Connecting The Instrument - ABB LWT300 Series User Manual

Connecting the instrument

WARNING
All connections must be established in a de-energized state. Before working on the circuit,
secure the breaker to prevent any accidental power-up.
In an explosion proof/flameproof installation, do not remove the covers while the
instrument is energized.
ELECTROSTATIC DISCHARGES
Electronic components are sensitive to electrostatic discharges.
Before performing any connection, operators shall make sure that they have discharged all
static electricity from their body before touching electronic components.
NOTICE
Ensure that a drip loop
the sensor. If necessary, rotate the transmitter housing as necessary.
—
Figure 19 Typical LWT Modbus connection
Power supply
10.5 to 28.5 V DC
Modbus®
A (+)
Master
Device
B (–)
28
User Guide
1 (water trap) is used when installing the connecting cables for
+
–
RS-485
Communication
Link
+
A (+)
PWR
–
B (–)
LWT Modbus®
GND
Instrument