ABB LWT300 Series Quick Start Manual page 3

Basic physical installation
Below is a list of basic steps necessary to properly install LWT series instruments, as recommended by
ABB. All installations should be performed by certified and authorized personnel in accordance with all
applicable local security codes (electrical, engineering, etc.).
Here are the basic installation steps:
1 Access and properly secure the installation site (vessel depressurization and cool down, mains power
down, etc.).
2 Attach the probe to the head/coupler assembly (once it is attached, handle it carefully to avoid
bending the coupler/probe assembly).
3 Slide the probe in the vessel and attach the probe/coupler assembly on the flange.
4 Connect the mains to the head unit.
5 Power up and configure the instrument.
The steps indicated above are explained in more detail in the LWT series User Guide.
Simple connection diagram
Here is a simple power connection diagram for LWT series instruments installed in a non-explosive
location.
—
Figure 2
Modbus connection diagram
Power supply
10.5 to 28.5 V DC
Modbus®
A (+)
Master
Device
B (–)
NOTICE
Replace the temporary plastic caps with hermetic caps and/or cable glands rated for the
environment.
+
–
RS-485
Communication
Link
LWT300 series (Modbus) Quick Start Guide
+
A (+)
PWR
–
B (–)
LWT Modbus®
GND
Instrument
3