Therm-Freezer

Supported Applications

The ACI Thermistor Freezer Series provides temperature sensing for refrigerated, freezer, and hydronic heating applications requiring a remote sensor. The series is designed for use in pharmaceutical environments as well as general commercial cooling systems.

• Refrigerators and freezers
• Hydronic heating
• Pharmaceutical storage monitoring
• Remote sensor installations where the enclosure must be mounted outside the unit

Operating Conditions & Performance

The series utilizes a Non-Linear, NTC (Negative Temperature Coefficient) thermistor element. The documented performance envelope includes:

• Sensor Operating Temperature Range: -40 to 125°C (-40 to 257°F)
• Enclosure Operating Temperature Range: -40 to 70°C (-40 to 158°F)
• Storage Temperature Range: -40 to 80°C (-40 to 176°F)
• Operating Humidity Range: 10 to 95% RH, non-condensing
• Accuracy (at -25 to 70°C / -13 to 158°F): +/- 0.5°C (+/- 0.9°F)

The sensor output at 25°C (77°F) is specified as A/CP (Type II): 10KΩ nominal or A/AN (Type III): 10KΩ nominal, with a Power Dissipation Constant of 2 mW/°C for both series.

Configuration Options

The ACI Thermistor Freezer Series is configured via an ordering grid that defines sensor curves, enclosure options, and lead lengths. Key configurable dimensions include:

• Sensor Elements: Available in AN (Type III) or CP (Type II) thermistor configurations.
• Housing Options: Configurable with no enclosure or a NEMA 4X Weather Proof Plastic Enclosure made of Polystyrene | UL94-V2. The enclosure features an IP 68 (NEMA 6P) cable gland rating for wire clamping sizes from 0.098" (2.5 mm) to 0.256" (6.5 mm).
• Probe Construction: A 316 Stainless Steel probe with a diameter of 0.1875" (4.76 mm) and length of 2" (50.8 mm). The series uses ACI's encapsulation process to eliminate moisture effects.
• Cable Specifications: A standard 30' (9.15 m), 3 Conductor, 24 AWG Silver Plated Copper cable with FEP/FEP (Teflon) Jacketed insulation in white. The electrical connection consists of three conductors (White and Two Red Wires); polarity is sensitive requiring red wires to be tied together.
• Approvals: CE, UKCA, WEEE, RoHS2

Accessories for Thermal Buffering

To achieve a slower response time (Thermal Buffer), the series supports Single or Triple Point Glycol Kits. Available accessory configurations include 2 oz and 8.5 oz Nalgene bottles with mounting brackets, offered in Glass Beads or Food Grade Glycol fill options.

Key Product Differences

Variants within this series are distinguished by the sensor curve type (AN vs CP) and the inclusion of an enclosure:

• Sensor Curve: Models differ between A/CP (Type II) and A/AN (Type III) thermistor outputs, both nominal 10KΩ at 25°C.
• Housing Configuration: Standard models are offered without an enclosure. Weatherproof variants include a NEMA 4X rated plastic enclosure with dimensions of approximately 64.77 mm width x 93.98 mm height x 56.13 mm depth (2.55" x 3.70" x 2.21").
• Lead Length: The standard configuration includes a fixed 30' lead length.

The series is covered by ACI's Five (5) Year Limited Warranty. Installation notes specify that the enclosure must be mounted outside of the freezer/cooler, with wiring routed through door seals or probe access ports to maintain thermal integrity.