Table of Contents
Advertisement
2 Functions
Phase-segregated
Phase segregated initiation of the breaker failure protection is necessary if the circuit
initiation
breaker poles are operated individually, e.g. if single-pole automatic reclosure is used.
This is possible if the device is able to trip single-pole.
If the breaker failure protection is intended to be initiated by further external protection
devices, it is recommended, for security reasons, to connect two binary inputs to the
device. Besides the three trip commands of the external relay to the binary input „>BF
Start L1", „>BF Start L2" and „>BF Start L3" it is recommended to connect
also, for example, the general device pickup to binary input „>BF release". Figure
2-67 shows this connection.
Nevertheless, it is possible to initiate the breaker failure protection in single-channel
mode should a separate release criterion not be available. The binary input „>BF
release" must then not be assigned to any physical input of the device during con-
figuration.
If the external protection device does not provide a general fault detection signal, a
general trip signal can be used instead. Alternatively, the parallel connection of a sep-
arate set of trip contacts can produce such a release signal as shown in Figure 2-68.
Figure 2-67
Figure 2-68
The start condition logic for the delay time(s) is basically designed as in the common
phase initiation, the difference is that this logic is designed separately for each phase
182
Breaker failure protection with phase segregated initiation — example for initia-
tion by an external protection device with release by a fault detection signal
Breaker failure protection with phase segregated initiation — example for initia-
tion by an external protection device with release by a separate set of trip con-
tacts
7SD610 Manual
C53000-G1176-C145-4
Advertisement
Table of Contents
