Checking the PV System for Ground Faults


Qualified person

If the red LED is glowing and the event number 3501, 3601 or 3701 is being displayed in the Results menu on the inverter user interface, there may be a ground fault present. The electrical insulation from the PV system to ground is defective or insufficient.

DANGER

Danger to life due to electric shock when touching live system components in case of a ground fault

If a ground fault occurs, parts of the system may still be live. Touching live parts and cables results in death or lethal injuries due to electric shock.

  1. Disconnect the product and battery from voltage sources and make sure it cannot be reconnected before working on the device.
  2. Only touch the cables of the PV modules on their insulation.
  3. Do not touch any parts of the substructure or frame of the PV array.
  4. Do not connect PV strings with ground faults to the inverter.

WARNING

Danger to life due to electric shock from destruction of the measuring device due to overvoltage

Overvoltage can damage a measuring device and result in voltage being present in the enclosure of the measuring device. Touching the live enclosure of the measuring device results in death or lethal injuries due to electric shock.

  1. Only use measuring devices with a DC input voltage range of 1000 V or higher.

Procedure:

In order to check the PV system for ground faults, perform the following actions in the prescribed order. The exact procedure is described in the following sections.

  • Check the PV system for ground faults by measuring the voltage.

  • If the voltage measurement was not successful, check the PV system via insulation resistance measurement for ground faults.