Alstom SHPM 101 - Page 51

SERVICE MANUAL R5888B
QUADRAMHO Chapter 1
Appendix A
Page 7 of 8
Z
B
Zone -1
Zone -2
Zone -3
Z
Zone -1
Zone -2
Zone -3
A
XX XX XX XX
OR
Zone -2
Zone -3
tZ2
tZ3
Relay A
Trip A
AND
Zone -1
OR
CB
contact
Signaling
channels
=
CB contact closed when circuit breaker is open
AND
Undervoltage
detector
Zone -2
Zone -3
tZ2
tZ3
Relay B
Trip B
AND
Zone -1
OR
CB
contact
AND
Undervoltage
detector
OR
Figure 7: POR-simplified distance scheme logic (with ‘open terminal’ signal echo feature and weak
infeed signal echo and trip feature)