Technical Data
10-18 7SJ62 Manual
C53000-G1140-C121-1
10.4 Directional Time Overcurrent Protection (67 and 67N Elements)
Overcurrent Ele-
ments
The same specifications and characteristics apply as for non-directional time overcur-
rent protection (see Sub-sections 10.2 and 10.3).
Determining Direc-
tion
Moreover, the following data apply for determining fault direction:
For Phase Faults Polarization With short-circuit free voltages, with
voltage memory (memory duration is 2
cycles) for measurement voltages that are
too low.
Forward Range Can be set in 3 stages (3 protection areas):
Inductive 45° ± 86°
Resistive 0° ± 86°
Capacitive –45° ± 86°
(if short-circuit free voltage vertical to
short circuit voltage)
Directional Sensitivity Unlimited for one and two phase faults.
For three phase faults, dynamically unlimit-
ed, steady-state approx. 7V phase-to-phase.
For Ground Faults Polarization With zero sequence quantities
Forward Range Can be set in 3 stages (3 protection areas)
Inductive 45° ± 84°
Resistive 0° ± 84°
Capacitive –45° ± 84°
Directional Sensitivity approx. 5 V displacement voltage, mea-
sured
approx. 12 V displacement voltage, cal-
culated
Inherent Operating
Times
Pickup times without intentional delay or inrush stabilization. With inrush stabilization,
add 10 ms.
67-1, 67-2, 67N-1, 67N-2
– Current = [2 x pickup] approx. 45 ms
– Current = [10 x pickkup] approx. 40 ms
Dropout Times
67-1, 67-2, 67N-1, 67N-2 approx. 40 ms
Tolerances Phase angle errors under reference conditions
– For phase faults and for ground faults ± 3° electrical
Influencing Vari-
ables
Frequency Influence
– With no memory voltage approx. 1° in range 0.95 < f/f
N
< 1.05
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