4.4 CIRCUIT BREAKER FAIL LOGIC - PART 4
V00742
1
&
1
CB1 Fail1 Trip A
CB1 ZCD State A
WI INFEED A
TripStateA CB1
CB1 Fail1 Trip
CB1 Fail Alarm
CB1 Fail2 Trip
1
1
1
From phase B equivalent
From phase C equivalent
LatchATripResetIncomp
1
Latch3PhTripResetIncomp
LatchNonITripResetIncomp
&
CB1 Fail1 Status
Enabled
CB1 Fail1 Timer
1
&
1
CB1 Fail2 Trip ATripStateA
&
CB1 Fail2 Status
Enabled
1
&
ZCD StateSEF
TripStateSEF
&
CB1 Fail1 Status
Enabled
1
&
TripStateSEF
&
CB1 Fail2 Status
Enabled
CB1 Fail1 Timer
t
t
t
t
0
0
0
0
CB1 Fail2 Timer
CB1 Fail2 Timer
834
298
835
1672
1675
Figure 200: Circuit Breaker Fail logic - part 4
Note:
This diagram shows only phase-A for the first CB (CB1) of a dual-CB device. The diagrams for phases B and C and for the
second CB (CB2) follow the same principle and are not repeated here.
Chapter 12 - CB Fail Protection P446SV
354 P446SV-TM-EN-1