ABB Relion 670 Series Commissioning Manual page 168

Section 11
Commissioning and maintenance of the fault clearing system
11.2.2.8 Restoring
Maintenance is very important to improve the availability of the protection system by detecting
failures before the protection is required to operate. There is however little point in testing healthy
equipment and then putting it back into service with an open terminal, with a removed fuse or open
miniature circuit breaker with an open connection, wrong setting, and so on.
Thus a list should be prepared of all items disturbed during test so that all can be put back into
service quickly and without overlooking something. It should be put back into service item by item
and signed by the responsible engineer.
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Commissioning manual