⎯
412
⎯
6
F
2
S
0
8
4
6
3.7 Current
setting
a. Definite time earth fault protection (EF)
The EF element may be used either to provide back-up earth fault protection or,
alternatively, open circuit protection. For example, to detect open faults of the CT circuit,
the operating value of the detector should be lower than the normal load current on the line:
EF
≤
(normal load current/CT ratio)
×
0.5
=
(594.7
×
5/600)
×
0.5
=
2.48A
Element Setting
(A)
EF 2.4
b. Directional earth fault element (DEF)
The DEF element should not be operated by the unbalance current or voltage present in
normal conditions. It is recommended to set the current and voltage after measuring the
actual unbalance residual current and voltage on the site.
DEFFI, DEFRI > Max. zero sequence current (3Io) in normal conditions
DEFFV, DEFRV > Max. zero sequence voltage (3Vo) in normal conditions
Element Setting
DEFFI 2.5
(A)
DEFRI 2.5
(A)
DEFFV 21.0
(V)
DEFRV 21.0
(V)
DEFF
θ
85
DEFR
θ
85
c. IDMT overcurrent element (EFI)
The EFI element should not be operated by the unbalance current present under normal
conditions. It is recommended to set the current after measuring the actual unbalance
residual current for the protected line.
EFI > Max. zero sequence current (3Io) in normal condition
Element Setting
EFI 2.5
(A)
TEFI 0.5
MEFI S
DEFI F
d. Switch-on-to-fault/stub protection (OCH)
The setting of the OCH element should be lower than the minimum fault current (Ifmin) at
the busbar:
OCH < (Ifmin/CT ratio)
×
0.5
=
{(0.8(margin)
×
2.47kA)/(600/5)}
×
0.5
Содержание GRZ100 B Series
Страница 264: ... 263 6 F 2 S 0 8 4 6 Appendix A Block Diagram ...
Страница 271: ... 270 6 F 2 S 0 8 4 6 ...
Страница 272: ... 271 6 F 2 S 0 8 4 6 Appendix B Signal List ...
Страница 307: ... 306 6 F 2 S 0 8 4 6 ...
Страница 308: ... 307 6 F 2 S 0 8 4 6 Appendix C Variable Timer List ...
Страница 310: ... 309 6 F 2 S 0 8 4 6 Appendix D Binary Input Output Default Setting List ...
Страница 321: ... 320 6 F 2 S 0 8 4 6 ...
Страница 322: ... 321 6 F 2 S 0 8 4 6 Appendix E Details of Relay Menu and LCD Button Operation ...
Страница 331: ... 330 6 F 2 S 0 8 4 6 ...
Страница 340: ... 339 6 F 2 S 0 8 4 6 Appendix G Typical External Connections ...
Страница 377: ... 376 6 F 2 S 0 8 4 6 ...
Страница 384: ... 383 6 F 2 S 0 8 4 6 Appendix J Return Repair Form ...
Страница 388: ... 387 6 F 2 S 0 8 4 6 Customer Name Company Name Address Telephone No Facsimile No Signature ...
Страница 389: ... 388 6 F 2 S 0 8 4 6 ...
Страница 390: ... 389 6 F 2 S 0 8 4 6 Appendix K Technical Data ...
Страница 401: ... 400 6 F 2 S 0 8 4 6 ...
Страница 402: ... 401 6 F 2 S 0 8 4 6 Appendix L Symbols Used in Scheme Logic ...
Страница 405: ... 404 6 F 2 S 0 8 4 6 ...
Страница 406: ... 405 6 F 2 S 0 8 4 6 Appendix M Example of Setting Calculation ...
Страница 417: ... 416 6 F 2 S 0 8 4 6 ...
Страница 418: ... 417 6 F 2 S 0 8 4 6 Appendix N IEC60870 5 103 Interoperability and Troubleshooting ...
Страница 430: ... 429 6 F 2 S 0 8 4 6 Appendix O Programmable Reset Characteristics and Implementation of Thermal Model to IEC60255 8 ...
Страница 434: ... 433 6 F 2 S 0 8 4 6 Appendix P Inverse Time Characteristics ...
Страница 437: ... 436 6 F 2 S 0 8 4 6 ...
Страница 438: ... 437 6 F 2 S 0 8 4 6 Appendix Q Failed Module Tracing and Replacement ...
Страница 444: ... 443 6 F 2 S 0 8 4 6 Appendix R Ordering ...
Страница 447: ......