How to use MultiPlus-II 48V/15kW Inverter as Main Inverter with second Inverter

Q&A and troubleshooting
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Hello Team.
I believe this is first time writing here. So please be patient with me :slight_smile:

My existing setup.

Victron over shunt is checking amount of Power put into system , charging, discharging, Solar, Generator, Grid and all that. All is wroking fine.

I’m using two 11kW Inverters connected parallel for total power 22kW. But because those inverters are not with transformers and because they are designed with different approach in mind (at least for my needs) i want to change it to :

Planned Setup :

  1. Charging - Solar , monitoring and all that will stay same as I have
  2. I want to use MultiPlus II 48V/15kW as Main Inverter.
  3. Another Inverter (MPP Solar 48V/11kW) will be used , second one will be used for charging from High Voltage Solar Array

So far All is easy not a problem Now I need to solve one issue

  1. Situation 1 → Multiplus 15Wk → using All power lets say 15kW for suppling Loads 14kW(±)… No problem All is working - OK
  2. Situation 2 → Multiplus 15kW →
    • Load increased to 18kW for lets say 5 minutes. Now Multiplus can’t provide so much power so It will Activate Aux-relay (Over Power 14kW for example situation → Activate ) /Generator Function/Relay will activate High Power Relay (Lets say 100Amp Relay on AC IN)
    • Now Another Inverter will connect to AC1(Input 1 on Multi 48/15kW) → This will activate Power Assist Function It will switch AC 1 to Limit i set for setting Lets say (45Amp - about 10kW Power)
    • Now Power demand for Load after 5 minutes will lower to 9kW and This will disconnect AUX Relay (it will disconnect additional Relay) and my smaller Inverter will disconnect.

Now My worry is. Will it work like this ?

or

Setting Generator Input for AUX Relay is not needed
and Power Assist feature works as I would hope it would work by using AC In only when power is demanded for higher Load than 15kW ?

From Multi Inverter I’m not using Charging Function so no worry about that.

I’m worried about switching relay on and Off from One Power Supply to Another one.
So main Load will switch OFF and On for I don’t know 10ms from one source to another one.
Is this really happening ?

I have sensitive Electronics where i don’t want it to be switched and also Voltage must stay same what ever it is… 220-240V Is fine but it must not be switched on/off even for small amount of time.

Grid I have 3 Phase 230V and I’m using it just to charger batteries when needed (in Low SOC and low Voltage) so Grid is not used in my case …only during winter Once per 3-4 days

I might try explain more if needed. Personally I tested only Generator function in Assistance option and that is working fine for my different much smaller Multiplus II 48V - 3000W Inverter (used for different laboratory equipment)
Any help here ? Thanks.