34
6
F
2
S
0
7
8
9
2.8 Overexcitation Protection
Overexcitation protection is applied to protect transformers from overvoltage and overfluxing
conditions.
Any single phase-to-phase connected voltage is used to detect overexcitation. Trip and alarm
characteristics, which are based on a measurement of the voltage/frequency ratio, are provided.
Figure 2.8.1 shows the scheme logic of overexcitation protection. Overexcitation element V/F
responds to voltage/frequency and outputs three signals. Signal T has an inverse time
characteristic. Signals H and A have high-set and low-set definite time characteristics
respectively. Signal T and signal H with a delayed pick-up timer TVFH are used for tripping.
Signal A is used for alarm with a delayed pick-up timer TVFA.
Figure 2.8.1 Scheme Logic of Overexcitation Protection
Overexcitation protection can trip up to five breakers. Any of the breaker tripping signals V/F-1
to V/F-5 can be blocked by the scheme switch [V/F1] to [V/F5] settings.
Alarm signal V/F-A can be blocked by the scheme switch [V/FA] setting.
V/F
V/F-1
[V/F1]
1
&
A
H
T
TVFH
1 - 600s
1 - 600s
V/F-2
V/F-3
V/F-4
V/F-5
V/F-A
[V/FA]
&
TVFA
[V/F2]
&
[V/F3]
&
[V/F4]
&
[V/F5]
&
0
t
0
t
“ON”
“ON”
“ON”
“ON”
“ON”
“ON”
Summary of Contents for GRT100 Series
Page 142: ... 141 6 F 2 S 0 7 8 9 Appendix A Block Diagram ...
Page 144: ... 143 6 F 2 S 0 7 8 9 Appendix B Signal List ...
Page 159: ... 158 6 F 2 S 0 7 8 9 ...
Page 160: ... 159 6 F 2 S 0 7 8 9 Appendix C Variable Timer List ...
Page 162: ... 161 6 F 2 S 0 7 8 9 Appendix D Binary Output Default Setting List ...
Page 165: ... 164 6 F 2 S 0 7 8 9 ...
Page 166: ... 165 6 F 2 S 0 7 8 9 Appendix E Details of Relay Menu and LCD and Button Operation ...
Page 174: ... 173 6 F 2 S 0 7 8 9 Appendix F Case Outline Flush Mount Type Rack Mount Type ...
Page 179: ... 178 6 F 2 S 0 7 8 9 ...
Page 180: ... 179 6 F 2 S 0 7 8 9 Appendix G External Connections ...
Page 185: ... 184 6 F 2 S 0 7 8 9 ...
Page 200: ... 199 6 F 2 S 0 7 8 9 ...
Page 201: ... 200 6 F 2 S 0 7 8 9 Appendix J Return Repair Form ...
Page 205: ... 204 6 F 2 S 0 7 8 9 Customer Name Company Name Address Telephone No Facsimile No Signature ...
Page 206: ... 205 6 F 2 S 0 7 8 9 ...
Page 207: ... 206 6 F 2 S 0 7 8 9 Appendix K Technical Data ...
Page 220: ... 219 6 F 2 S 0 7 8 9 ...
Page 221: ... 220 6 F 2 S 0 7 8 9 Appendix M Symbols Used in Scheme Logic ...
Page 224: ... 223 6 F 2 S 0 7 8 9 ...
Page 225: ... 224 6 F 2 S 0 7 8 9 Appendix N Implementation of Thermal Model to IEC60255 8 ...
Page 228: ... 227 6 F 2 S 0 7 8 9 ...
Page 229: ... 228 6 F 2 S 0 7 8 9 Appendix O IEC60870 5 103 Interoperability and Troubleshooting ...
Page 241: ... 240 6 F 2 S 0 7 8 9 Appendix P Modbus Interoperability ...
Page 255: ... 254 6 F 2 S 0 7 8 9 ...
Page 256: ... 255 6 F 2 S 0 7 8 9 Appendix Q Inverse Time Characteristics ...
Page 259: ... 258 6 F 2 S 0 7 8 9 ...
Page 260: ... 259 6 F 2 S 0 7 8 9 Appendix R Failed Module Tracing and Replacement ...
Page 266: ... 265 6 F 2 S 0 7 8 9 Appendix S Ordering ...
Page 269: ... 268 6 F 2 S 0 7 8 9 3 1 Oct 2 2017 Republished under spin off company ...
Page 270: ......