victron energy MultiPlus II 48/3000/35-32 230V Inverter or Charger Installation Guide
- June 12, 2024
- victron energy
Table of Contents
MultiPlus II 48/3000/35-32 230V Inverter or
Charger
Installation Guide
MultiPlus II 48/3000/35-32 230V Inverter or Charger
My new installed base is in
a heat isolated shed with relatively constant temperature and good
ventilation. Winter doesn’t seem to be an issue, the temperature has never
dropped under 8°C in the last years.
What I am concerned about is the summers with nowadays usual 35+ °C. Time to
time my inverters might run at their max specification power which creates
significant heat and heated up already the shed to ~25°C while the outside
temperature was about 18°C. I am installing a ventilation system with temp
sensor in order to tackle with the heat issue.
In addition, I played a bit with the ESS settings on the GX and my conclusions
are as follows.
When there is no “Maximum inverter power” set in the GX, then the inverter
will provide the power what is requested on the Critical load output and
eventually, it limits itself to its maximum power (I hope) depending on the
ambient temperature and the load and compensate from the grid the additionally
required power.
However, I have seen the following situation in my 3-phase installed base. I
ran 3300W on L3 for about 10min and the inverter didn’t throw any
alarm/warning signal stating, that I am overloading the MP2 on that particular
phase. In order to avoid any damage, I switched off the extra load.
Then I conducted the tests below playing with the “Limit inverter power” and
“Maximum inverter power” in GX under ESS.
The conclusion is that the “Maximum inverter power” corresponds to the power
of the combined power of the 3 inverters (MP2) in my 3-phase systems and not
the individual inverters. This should be ok in case of parallel systems, but
in 3-phase system the “Maximum inverter power” should correspond to the power
of the individual phases, instead of the aggregate of them. Or at least it
should have the option to select such operational mode.
This way one would be able to set a limit on the inverters serving a
particular phase instead of the whole installation. The GX actually handles
(to a certain degree) a 3-phase MP2 system as a single unit.
In my particular case, if I want to make sure during the hot summer days the
inverters are not fried, then I switch on the “Limit inverter power” with a
certain max inverter power.
Let’s say I take into consideration the Multi’s datasheet:
Continuous output power at 40°C (per Multi): 2200W
and set this value for the “Maximum inverter power”. This will serve me well
in terms of not generating too much heat, but I am wasting lots of solar power
-assuming the solar generates more than required- because the MP2s will limit
the output power at 2200W aggregate power with a possible scenario of
L1=L2=L3=733W from the inverter. (It will limit the power to the grid too
because it is also inverter power)
Then I could set the max power to 3x 2200 = 6600W (concerning the 3-phases).
If I do this, I could come to the scenario: L1=5000W load, L2=L3=1000W (7000W
aggregate), which would result in the inverter on L1 will run at its max
(whatever the factory set its limit to) power and overheating. The rest of the
power on this particular phase is compensated from the grid of course. The
other inverters are happily dealing with their own 1000W each.
However, if I was able to decide what the “Maximum inverter power” corresponds
to, whether per system or per phase, then I could chose for example per phase
and I would limit each of my inverter’s output power to 2200W in the hot
summer days in order to avoid overheating, yet using the inverters more
efficiently.
There should be a knob in GX to switch between these modes, something like
this (see below). 
I don’t
think that his is too big of a challenge, so this should be put on the list of
new features.
See my experiments below.
Test Case1:
Limit inverter power 1: YES
Maximum inverter power 1: 1000W
Battery is charged over “Active SOC limit”: YES
Active SOC limit: 55%
SOC: 89%
Fans stopped spinning -> MP2 passing through the Grid portion, it is not
converted in any way, therefore, no loss occurs on the Grid portion.
1 : corresponds to full inverter power, in case of multi-phase systems the
combined power of all phases
Critical loads:
Critical loads = Grid + Discharging -> 3200W = 2200W + 1000W
Battery:
Charging = PV Charger – Discharging – Charging & Calculation Losses 732W =
1818W – 1000W – 86W
Inverter (MultiPlus 2):
Discharging = Maximum inverter power
1000W = 1000W
Test
Case2:
Limit inverter power 1: YES
Maximum inverter power 1: 2400W
Battery is charged over “Active SOC limit”: YES
Active SOC limit: 55%
SOC: 86%
Fans started spinning -> MP2 inverts all the required power, because it is
below the maximum inverter power. There is no Grid portion, all power comes
from the PV Charger and Battery combined
1 : corresponds to full inverter power, in case of multi-phase systems the
combined power of all phases
Critical loads:
Critical loads = Grid + Discharging
3500W = 1100W + 2400W
Battery:
Charging = PV Charger – Discharging – Charging & Calculation Losses
-1360W = 1180W – 2400W – 140W
Inverter (MultiPlus 2):
Discharging = Maximum inverter power
2400W = 2400W
Juniper Business Use Only
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>