9 Troubleshooting
SMA America, LLC
76
SB3-5TLUS22-IA-en-10
Installation Manual
9.4 Cleaning the Inverter
• If the cooling fins on the rear of the enclosure are dirty, clean them with a soft brush.
• If the air ducts on the top of the inverter are dirty, clean them with a soft brush.
9.5 Checking the PV Plant for a Ground Fault
If the inverter displays the event numbers 3501, 3601 or 3701, there could be a ground fault. The
electrical insulation between the PV plant to ground is defective or insufficient.
Proceed as follows to check each string in the PV plant for ground faults.
1. Disconnect the inverter from the power supply (see Section 9).
2. Measure voltages:
• Measure the voltages between the positive terminal and the ground potential.
• Measure the voltages between the negative terminal and the ground potential.
• Measure the voltages between the positive and negative terminals.
If the following results are present at the same time, there is a ground fault in the PV plant.
☑ All measured voltages are stable.
☑ The sum of the two voltages against the ground potential is approximately the same as the
voltage between the positive and negative terminals.
•
Damage to the display due to the use of cleaning agents
• If the inverter is dirty, clean the enclosure lid, the display, and the LEDs using only clean
water and a cloth.
Danger to life due to electric shock
In the event of a ground fault, high voltages can be present in the PV module construction.
• Only touch the cables of the PV modules on their insulation.
• Do not connect DC cables with ground faults to the inverter.
