SMA event 3501 insulation failure: what it means and what to do

Common causes

• Defective or insufficient electrical insulation between the PV system and ground, which SMA describes as a ground fault in the PV array.

Safe steps to try

1. Keep clear of the array and the wiring SMA warns that in the event of a ground fault, high voltages can be present in the PV module construction. Do not open the inverter, a disconnect, a junction box or any conduit, and do not touch the panels, racking or wiring.
2. Note the code, the time and the weather Write down 3501, any other event numbers, the time of day and whether it was raining or damp. A technician uses this to narrow down where the fault is.
3. Book a technician SMA's procedure is to disconnect the inverter from all voltage sources and measure each string against ground. That is work for a qualified person with the right test equipment.

Frequently asked questions

Is a ground fault dangerous?

It can be. SMA warns of danger to life from electric shock during a ground fault because high voltages can be present in the PV module construction. That is why you should keep away from the panels, racking and wiring until a technician has checked them.

What are events 3601 and 3701?

They are related. SMA uses 3601 when the leakage current from the inverter and array is too high, and 3701 when it detects a residual current through brief grounding of the array. For all three events SMA's corrective step is the same: check the PV system for ground faults.

Other SMA faults

• SMA event 1302 waiting for grid voltage: what it means and what to do
• SMA event 7702 Interference device: what it means and what to do
• SMA event 8206 electric arc detected: what it means and what to do
• SMA event 4301 electric arc detected: what it means and what to do