We are experiencing issues when using the external CT clamp on the Multiplus II 5000 inverters.
We have recently installed around 15 systems with the external CT clamp and on approximately 4 or 5 of them we are experiencing Error 24 occasionally when grid power returns after a grid power failure. We are not using the second output of the inverter. We are running ESS.
From the Victron website:
"Error 24 is raised when a Multi or Quattro detects current flowing through the back-feed relay during a period when the relay should be open."
The error seems to occur more often when there are inductive loads like swimming pool motors connected to the non essential loads between the CT clamp and inverter. It also seems to occur more frequently the larger the non essential load is. From numerous tests on these sites, when we unplug the CT clamp the issue no longer occurs.
We have confirmed that are no issues with neutrals etc. The issue seems to be related to the surge in current through the CT clamp when the grid power returns and all non essential loads start up. We have tried multiple Grid codes as well as disabling LOM detection but nothing seems to lower the systems sensitivity when grid power returns.
