Toshiba GR-200 Series Instruction Manual page 264

Timing diagrams
2.22.5
Single shot scheme for an Arcing fault (Shot1 and successful
(i)
operation)
Figure 2.22-10 illustrates an example for which the single shot scheme has been selected (i.e.
[ARCNUM]=S1); an arcing fault is cleared following the operation of the protection relay and
the issue of the 'GEN.TRIP' signal for the tripping of the CB. The 'GEN.TRIP' also initiates the
ARC function and an 'ARC CLOSE COMMAND' signal is issued following the expiration of the
dead time set for [TSHOT]. When On is set for [ARC-SucChk], this scheme will determine that
the ARC was successful when the 'CB ALLPH CLOSE' signal is detected following the issuing
of the 'ARC CLOSE COMMAND' signal; the operation of the ARC function is reset if it operates
successfully (i.e., the 'ARC IN-PROG' signal is turned off).
Fault current
Closed
CB status
Open
Operated
Relay operation
Issued
GEN.TRIP
ARC IN-PROG
ARC-S1 IN-PROG
ARC SHOT1
Dead Time [TSHOT]
)
ARC-S2 IN-PROG
ARC SHOT2
ARC-S3 IN-PROG
ARC SHOT3
ARC CLOSE COMMAND
Closed
CB ALLPH CLOSE
ARC CLOSE SUCCESS
ARC CLOSE FAIL
ARC FT
Figure 2.22-10 Single shot scheme [ARCNUM]=S1 for an Arcing fault; operation is successful
Note: As cited in Chapter 2.22.4(iii), the permissive signal 'ARC-VCHK' is required for
operation, but is omitted here for the sake of clarity. The pulse width of the 'ARC
CLOSE COMMAND' signal is defined using the setting [TCCW].
Single shot scheme for an Arcing fault; CB fails to reclose
(ii)
Figure 2.22-11 also shows the single shot scheme. However, the CB fails to reclose on receiving
the 'ARC CLOSE COMMAND' so that the ARC function initiates the 'ARC CLOSE FAIL' signal
within the setting time [TARCDSUC]. Consequently, the ARC function goes to the final trip
(FT) stage so that the ARC will not issue another 'ARC CLOSE COMMAND' signal hereafter.
[TCCW]
)
20ms
)
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6F2T0200 (0.15)
GRE200 (1,2)