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robinschrooten avatar image
robinschrooten asked

3-f multiplus-II huge grid feed-in.

Hi,

I have a system, containing 3 multiplus-II (48/5000/70-50) systems, configured as 3 phase. It is attached to 4x pylontech US5000.

I used VEconfigure3 to configure ESS, as explained in the following link
https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom#veconfigure_settings

For grid metering, I am using the transformer ct-clamps, placed on the beginning of the installation and directly connected to the multiplus. The arrows on the clamp are pointing away from the grid.

There are also grid-tied PV panels connected to the AC-in side of the vicgtrons (not configured on victron as it should not be required))

When I activate the system, it starts discharge the batteries at +8000W... basically to the grid. I don't have anything in my home active that can use that amount of power. I am also seeing odd values in the VRM from time to time...

When I look at my digital grid meter readings, I see that all that power is just fed into the grid... When powering off the victron's, ess-grid-feed-in1.jpg

ess-grid-feed-in2.jpg


VEconfigure settings:
config-general.jpg

config-inverter.jpg

config-charger.jpg

config-virtualswitch.jpg

config-assistant.jpg


In addition, when the battery voltage gets low, it start charging again from the net, and once the charge is high enough again, it's starts re-injecting it again in the net.

ess settingsess dischargingfeed-in
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3 Answers
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robinschrooten answered ·

There is also a CerboGX device installed... firmware version is 3.10

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robinschrooten answered ·

I have set the multiplus nox to charge-only, so that I don't get excessive feed-in during troubleshooting
The grid metering on the cerbo/multiplus, is showing about 10w feed from teh grid, while when I look on my meter, I have about 2000W feed-in on the grid on each phase... something is really wrong with the current measurement here...
chargingonly.jpg


chargingonly.jpg (21.2 KiB)
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robinschrooten answered ·

Fixed it... issue occured due to the external CT clamp beeing connected in the wrong way. I have the new version (not the audio plug type, but the ones with the 2 connectors). The documentation on how to cponnect these was not very clear... turns out, the red wire should be in the middle (that was correct), and the white one should NOT be on the front of the 3-point connector on the inverter, but on the back...

Some sort of identification on the inverter would have been welcome here...

mp2-ct.jpg

img-20240131-091554.jpg


mp2-ct.jpg (66.4 KiB)
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