59
6
F
2
S
0
7
8
9
Watchdog Timer
A hardware timer which is cleared periodically by software is provided and it is checked that the
software is running normally.
DC Supply monitoring
The secondary voltage level of the built-in DC/DC converter is monitored and checked that the
DC voltage is within a prescribed range.
3.3.3 Failure Alarms
When a failure is detected by the automatic supervision, it is followed with LCD display, LEDs
indication, external alarms and event recording. Table 3.3.1 summarizes the supervision items
and alarms.
The LCD messages are shown on the "Auto-supervision" screen which is displayed
automatically when a failure is detected or displayed by pressing the
VIEW
key. The event
record messages are shown on the "Event record" screen by opening the "Record" sub-menu.
Those alarms are retained until the failure is recovered.
Those alarms can be disabled collectively by setting the scheme switch [AMF] to OFF. The
setting is used to block unnecessary alarms during commissioning test or maintenance.
When the Watchdog Timer detects that the software fails to running normally, LCD display and
event recording on the failure cannot be expected.
DC supply failure disables the LCD display and event recording on the failure as well.
For the discrimination of the two failures mentioned above, refer to Section 6.7.2.
Table 3.3.1 Supervision Items and Alarms
Supervision Item
LCD Message LED
"IN SERVICE"
LED
"ALARM"
Ext. alarm
Event record
Message
AC input
imbalance monitoring
(1)
On/Off (2)
On
(4)
CT err
Relay fail
A/D accuracy check
(1)
Off
On
(4)
Relay fail
Memory monitoring
Watchdog Timer
----
Off
On
(4)
----
DC supply monitoring
----
Off
(3)
(4)
Relay fail
(1): Diverse messages are provided as expressed with "---fail" in the Table in Section 6.7.2.
(2): The LED is on when the scheme switch [SVCNT] is set to "ALM" and off when set to
"ALM & BLK" (refer to Section 3.3.4).
(3): Whether the LED is lit or not depends on the degree of the voltage drops.
(4): The binary output relay "FAIL" operates.
3.3.4 Trip Blocking
When a failure is detected by the following supervision items, the trip function is blocked as long
as the failure exists and restored when the failure is removed.
A/D accuracy check
Memory monitoring
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: ......