Intermicom 64 Communication - GE MiCOM P40 Agile Technical Manual

Chapter 25 - Commissioning Instructions
7

INTERMICOM 64 COMMUNICATION

If the IED is used in a scheme with InterMiCOM
purposes.
IM64 is fibre-based. Several different fibre-optic interfaces are available. In general, 1550 nm single-mode fibres, or
1300 nm single-mode or multimode fibres are used for direct connection. 850 nm multimode fibres are generally
used with multiplexing telecommunications equipment.
Note:
It is important that fibres used for testing are correct for the specified interface(s).
Optical fibres should be terminated with BFOC2.5 (ST2.5) connectors. For multimode applications use 50/125 µm
core fibre. Make sure fibre test leads used for measurements are long enough for mode stripping (a method of
reducing loss within the core). We recommend a minimum length of 10 m (30ft) for this.
If IEDs communicate using multiplexed electrical communication channels, a bidirectional optical-to-electrical
signal converter, such as a P59x, is used. The P59x range consists of three devices: P591 for G703, P592 for V.35
and P593 for X.21.
The P59x is situated near the multiplexer, between the fibre from the IED and the electrical interface of the
multiplexer. Apply the loopback either at the P59x or the multiplexer to ensure as much of the circuit as possible is
tested. If the IED is connected to a multiplexer, the loopback testing is exactly the same whether connected directly
or via a multiplexer. The P59x interface units require additional tests (see P59x documentation).
If Current Differential protection is used, set CONFIGURATION > Current Diff to Enable.
If Current Differential protection is not used, set CONFIGURATION > InterMiCOM64 to Enable.
Warning:
NEVER look directly into the transmit port or the end of an optical fibre, as this could
severely damage your eyes.
7.1 CHECKING THE INTERFACE
Before carrying out the loopback test, you need to check that the interface is transmitting a suitable signal. To
check this ...
1. Set COMMISSIONING TEST > Loopback Mode to External.
2. Using an appropriate fibre-optic cable, connect the Channel 1 transmitter (TX1) to an optical power meter.
Check that the average power transmitted is within the range given in the following table.
3. Record the transmit power level.
4. Repeat for Channel 2 if applicable.
Power
Maximum transmitter power (average value)
Minimum transmitter power (average value)
654
64
communication, you need to configure a loopback for testing
850 nm
multi-mode
-19.8 dBm
-22.8 dBm
1300 nm
multi-mode
-3 dBm
-9 dBm
P543i/P545i
1300/1550 nm
single-mode
-3 dBm
-9 dBm
P54x1i-TM-EN-1