P746/EN OP/G31
Operation
(OP) 5-
14
MiCOM
P746
OP
1.3.2.1.8 Local re-trip after time tBf3
This re-trip command can be applied via either the main or back up trip coil. It is possible to
choose between the 3 following modes:
•
Local re-trip activated/deactivated via PSL. The relay used for this function can use the
same fixed logic for the busbar protection or other independent relays.
•
A re-trip can be applied after a time tBF3. This is typically set at 50ms when a single
phase trip and re-trip is used. This prevents loss of phase selectivity by allowing the main
protection trip to execute via the main CB trip coil before re-trip command is executed by
the back-up CB trip coil.
•
Single or three phase re-trip is possible. If the feeder protection executes single-phase
tripping, the three-phase re-trip must be carried out in time tBF3 and this must be
adjusted to have a value higher than the normal operation time of the circuit breaker.
Typical setting under this condition is 150ms.
1.3.2.1.8.1 General zone trip after time tBF4
When both the local trip and re-trip have failed, the countdown continues with a second timer
adjusted to have a value of tBF4 - tBF3. The end of this time thus corresponds to total time
tBF4, beyond which a persistent circuit breaker failure condition is declared.
Information is then relayed for routing, and the associated circuit breakers, in the adjacent
zone(s) for a general three-phase back-trip.
1.3.2.1.9 CB Fail alarm
The CB Fail alarm is raised on any timer reached (tBF1 or tBF2 or tBF3 or tBF4)
1.3.2.1.10 Separate external 50BF protection to the busbar protection
This is the most common solution utilising conventional wiring. The 50BF relay is completely
independent of all others. When a circuit breaker failure condition occurs the external
protection trips all adjacent circuit breakers as defined in the separate scheme (DDB Ext. CB
fail).
In view of the connection between the functions of the busbar protection and the circuit
breaker failure protection some operators prefer one of the more integrated system solutions
previously mentioned.
Summary of Contents for MiCOM P746
Page 4: ......
Page 5: ...Pxxx EN SS G11 SAFETY SECTION...
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Page 8: ...Pxxx EN SS G11 Page 2 8 Safety Section BLANK PAGE...
Page 16: ...P746 EN IT G31 Introduction MiCOM P746...
Page 18: ...P746 EN IT G31 Introduction IT 1 2 MiCOM P746 IT BLANK PAGE...
Page 26: ...P746 EN TD G31 Technical Data MiCOM P746...
Page 38: ...P746 EN GS G31 Getting Started MiCOM P746...
Page 78: ...P746 EN ST G31 Getting Started MiCOM P746...
Page 80: ...P746 EN ST G31 Settings ST 4 2 MiCOM P746 ST BLANK PAGE...
Page 112: ...P746 EN ST G31 Settings ST 4 34 MiCOM P746 ST BLANK PAGE...
Page 114: ...P746 EN OP G31 Operation MiCOM P746...
Page 136: ...P746 EN OP G31 Operation OP 5 22 MiCOM P746 OP BLANK PAGE...
Page 138: ...P746 EN AP G31 Application Notes MiCOM P746...
Page 142: ...P746 EN AP G31 Application Notes AP 6 4 MiCOM P746 AP BLANK PAGE...
Page 194: ...P746 EN AP G31 Application Notes AP 6 56 MiCOM P746 AP BLANK PAGE...
Page 196: ...P746 EN PL G31 Programmable Logic MiCOM P746...
Page 238: ...P746 EN MR A11 Measurements and Recording MiCOM P746...
Page 240: ...P746 EN MR A11 Measurements and Recording MR 8 2 MiCOM P746 MR BLANK PAGE...
Page 258: ...P746 EN FD G31 Firmware Design MiCOM P746...
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Page 348: ...P746 EN MT A11 Maintenance MiCOM P746...
Page 350: ...P746 EN MT A11 Maintenance MT 11 2 MiCOM P746 MT BLANK PAGE...
Page 364: ...P746 EN MT A11 Maintenance MT 11 16 MiCOM P746 MT BLANK PAGE...
Page 366: ...P746 EN TS G31 Troubleshooting MiCOM P746...
Page 368: ...P746 EN TS G31 Troubleshooting TS 12 2 MiCOM P746 TS BLANK PAGE...
Page 382: ...P746 EN SC G31 SCADA Communications MiCOM P746...
Page 424: ...P746 EN SC G31 SCADA Communications SC 13 42 MiCOM P746 SC BLANK PAGE...
Page 426: ...P746 EN SG F21 Symbols and Glossary MiCOM P746...
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Page 440: ...P746 EN IN G31 Installation IN 15 2 MiCOM P746 IN BLANK PAGE...
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Page 470: ...P746 EN HI G31 Remote HMI HI 16 2 MiCOM P746 HI BLANK PAGE...
Page 500: ...P746 EN HI G31 Remote HMI HI 16 32 MiCOM P746 HI BLANK PAGE...
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Page 504: ...P746 EN CS A11G31 Cyber Security CS 17 2 MiCOM P746 CS BLANK PAGE...
Page 524: ...P746 EN VH G31 Firmware and Service Manual Version History MiCOM P746...
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