Commissioning P54x/EN CM/La4
MiCOM P543, P544, P545 & P546
CM) 10-25
CM
Pin Connection
1 No Connection
2 RxD
3 TxD
4 DTR#
5 Ground
6 No Connection
7 RTS#
8 CTS#
9 No Connection
Table 7: Second rear communications port EIA(RS)232 terminals
# - These pins are control lines for use with a modem.
Connections to the second rear port configured for EIA(RS)232 operation can be made using
a screened multi-core communication cable up to 15 m long, or a total capacitance of
2500 pF. The cable should be terminated at the relay end with a 9-way, metal shelled,
D-type male plug. The terminal numbers for the relays EIA(RS)232 port are given in
Table 7.
Ensure that the communications baud rate and parity settings in the application software are
set the same as those in the relay. The relays courier address in cell [0E90:
COMMUNICATIONS, RP2 Address] must be set to a value between 1 and 254. The second
rear communications port configuration [0E88: COMMUNICATIONS RP2 Port Config.] must
be set to EIA(RS)232.
Check that communications can be established with this relay using the portable PC.
5.2.10 Current inputs
This verifie
s that the accuracy of current measurement is within the acceptable tolerances.
All relays will leave the factory set for operation at a system frequency of 50 Hz.
If operation at 60 Hz is required then this must be set in cell [0009: SYSTEM
DATA, Frequency].
Apply current equal to the line current transformer secondary winding rating to each current
transformer input of the corresponding rating in turn, see Table 1 or external connection
diagram (P54x/EN IN) for appropriate terminal numbers, checking its magnitude using a
multimeter/test set readout. The corresponding reading can then be checked in the relay’s
MEASUREMENTS 1 column and value displayed recorded.
The measured current values displayed on the relay LCD or a portable PC connected to the
front communication port will either be in primary or secondary Amperes. If cell [0D02:
MEASURE’T SETUP, Local Values] is set to ‘Primary’, the values displayed should be equal
to the applied current multiplied by the corresponding current transformer ratio set in the ‘CT
and VT RATIOS’ menu column (see Table 8). If cell [0D02: MEASURE’T SETUP, Local
Values] is set to ‘Secondary’, the value displayed should be equal to the applied current.
Note: If a PC connected to the relay via the rear communications port is
being used to display the measured current, the process will be
similar. However, the setting of cell [0D03: MEASURE’T SETUP,
Remote Values] will determine whether the displayed values are in
primary or secondary Amperes. The measurement accuracy of the
relay is ±1%. However, an additional allowance must be made for the
accuracy of the test equipment being used.
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