Commissioning P54x/EN CM/La4
MiCOM P543, P544, P545 & P546
CM) 10-57
CM
9. END TO END PROTECTION COMMUNICATION TESTS
If, as is likely to be the case, the P54x relay is being used in a scheme with phase differential
or InterMiCOM
64
communications it will be necessary to perform end-to-end tests of the
protection communications channels. If this is not the case, skip to section 11.
I
n section 6 communications loopbacks were applied to enable completion of the local end
tests. In this sectio
n any loopbacks are removed and, if possible, satisfactory
communications between line ends of the P54x relays in the scheme will be confirmed.
Note: End-to-end communication requires the provision of a working
telecommunication channel between line ends (which may be a
multiplexed link or may be a direct connection). If the
telecommunication channel is not available, it will not be possible to
establish end-to end communication. Nonetheless unless otherwise
directed by local operational practice, the instructions in section 9
sho
uld be followed such that the scheme is ready for full operation
when the telecommunications channels becomes available.
Note: The trip circuit should remain isolated during these checks to prevent
accidental operation of the associated circuit breaker.
9.1 Remove local loopbacks
As
well as removing the loopback test, this section checks that all wiring and optical fibers
are reconnected. If P592 or P593 interface units are installed the application-specific
settings will also be applied.
Check the alarm records to ensure that no communications failure alarms have occurred
whilst the loopback test has been in progress. Note that if it was necessary to ‘fail’ the
communications whilst testing the non-current differential elements, it may be prudent to
observe the communications behavior for a few minutes before proceeding to remove the
loopbacks.
Set cell [0F15 Test Mode] to ‘Disabled’.
Set cell [0F13 Loopback Mode] to ‘Disabled’.
Restore the communications channels as per the appropriate sub-section below.
9.1.1 Direct fiber and C37.94 connections
I
n section 6.1, most of the required optical signal power levels were measurements were
taken. If all signaling
uses P59x interface units, then no further measurements are required.
If direct fiber or C37.94 communications are used then it will be necessary to make further
measurements.
9.1.1.1 Direct fiber connections
It is nece
ssary to check the optical power level received from the remote relay(s).
Remove the loopback test fiber(s) and at both ends of each channel used, reconnect the
fiber optic cables for communications between relays, ensuring correct placement.
When connecting or disconnecting optical fibers care should be taken not to look
directly into the transmit port or end of the optical fibers.
For each channel fitted, in turn, remove the fiber connecting to the optical receiver (RX) and,
using an optical power meter measure the strength of the signal received from the remote
relay. The measurements should be within the values shown in the tables below :-
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