Alstom MBCH - FLOWCHART 2; Relay Operation and Tripping Contact Check

25
Flowchart 2
Is
the relay
an MBCH 12
version
?
Set Is = 0.5 In
on relay frontplate.
Monitor TP4
Inject In into
terminals 27 and
28.
Monitor tripping contacts
Conclusion:
faulty pcb 1, pcb 2 or
transformers T1 or T2
Conclusion:
faulty pcb1
Conclusion:
faulty pcb1
Follow
Flowchart 4
Follow
Flowchart 3
Monitor R2.
Inject In into
terminals 27 and 28.
R2
voltage
correct
?
Do
tripping
contacts
close
?
TP4
voltage
correct
?
YES
YES
YES
YES
YES
YES
NO
YES
YES
NO
NO
NO