Toshiba GRL100-701B Instruction Manual page 124

When the three-shot mode is selected for the multi-shot mode, autoreclose is retried again after
the above tripping occurs. At this time, the TS3 and TS3R are started. The third shot autoreclose
is performed only when the voltage and synchronism check element operates after the period of
time set on the TS3 has elapsed. At this time, outputs of the step counter are: SP1 = 0, SP2 = 1,
and SP3 = 0.
The three-shot mode of autoreclose is then completed. Therefore, the tripping following the
""reclose-onto-a-fault"" becomes the final tripping (FT = 1).
If the voltage and synchronism check element does not function within the period of time set on
the TS3R, the multi-shot autoreclose is cancelled.
When the four-shot autoreclose is selected, low-speed autoreclose is retried once again for
tripping that occurs after the "reclose-onto-a-fault". This functions in the same manner as the
three-shot autoreclose.
Use of external automatic reclosing equipment
To use external automatic reclosing equipment instead of the built-in autoreclose function of the
GRL100, the autoreclose mode switch [ARC-M] is set to "EXT1P", "EXT3P" or "EXTMP".
When "EXT1P" is selected, the GRL100 performs single-phase tripping for a single-phase fault
and three-phase tripping for a multi-phase fault. When "EXT3P" is selected, three-phase tripping
is performed for all faults. When "EXTMP" is selected, fault phase tripping is performed for all
faults.
One binary signal for each individual phase is output as an autoreclose start signal.
2.15.2.2 Two-breaker autoreclose
As shown in Figure 2.15.2.7, in the one-and-a-half breaker busbar arrangement, two circuit
breakers, the busbar breaker and the center breaker, must be reclosed. The GRL100 are provided
with the two-breaker autoreclose scheme.
Figure 2.15.2.7 One-and-a-Half Breaker Busbar Arrangement
Multi-shot autoreclose is not applicable to two-breaker autoreclose; the scheme switch
[ARC-SM] is set to "OFF" for a default setting.
Busbar
breaker
V B
Center
breaker
V L1
V L2
 123 
6 F 2 S 0 8 5 0
Protected line
Adjacent line