Wiring testing device

A wiring testing device configured to test the wiring correctness of an inverter, that serves to convert a direct voltage into a three-phase alternating current, the inverter configured to be connected to a low-voltage three-phase system with a neutral conductor serving as a reference point for grid-side conductor voltages, comprising:

• a test circuit configured to measure the grid-side conductor voltages and determine an average value from the sum of the instantaneous values of the grid-side conductor voltages;
• a display unit configured to display an error message if the average value exceeds a threshold voltage for a defined time period;
• and
• a capacitor connected between a phase of the three-phase system and the neutral conductor configured to generate a voltage imbalance if the neutral conductor connection is missing,
• wherein the test circuit is configured to measure the conductor voltages and determine the voltage imbalance, and
• wherein the display unit is configured to generate an error message if the neutral conductor connection is found missing.