51
5.
Commissioning and maintenance
The relay should be subject to regular tests and maintenance in
accordance with national regulations and instructions.
Prior to commissioning, the functionality of the application-specific relay
configuration and settings have to be tested.
During relay commissioning, the operation of short-circuit and ground-fault
protection is to be tested by using secondary injection testing to secure personal
safety. Additionally, correct operation of input and output signals to and from the
relay should be verified.
The relay is a numerical protection relay with functionality implemented in the relay
software configuration. Software functionality does not change over time and the
relay performs extensive self-supervision during operation. Therefore, it is not
necessary to perform extensive relay testing during periodic maintenance.
When the protection relay is operating under the specified conditions (refer to the
Technical Reference Manual), the manufacturer recommends preventive
maintenance to be performed every five years. This periodically performed
preventive maintenance is to be carried out to secure correct and safe operation of
the relay. When performing preventive maintenance, the correct functionality of the
relay is to be verified as well as the wiring circuitry to and from the relay.
If the environmental conditions at the relay operating site differ from
those specified, for instance temperature and humidity, or if the
atmosphere around the relay contains chemically active gases or dust,
the relay ought to be visually inspected.
At the visual inspection, the following should be observed:
*
Signs of mechanical damage on the relay, contacts and relay case.
*
Rust spots or signs of corrosion on the terminals or case.
Do not open the secondary circuit of a current transformer during any
phase of the testing when the primary circuit is live. The high voltage
generated by an open CT secondary circuit may be lethal and damage
instruments and insulation.
5.1.
Commissioning instructions
Relay commissioning is carried out to confirm correct operation of the relay when it
is taken into use.
Feeder Protection Relay
Operator's Manual - ANSI Version
REF 610
REF 610
1MRS755539
