question

max78 avatar image

3 phase ess with backup generator (4th Multiplus 2)

Hi,



I like to build a 3 phase system with 3 Multiplus 2 an Pylontech batteries

My idea for the generator is:

* use a 4th Multiplus 2 with the 1 phase generator for charging. Does this work? Do I have more power on this phase?

* or can I use a cheap charger without CAN to charge the Pylontech with the generator?



And I have another question:

* is there a cheap way for more amps for the transfer switch (anti islanding)?

Thanks, Markus

Multiplus-IIGeneratorPylontech3 phase
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Regarding single phase genset input you can use separate Multiplus or separate charger ,its depends on your application and battery charging current.Go with cheap solution but you cant monitor 4th inverter on VRM.

2 Answers
Rob Fijn avatar image
Rob Fijn answered ·

Hello Max78, The BMS of the Pylontech battery needs to communicate with the charger. A forth MulitPlus-II should work, must be connected to the BMS-CAN

regards, Rob

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For pylon tech only for charging CV AND CC mode of charging would be fine which will done by multiplus II, no need of BMS connected with inverter through GX device.


max78 avatar image
max78 answered ·

Thanks a lot for the quick answers.


Do you mean I need no Bus connection for charging with the generator (maybe a cheap and easy charger)?


Can I use the 4. Multiplus 2 only for charging or is there more output power on L1 (in the 3 phase ESS Config) when there is no grid?

Do I have to config 2 groups? And connect the output together?

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Better to use 4th multiplusII ONLY for charging because 4th multplus will not combine with 3 inverters .4th inverter needs to be connected separately with battery and charge the battery with genset.

rest 3 inverters configure as 3 phase and used there a load on 3 phases.

if you use 4th inverter output then your battery discharge current will be unbalanced which leads problem in 3 phase system.