ESS and PowerAssist

Q&A and troubleshooting
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1

Hi

I have my MP2 + Cerbo configured in ESS mode; all works great.

For future, I would also like to use PowerAssist to ensure that I will not blow the main fuse under heavy loads.

However, I am not able to find how to get this to work. Documentation states that PowerAssist setting will be ignored when ESS is enabled.

Is there a way around it (with diy software?).

Principally, there is not a reason why it cannot work…IMO…it does require more complicated control loops though.

If you have this combi (ESS & PowerAssist) working, I appreciate a ping :slight_smile:

Thanks Hans

2

With ESS you set the Max Amps allowed for import en export in the console under ESS / Peakshaving , this mostly corresponding the main fuses specs.

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The mp’s will provide the rest if you draw more than specified at max amps import with an max system power you set at the maximum inverter power under ESS.

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Ps. Beware that I set 32Amps for import but at the incoming grid junction it’s just 30Amps effectively.
Therefore I did set it a little bit higher.

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2 Likes
3

Are you not afraid to blow the main incoming grid fuse that way? Or is main fuse higher than 33A

In NL you have to set mp2 max input current lower than grid current to now blow the incoming grid fuse (only grid company can change that if it blows, with additional costs)

4

Main fuses are accessible C25A MCB units. More than 10 hours import or export with 21kW does not have much impact.

Only DC combined grid 21kW + PV approx. 20kW will let the DC system get a bit more warm than usual, but around 780amps that’s ok. This is only sometimes the case under ideal sunny circumstances.

Periodic IR camera checks don’t show any heating concerns.

5

Ah okay!