Copyright HK Instruments 2021
www.hkinstruments.fi
Installation version 7.0 2021
INSTALLATION
INSTRUCTIONS
CARBON DIOXIDE TRANSMITTERS
CDT-MOD-2000 Series
• READ THESE INSTRUCTIONS CAREFULLY BEFORE
ATTEMPTING TO INSTALL, OPERATE OR SERVICE THIS
DEVICE.
• Failure to observe safety information and comply with
instructions can result in PERSONAL INJURY, DEATH AND/OR
PROPERTY DAMAGE.
• To avoid electrical shock or damage to equipment, disconnect
power before installing or servicing and use only wiring with
insulation rated for full device operating voltage.
• To avoid potential fire and/or explosion do not use in potentially
flammable or explosive atmospheres.
• Retain these instructions for future reference.
• This product, when installed, will be part of an engineered
system whose specifications and performance characteristics
are not designed or controlled by HK Instruments. Review
applications and national and local codes to assure that the
installation will be functional and safe. Use only experienced and
knowledgeable technicians to install this device.
Thank you for choosing an HK Instruments CDT-MOD-2000 series
carbon dioxide transmitter. The CDT-MOD-2000 series is intended
for use in commercial environments in HVAC/R applications. The
CDT-MOD-2000 series measures carbon dioxide (CO
2
), utilizing the
industry standard NDIR measurement principle, and temperature
(T). Optional relative humidity (rH) measurement is also available in
the same device. The CDT-MOD-2000 series devices are available
with large touchscreen display making the configuration of the de-
vice quick and easy. Configuration is also possible via Modbus net-
work.
The CDT-MOD-2000 series transmitters calibrate themselves auto-
matically using ABC
TM
logic. The ABC
TM
logic requires that the space
in which the transmitter is used needs to to be unoccupied for four
hours per day so that the indoor CO
2
concentration drops to the
outside level. CDT-MOD-2000-DC is a dual channel model with a
measuring channel and a reference channel that makes a continuous
comparison and the necessary adjustment accordingly. CDT-MOD-
2000-DC is also suitable for buildings that are continuously occu-
pied.
• humidity in various industrial applications
• temperatures in HVAC/R environment
• CDT-MOD-2000-DC series devices can also be used in applications
where there is a constant source of carbon dioxide present (for
example hospitals and greenhouses)
SPECIFICATIONS
Performance
Measurement ranges:
CO
2
: 400–2000 ppm
Temperature: 0...50 °C
Relative humidity: 0–100 %
Accuracy:
CO
2
: ±40 ppm + 2 % of reading, DC model: 75 ppm or 10 %
of reading (whichever is greater)
Temperature: <0.5 ºC
Relative humidity: ±2...3 % at 0...50 °C and 10–90 % rH
Total error band includes accuracy, hysteresis and
temperature effect over 5...50 °C and 10–90% rH.
Technical Specifications
Media compatibility:
Dry air or non-aggressive gases
Measuring units:
ppm, °C and % rH
Measuring element:
CO
2
: Non-dispersive infrared (NDIR)
Temperature:
Pt1000 (models without rH-measurement)
Integrated (models with rH-measurement)
Relative humidity: Thermoset polymer capacitive sensing
element
Calibration:
Automatic self-calibration ABC Logic
TM
or continuous
comparison (DC)
Environment:
Operating temperature: 0...50 °C
Storage temperature: -20...70 °C
Humidity: 0 to 95 % rH, non condensing
Physical
Dimensions:
Case: 99 x 90 x 32 mm
Weight:
150 g
Mounting:
3 screw holes slotted, 3.8 mm
Materials:
Case: ABS
Protection standard:
IP20
Display (Optional)
Touchscreen
Size: 77.4 x 52.4 mm
Electrical connections:
Power supply:
5-screw terminal block
(24 V, GND)
0.2–1.5 mm
2
(12–24 AWG)
Relay out:
3-screw terminal block
(NC, COM, NO)
0.2–1.5 mm
2
(12–24 AWG)
Electrical
Input: 24 VAC or VDC, ±10 %
Current consumption: max 90 mA (at 24 V) +
10 mA for each voltage output or 20 mA for
each current output
Relay out:
SPDT Relay, 250 VAC / 30 VDC / 6 A
Adjustable switching point and hysteresis
One analog output for selected media:
0/2*–10 VDC, Load R minimum 1 kΩ
*(2–10 VDC display models only)
or
4–20 mA, maximum load 500 Ω
Communication
Protocol: MODBUS over Serial Line
Transmission Mode: RTU
Interface: RS485
Byte format (11 bits) in RTU mode:
Coding System: 8-bit binary
Bits per Byte:
1 start bit
8 data bits, least significant bit sent
first
1 bit for parity
1 stop bit
Baud rate: selectable in configuration
Modbus address: 1−247 addresses selectable in
configuration menu
Conformance
Meets requirements for CE marking:
EMC Directive 2014/35/EU
RoHS Directive 2011/65/EU
LVD Directive 2014/35/EU
WEEE Directive 2012/19/EU
INTRODUCTION
APPLICATIONS
WARNING
CDT-MOD-2000 series devices are commonly used to monitor:
• CO
2
and humidity levels in offices, public spaces, meeting rooms
and classrooms
• CO
2
levels of return air in ventilation systems
• incoming air and return air humidity levels in ventilation system
COMPANY WITH
MANAGEMENT SYSTEM
CERTIFIED BY DNV GL
= ISO 9001 = ISO 14001 =
RoHS 2
2011/65/EU
