ABB REX 521 Technical Reference Manual, Standard Configurations page 76

REX 521
76
Protection Relay
Technical Reference Manual, Standard Configurations
Using a digital input directly
One of the digital inputs (DI1...DI9) can be selected directly to permit close
operations. Use the selector named Close enable in the relay menu or the Relay
Setting Tool to select the input. Furthermore, an input activation delay and inversion
can be selected from the general digital input settings menu. Observe that the logical
state 1 enables and the logical state 0 disables closing of the circuit breaker.
Using earth-switch state (disconnector state not available)
If the status indication signals of the earth switch are connected to the digital inputs
and routed to ES pos. open and ES pos. close, these indications can be included in
the interlocking scheme. The signal marked "Interlocking_A" will be logical 0 when
the earth switch is closed and logical 1 when the earth switch is open. Use this signal
to enable close operations by selecting "Interlocking_A" in the Close enable
selector.
ES pos. open
ES pos. close
Fig. 5.2.1.-1 Interlocking using earth-switch state
Using disconnector state (earth-switch state not available)
If the status indication signals of the disconnector are connected to the digital inputs
and routed to DC pos. open and DC pos. close, these indications can be included in
the interlocking scheme. The signal marked "Interlocking_A" will be logical 1 when
the disconnector is closed and logical 0 when the disconnector is open. Use this
signal to enable close operations by selecting "Interlocking_A" in the Close
enable selector.
DC pos. open
DC pos. close
Fig. 5.2.1.-2 Interlocking using disconnector state
Using disconnector and/or earth-switch state
If both the disconnector and the earth-switch indications are available and routed to
DC pos. open, DC pos. close, ES pos. open and ES pos. close, these indications can
be included in the interlocking scheme. The signal marked "Interlocking_A" will be
logical 1 when the disconnector is closed or the earth switch is open. The signal
marked "Interlocking_B" will be logical 1 when the disconnector is closed and the
earth switch is open. Use any of these two signals to enable close operations by
selecting either "Interlocking_A" or "Interlocking_B" in the Close enable
selector.
&
Interlocking_A
&
Interlocking_A
1MRS751802-MUM