Hi, I have two problems I need help with please:
Equipment:
2 X Multiplus 48/5000/70-48 units in parallel
4 X Revov 1st Gen B100 1C batteries
1 X Victron Cerbo GX
1 X Victron BlueSolar Charger MPPT 150/100
9 X Jinko 550W panels
Problems:
1: When Escom is not available the system maxes out at about 3400W. Overload protection kicks in and system shuts down. As if only one Multi capacity is available.
2: MPPT not supplying power to the critical or non-critical loads when Escom is available.
Example:
If Escom is on, Escom supplies the bulk of the critical and non-critical consumption. The solar production is severely limited. Production from the solar is less than 400w if the batteries are full.
If I disconnect Escom the solar production increases and supplies the 3000W needed for the critical side.
I have no experience with MultiP’s in parallel, but theoretically your panels (even if optimally angled) have roughly 5000W Pv, but in real live (my system at least) you could deduct 1-1,5 Kw from that due to losses etc.
So your production seems on par.
Mppt’s are only there to charge the batteries so what your system can produce is not limited by them.
Is this not some of the new software upgrades/functionality we now have that is not set correctly? There’s quite a few new features which I don’t understand fully yet. Peak shaving power being one of them I seem to recall.
Agreed, but their basic function is to keep batteries happy and if full, to supply the loads.
Point I am trying to make is that if batts are full the MPPT can still deliver a 100 DC amps in theory for conversion to AC and use by the inverter. With the system the OP has, an MPPT is not really going to be the limiting factor here.
MPPT should supply all it can if the loads are high enough, and then the system will be limited by what the inverter can produce, which in turn is dependent on what the BMS will allow in terms of battery discharge.
When Dion gives me access, I will have a quick look.
For I agree, it is software settings and/or firmware related. I can make a quick check for the obvious.
If not, then Dion will need more help for I don’t do parallel systems. Victron is very clear about that. One needs in-depth knowledge. Hope it gets solved with the quick check.
Not theory, fact.
I do that every day. SOC is 100%, set to Keep Charged actually.
At the time the panels produce the max the MP needs to heat geysers. At times >4kw.
Little to nothing goes to the batteries.
Caveat:
Also the spot with Lifepo4 that when a big load goes off, where must the power (±4kw) go for those few seconds on a charged Lifepo4 bank before MPPT’s throttle back?
Also why I stop at 3.45v max charge.
BMS has so “headroom”.
Are you sure it is overload protection, or is that a guess? You’ve ruled out the possibility that the batteries may drop out on voltage if worked hard? Is the shutdown immediate, or does it take some seconds/minutes?
Even a single 5kVA unit should not max out at 3400W, it should be able to push a constant 4kW.
Are you using ESS? Is the ESS mode set to Keep batteries charged or something else? Is the battery full at this point? Do you have DVCC enabled? Very important to check all that.
The MPPTs do their own thing, they aim only for the voltage they have been told by the battery (via the GX). If the battery voltage reaches the target, the MPPT will stop charging. The system should create a small difference in the voltage target to prioritise solar energy, and it is possible something is going wrong there, but first it is important to make sure all these other things are set up correctly.
Also, as a diagnostic step, what happens if you enable the option to feed excess DC-coupled PV into the grid (in this situation where PV seems limited), does the solar chargers ramp up and the energy is fed into the grid, or not?
1: Are you sure it is overload protection, or is that a guess?
That is the message in the alarm logs.
2: Is the shutdown immediate
More or less immediate.
3: Are you using ESS? Is the ESS mode set to Keep batteries charged or something else?
Yes, Optimized (without BatteryLife)
4: Is the battery full at this point?
Full
5: Do you have DVCC enabled?
Yes
6: what happens if you enable the option to feed excess DC-coupled PV into the grid
I am to scared to enable this. I do not want to feed back into the grid.
You need to check that your parallel wiring is properly connected to both inverters, and of a similar length/resistance. Although in this case it is like at least one of those wires are completely disconnected…
