Balco-Duct

Supported Applications

The ACI Balco Duct Series is a single-point temperature sensor designed for use with electronic controllers in commercial heating and cooling building management systems. The series features the Balco RTD (Positive Temperature Coefficient) element, manufactured using a double encapsulation process to eliminate moisture effects and improve thermal response. Documented applications include Roof Top Units, Air Handlers, and monitoring Supply/Discharge/Return/Mixed Air Temperatures.

Operating Conditions & Performance

The Balco RTD sensor operates within a temperature range of -40 to 115°C (-40 to 239°F). Sensor accuracy is specified as +/- 1% at 70°F (21.1°C), with a nominal response time of 8 seconds for a 63% step change. The sensor exhibits stability of +/- 0.05% after 1,000 hours at 150°C (302°F). Operating humidity is rated from 10 to 95% RH, non-condensing.

Enclosure-specific operating temperature ranges vary by material and rating:

• -GD Enclosure: -40 to 115°C (-40 to 239°F)
• -PB Enclosure: -30 to 90°C (-22 to 194°F)
• -BB Enclosure: -40 to 121°C (-40 to 250°F)
• -4X Enclosure: -40 to 70°C (-40 to 158°F)

Storage temperature range is listed as -40 to 85°C (-40 to 185°F).

Configuration Options

The series supports multiple configurations for probe length, enclosure type, and optional certifications. The sensor utilizes a two-wire (non-polarity sensitive) electrical connection with Etched Teflon colored lead wires.

Probe Dimensions & Materials

• Diameter: 0.250" (6.35mm)
• Material: 304 Stainless Steel probe with Galvanized Steel flange.
• Probe Lengths: Available in 4", 6", 8", 12", and 18" options.
• Lead Wires: Two, 22 AWG (0.65mm) Silver Plated Copper conductors with Etched Teflon insulation rated MIL-W-16878/4 (Type E).

Housing & Enclosure Options

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

Mounting & Accessories

The sensor is designed for duct mounting via a hole with an included foam pad seal. The foam pad material consists of Neoprene/EPDM/SBR Polymer, rated UL94-HBF; FMVSS-302; MIL-R-6130C. An optional NIST Certificate (3 Points) is available.

Key Product Differences

Variants within the Balco Duct series are distinguished by probe insertion length and enclosure selection, which dictate specific operating temperature limits and physical dimensions. The sensor output remains consistent across variants at 1000 Ohms nominal (Orange/Yellow lead wire colors) with a Temperature Coefficient of 4618 ppm/°C from 0-100°C.

Lead length varies by probe size: probes in the 4", 6", and 8" lengths include 14" (35.6 cm) leads, while 12" and 18" probes include 24" (61 cm) leads. Agency approvals for the series include CE, RoHS2, and WEEE.