What you will see
- Faults worded as isolation fault, insulation resistance low, PV ISO or ground fault.
- The inverter stays off in the early morning and starts later once the sun dries things out.
- The problem appears after monsoon rain or washing.
Why it happens
The inverter checks that the solar wiring is properly insulated from earth before it starts. Water in a connector, a cable with damaged insulation, a cracked panel backsheet or a poorly sealed junction box lets a small current leak to earth, and the inverter refuses to run.
If it clears once things dry, the fault is still there. It will usually get worse over time.
What you can check yourself
- Note whether the fault appears only in wet conditions or all the time.
- From the ground, look for cables lying in standing water, sagging runs or rodent damage.
- Tell us when the panels were last washed and how.
What not to do
- Do not touch, unplug or open MC4 connectors, junction boxes or DC isolators. The DC side is live whenever there is daylight.
- Do not spray water directly at connectors or the inverter when washing.
When to call us
- Every time. Isolation faults need testing with proper instruments, string by string.
Monsoon season across Punjab
Isolation faults rise after monsoon rain in Faisalabad, Lahore and across Punjab. Our technicians test string by string with proper instruments to find the leak before it gets worse.
Send us
The fault code, the weather when it happened and a photo of the array and cable runs.