Today we released a firmware update for the Multi RS that adds the option to configure three phase systems. (!). A major next step towards making the RS a full featured Victron inverter/charger.

Note that paralleling multiple units on one phase is not possible. Hence, maximum system size with Multi RS-es is 3 x 6000VA units.

All three phases must be powered before the system connects to the AC-input.

New settings:

• System configuration: Use "standalone" for a system with one RS. The "Single phase" setting is only allowed for multiple Inverter RS-es on a single phase. Use "Three phase" when configuring a three phase system.
• Phase select: select the phase, L1, L2 or L3.

Besides above common settings, there are four more that relate to redundancy. Both parallel redundancy, for the Inverter RS, as well as redundancy for three phase systems in which there is no three phase load.

• Prevent CAN network islanding: in case for example three Multi RSes are configured in three phase, each individual unit will only continue to work in case it sees at least one other unit. For the Multi RS, this feature is only relevant in combination with the "Continue with missing phase" feature
• Number of inverters in the system: set this to three for a three phase Multi RS system.
• Minimum number of inverters to start: set this to 1 for a three phase Multi RS system. It relates to multiple units on a single phase, which is only relevant for Inverter RS systems.
• Continue with missing phase: defines what to do in case one of the three units has failed. When continue with missing phase is enabled, the system will keep delivering power to the other two phases. Careful: use this in systems that only have single phase loads. Using this feature in systems containing three phase loads might result in those loads, for example an electric motor, being damaged.

Note that the "Accept phase rotation"-option, as recently added to our VE.Bus inverter/chargers, is not yet available for the RS. Its a niche feature that is planned for later. More details on that feature here.

Nice to know: firmware update without loss of power

Just like a single phase unit, also a three phase system can be firmware updated without losing power on the AC output. Make sure that there is stable AC input available when starting the update, since in such case the unit currently being updated will switch to AC-passthru mode.

Known issues

• The 'UPS function' is too sensitive in 3 phase operation compared to stand-alone operation. Disable the 'UPS function' in case the Multi disconnects frequently from the AC input.
• Charge currents are not yet balanced across the 3-phases when the charger is in voltage-controlled mode.

Files and full change log 

Firmware files and detailed change log are available here on Victron Professional.

How to install

Updating the RS can be done using either VictronConnect or directly from the VRM Portal website.

A new version of the VictronConnect App, adding this new v1.13 firmware version, will be released in a few weeks. Until then, the manual firmware update method or remote update via VRM can be used.

For further details, see product manuals.

Summary of RS feature set:

• Inverter RS: a maximum of 12 units can be used, in parallel, three phase or a combination of both. For example builing a three phase system with 4 units per phase is possible. Also, this feature includes parallel redundancy. Further details on that in this v1.12 announcement.
• Multi RS: a maximum of 3 units can be used, in three phase operation. Parallel is not possible.
• Using a generator as mains works, since mid last year, v1.11. Both in single and three phase set-ups.

Next up: ESS & Energy Meter support

ESS, and supporting external energy meters are the next focus areas for (Multi) RS development. Extending to Multi RS system size to beyond 3 units comes after that.