Toshiba GRL100-701B Instruction Manual page 107

Setting
The setting elements necessary for the breaker failure protection and its setting ranges are as
follows:
Element Range
−
OCBF
0.5 10.0A
−
(0.1 2.0A
TBF1 −
50 500ms
−
TBF2
50 500ms
[BFEXT] ON/OFF
[BF1] T/TOC/OFF
[BF2] ON/OFF
(*) Current values shown in parentheses are in the case of 1A rating. Other current values are in
the case of 5A rating.
The overcurrent element OCBF checks that the breaker has opened and the current has
disappeared. Therefore, since it is allowed to respond to the load current, it can be set from 10 to
200% of the rated current.
The settings of TBF1 and TBF2 are determined by the opening time of the original breaker (Tcb
in Figure 2.11.2) and the reset time of the overcurrent element (Toc in Figure 2.11.2). The timer
setting example when using retrip can be obtained as follows.
Setting of TBF1 = Breaker opening time + OCBF reset time + Margin
= 40ms + 10ms + 20ms
= 70ms
Setting of TBF2 = TBF1 + Output relay operating time + Breaker opening time +
= 70ms + 10ms + 40ms + 10ms + 10ms
= 140ms
If retrip is not used, the setting of TBF2 can be the same as that of TBF1.
Step Default
0.1A 4.0A
0.1A 0.8A) (*)
1ms 150ms
1ms 200ms
OFF
OFF
OFF
OCBF reset time + Margin
 106 
6 F 2 S 0 8 5 0
Remarks
Overcurrent setting
Retrip timer
Adjacent breaker trip timer
External start
Retrip mode
Adjacent breaker trip