Figure 91: Circuit Breaker Fail Logic - Single Phase Start; Figure 92: Circuit Breaker Fail Trip And Alarm - GE P24DM Technical Manual

Chapter 8 - CB Fail Protection
External Trip A External Trip A
IA< Start IA< Start
ZCD IA<
CB Fail Alarm CB Fail Alarm
External Trip A External Trip A
Ext Prot Reset Ext Prot Reset
Prot Reset & I< Prot Reset & I<
I< Only I< Only
CB Open & I< CB Open & I<
Pole Dead A Pole Dead A
External Trip B External Trip B
IB< Start IB< Start
ZCD IB<
CB Fail Alarm CB Fail Alarm
External Trip B External Trip B
Ext Prot Reset Ext Prot Reset
Prot Reset & I< Prot Reset & I<
I< Only I< Only
CB Open & I< CB Open & I<
Pole Dead B Pole Dead B
External Trip C External Trip C
IC< Start IC< Start
ZCD IC<
CB Fail Alarm CB Fail Alarm
External Trip C External Trip C
Ext Prot Reset Ext Prot Reset
Prot Reset & I< Prot Reset & I<
I< Only I< Only
CB Open & I< CB Open & I<
Pole Dead C Pole Dead C

Figure 91: Circuit Breaker Fail logic - single phase start

CB Fail 1 Status
Enabled
CBF3 PhStart
CBFExtPhAStart
CBFExtPhBStart
CBFExtPhCStart
CB Fail 2 Status
Enabled
CBF3 PhStart
CBFExtPhAStart
CBFExtPhBStart
CBFExtPhCStart

Figure 92: Circuit Breaker Fail Trip and Alarm

184
S S S
Q Q Q
R R R
D D D
1
&
S S S
Q Q Q
R R R
D D D
&
1
&
S S S
Q Q Q
R R R
D D D
1
&
S S S
Q Q Q
R R R
D D D
&
1
&
S S S
Q Q Q
R R R
D D D
1
&
S S S
Q Q Q
R R R
D D D
&
1
&
&
1
&
1
&
1
&
1
&
1
&
1
1
1
1
Note on SR Latches
All latches are reset dominant and are triggered on the positive edge. If
the edge occurs while the reset is active, the detection of the edge is
delayed until the reset becomes non -active.
1
1
P24xM
CBFExtPhAStart
CBFExtPhBStart
CBFExtPhCStart
V00657
Bfail1 Trip 3ph
1
CB Fail Alarm
Bfail2 Trip 3ph
V00676
P24xM-TM-EN-2.1