MPP no solar input

[NMNeil]

It's a PIP-LV-MK 3KW 48volt.
Been running just fine for about 6 months, now for no apparent reason it can't 'see' the solar input.
Did the obvious and checked the panel output, 90 volts and the current was quickly rising as the sun came up, but I had to stop at 10A which is the limit of my multi meter.
So here's the weird bit. Reading at the solar panel input terminals on the MPP unit with the panels connected, 90 volts, disconnect the panels and the voltage at the terminals is 55 volts. Completely remove the solar input wires and it's still 55 volts. The 120 volt output is still working no problem, just no charging.
Before I contact Ian, as it's still under warranty, am I looking at a new MPPT board, or can anyone suggest any alternatives to the problem that I've overlooked?

 

[sunshine_eggo]

Several examples of MPP/Growatt units getting wonky on their PV input... they just won't charge no matter what. It is often resolved by a hard reboot:

Disconnect PV
Disconnect Battery
Reconnect Battery
Reconnect PV

 

[NMNeil]

Several examples of MPP/Growatt units getting wonky on their PV input... they just won't charge no matter what. It is often resolved by a hard reboot:

Disconnect PV
Disconnect Battery
Reconnect Battery
Reconnect PV

Already tried that, but no change.
As the voltage at the solar input terminals is exactly 55 volts and I have the unit configured so that 55 volts is the bulk charging voltage, that may have something to do with it.
I've sent Watts247 an e-mail so hopefully they can shed some light on the problem.
As the 120 volt output is fine I'm considering just getting a cheap (Bluesky) MPPT 60A charger to keep the batteries charged until I can get this resolved.

 

[sunshine_eggo]

Already tried that, but no change.
As the voltage at the solar input terminals is exactly 55 volts and I have the unit configured so that 55 volts is the bulk charging voltage, that may have something to do with it.
I've sent Watts247 an e-mail so hopefully they can shed some light on the problem.
As the 120 volt output is fine I'm considering just getting a cheap (Bluesky) MPPT 60A charger to keep the batteries charged until I can get this resolved.

Good plan. Certainly better than running them dry! I have a cheap 2 stage 60A MPPT as backup to my Victron.

 

[NMNeil]

I'm wrong, the voltage at the solar input terminals is swinging between 30 and 55 volts.

 

[RCinFLA]

I'm wrong, the voltage at the solar input terminals is swinging between 30 and 55 volts.

Charge controller is attempting to start up but PV voltage is collapsing below minimum SCC operating voltage.

If one or more of panels bypass diodes shorted out it could explain your recent issue. Check the unloaded Voc voltage to see if it is what it should be. While you are at it, you could also check Isc current from string.

 

[NMNeil]

Charge controller is attempting to start up but PV voltage is collapsing below minimum SCC operating voltage.

If one or more of panels bypass diodes shorted out it could explain your recent issue. Check the unloaded Voc voltage to see if it is what it should be. While you are at it, you could also check Isc current from string.

The voltage is around 102 when I last measured it. Connected a 4 ohm 10 watt resistor across the panels input and got a voltage drop of around 30 volts across the resistor and getting very hot very fast, so I have plenty of solar power. I= V/R so 7.5 amps and P = V*A giving 756 watts.
I'm communicating with Watts 247 at the moment, and I'm hoping that it's just the MPPT board that's gone bad.

 

[alejandrowa]

Hi @NMNeil

Did you get your issue resolved? I have the same problem.

Thanks