Growatt Solar Inverter 5kW 48V SPF5000

Hi there, have the invert on my shed and its sending power back up the solar tails. Is there a setting to prevent this?
or is it this way to transfer power to another inverter in series?

The roof is charged at 54v from the batteries back through the inverter and then back to the roof..??

Was going to get some diodes to prevent this but wondering if its just a wiring issue?

Edited March 23, 20251 yr by Shsun_SA
forgot to add the inverter spec

Is this a setting of over charge current setting?

1 hour ago, Shsun_SA said:

Is this a setting of over charge current setting?

There shouldn't be a setting to have PV at potential or not. That being said, I know some inverters have the tendency to shock you if you touch the PV input. I would check all wiring, fuses and MC4 plugs to make sure they cannot easily cause tracking to a structure.

Will try insulate everything, some rubber edging under the panels and check the plugs, etc. Thanks

Just wondering if there was a setting to dump power over back through the panels. Silly but just curious :)

On 2025/03/23 at 7:57 PM, Shsun_SA said:

Growatt Solar Inverter 5kW 48V SPF5000

Hi there, have the invert on my shed and its sending power back up the solar tails. Is there a setting to prevent this?
or is it this way to transfer power to another inverter in series?

The roof is charged at 54v from the batteries back through the inverter and then back to the roof..??

Was going to get some diodes to prevent this but wondering if its just a wiring issue?

You need to properly earth your panels and frames.
Inline mc4 diodes will help a bit, but IMHO 1st prize is still correct earthing :)

On 2025/03/24 at 3:57 AM, Shsun_SA said:

Hi there, have the invert on my shed and its sending power back up the solar tails. Is there a setting to prevent this?

Sorry for the late reply.

My guess is that your model is a high PV voltage one (as almost all inverters are these days). If so, there is a high AC (but not sinusoidal) potential between the PV input terminals and earth. This is an unavoidable side effect of the popular transformerless designs with high PV voltage. I'd say you are seeing leakage, or capacitive coupling, or both, from the panel wiring to the roof. It could also be the panels themselves, especially when they are wet. It may be that you happen to get approximately battery voltage at the roof. Be thankful that it's not high enough to be a shock hazard, at least so far.

Earthing the panels should provide a path for the leakage to earth. If the leakage is large enough, the inverter should detect it and stop with a fault code, before it damages its electronics.