In order to take advantage of the different earth-fault detection methods in various fault situations, the freely programmable earthfault-detection and short-circuit-indicator EOR-3D makes it possible to select and combine the following methods:
Transient-method using qu2 und qui algorithms
- for single faults
- intermittent and restriking faults
- fault detection in loops with high circulating current
Direction of reactive power of the zero-sequence system, resp.sin(ϕ) method
Direction of active power of the zero-sequence system, resp. cos(ϕ) method, suitable instrumenttransformers assumed
Harmonics method including evaluation of the associated reactive power direction for a freely selectable frequency
Pulse-method: traditional as well as using the new high-power current injection (HPCI). Using the EOR-3D, overcompensation is not mandatory
Indication of short-circuits to earth in low resistance resp. solidly grounded networks
Directional short-circuit indicator with suppression of signals, caused by atmospheric interference
Short-circuit recognition with adaptive trigger levels
Recognition of cross country earth-faults
Recognition of series faults by monitoring the current unbalance
Recognition of ferroresonance