P746/EN CM/F21
Commissioning and Maintenance
(CM) 10-22
MiCOM P746
Example:
Phase comparison threshold x% = 50%,
Busbar protection bias slope k% = 60% (thus m% = 57% and n% = 63%)
ID>2 = 1100 A (thus minimum bias current = ID>2/ k% = 1100 / 0.6 = 1834 A)
CT1 = 1000/1 (thus):
•
Maximum current of 50% of 1000 A = 500 A to not be used by the phase comparison
•
Maximum of bias current = 2 x I
1
./ (1 – n) = 2 x 500 / 0.43 = 2325 A
CT2 = 2000/1 (thus):
CM
•
Maximum current of 50% of 2000 A = 1000A to not be used by the phase comparison)
•
Maximum of bias current = 2 x I
2
./ (1 – n) = 2 x 1000 / 0.43 = 4650 A
First test:
•
Chose min I
bias
= 2 kA (more than 1834 A and less than 4650 A)
•
Inject outgoing I
1
= 1000 A prim (1 A sec) and ingoing I
2
.= 1000 A prim (0.5 A sec) for
10s.
−
I bias = 1000 + 1000 = 2000 A
−
I diff = 1000 – 1000 = 0 A
•
Check on the P746 HMI Tool that the right I
bias
= 2 kA is displayed and the differential
current is 0.
•
Inject outgoing I
1
= 1570 A prim and ingoing I
2
.= 430 A prim for 40ms
−
I bias = 1570 + 430 = 2000 A
−
I diff = 1570 – 430 = 1140 A
−
1140 A = 57% of 2000 A
•
No trip
Summary of Contents for MiCOM P746
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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...
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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...
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Page 258: ...P746 EN FD G31 Firmware Design MiCOM P746...
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Page 348: ...P746 EN MT A11 Maintenance MiCOM P746...
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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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