Routine Checks and Maintenance
9-2 7SA6 Manual
C53000-G1176-C156-2
9.1 General
Siemens numerical protective and control SIPROTEC
®
4devicesaredesignedtore-
quire no special maintenance. All measurement and signal processing circuits are fully
solid state. All input modules are also fully solid state. The output relays are hermeti-
cally sealed or provided with protective covers.
Since the device is almost completely self-monitored, from the measuring inputs to the
output relays, hardware and software problems are automatically reported. The self-
monitoring ensures the high availability of the device and generally allows for a cor-
rective rather than preventive maintenance strategy. Therefore, maintenance checks
in short intervals are not required.
Operation of the device is automatically blocked when a hardware failure is detected.
The “live status” relay drops out to provide an alarm by its breaking contact. If a prob-
lem is detected in the external measuring circuits, the device normally only provides
messages.
Recognized software failures result in the resetting and restarting of the processor
system. If such a failure is not resolved by the restart, further restart attempts are ini-
tiated. If a problem is still present after three restart attempts, the device is automati-
cally taken out of service. Then the “live status” contact drops out to provide an alarm
and the red “ERROR” LED on the front panel illuminates.
The reaction of the device to failures and problems can be viewed in chronological se-
quence in the operational messages (event log). See Sub-section 7.1.1. The messag-
es can be used to diagnose the problem.
When the device communicates with a master control system of the substation or oth-
er central control systems, the event and alarm messages are also sent over the serial
interface.
To Next Page
Loading...
Need help?
General