llyr-roberts avatar image
llyr-roberts asked

ESS issues when switching from Inverter/Charger to External Meter Grid Metering

Hi all,

I have a very simple ESS setup which works as expected under the internal grid meeting.

Multiplus II 5000VA with Cerbo GX + 2x Pylontech US3000C

Everything works well although in order to get the Critical Load function to operate with a grid failure, you must enable an External Meter. Fine:

In my case, I have the official Victron Current sensor 100A:50mA with the jack cut off and wired as per the manual. Please see here: (3.5mm jack was deemed unreliable hence a connector block on new models)

I've verified that the external current sensor is operating correctly because it provides sensible values on a known load. Plus same values as if it were working in the internal current sense.

Anyway, as soon as I switch my Multiplus Grid Meeting from Internal (Inverter/Charger) to External Meter.

Any form of charging and discharging from the Pylontechs fails to happen!

(Unit stays in grid passthrough mode)

Any suggestions on what could be my issue?

Many Thanks!

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rata1 avatar image rata1 commented ·

The external CT clamp connected to the MP is still "internal sensor" despite it being external.

Make sure you also tick the external meter in VEConfigure as well.

For grid failure it's just grid on ACin and loads on ACout. if yours is like this I would stick with the internal CT. In a parallel system I wouldn't.

If you set it to external meter it is looking for an ET meter or something and it isn't there.

Hope that helps.

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1 Answer
llyr-roberts avatar image
llyr-roberts answered ·

Could be an edge case bug as described here?

"Critical Loads" disappear with the setting "Internal sensor" because with this setup all loads have to be connected to AC OUT 1 and/or AC OUT 2.

There are no non-critical loads in this scenario.

At least this answers my first question.

I didn't know you could use the system without isolating AC-in and AC-out, all three AC outputs are common under this topology.

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