General - Siemens SIPROTEC 7SJ62 Instruction Manual

Routine Checks and Maintenance
9.1

General

9-2
Siemens numerical protective and control SIPROTEC
maintenance. All measurement and signal processing circuits are fully solid state. All
input modules are also fully solid state. The output relays are hermetically 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" contact drops out to provide an alarm. Messages related to the prob-
lem are given in the Event Log. If a problem is detected in the external measuring cir-
cuitry, the device will typically give a message in the Event Log. The output contacts
are programmable; therefore, alarms for device failures can be configured by the user.
Recognized software failures result in the resetting and restarting of the processor
system. If such a failure is not resolved by the restart, further restarts are initiated. If a
problem is still present after three restart attempts, the device is automatically 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 Event Log. The messages can be used to diagnose the problem. See
Sub-section 7.1.1.
When the device communicates with a substation controller (SCADA), the event and
alarm messages are also sent over the serial interface.
®
4 devices require no special
7SJ62 Manual
C53000-G1140-C121-1