Areva MiCOM P441, Техническое руководство

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Relay Description P44x/EN HW/E33
MiCOM P441/P442 & P444 Page 11/44
2.5.1 Power supply board (including RS485 communication interface)
One of three different configurations of the power supply board can be fitted to the relay.
This will be specified at the time of order and depends on the nature of the supply voltage
that will be connected to the relay. The three options are shown in table 1 below.
Nominal dc range Nominal ac range
24 – 48V dc only
48 – 110V 30 – 100V rms
110 – 250V 100 – 240V rms
TABLE 1 - POWER SUPPLY OPTIONS
The output from all versions of the power supply module are used to provide isolated power
supply rails to all of the other modules within the relay. Three voltage levels are used within
the relay, 5.1V for all of the digital circuits, •16V for the analogue electronics, e.g. on the
input board, and 22V for driving the output relay coils. All power supply voltages including
the 0V earth line are distributed around the relay via the 64-way ribbon cable. One further
voltage level is provided by the power supply board which is the field voltage of 48V. This is
brought out to terminals on the back of the relay so that it can be used to drive the optically
isolated digital inputs.
The two other functions provided by the power supply board are the RS485 communications
interface and the watchdog contacts for the relay. The RS485 interface is used with the
relay’s rear communication port to provide communication using one of either Courier,
Modbus or IEC60870-5-103 protocols. The RS485 hardware supports half-duplex
communication and provides optical isolation of the serial data being transmitted and
received.
All internal communication of data from the power supply board is conducted via the output
relay board which is connected to the parallel bus.
The watchdog facility provides two output relay contacts, one normally open and one
normally closed which are driven by the processor board. These are provided to give an
indication that the relay is in a healthy state.
2.5.2 Output relay board
The output relay board holds seven relays, three with normally open contacts and four with
changeover contacts. The relays are driven from the 22V power supply line. The relays’ state
is written to or read from using the parallel data bus. Depending on the relay model seven
additional output contacts may be provided, through the use of up to three extra relay
boards.
2.6 IRIG-B board (P442 and P444 only)
The IRIG-B board is an order option which can be fitted to provide an accurate timing
reference for the relay. This can be used wherever an IRIG-B signal is available. The IRIG-B
signal is connected to the board via a BNC connector on the back of the relay. The timing
information is used to synchronise the relay’s internal real-time clock to an accuracy of 1ms.
The internal clock is then used for the time tagging of the event, fault maintenance and
disturbance records.
The IRIG-B board can also be specified with a fibre optic transmitter/receiver which can be
used for the rear communication port instead of the RS485 electrical connection (IEC60870
only).
2.7 2nd rear communication and InterMiCOM teleprotection board (optional)
On ordring this board within a relay, both 2nd rear communications K-Bus and InterMiCOM
(available in next version C1.0) will become connection and settings options. The user may
then either one, or both, as demanded by the installation.
SK4 : The second rear communications port runs the courier language. This can be used
over one of three physical links : twisted pair K-Bus (non polarity sensitive), twisted pai
EIA(RS)485 (connection polarity sensitive) or EIA(RS)232.