28
CURRENT
SETTING I>
CB STATUS
I> START=
SIGNAL 3
OUTPUT
AND AR2-
SIGNAL
I>TRIP= TRIP
OUTPUT
t>
ON
OFF
ON
OFF
ON
OFF
CB OPEN
BY AR
ON
OFF
I> ALARM=
SIGNAL1
OUTPUT
ON
OFF
CB CLOSE
BY AR
DEAD TIME (S26)
DEAD TIME (S36)
ON
OFF
SHOT 1
SHOT 2
FINAL TRIP
S24
S34
CURRENT
SETTING I>
CB STATUS
I> START=
SIGNAL 3
OUTPUT
I>TRIP=TRIP
OUTPUT
AND AR2
SIGNAL
t>
ON
OFF
ON
OFF
ON
OFF
CB OPEN
BY AR
ON
OFF
I> ALARM=
SIGNAL1
OUTPUT
t>
t>
ON
OFF
CB CLOSE
BY AR
DEAD TIME (S26)
DEAD TIME (S36)
ON
OFF
SHOT 1
SHOT 2
FINAL TRIP
S24=0
S34=0
Fig. 18. a) Signal flow diagram for an AR cycle started by the start signal of the I> stage
b) Signal flow diagram for an AR cycle started by the trip signal of the I> stage
Auto-reclosing can be inhibited in the following
ways;
- By setting input 10 in a special mode and
applying an external voltage to the input. The
inhibit function is active as long as a control
voltage is applied to the input. When the
voltage disappears the reclaim time starts.
- By giving the SPA bus variable S78 the value
0.
- By turning the front panel switch SG1/2 to
position 1.
An auto-reclose sequence that has started can be
interrupted in the following ways;
- By setting input 10 in a special mode and
applying an external voltage signal to the
input (signal ARINH).
- Via the SPA bus by means of variable S79.
- By giving an open command to a circuit
breaker that is already open, during the dead
time.
The reclaim time always starts when an auto-
reclose sequence is interrupted.
When the circuit breaker is closed locally or via
the serial bus the reclaim time starts and auto-
reclosing is inhibited. Before the auto-reclose
program opens or closes the circuit breaker the
interlocking program is checked and if the op-
eration is enabled it is executed.
For double busbar systems with two circuit
breakers (duplex systems) the auto-reclose pro-
gram includes a so called duplex logic. The
duplex logic operates according to the following
rules:
- The auto-reclose program always gives an
open command to both circuit breakers
- The circuit breaker is considered to be closed
if one of the breakers is closed, i.e. the closed
status data is an or-function of the circuit
breaker closed data
- The circuit breaker that was the last one to be
closed will be closed by the auto-reclose pro-
gram
Each auto-reclose cycle has four counters. One
counter counts the total number of cycles. The
other three counters are used for counting the
cycles started by the start initiating signals AR1,
AR2 and AR3. The counter value is incre-
mented by one when the circuit breaker is
closed.
Five event codes have been reserved for each
auto-reclose cycle. One event code indicates
that an auto-reclose cycle is in progress and
another that a close pulse has been given. The
other three codes indicate that an auto-reclose
cycle is in progress and that it has been started by
AR1, AR2 or AR3. The event "AR in progress"
event is generated when the starting time of an
AR cycle has elapsed.