ondra avatar image
ondra asked

DC loads/DC system in ESS


I have a 3-phase system 3x5kVA MPII, 1xMPPT, 2xFronius Symo, BMZ lion battery 48V with BMS, everything is controlled by Cerbo + ESS assistant. Everything has current FW, AC Coupled feed in excess - ON, DC Coupled feed in excess - OFF. Now I canceled home UPS APC (for home server, CCTV...) installed Phoenix inverter and SmartShunt. I turned it on in Settings - System - Has DC system ON. I set the SmartShunt as DC Loads. Unfortunately, I have two problems.

The first problem - the DC loads field does not appear on the display. It only appears immediately after a restart, or on the display that I'm not using.

Normal view ( No icon DC Power displayed ):


Display after restart Cerbo: (as soon as ESS assistant starts, the DC loads field disappears)


Another screen I don't use, here is the DC loas to see:


Would it be possible to modify the FW to show the DC load on the "primary" screen like here?


The second problem - if the battery is charged, CCL 0A. When I turn on the DC load, the battery discharges and micro-cycles (100% -> 97% -> 100%...). Unfortunately, the MPPT does not supply any power (to balance the draw from the battery), the Symo supplies power to the grid. Is this normal behavior? Shouldn't the MMPT regulator supply the same power as the Phoenix draws so that the battery is not constantly being discharged and charged? It can be seen in the pictures above.

Thank you for the responses, or for the advice.


dc system
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ronski avatar image ronski commented ·

I also have the same problem, DC loads was displayed, after I added the ESS assistant it disappeared.

Actually this could be the cause they also have ESS enabled.

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nuxland avatar image nuxland ronski commented ·
In ESS menu if you use "Grid Metering" - External meter then DC Load is not show'n.

If you change it to Inverter/Charger then it is shown.

But you can change it to Inverter/Charger only when you do not have any load between External Meter and Inverter input. But if you have then there is no way to see DC Load on main screen and VRM.
I found one more thing that my PV Inverter (using separate external meter for that) does show power per phases when using External meter but does not show it when using Inverter/Charger in VRM :(

PS! I have all my house load behind AC OUT 1

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ronski avatar image ronski nuxland commented ·

No idea why, but "Grid Metering" was set to external meter, pretty sure I didn't set it as I don't have an external grid meter, like you my whole house load will be on AC OUT 1. I do have an ET112, but its measuring the power from an AC connected inverter also on AC OUT 1. As a bonus critical loads has gone, which I'm not using.

Thanks for the reply/answer.

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1 Answer
janr-1 avatar image
janr-1 answered ·


Did you find a solution in the mean time?

I have exactly the same problem with "DC-loads" (an external charger in my case). DC-Loads are visible directly after booting the GX, but they disappear once ESS has started.

My GX (MultiPlus 2 3000 GX) has firmware 2.89.



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