Balco-Duct-No-Box

Supported Applications

The ACI Balco Duct No Box series is a single-point temperature sensor designed for use with electronic controllers in commercial heating and cooling building management systems. The duct style sensor is intended for smaller duct applications, where the probe tip should be positioned in the approximate center of the duct to ensure accurate readings.

Installation guidelines specify that the duct probe should be placed three to four duct segments down from any bend or obstructions and away from 90° bends. The sensor must be mounted on the top or sides of the duct work; mounting on the bottom risks damage due to moisture accumulation. For larger ducts, ACI references rigid or bendable copper averaging sensors for increased sensing points.

Operating Conditions & Performance

The series operates within a process temperature range of -40 to 115°C (-40 to 239°F). The storage temperature range is documented as -40 to 85°C (-40 to 185°F), and the operating humidity range is 10 to 95% RH, non-condensing.

Performance specifications for the Balco RTD sensor include:

• Sensor Output: 1000 Ohms nominal at 70°F (21.1°C).
• Accuracy: +/- 1% at 70°F (21.1°C).
• Response Time: 8 Seconds nominal for a 63% step change.
• Sensor Stability: +/- 0.05% after 1000 Hours @ 150°C (302°F).

The sensor utilizes ACI's double encapsulation process with high-quality, thermally conductive epoxy to eliminate moisture effects and increase thermal response times.

Configuration Options

This series is configured as a "Duct without Box" (DO) model featuring a mounting flange only. The probe diameter is 0.250" (6.35mm), constructed from 304 Stainless Steel, with a galvanized steel flange.

Probe Lengths

The series supports the following insertion lengths to accommodate various duct widths:

• 4" Probe
• 6" Probe
• 8" Insertion Length
• 12" Insertion Length
• 18" Insertion Length

Lead Wire and Cable Options

Sensors feature etched Teflon (PTFE) colored leads with silver-plated copper conductors. Standard lead lengths are 14" for 4", 6", and 8" probes, and 24" for 12" and 18" probes. Conductor size is 22 AWG (0.65mm).

Optional plenum-rated cable configurations include:

• 6'CL2P: 6 ft (1.83m), 2 Conductor Plenum Rated Cable
• 10'CL2P: 10 ft (3.05m), 2 Conductor Plenum Rated Cable
• 20'CL2P: 20 ft (6.10m), 2 Conductor Plenum Rated Cable

Materials and Approvals

The fitting material is Polyamide 66 (High Performance Nylon) with a UL94-HB flammability rating. The included foam pad is made of Neoprene/EPDM/SBR Polymer, rated UL94-HBF; FMVSS-302; MIL-R-6130C. Agency approvals include CE, RoHS2, and WEEE.

Key Product Differences

The primary variation within this series is the probe insertion length (4", 6", 8", 12", or 18") selected to match duct dimensions. Additionally, models are available with standard etched PTFE leads or extended plenum-rated cable options (-CL2P suffixes). An optional NIST Certificate (3 Points) is available for custom ordering.

Model numbers follow the format A/ - - - - - . For example, a 4" probe with standard leads is ordered as A/BALCO-DO-4", while a version with a 6-foot plenum cable is A/BALCO-DO-4"-6'CL2P.