Note:
For 5A CT secondaries, we recommend using 2 x 2.5 mm
2
PVC insulated multi-stranded copper wire.
4.5 VOLTAGE TRANSFORMER CONNECTIONS
Voltage transformers should be wired with 2.5 mm
2
PVC insulated multi-stranded copper wire terminated
with M4 ring terminals.
The wire should have a minimum voltage rating of 300 V RMS.
4.6 WATCHDOG CONNECTIONS
These should be wired with 1 mm PVC insulated multi-stranded copper wire terminated with M4 ring
terminals.
The wire should have a minimum voltage rating of 300 V RMS.
4.7 EIA(RS)485 AND K-BUS CONNECTIONS
For connecting the EIA(RS485) / K-Bus ports, use 2-core screened cable with a maximum total length of
1000 m or 200 nF total cable capacitance.
A typical cable specification would be:
●
Each core: 16/0.2 mm
2
copper conductors, PVC insulated
●
Nominal conductor area: 0.5 mm
2
per core
● Screen: Overall braid, PVC sheathed
To guarantee the performance specifications, you must ensure continuity of the screen, when daisy chaining
the connections.
4.8 IRIG-B CONNECTION
The IRIG-B input and BNC connector have a characteristic impedance of 50 ohms. We recommend that
connections between the IRIG-B equipment and the product are made using coaxial cable of type RG59LSF
with a halogen free, fire retardant sheath.
4.9 OPTO-INPUT CONNECTIONS
These should be wired with 1 mm
2
PVC insulated multi-stranded copper wire terminated with M4 ring
terminals.
Each opto-input has a selectable preset ½ cycle filter. This makes the input immune to noise induced on the
wiring. This can, however slow down the response. If you need to switch off the ½ cycle filter, either use
double pole switching on the input, or screened twisted cable on the input circuit.
Caution:
Protect the opto-inputs and their wiring with a maximum 16
A high rupture
capacity (HRC) type NIT or TIA fuse.
4.10 OUTPUT RELAY CONNECTIONS
These should be wired with 1 mm PVC insulated multi-stranded copper wire terminated with M4 ring
terminals.
Chapter 13 - Installation MiCOM P747
338 P747-TM-EN-1