Signal Cable Connection; Dc Power Supply; Analog Output - ABB LST100 Operating Instructions Manual

3 Electrical connection

3.2 Signal cable connection

The LST100 is designed to operate from battery and solar
power sources.
Installation notes:
– Use 7-core shielded cable for power supply and signal
connections.
– Use twisted cable with a specific cross section and
length. For longer lines, cable with a greater cross
section is required.
– Use the cable shielding to make ground connections.
The signal cable is connected to the terminals shown in Fig. 3.1.
NOTICE – Property damage
Do not connect the shielding to different grounds
at each end of the cable.
Fig. 3.1: LST 100 electrical terminals
10 OI/LST100-EN | LST100 – Ultrasonic level transmitter

3.2.1 DC power supply

The LST100 operates from a 12 V DC power supply that
is connected to the terminals shown in Fig. 3.
Fig. 3.2: 12 V DC power supply terminals
The power supply voltage is: 9 to 16 V DC.
– The minimum power capability of the battery and solar
power supply is: 120 mW.

3.2.2 Analog output

LST100 has a 1 to 5 V analog output that is connected using
the terminals shown in Fig. 3.3.
Test
Ground (earth)
+
12 V DC
–
+
DAC
–
Fig. 3.3: Analog output terminals
–
RS 485
+
The LST100 uses a 1 to 5 V analog output to display
measurement results and alarm data.
The output voltage is the process variable during normal
conditions. It can also be a fixed value as a failsafe or to
indicate alarm conditions.
– The voltage output range of a valid signal is 0.97 to
5.2 V DC.
– A high alarm is defined as >5.4 V and a low alarm is
defined as <0.95 V.
– The refresh frequency of the 1 to 5 V output is 1 second.
+
12 V DC
–
+
–
IMPORTANT (NOTE)
Use twisted wire to improve resistance to
interference.
DAC