Problem: Inverter not detecting PV input.

[Spikeuk]

Off grid setup not detecting any PV input... any help suggestions would be greatly welcomed, I am but a noob,...

I have finally finished assembling my 48v Lifepo4 16s battery and hooked it up to inverter.

Heres my setup:

Inverter : I have the following inverter off grid 5kw https://voltaconsolar.com/off-grid/conversol-v7-off-grid-inverter.html (rebranded Voltronic Axpert King/ MPP Solar....)

Panels: 10 x 345w JA Solar Mono MBB Percium Half-Cell 9.86A 41.76VOC ( in series)

BMS : Selpos 48V 200Amp

cells 16 x 280AH Lifepo4 48v

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BMS seems to start OK - shows 50% SOC green status lights = good. (I havent changed any settings at all from stock.)

Connected to the inverter , used pre charge resister and set battery isolator to on.

Inverter boots up and runs. (again I have not changed stock settings)

Can see battery voltage - so far so good!.

I did notice that SOC went down to 6% suddenly!? after 5 mins or so is this normal.

However - PV input remains at 0, tried tripping PV isolator doesnt seem to do anything.

Panels are in 1 string of 10 series voc 417.6 9.86A (Inverter should be able to handle 500Vdc )

I tried my multimeter on the fuse isolator outside - I think I can only get 370V? - if I divide this by 41.76 I get 8.86 panels, does this mean 1 panel is not working? (or is it just the bird poos /dirty panel) *Im in UK and suprisingally its the hottest day of the year today - extremely sunny!

I did 'hear' a spark once when I tripped the outside fuse box for the PV string....

If I isolate the panels I can see 51V on the Inverter PV terminals - is this something to do with battery configuration? (its all off grid) is this battery feedback , feeding back to the panels?

Any pointers on checks I need to do, the inverter doesnt have any fault code displayed...


48 v Battery > BMS > Class T Fuse > Isolator switch / Pre charge resister > Inverter
Panels > Fuse box outside > DC Isolator inside > Inverter

 

[timselectric]

Check BMS settings to see if charging is turned on.

 

[burgerking]

However - PV input remains at 0, tried tripping PV isolator doesnt seem to do anything.

indicative either:
1. inverter is NOT connected to PV (loose connection, broken wire
2. fuse/breaker popped
3. or a tripped SPD

Panels are in 1 string of 10 series voc 417.6

where did you measure this? on the panels, on the fuse box, or individually?
and when did you measure this? before connecting to inverter? after?

Everything has to be reported in sequence to give us the picture of where/what happen.

Any pointers on checks I need to do, the inverter doesnt have any fault code displayed...

check the voltages on all PV lines to trace the problem. you can start from the inverter PV input, then to the next stop the PV disconnect box (test both sides), then upto the PV fusebox (test both sides) and finally if you are still getting zero, physically disconnect the PV (be careful) and check voltage there.

ALWAYS with caution. PV kills.

 

[Spikeuk]

Thanks guys, I stepped through my whole setup again - I traced everything from panels, I realised the DC Isolator was not wired correctly - rewired now its working!