1. An earth fault is found in the protected line causing the I0Dir> protection to start
calculating the operating time for a trip.
2. The I0Dir> trips and gives the "Open" command to the breaker's open coil. The auto-
recloser function is initiated and the AR Running
AR Running, AR2 R
AR2 Request
equested
ed and SSho
hot 1 Running
t 1 Running signals
are activated.
3. The circuit breaker is opened and the I0Dir> TRIP signal is released and simultaneously the
REQ2 trip signal for the auto-recloser is released. The recloser starts calculating the SSho
hot1
t1
Dead T
Dead Time
ime to close the breaker.
4. The SSho
hot1 Dead T
t1 Dead Time
ime (200 ms) is exceeded and the function sends a "Close" request to the
object breaker: the conditions are met and the breaker's "Close" command is sent to the
breaker's close coil.
5. The circuit breaker is closed towards the fault as it was not cleared by Shot 1. The I0dir>
stage picks up and starts calculating the operating time for a trip. A "Close" command is
dropped after the breaker's "Closed" indication is received and the auto-
recloser function starts calculating SSho
hot1
t1 R
Reclaim T
eclaim Time
ime.
6. The I0Dir> stage trips a second time and gives the REQ2 request to the function. However,
as the function is in the process of calculating the Shot1 Reclaim Time when it receives this
request, the function moves on to the next available shot (Shot 2) for the request. The SSho
hot2
t2
Running
Running signal is set to active and the SSho
hot1 Running
t1 Running is terminated.
7. The circuit breaker is opened and the I0Dir> TRIP signal is released and simultaneously
REQ2 trip signal for the auto-recloser is released. The recloser starts calculating the SSho
hot2
t2
Dead T
Dead Time
ime to close the breaker.
8. The fault is cleared during SSho
hot2 Dead T
t2 Dead Time
ime. After that time (60 s) is exceeded, the function
sends a "Close" request to the object breaker: the conditions are met and the breaker's
"Close" command is sent to the breaker's close coil.
9. The circuit breaker is closed and since the fault has been cleared, no pick-ups are detected.
The "Close" command is dropped after the breaker's "Closed" indication is received and the
auto-recloser function starts calculating SSho
hot2
t2 R
Reclaim T
eclaim Time
ime.
10. The SSho
hot2 R
t2 Reclaim T
eclaim Time
ime (10 s) is exceeded, and so the AR Running
AR Running, SSho
hot 2 Running
t 2 Running and
AR2 R
AR2 Request
equested
ed signals are terminated, and the AR R
AR Reclaim
eclaim calculation begins. The
difference between auto-reclosing and shot-specific reclaim times is that the function jumps
to the next available shot should the fault return. If a fault returns after a successful cycle and
the function's AR Reclaim signal is active, the function jumps directly to the Final Trip state
and then enters the lock-out state. The user can control this behavior through the function
settings. Both reclaim times can be set to 0 s when they are not needed, and the function
skips all timers that are set to zero.
11. The AR R
AR Reclaim
eclaim time is exceeded and the function is set to "Ready" to wait for the next
request.
Auto-recloser sequence from Trip with two shots (high-speed succeeds).
This auto-recloser scheme has the same starters and shots as the two previous examples. The setting
and signals are also the same. However, in this example the fault is cleared by the high-speed shot.
Figure. 5.4.4 - 194. Settings for I0dir> with two shots.
A
AQ
Q-F215
-F215
Instruction manual
Version: 2.04
309