PRS-7910
58 PRS-7910
12 Maintenance
12.1 Maintenance Schedule
It is recommended that products supplied by CYG receive periodic monitoring after installation. In
view of the critical nature of protective relays and their infrequent operation, it is desirable to
confirm that they are operating correctly at regular intervals.
This relay is self-supervised and so requires less maintenance than earlier designs of relay. Most
problems will result in an alarm so that remedial action can be taken. However, some periodic
tests should be done to ensure that the relay is functioning correctly and the external wiring is
intact.
12.2 Regular Testing
The relay is almost completely self-supervised. The circuits which can not be supervised are
binary input, output circuits and human machine interfaces. Therefore regular testing can be
minimized to checking the unsupervised circuits.
12.3 Failure Tracing and Repair
Failures will be detected by automatic supervision or regular testing.
When a failure is detected by supervision, a remote alarm is issued and the failure is indicated on
the front panel with LED indicators and LCD display. It is also recorded in the alarm record.
Failures detected by supervision are traced by checking the history alarm reports through the HMI.
See Section 8.3.2 for the details of the alarm events.
When a failure is detected during regular testing, confirm the following:
• Test circuit connections are correct
• Modules are securely inserted in position
• Correct DC power voltage is applied
• Correct AC inputs are applied
• Test procedures comply with those stated in the manual
12.4 Replace Failed Modules
If the failure is identified to be in the relay module and the user has spare modules, the user can
recover the protection by replacing the failed modules.
Repair at the site should be limited to module replacement. Maintenance at the component level is
not recommended.
Check that the replacement module has an identical module name and hardware type-form as the
To Next Page
Loading...
Need help?
General