
T3A Transmitter • 17
Figure 5: Wiring Power and Signal Wiring
7. If shielded cable is used, connect the cable’s drain wire to an available chassis (earth)
ground at the controller. RKI controllers typically have a ground stud that can be used to
ground the cable’s drain wire.
Connecting RS-485 Modbus
The T3A supports Modbus RTU over a RS-485 link.
1. If necessary, unscrew the enclosure lid and pull the internal system out by the
thumbscrews.
CAUTION:
Be sure power to the T3A is off before pulling out the internal system.
2. Feed the RS-485 cable through the power hub and into the enclosure.
WARNING: Use appropriate construction technique to maintain the explosion proof
classification of the assembly.
3. Connect the RS-485 B (BROWN) wire to the
B
terminal.
Table 3: T3A Terminal Block Wire Gauges
Terminal Block
Wire Gauge
Power terminal
Min: 26 AWG
Max: 14 AWG
Relay 1 & 2 terminal
Modbus terminal
Min: 26 AWG
Max: 16 AWG
Fault terminal
Содержание 71-0533
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