Areva MiCOM P341, Operation Manual

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Operation Guide P341/EN O/B11
Commissioning and CHAPTER 3
Maintenance Page 7/80
MiCOM P341
which the relay is supplied have been applied the default settings should be restored
prior to commissioning. This could be done by:
• Obtaining a setting file on a diskette from the customer (this requires a portable
PC with appropriate setting software for transferring the settings from the PC to
the relay)
• Extracting the settings from the relay itself (this again requires a portable PC with
appropriate setting software). If the programmable scheme logic has been
changed from the supplied one, this is the only way of restoring it for
commissioning.
• Manually creating a setting record. This could be done using a copy of the setting
record located at the end of this chapter to record the settings as the relay’s menu
is sequentially stepped through via the front panel user interface.
If password protection is enabled and the customer has changed password 2 that
prevents unauthorised changes to some of the settings, either the revised password 2
should be provided, or the customer should restore the original password prior to
commencement of testing.
Note: In the event that the password has been lost, a recovery password can be
obtained from ALSTOM by quoting the serial number of the relay. The
recovery password is unique to that relay and is unlikely to work on any
other relay.
4.1 With the relay de-energised
The following group of tests should be carried out without the auxiliary supply being
applied to the relay and with the trip circuit isolated.
The current and voltage transformer connections must be isolated from the relay for
these checks. If an MMLG test block is provided, the required isolation can easily be
achieved by inserting test plug type MMLB01 which effectively open-circuits all wiring
routed through the test block.
Before inserting the test plug, reference should be made to the scheme (wiring)
diagram to ensure that this will not potentially cause damage or a safety hazard. For
example, the test block may be associated with protection current transformer circuits.
It is essential that the sockets in the test plug which correspond to the current
transformer secondary windings are linked before the test plug is inserted into the test
block.
DANGER: NEVER OPEN CIRCUIT THE SECONDARY CIRCUIT OF A CURRENT
TRANSFORMER SINCE THE HIGH VOLTAGE PRODUCED MAY BE LETHAL
AND COULD DAMAGE INSULATION.
If a test block is not provided, the voltage transformer supply to the relay should be
isolated by means of the panel links or connecting blocks. The line current
transformers should be short-circuited and disconnected from the relay terminals.
Where means of isolating the auxiliary supply and trip circuit
(e.g. isolation links, fuses, MCB, etc.) are provided, these should be used. If this is
not possible, the wiring to these circuits will have to be disconnected and the exposed
ends suitably terminated to prevent them from being a safety hazard.