The AS4777 MultiPlus-II series units may fail / stop (Error #11 reported on the CCGX) when AC power is connected and just after the AS4777 grid relay test is conducted.
The relay test concerned happens only (a) after the grid is connected and (b) when the battery system has sufficient charge.
This is because the test, when running, has to unplug the grid connection for a few minutes, and hence the site has to be able to run for that test period entirely on battery power.
There are multiple reasons for this error and for this ('error 11') failure mode to occur.
These are documented in detail here:
You need to work through all of the steps noted in the link above, if you get an 'Error 11' on your site.
There is, however, a specific and subtle issue that is unusual compared to 'typical' battery inverters installed on-grid in Australia, and that applies to AS4777 compliant on-grid connections in Australia.
The MultiPlus-II series, by default, requires that there is no hardwired neutral path between the input and output sides of the unit.
The MultiPlus-II checks for this situation specifically and will stop with Error 11 if it detects such a hardwired neutral is present. Many other Australian battery inverters either expect such a neutral path to exist or at least allow for it to exist.
By default, then, the MultiPlus-II firmware expects the following to be the case:
- That there is no neutral link connecting the input and output sides of the MultiGrid/MultiPlus-II
- That that any 'system bypass' switch installed externally to the Victron system (not, at face value, a bad idea in case of Victron hardware faults) is a double pole switch, so that the neutrals are not connected ‘across’ the MultiPlus as a side effect of the presence of the bypass switch.
There are some Australian situations where local wiring rules and/or physical logistics for the installation (e.g. multiple separate buildings in a campus) that make this very hard - or even impossible - to achieve. In addition, some installations can be prone to potential false-triggering of earth-leakage breakers in the 'not joined neutral' configuration, when the system moves between on-grid and off-grid operating modes.
When this issue was first apparent, Victron Energy provided Redflow with an interim 'workaround' firmware build for the MultiPlus-II hardware series, that would allow for a hard-wired neutral path between the AC-In and AC-Out sides of the MultiPlus-II units.
Victron have subsequently released updated firmware for the MultiPlus-II units which allows for a 'hardwired neutral' site installation if desired, without loading 'special' firmware to do it.
With MultiPlus-II Firmware version 466 or later, there are now two versions of the AS4777 grid code entry available to choose from via VE.Configure, as below:
If your installation requires (or simply 'works better') with a hard-wired neutral path between input and output sides of the MultiPlus-II series, then you should upgrade to firmware 466 (or later) and select the 'AC Neutral Path externally joined' version of the AS4777 grid code from the grid code list above in VE.Configure.
There is also one Redflow-specific BMS setting to keep in mind for AS4777 installations, on the "CANBus" BMS page. This is a setting called "Discharge-Disabled SoC Threshold". It is, by default, set at 10% SoC. This defines the minimum SoC at which to conduct the relay test. Do not reduce or completely disable this setting when on an AS4777 grid-connected site, or it is very likely that you will lose site power during grid relay testing.
Note: There are other reasons for Error 11 as well - your 'error 11' may also be because of one of those other reasons noted at the Victron link above - so it is a good idea to work through that entire diagnostic step set provided on the Victron site, if the advice above does not resolve your issue.
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