question

These are my ESS settings, and it works fine for me , but some more information like battery size inverter model firmware version PV system

all this will help as you have not given enough info

However a very ruff guess

If your voltage is dropping that low on a 48 volt system then there is something wrong with the capacity setting in the Inverter, so in the VE configure software using the Mk3 VE bus unit, has the battery capacities been set correctly. or the battery bank is two small for the inverter

My ess settings are

Optimized with battery life

Some more details. battery bank is 440 ah 48v Victron AGM. i have 24 x 355 watt panels in 2 strings of 12 (groups of 3). Loads are not high only drawing max 2000 watt atm but we will be adding more loads. regulators are MPPT 150/100 . Idea of install is to save power and run most of the house off PV in the day and at night run of batteries as long as they will allow. Invertors are 2 x 5kva multipluss in parralel. The fault appears at around the same time each night, system is already running on gridd and battery voltages are stable around 49 to 50. its around 1 30 am that i get the fault. i have to switch invertors both off and on and system goes on again. last night my client was away so no major loads and it happened again.

have you got AES turned on or off.

if on turn it off and see if that stops it

Ideally we need to be able to duplicate the issue at call, otherwise its a guessing game.

further info needed

are you running any assistants

is the firmware uptodate ie 433 so what are the firmware version, some screen shots please

are all the battery cables to to each inverter, EXACTLY SAME LENGTH,

have you got a CCGX or venus GX connected to the system and is it connected to the vrm so that you can see all the parameters that are happening at that point.

the error 17 means it cant see the master. so are the network cables of good quality.

Whats happening at that exact time like loads

what are the grid selection codes that you used for grid type. maybe change them to test if this stops it (just for testing dont leave them on the incorrect standard)

Only assistant i am running is ESS.

i checked on Wednesday for all the latest firmware on all the devices i will have to check again on site.

cables are the same yes i always make sure of that.

i am on the vrm but connection keeps dropping i need to put a repeater in for the client and will do that on monday.

i will redo the network cables on monday with cat 6 shielded.

I do need feed back into the grid is its not allowed in south africa, i have a gridd meter on to monitor this and a anti islanding device.

I used UK codes as there is non for South Africa, i was advised by my re seller that this is a good option.

I cannot see anything on the logs that indicate why this can happen. i can share VRM portal as long as you dont make any changes withoput letting me know.

MAKE sure you have AES turned OFF as this also could be a possible issue

Thanks so much Paul you really a good source of info. just a question how can i make the invertor switch over to AC before it reaches the cutoff voltage ?

yes after looking at your VRM record , I would suspect the master is shutting down from LOW voltage 100% for sure. and then a error 17 is coming in and reporting the master is lost.

In the ESS there are also shut down voltages and these will need to be adjusted to suit your batteries, to a lower figure and that will solve your issue