Therm-Copper-Ave

Supported Applications

The ACI Thermistor Copper Averaging Sensors are multi-point temperature sensors designed for use with electronic controllers in commercial heating and cooling building management systems. The series provides a better average temperature of the air inside the duct compared to single point duct sensors.

• Duct air temperature averaging
• Commercial HVAC control loops

Operating Conditions & Performance

The Copper variation operates within a process and measurement range of -40 to 80 °C (-40 to 185 °F). The Flexible variation, available in the broader family context but distinct from this specific copper series title, covers 0 to 75 °C (32 to 167 °F) for process and measurement. Ambient operating temperatures vary by enclosure: -40 to 115 °C (-40 to 239 °F) for Galvanized Steel [GD] and Aluminum [BB]; -30 to 90 °C (-22 to 194 °F) for ABS Plastic [PB]; and -40 to 70°C (-40 to 158°F) for Polystyrene Plastic [4X]. Operating humidity is rated at 10 to 95% RH, non-condensing.

Accuracy specifications depend on the sensor series and probe length. For standard thermistor configurations (excluding A/1.8K and A/10KS), accuracy is +/-0.20 °C (+/-0.36 °F) for both 8' & 12' lengths and 24' & 50' lengths within the 0-70°C range. The A/1.8K Series lists an accuracy of +/-1.00 °C (+/-1.80 °F), while the A/10KS Series is rated at +/-0.60 °C (+/-1.10 °F). Response time (63% step change) is 15 Seconds nominal.

Configuration Options

Sensor Elements and Outputs

• A/1.8K: 1.8 KΩ nominal (Red/Yellow)
• A/3K: 3 KΩ nominal (White/Brown)
• A/AN (Type III): 10 KΩ nominal (White/White)
• A/AN-BC: 5.238 KΩ nominal (White/Yellow)
• A/CP (Type II): 10 KΩ nominal (White/Green)
• A/CSI: 10 KΩ nominal (Green/Yellow)
• A/10KS: 10 KΩ nominal (White/Blue)
• A/10K-E1: 10 KΩ nominal (Orange/Gray or Gray/Orange depending on source context, listed as Orange/Gray in primary data sheet table)
• A/20K: 20 KΩ nominal (Brown/Blue)
• A/50K: 50 KΩ nominal (Brown/Yellow)
• A/100KS: 100 KΩ nominal (Black/Yellow)

Probe Configuration

The series features a copper sensing element with a diameter of 0.210" (5.34 mm) nominal. Lead wires are Etched Teflon (PTFE) Colored Leads meeting MIL-W-16878/4 (Type E). The number of sensing points is determined by probe length: four sensing points for 8' and 12' lengths, and nine sensing points for 24' and 50' lengths. Electrical connections utilize two non-polarity sensitive wires.

Enclosures

• -GD Enclosure: Galvanized Steel, NEMA 1 (IP10)
• -PB Enclosure: ABS Plastic, UL94-HB, Plenum Rated
• -BB Enclosure: Aluminum, NEMA 3R (IP 14)
• -4X Enclosure: Polystyrene Plastic, UL94-V2, NEMA 4X (IP 66)

Accessories and Options

The series supports optional copper capillary mounting clips (ACI Item #130525) or universal plastic mounting clips (ACI Item #145421). NIST certificates are available as an option.

Key Product Differences

Variants differ primarily by sensor series output resistance, probe length (8', 12', 24', 50'), and enclosure type. The model number guide follows the format: A/ - - - - - . For example, a standard configuration is represented as A/1.8K-A-12-GD-NIST.

The copper sensing element provides improved thermal conductivity and higher corrosion resistance compared to aluminum style averaging sensors. The sensor elements are sealed to prevent moisture intrusion and include a foam pad (Neoprene/EPDM/SBR Polymer) to seal the duct and dampen vibrations. Installation requires drilling a 3/8" (9.53 mm) hole in the duct, with bends for copper tubing having a minimum radius of 2" (50.8 mm).