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rtj asked

MultiPlus-II exceeds AC-in Current Limit setting during Scheduled Charge

I have a MultiPlus-II 48/5000/70-50 connected in-line to the grid, as well as a battery and PV system using a SmartSolar MPPT VE.can 150/100 rev2. Everything is connected to a Cerbo-GX, ESS is installed, DVCC is active.

Due to the contractual power limit from my energy provider, I have a 25A magnetic circuit breaker installed upstream of the MultiPlus. I have also set the MultiPlus AC-in Current Limit to 23.5A (a bit lower than the breaker, just in case), to avoid tripping the breaker in case of a load spike.

Here's the problem: I've tried activating ESS Scheduled Charge to top-up the battery at night (when it is cheaper) but every time Scheduled Charge kicks in the 25A breaker trips. If I turn Scheduled Charge off, everything goes back to normal (once I flip the breaker).

So my question is, does the AC-in Current Limit setting actually limit ALL of the AC current input to the MultiPlus, or does it only work for the "pass-through" AC? Would the "charger" part of the MultiPlus ignore this current limit and draw the full 70A from AC that it is capable of?

Otherwise, I can't figure out why the breaker trips when Scheduled Charge kicks in.

Any ideas?

Multiplus-IIESScurrent limit
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2 Answers
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rtj answered ·

I lowered the DC charge current limit as a temporary solution and it worked, but it also limited the power coming from the mppt charger, which means this isn’t the most efficient solution as a bunch of solar energy is wasted. After some investigating, it turns out there was an issue with the way the grid installation was originally set up (a few years back), the problem wasn’t the Multiplus. Rewiring the connection to the grid seems to have fixed my problem.

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tnt369 answered ·

I have similar problem at my Quattro. I make a workaround with reducing the charging current (DC) to a low value (approx. 15A). This avoid the breaker from tripping. Charging needs longer but it have 8 hours in the night, that is enough to recharge the batterys.

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