Ametek UPLC-II System Manual page 65

Table 3–5. Operation of the Underreaching Transfer Trip Scheme
OPERATION FOR EXTERNAL AND INTERNAL FAULTS
Type of Fault
External (F E )
Internal (F I )
(Fault near station H)
† Omitted in non-permissive systems.
Breaker 1 Trip Fault Detectors (P 1 )
Breaker 2 Trip Fault Detectors (P 2 )
Contact Logic (per Terminal)
Omit and Bypass
for Non-Permissive
Schemes
Solid State Logic (per Terminal)
P
FD
Audio Tone
Receiver
Permissive Schemes
Figure 3–10. Basic Logic Diagrams for Underreaching Transfer Trip Systems
January 2016
Events at Station G
P 1 does not operate.
No channel signal sent to H.
No trip.
P 1 does not operate.
No channel signal sent to H.
† (FD
1 operates).
Transfer-trip (f 2 ) from sta-
tion H operates RR or
inputs to AND (or OR if non-
permissive).
Trip.
Breaker 1 Permissive Fault Detectors (FD 1 )
G
F I
Protected Line
1
Breaker 2 Trip Fault Detectors (P 2 )
Audio Tone
Receiver f 2
Channel
except Power Line Carrier
Audio Tone
Transmitter f 1
FD P
Audio
RR
Tone RR
Receiver
Key Audio Tone Transmitter
to Remote Station
Trip
Coil
52a
Key Audio Tone Transmitter
to Remote Station
AND OR Trip
Chapter 3. applications
Events at Station H
P 2 does not operate.
No channel signal sent to G.
No trip.
P 2 operates and trips direct-
ly.
Transfer-trip signal keyed to
station G.
† (FD
2 operates).
Trip.
H
F E
2
Audio Tone
Transmitter f 2
Audio Tone
Receiver f 1
Key Audio Tone Transmitter
to Remote Station
P
Trip
OR
Audio Tone
Recovery
Non-Permissive Schemes
3
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