In case the inverter is used to charge the batteries and the grid setup is "feeding energy from DC to grid not allowed", does the AC input acts like a load (from the point of wiew of the grid)? Is it right? Are there any risks to have some unwanted feedback on the grid? Or Is it necessary to add some kind of anti-islanding relay before the AC input? Thanks
For germany you need a Multiplus with VDE-AR-N 4105 certification.
Show here: https://www.victronenergy.de/upload/documents/Certificate-ESS-Germany-VDE-AR-N-4105-2018-11-MultiPlus-II-48V-3kVA-(GX)-48V-5kVA-(GX)-24V-3kVA-(GX)-NA-Schutz.pdf
You must check if your device is certified.
My Quattro-II ist not certified yet and need to put a anti-islanding-box in front.
This is mandatory in german as soon you connect your Multi to the grid per ACin1 doesnt matter if you have ESS installed or not.
ACIN will not be active until you enable charging when the inverter will be turned off and ACIN activated. Since the inverter is turned off, there will be no risk of feeding in while the batteries are charged. Below is inverter only and charging only.
I'm using this setup: https://community.victronenergy.com/storage/attachments/3299-virtual-switch-ignore-ac-lesson.pdf. During the winter, the charger of the inverter will works to feed the batteries until it reaches the desired voltage. In the same time it feeds the AC Out from the AC In. So I guess there isn't current from the DC side to AC In, as declared into the grid setup, also if there are some solar chargers at work on the DC bus. If it's right, I can't understand why I must put a Ziehl anti-islanding relay SPI1021 (€700) between the grid and the AC In.
In germany (i dont know how this is in other countries) it doesnt matter the configuration of your installation. As soon as you connect your Multi to the grid you have to provide a certification VDE-AR-N 4105 or put a expensive anti.islanding-box in forward.
Its not a question of configuration its a law for safety purposes.
Certified products have built in two relays for redundancy purposes like the Ziehl relay.
Its part of the ground relay.
In case of grid failure this relay has to cut off your installation from the grid to avoid feedback.
This does not matter what you have configured, its a safety feature which is mandatory in germany.
My 3 Quattro-II have built in these two relays but there is no certifidation yet. Thats because i had to put a anti-islanding-box in front (1000 EUR).
Without this certification i cant regsiter my installation.
