CaptiveAire RTULink, Installation, Operation And Maintenance Manual

Page: 17 / 56

17
Relative Humidity
– Duct Mount (Return or Discharge)
If a duct mounted humidity sensors is called for in the specifications, follow the instructions in this section.
A duct mounted (return or discharge
duct) humidity sensor (PN: A/RH3-
DO10) shall be installed in the duct of
the RTU.
Figure 17 shows a detail and
terminology of the sensor.
A 1” hole
should be drilled in the duct so the
sensor probe can be inserted into the
airstream. The sensor should be
secured to the duct using the
mounting flanges. Ensure that any
holes in the duct are properly sealed.
Use EMT conduit where sensor wiring
would be exposed to the elements
when routing wire back to the
RTULink control board. Standard 18-
5 thermostat wire should be used for
sensor wiring.
The sensor has a bank of eight dip
switches that control the range of the
output voltage of the humidity sensor.
Switches seven (7) and eight (8) need
to be turned ON and the rest should
remain OFF. These dip switches can
be seen in the sensor detail in
Figure
18 .
Figure 18 is a wiring diagram of a duct
mounted humidity sensor that is wired
to the “RTU” Input 1 on the RTULink.
Once the sensor is wired to an input,
enter the configuration menu via the
onboard HMI and configure the
corresponding input for the humidity
sensor that was installed. In the
example in Figure 18, the sensor was
installed in the return duct, so
“RTU IN
1” would be configured for “RA RH”.
Figure 17. Duct Mount Humidity Sensor
Figure 18. RTULink - Duct Mount RH