Series-CDTC

Supported Applications

The Series CDTC Communicating Carbon Dioxide Detector combines the function of several room sensors into a single, compact housing. Each unit measures carbon dioxide, temperature, and temperature set point with override, making it a practical all-in-one sensor for demand-controlled ventilation in occupied spaces. Unlike the companion CDTA line, the CDTC does not include a humidity sensor.

Because communication is field-selectable between Modbus® and BACnet, the detectors can be daisy chained with only four wires for both power and communication signal, which streamlines wiring in building-automation and retrofit projects. Install away from locations with severe shock or vibration, excessive moisture, or corrosive fumes, and disconnect the power supply before installation to prevent electrical shock and equipment damage.

Operating Conditions & Performance

The CO2 sensor measures either 0 to 2000 or 0 to 5000 PPM depending on model, and the temperature channel measures across 0 to 50°C.

• CO2 accuracy: ±40 PPM ±3% of reading on the 2000 PPM model and ±50 PPM ±5% of reading on the 5000 PPM model.
• Temperature accuracy: ±1°C at 25°C.
• Response time: 2 minutes.
• Power requirements: 10-42 VDC / 10-30 VAC, with a 1/8 unit device load.
• Output: 2-wire RS-485, Modbus® RTU or BACnet MS/TP communication protocol.

The sensing elements are an NDIR CO2 sensor with a 15 year life expectancy and a 10KΩ thermistor for temperature. The device operates from 0 to 50°C with an ambient humidity limit of 0 to 85% (non-condensing). It measures 114.30 mm high by 71.12 mm wide by 27.69 mm deep and weighs 4.4 oz (125 g). A 120Ω terminating resistor can be switched in between A[-] and B[+]. Agency approvals are BTL and CE.

Configuration Options

All models share the same communicating platform, four-wire daisy-chain wiring, and set-point-with-override capability; they differ by CO2 measuring range and display option.

• CO2 range: models are offered for either a 0 to 2000 PPM or a 0 to 5000 PPM span.
• Display: an on-board LCD version is available to show any of the measured parameters.
• Set point range: the temperature set point is field adjustable, defaulting to 20°C for the low limit and 35°C for the high limit and spanning from 0°C up to 50°C.

Key Product Differences

The lineup pairs each CO2 range with a display option:

• CDTC-2N000 — 2000 PPM CO2 detector without display.
• CDTC-2N000-LCD — 2000 PPM CO2 detector with LCD.
• CDTC-5N000 — 5000 PPM CO2 detector without display.
• CDTC-5N000-LCD — 5000 PPM CO2 detector with LCD.