ·
Are 10kWh batteries also not enough for a 5kva inverter to handle this.



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nickdb avatar image nickdb ♦♦ werner567 commented ·

In theory it has double the DCL of one battery, but it all comes down to the BMS and all aren’t equal.

Other brands have had issues with smaller packs. These are LF inverters so the battery needs to not be overly sensitive. These issues only occur with marginally sized packs.

Assuming a properly installed and wired system. Always worth cross checking the install guide has been followed.

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