Bluesolar MPPT 150/35 - unexpected Error 33

DIY
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1

Hi all,

I’m getting Error 33 (PV overvoltage) on a Victron Bluesolar MPPT 150/35 and I’m trying to understand why.

System details:

MPPT: Victron SmartSolar 150/35
Battery: 24V LiFePO4

PV array on this MPPT:
3 panels in series (3S)

Panel specs (per module):
Pmax: 200 W
Vmp: 36.2 V
Imp: 5.53 A
Voc: 40.5 V
Isc: 6.34 A
Temp coeff Voc: -0.36 %/°C

String specs (3S):
Pmax: 600 W
Vmp: 108.6 V
Voc: 121.5 V

Issue:
I’m getting Error 33 around midday at ca. 10°C ambient temperature.

Based on the specs, I would expect Voc to be around ~128V at that temperature, which is well below the 150V limit.

Additional system:
I have a second MPPT 150/35 with a separate array (4x 50W panels in 2S2P). Both MPPTs are connected to the same battery and to the Cerbo GX but PV inputs are not intentionally connected.

Questions:

  • Could I realistically hit >150V with this setup at ~10°C?
  • What could cause PV overvoltage in this situation?
  • Any known issues with wiring, connectors, or MPPT interaction that could explain this?

Thanks in advance!

2

Temperature and cloud edge effect could pop it up and over

Have a look at your vmax though in mppt history
Or vrm advanced

3

According to the calculator, panels would max out at 137V at -10C
The 150/35 is what it recommends.
Maybe the panel specs aren’t correct?