Xylem H-4161 - Manual (Page 9)

Chapter 2
Installation And Maintenance
H-4161
Installation And Maintenance 2-1
2.1 General Installation Recommendations
The enclosure and connectors are not weather tight. The H-4161 must be installed in a protected location
or a weather tight enclosure. The enclosure has a 5-terminal connector for making power and SDI-12
connections and a 2-terminal connector for connecting the 4-20mA output connections. The connectors
can be detached while making the connections.
Caution: Remove all power from the unit before making any connections.
Before beginning the installation take a minute to plan out your station grounding and wiring scheme.
2.2 Making Power and SDI-12 connections
Connect the +12V and GND terminals to a 12V power source. If the H-4161 is to be used to Monitor,
connect the primary SDI-12 data terminal to the SDI-12 bus between your data logger and its sensors. If
the H-4161 is to be used to Initiate, connect the auxSDI-12 terminal to the sensor to be monitored. The
sensor address of the sensor connected to the auxSDI-12 terminal must be “0" (this cannot be changed in
the H-4161). The sensor address must be set before connecting the sensor to the H-4161.
2.3 Making the 4-20mA connections
The H-4161 has a 2-wire “self powered” current loop transmitter. Current loop sensors output a current
rather than a voltage. The 4-20mA output will drive standard industrial telemetry and process control
instrumentation. Use shielded twisted-pair cable and take precautions to protect the wiring from noise
and interference. Your loop power source, loop receiver and the H-4161's output should all be connected
in series. The loop power supply must be sufficient to maintain 5.5V to 35V across the H-4161s output
terminals, in addition to whatever voltage is needed to maintain 20mA across the loop receiver and
interconnect wiring. The gauge station +12.0V SDI-12 power source will work if the resistance of your
loop receiver and wiring is less than 250 ohms.
Make certain their is 5.5 to 35V across the 4-20mA output terminals.
Make certain the H-4161 is receiving +12V power from the SDI-12 data bus.
Use shielded, twisted-pair cables for the 4-20mA connections in noisy environments.