PV voltage goes to 0 volt

[PedroPR]

Hi, I have 2 SPF 3000TL 48volts in 240v 2 phases configuration. It works fine by more than a 6 months, and couple of days ago one of the units shows 0 volts, amp and watts on the PV’s. The other unit works fine. When I open the PV circuit it gave 130v (3 pannels 400W each) but when I pass the PV breaker again the voltage goes down to 3v.

Any idea? The growatt 3000 has a rest that I’m missing?

Thanks in advance!
Pedro

 

[Think About It]

Seems like a high resistance in the PV circuit. Try swapping the MPPTs from the inverters and see if the problem follows the inverter or the string.

 

[MisterSandals]

but when I pass the PV breaker again the voltage goes down to 3v.

What breaker do you have?
Have a pic?
Have you tested the breaker for continuity or resistance (heat?)?

 

[PedroPR]

What breaker do you have?
Have a pic?
Have you tested the breaker for continuity or resistance (heat?)?

Let me take the photo to send it in a minute.

Thanks

 

[PedroPR]

What breaker do you have?
Have a pic?
Have you tested the breaker for continuity or resistance (heat?)?

I assume the continuity is ok because the drop of voltage when the breaker is on.

I keep the breaker open to avoid any possible damage

 

[MisterSandals]

Any idea? The growatt 3000 has a rest that I’m missing?

I missed this.
If the solar is only used for charging batteries and the battery(s) are full, then 0 volts, 0 amps and 0 watts will be pulled from the panels. Is this the case?

Those look like high quality breakers.

 

[Think About It]

I missed this.
If the solar is only used for charging batteries and the battery(s) are full, then 0 volts, 0 amps and 0 watts will be pulled from the panels. Is this the case?

Those look like high quality breakers.

Agreed, and if the string had a very high resistance it will show voltage without load but will drop substantially and potentially to zero under load.

 

[PedroPR]

Agreed, and if the string had a very high resistance it will show voltage without load but will drop substantially and potentially to zero under load.

Few days out, sorry, today I swap the PV’s from one box to the other. The box (3000 TL) that got problems continue the same. It does’n detect the PV’s, as you said the load looks as higher and drop to zero the voltage. Looks like a hardware issue, any idea on how to solve it? Beyond to complete box replacing? Thanks in advance