ESK - detects earth faults and phase faults in air- and gas-insulated medium voltage switchgear

Detection of earth faults and phase faults in medium voltage switchgear up to 110 kV

The vast majority of arc faults in medium-voltage switchgear are triggered by a single-phase earth fault, which within a very short time transforms into a two- or three-phase short circuit, causing severe damage to the switchgear. In addition to the physical damage caused, this arc fault poses an enormous danger to maintenance personnel on duty.

In this respect, the optical system sets new standards: By combining arc monitoring with additional protection systems, the shutdown process can be significantly accelerated and the earth fault can be eliminated before it reaches destructive dimensions.

The LiBo system detects even the smallest arcs, such as those generated by an earth fault. In combination with voltage or current monitoring, the affected switchgear can be reliably shut down long before the arc fault destroys the unit.

If both systems report the occurrence of an earth fault or arc, the circuit breaker can be opened immediately and the two- or three-pole short circuit will be prevented.

The combination of both systems significantly increases the safety and availability of the switchgear. Thus, the existing protection system is extended by an additional, faster safety device. Of course, this system can also be retrofitted.

In the medium voltage range, the ESK can likewise be used for voltage monitoring.
Use cases:
  • Testing / commissioning
  • Monitoring
Erdschlusskennung – Steuereinheit für MIttelspannungsanlagen

The electronic unit of the earth fault detection system monitors and protects your equipment

Current in relation to time - earth fault and short circuit

(Left: earth fault / Right: short circuit) The diagram illustrates how destructive a short circuit is in relation to an initial earth fault

The combination of the ESK with the LiBo system offers the following advantages:
  Reliable detection of earth faults / phase faults
  Shutdown before a short circuit occurs
  Insensitivity to electromagnetic interference sources (e.g. UHF signals, radio/TV, cellphones, electrical machines)
  Compatible with all switchgear in the medium-voltage range
  Simple and inexpensive installation