I have two identical systems
3 x Multi RS + 2 x MPPT RS
actual firmware update
Interesting situation: both of 2 systems turn off 2 x MPPT RS in sunny weather conditions… but still working good and nice in cloudy conditions)
Looks like additional overcurrent protection insurance came in latest update.
Thanks to all,
Andrija
Turn off SCS (current sensor sensor sharing) was solve problem just for 3 minutes after GX rebooting, but after 3 minutes still off 2 x MPPT RS
Maximum charge current set to 170A, but it’s around 120A (which is maximum sun power from 3 x Multi RS)
Thx
What kind of batteries/BMS do you use? Activating all the DVCC options seems odd to me, thats not ususally the case for managed batteries, but still could be for some
I don’t use communication with battery BMS option at all. In my case it’s impossible (
Instead of this, I use Victron BMW monitor to operate correctly with battery, an it works a few years very well !!
As I wrote, it looks like system very insured by itself from battery overcurrent, and it came with 2 or 3 latest firmware updates.
It’s not a big deal, because undercurrent still useful, and can utilize up to 85% of sun power, it’s ok for running systems. Just information for others.
Thank you for your attention!
Update
When 3phase Multi RS system riches 9kW sun power (which is 50% of maximum 18kW for this model) it sends command to MPPT RS turn off solar generation
1 system:
2 system:
I believe it is here.
Thx, Andrija
@Andrija
Do you have them all on one can connection?
Off course all of them connected to the same VE.Can chain, and all of them has the same VE.Can system instance.
I tried to show this on screenshots.
Thanks
You don’t have a managed battery so the inverter charge algorithm is used.
Yet you have set a managed battery voltage limit in DVCC which does not apply to your use-case.
Showing charts of PV power won’t help much as you need to see what the battery voltage at the MPPT terminals is doing, this is usually a deciding factor in chargers throttling or stopping.
That wasn’t the question. Have you measured the voltage at each of the MPPT’s, inverters etc to confirm they all agree?
What battery monitor is set under the GX → settings → system settings → battery monitor? (be sure that auto mode isn’t selecting the wrong one).
There are 2 minutes between 1 screen shot and 2+3 screen shots and charging running, and we have + 0,01V
Voltage measurements is perfect in all of this devices, it’s always in ± 0.01 V
DVCC
This is a lithium battery right?
If so do you have a lithium charge profile loaded?
You have equalisation set which would normally be 0V on a lithium profile.
Li-NMC (Lithium Nickel Manganese Cobalt Oxide)
User defined battery profile
Equalization is disabled, but for some reason I setup voltages same with absorption, but equalization phase is off
Ah ok.
It will be user defined but the chemistry will be set for lithium. You would edit the values to be appropriate for your battery.
When 3phase Multi RS system riches 9kW sun power (which is 50% of maximum 18kW for this model) it sends command to MPPT RS turn off solar generation
2 x MPPT RS are slaves
3 x Multi RS system is master
I believe it is the thing
That’s why I think in this way:
earlier, 2 or 3 firmware updates before, first MPPT RS always was Group Master, second was Standalone, both of them can’t see sun power from Multi RS, and situation like this didn’t happen
Now, actual firmware, 2 x MPPT RS are slaves, it’s absolutely logical and reasonable, both of them now see sun power from Multi RS, which is great, and something in Master-Slave algorithm “tells” to MPPT RS slow down sun power after Multi RS rich 50% of maximum their Sun Power
or
~9-10 kW from network total power is maximum charge power for 2 x MPPT RS at this battery voltage, which can also “tells” them slow down Sun Power
It’s not a problem, just my opinion
I found the switch)
After a few days of experimenting:
Settings/System Setup/Charge control/DVCC/Limit charge current
If it off, 3Multi RS + 2MPPT RS working as expected.
But I need to limit charge current…
If I switch it on:
2 x MPPT RS immediately turning off sun power, and system trying to limit charge current only for 3 Multi RS. And it’s working good, but looks like other devices in this case are “out of game” for some reasons (
Thanks all in advance!
Play a little with the Max charge current of each Multi RS.
You have it set to 75A now.
And when you enable the Limit Charge Current, the implementation of DVCC will do 3 x 75 = 225A.
Which is greater than the 200A current limit imposed on DVCC’s Limit charge current.
So it will disable on some conditions MPPT RSes, because how it distribute current to chargers.
It goes on the assumption that the Multi RSes, with their 75A, will manage the total.
When it’s off, it will try to maximize all it can.
Try to set it to 50, which will be 3 x 50 = 150 and see if the MPPT RS will turn on for the rest of 200-150 = 50A
As a conclusion, for this to not happen, if you enable the Limit Charge Current, you need to set it with 5% greater than the total charging capacities of all chargers. For example, if all have it on all at 75A, then 75 x 5 = 375, so you must set it to about 395A.
This is also because it doesn’t take into account the DC (!!) current needed for the AC conversion/loads, in order to subtract it from the DC production.
Real magic happened)!
It’s working way better, now I can reach 170A of 200A total limit in combination of 48A charging current for each of 5 device, - of course I will play with it a couple of days (absorption faze happened)
Thanks Alex, have a nice day!
