Greystone Energy Systems CHTDT Modbus Series Installation Instructions Manual

network connection to offer a single-point solution for control of indoor air quality and comfort. Features
include a back-lit LCD and user menu for easy installation.
BEFORE INSTALLATION
Read these instructions carefully before installing and commissioning the transmitter. Failure to follow
these instructions may result in product damage. Do not use in an explosive or hazardous environment,
with combustible or flammable gases, as a safety or emergency stop device or in any other application
where failure of the product could result in personal injury. Take electrostatic discharge precautions
during installation and do not exceed the device ratings.
NOTE: This CO2 sensor incorporates a Self Calibration feature to correct CO2 sensor drift. This feature is
recommended for applications where the CO2 will be exposed to fresh air (400 ppm) at least one hour per
day. If the monitored space is occupied 24 hours or consistently maintains higher or lower levels of CO2, it
is recommended that this feature be turned off, but yearly calibration will be required. If the self calibration
is disabled at installation time without allowing for 7 day auto calibration cycle, then a manual calibration
should be performed to ensure accuracy of the device.
MOUNTING
The duct type sensor installs on the outside of a return air duct with the sampling tube inserted into the
duct.
Mount the sensor in an easily accessible location in a straight section of duct at least five feet from corners
and other items that may cause disturbances in the air flow. Avoid areas where the detector is exposed to
vibrations or rapid temperature changes.
The duct CO detector principal of operation
2
is based on the Venturi effect of the probe
that extends into the HVAC duct. Air flowing
through the duct is forced into the vent holes
on one side of the probe, into the enclosure,
over the CO sensor and then is drawn back
2
out of the enclosure via the probe vent holes
on the opposite side.
NOTE to ensure proper humidity and
temperature readings, the RH/T inlet on the
probe must be installed directly into the
airflow. See Figure 1.
Drill or punch a 7/8" or 1" hole in the duct at the
preferred location and insert the probe into the
hole to mark the enclosure mounting holes.
Remove the unit and drill the two mounting
holes. Clean all drilled holes of debris before
mounting the device.
IN-GE-CHTDTXXXMOD-04
INTRODUCTION
The CO2/RH/T transmitter incorporates three sensors in one duct mount
enclosure for the most efficient environmental monitoring and control
system. It uses Infrared Technology to monitor CO2 levels within a
range of 0 – 10000 ppm, a field-proven RH sensor to monitor relative
humidity from 0-100 %RH and a curve-matched thermistor to measure
temperature over common field-selectable ranges. The device includes
an LCD for configuration and operating parameters are programmed
using a keypad for specific applications. Options include a control relay.
The device includes Native Modbus MS/TP RTU protocol and an RS-485
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Duct Carbon Dioxide/Humidity/
Temperature Transmitter
CHTDT Modbus Series - Installation Instructions
Figure 1
Figure 2
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