
2-4
MIFII Digital Feeder Relay
GEK-106237P
2.4 OVERCURRENT ELEMENTS
2 PRODUCT DESCRIPTION
2
2.4OVERCURRENT ELEMENTS
2.4.1 PHASE TIME OVERCURRENT ELEMENT (51P)DIFFERENTIAL UNITS (87-1) (87-2)
A Phase Time Overcurrent unit is provided in the relay. There are three possibilities for the curve selection, depending on
the selected model.
IEC curves comply with the criteria specified in the IEC255-4 Standard and British Standard BS142
ANSI curves comply with ANSI C37.90 standards
IAC curves simulate the behaviour of GE IAC relays.
A time dial can be applied to any of these curves to optimize co-ordination with other devices in the net. Additionally, there
is a possibility to define a User’s Curve, which can be used for both three-phase overcurrent and ground elements.
In order to avoid undesired trips, time overcurrent elements will not pickup till a value of 1.05 * Set value.
Due to design criteria, actual pickup level has been INTENTIONALLY set to +5% over the set value to ensure that even in
the worst case scenario the relay will NEVER TRIP under the intended setting.This meets IEC international standards.
2.4.1.1 IEC CURVES
The general formula for IEC/BS142 curves is as follows:
Where:
D
=Time Dial setting (set in the relay by user).
V
= I / I
pickup setting
> 1.05
2.4.1.2 ANSI CURVES
The general formula for all ANSI curves is as follows:
Where:
M
=Time Dial setting (set in the relay by user).
V
= I / I
pickup setting
> 1.05
CURVE NAME
A
P
Q
B
K
Mod Inverse (IEC Curve A)
0.14
0.02
1
0
0
Very Inverse (IEC Curve B)
13.5
1
1
0
0
Extremely Inverse (IEC Curve C) 80
2
1
0
0
CURVE NAME
A
B
C
D
E
Inverse 0.0274
2.2614
0.3000
-4.1899
9.1272
Very Inverse
0.0615
0.7989
0.3400
-0.2840
4.0505
Extremely Inverse
0.0399
0.2294
0.5000
3.0094
0.7222
Содержание MIFII GEK-106237P
Страница 91: ...4 28 MIFII Digital Feeder Relay GEK 106237P 4 7 VIEW 4 COMMUNICATIONS 4 ...
Страница 121: ...8 4 MIFII Digital Feeder Relay GEK 106237P 8 3 ALPHANUMERIC DISPLAY AND LEDS 8 KEYPAD AND DISPLAY 8 ...
Страница 124: ...GEK 106237P MIFII Digital Feeder Relay 8 7 8 KEYPAD AND DISPLAY 8 5 MENU TREE 8 8 5MENU TREE ...
Страница 125: ...8 8 MIFII Digital Feeder Relay GEK 106237P 8 5 MENU TREE 8 KEYPAD AND DISPLAY 8 ...
Страница 126: ...GEK 106237P MIFII Digital Feeder Relay 8 9 8 KEYPAD AND DISPLAY 8 5 MENU TREE 8 ...
Страница 127: ...8 10 MIFII Digital Feeder Relay GEK 106237P 8 5 MENU TREE 8 KEYPAD AND DISPLAY 8 ...
Страница 128: ...GEK 106237P MIFII Digital Feeder Relay 8 11 8 KEYPAD AND DISPLAY 8 5 MENU TREE 8 ...
Страница 129: ...8 12 MIFII Digital Feeder Relay GEK 106237P 8 5 MENU TREE 8 KEYPAD AND DISPLAY 8 ...
Страница 130: ...GEK 106237P MIFII Digital Feeder Relay 8 13 8 KEYPAD AND DISPLAY 8 5 MENU TREE 8 ...
Страница 131: ...8 14 MIFII Digital Feeder Relay GEK 106237P 8 5 MENU TREE 8 KEYPAD AND DISPLAY 8 ...
Страница 171: ...11 4 MIFII Digital Feeder Relay GEK 106237P 11 1 MIFII FAQ 11 MII FAMILY FAQ FREQUENTLY ASKED QUESTIONS 11 ...
Страница 175: ...13 2 MIFII Digital Feeder Relay GEK 106237P 13 1 MIFII TROUBLESHOOTING GUIDE 13 TROUBLESHOOTING GUIDE 13 ...
Страница 184: ...GEK 106237P MIFII Digital Feeder Relay A 9 APPENDIX A A 6 MIFII THERMAL CURVES A Figure A 2 THERMAL CURVES FOR Τ1 3 MIN ...
Страница 185: ...A 10 MIFII Digital Feeder Relay GEK 106237P A 6 MIFII THERMAL CURVES APPENDIXA A ...
Страница 188: ...GEK 106237P MIFII Digital Feeder Relay B 3 APPENDIX B B 1 IEC BS142 CURVES B Figure B 1 IEC BS142 INVERSE CURVES ...
Страница 189: ...B 4 MIFII Digital Feeder Relay GEK 106237P B 1 IEC BS142 CURVES APPENDIXB B Figure B 2 IEC BS142 VERY INVERSE CURVES ...
Страница 193: ...B 8 MIFII Digital Feeder Relay GEK 106237P B 2 ANSI CURVES APPENDIXB B Figure B 4 ANSI INVERSE ...
Страница 194: ...GEK 106237P MIFII Digital Feeder Relay B 9 APPENDIX B B 2 ANSI CURVES B Figure B 5 ANSI VERY INVERSE ...
Страница 195: ...B 10 MIFII Digital Feeder Relay GEK 106237P B 2 ANSI CURVES APPENDIXB B Figure B 6 ANSI EXTREMELY INVERSE ...
Страница 198: ...GEK 106237P MIFII Digital Feeder Relay B 13 APPENDIX B B 3 IAC CURVES B Figure B 7 IAC INVERSE GES 7001 ...
Страница 199: ...B 14 MIFII Digital Feeder Relay GEK 106237P B 3 IAC CURVES APPENDIXB B Figure B 8 IAC VERY INVERSE GES 7002 ...
Страница 200: ...GEK 106237P MIFII Digital Feeder Relay B 15 APPENDIX B B 3 IAC CURVES B Figure B 9 IAC EXTREMELY INVERSE GES 7005 ...
Страница 201: ...B 16 MIFII Digital Feeder Relay GEK 106237P B 3 IAC CURVES APPENDIXB B Figure B 10 IAC INVERSE LONG GES 7004 ...
Страница 202: ...GEK 106237P MIFII Digital Feeder Relay B 17 APPENDIX B B 3 IAC CURVES B Figure B 11 IAC INVERSE LONG GES 7003 ...
Страница 203: ...B 18 MIFII Digital Feeder Relay GEK 106237P B 3 IAC CURVES APPENDIXB B ...
Страница 225: ...D 6 MIFII Digital Feeder Relay GEK 106237P D 1 TRIP CIRCUIT SUPERVISION FOR MII FAMILY RELAYS APPENDIXD D ...
Страница 245: ...F 8 MIFII Digital Feeder Relay GEK 106237P F 5 CONCLUSIONS APPENDIXF F ...