2.2 Distance protection
105
7SA522 Manual
C53000-G1176-C155-3
Zone Logic of the
Controlled Zone
Z1B
The controlled zone Z1B is usually applied as an overreaching zone. The logic is
shown in Figure 2-34. It may be activated via various internal and external functions.
The binary inputs for external activation of Z1B of the distance protection are
´!(1$%/(=%µ and ´!(QDEOH$5]RQHVµ. The former can for example be from
an external teleprotection device, and only affects Z1B of the distance protection. The
latter can also be controlled e.g. by an external automatic reclosure device. In addi-
tion, it is possible to use the zone Z1B as a rapid autoclosure stage that only operates
for single-pole faults, if for example only single-pole automatic reclose cycles are ex-
ecuted.
It is possible for the 7SA522 to trip single-pole during two-phase faults without earth-
connection in the overreaching zone when single-pole automatic reclosure is used.
As the device has an integrated teleprotection function, release signals from this func-
tion may activate the zone Z1B, provided that the internal teleprotection signal trans-
mission function has been configured to one of the available techniques with param-
eter 7HOHSURW'LVW i.e., the function has not been set to 'LVDEOHG.
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