ABB RED615 Technical Manual page 370

Section 4
Protection functions
364
high stage operates immediately when the differential current amplitude is higher
than the set value of the High operate value setting. If the ENA_MULT_HS input is
active, the High operate value setting is internally multiplied by the High Op value
Mult setting.
GUID-99000979-88BE-4A03-9F87-4A9608D91822 V1 EN
Figure 190: Operation logic of instantaneous high stage
Direct inter-trip
Direct inter-trip is used to ensure the simultaneous opening of the circuit breakers
at both ends of the protected line when a fault is detected. Both start and operate
signals are sent to the remote end via communication. The direct-intertripping of
the line differential protection is included into LNPLDF. The OPERATE output
combines the operate signals from both stages, local and remote, so that it can be
used for the direct inter-trip signal locally.
1YHT530004D05 D
615 series
Technical Manual