WDH harmonics detectors are electronic devices with an output relay that is connected when the harmonics current level measured in the circuit exceeds a threshold that can be adjusted.

• It monitors and acts in accordance with the true root mean square of the total harmonic current in a phase. The trigger level is adjusted with the potentiometer on the front of the unit.
• Delay: the output relay activation time can be adjusted (up to 30 s).
• The reset process is automatic with currents under 10% of the trip level (Hysteresis).
• Current measurement, depending on the type:
  • With built-in current transformer (net diameter ∅ 25 mm)
  • Separate transformer, input.../5 A ac