Depending of the starting principle (general trip or only instantaneous trip) adopted above
the delayed and back-up zones might not be required. Breaker failure trip local and remote
must however always be connected.
15.2.2.5 Control of the auto reclosing dead time for shot 1
Up to four different time settings can be used for the first shot, and one extension time.
There are separate settings for single-, two- and three-phase auto reclosing dead time, t1
1Ph, t1 2Ph, t1 3Ph. If no particular input signal is applied, and an auto reclosing program
with single-phase auto reclosing is selected, the auto reclosing dead time t1 1Ph will be
used. If one of the TR2P or TR3P inputs is activated in connection with the start, the auto
reclosing dead time for two-phase or three-phase auto reclosing is used. There is also a
separate time setting facility for three-phase high-speed auto reclosing without
synchrocheck, t1 3PhHS, available for use when required. It is activated by the RI_HS
input.
A time extension delay, tExtended t1, can be added to the dead time delay for the first shot.
It is intended to come into use if the communication channel for permissive line protection
is lost. In a case like this there can be a significant time difference in fault clearance at the
two line ends, where a longer auto reclosing dead time can be useful. This time extension
is controlled by the setting Extended t1 = On and the PLCLOST input. If this functionality
is used the auto recloser start must also be allowed from distance protection zone 2 time
delayed trip. Time extension delay is not possible to add to the three-phase high-speed
auto reclosing dead time, t1 3PhHS.
15.2.2.6 Long trip signal
In normal circumstances the auto recloser is started with a protection trip command which
resets quickly due to fault clearing. The user can set a maximum start pulse duration
tLongStartInh. This start pulse duration time is controlled by setting LongStartInhib.
When start pulse duration signal is longer than set maximum start pulse duration, the auto
reclosing sequence interrupts in the same way as for a signal to the INHIBIT input.
15.2.2.7 Maximum number of reclosing shots
The maximum number of auto reclosing shots in an auto reclosing cycle is selected by the
setting NoOfShots. A maximum of five shots can be done. The type of auto reclosing used
at the first auto reclosing shot is set by the setting ARMode. The first alternative is three-
phase auto reclosing. The other alternatives include some single-phase or two-phase auto
reclosing. Usually there is no two-pole tripping arranged, and then there will be no two-
phase auto reclosing.
1MRK 506 369-UUS - Section 15
Control
Line distance protection REL670 2.2 ANSI 659
Application manual
To Next Page
Loading...
