I have recently setup a victron multiplus 48/8000, cerbo gx, 2 x victron mppt 450/200 with 8 pv strings. I also have 3 x 15.2Kw batteries connected to the gx.
The gx can see all my battery settings, all the other devices and their settings just fine. Each PV string is the correct polarity and has voltages ranging from 230 to 330V.
My issue is that the mppt units show 0v for each string and say ‘no pv power’. I must be missing a step to get the units to start but cant find it. The multiplus charges/discharges the battery without an issue.
yeh charger is enabled. I feel it could be something to do with the battery bms connected via the can bus. I have had no issues with other systems using a victron shunt as the battery monitor.
This means that open circuit voltage is there. Did you measure at the MC4 connectors that would plug into the MPPTs? Or at the disconnect?
This means that the MPPTs dont see any voltage on the PV side. The first thing that comes to mind is wrong polarity. If the MPPT is off due to a setting or BMS control, then it would still have voltage present on the PV inputs, and also show this voltage. If you have an amp clamp capable of measuring DC, measure if theres a current flowing roughly equal to the Isc of the panels
Hi Mike,
Yeh thanks, the voltages are all from 230 - 330 dc and the +ve is to the red cabled mc4. I also have a green led on the board of the chargers and all the relays are in the OK position.
Did you test the PV voltage on the RS side of the board? i.e. after the fuses? Yuo can also test for continuity and volt drop (first) across the fuses. If there’s voltage on the red and black wires going into the RS and it’s still not showing up on the display - 60v should show, but 150v to start the tracker, then you need to RMA the unit. I used the 380v dc from a small inverter to test one that a client was querying.