I am designing a 3-phase system with 3 phoenix inverters, with separate batteries for each phase.
I suspect that this might cause a problem with the CAT-5 data cables between the units.
Is this data link galvanically isolated? Is it differential with sufficient common mode rejections? Or would it be necessary to common the battery negatives for it to work?
Hi @IanB
Yes this is a big problem, do -not- do this, please read the manual and get an experienced installer involved:
https://www.victronenergy.com/live/ve.bus:manual_parallel_and_three_phase_systems
Thank you @Daniël Boekel (Victron Energy Staff)
I presume, therefore, that it is only necessary for the battery negatives to be commoned. In this application, to common the positives as well would exceed the legal maximum number of battery strings in parallel.
Please -read- the manual, it's in there:
The VE.Bus cluster maintains a single 'global' status for SoC, DC voltage, and DC current. Every DC connection (on every Multi/Quattro and on every battery) has to be connected together to a single DC bus. Do not build systems with separated batteries on multiple (separated) DC bus structures connected to subsets of the Multi/Quattro units in the cluster. This will not work.
The manuals you supplied with the latest batch have sections called "4.2 Connection of the battery cables" and "4.3 Connection of the AC cabling", but no section called "DC and AC wiring" and no mention of the "VE. bus cluster".
On seeing a UTP cable with a RJ45 connector, one would normally expect an ethernet connection which is, of course, transformer isolated.
The manuals you supplied with the latest batch have sections called "4.2 Connection of the battery cables" and "4.3 Connection of the AC cabling", but no section called "DC and AC wiring" and no mention of the "VE. bus cluster".
On seeing a UTP cable with a RJ45 connector, one would normally expect an ethernet connection which is, of course, transformer isolated.
Did you read the link he provided when he stated that? https://www.victronenergy.com/live/ve.bus:manual_parallel_and_three_phase_systems
