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Trung avatar image
Trung asked

Multiplus different AC In and AC Out

Hi All

I wondered if anyone can give me some advice on how to resolve this matter...

Setup: MP2 5KVA, MPPT, 12KWh Lifepo4,CerboGX, not grid tied, Main AC In from grid to charge batteries.

Issue: I turned off the MP during a charging cycle since I did not need the batteries to be full (it was sunny the day after). Went to charge batteries again a few days later but, was not able to do it. Solar/MPPT is able to charge the batteries - no problems here. Inverter working as well - no probs.

As you can see from the photo blow - the AC In is at different voltage to the AC Out.

Tried: 1) Switching AC and main rocker switch and also breakers on/off - nothing. 2) Did a reset in Remote Console - nothing. 3) Selected "Weak AC In" in V Config

I have read that I may need to change the country grid in configuration in VE Config and have a range of AC In / Out so that the MP can latch on? VE Config needs a password - so I will be trying this next.

Any advice on the above issue/s will be much appreciated.

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Multiplus-II
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2 Answers
Alexandra avatar image
Alexandra answered ·

@TrungT

Its state is inverting, therefore it is not connected and synchronised to grid (even though it is present)

There can be several reasons, since it accepted grid before, you can leave the grid code. Check your inverter in the gx is not set to inverter only.

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Trung avatar image Trung commented ·

Hi Alexander

Many thanks for your prompt response - yes, that is the only things I can think of doing - other than that I am snookered or stuck. It was working great without any problems for 13-14 months.!!

I think you are correct and there is Loss of Mains (LOM) detection....

If I Disable it for the country that I am in, are there any precautions I need to take before or after doing so??

Many thanks


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Alexandra avatar image Alexandra ♦ Trung commented ·

No ESS assistant should be installed if you need grid code compliance. It is a local regulations issue more than anything else. So that really would need to be checked on your side. It is safe to say though if there is a built in grid code then you should use it.

And disabling LOM is a definite no for grid. It is dangerous for the people who work on electrical issues on the main lines.

You can go to type B if you feel that is the issue.

Why dont you use an AC ignore system instead to prioritize self consumption?

Check your incoming wiring, maybe something has worked loose / corroded or something over time? Neutral earth connections?

Often grid rejection can be an increase in resistance in wiring


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Trung avatar image
Trung answered ·

Hi Alexander

I am not using ESS assistant and have not tried AC Ignore System. I use a wifi switch/plug for greater flexibility.

I only have AC In and I am not grid tied on AC Out - that goes to a secondary ring in my house.

I shall have look at trying out Type B in the country grid code and see if the MP latches onto the AC Input. (I shall have a look for the UK).

In terms of disabling LOM - I thought this is an often done thing especially if you have a poor AC Input that can vary to AC Output such as generators.

I have checks the connection and feed into the MP - and, it is OK.

Ok...a bit of experimentation for me tomorrow then.

Many thanks again for your advice...

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