Balco-Probe-Only

Supported Applications

The ACI Balco RTD Probe Only series consists of temperature sensors designed for use in commercial heating and cooling building management systems. The probe-only configuration is intended for duct applications, including supply, discharge, return, mixed, and exhaust air sensing within roof top units and air handlers. Additionally, the sensor supports immersion temperature measurement when installed with a proper length thermowell.

Operating Conditions & Performance

The series operates across an ambient range of -40 to 121°C (-40 to 250°F) within humidity conditions from 10 to 95% RH, non-condensing. Storage temperature is rated for -40 to 85°C (-40 to 185°F). The sensor utilizes a Balco RTD (PTC Positive Temperature Coefficient) element with a nominal output of 1000 Ohms at 25°C (77°F), featuring orange/yellow lead wire colors. Accuracy is specified as +/- 1% at 70°F (21.1°C). The sensor stability is rated at +/− 0.05% after 1000 Hours @ 150°C (302°F).

Performance characteristics include a nominal response time of 8 Seconds for a 63% step change and a maximum operating current of 5mA. The temperature coefficient is documented as 4618 ppm/°C over the range of 0-100°C.

Configuration Options

The series offers configurable probe lengths, lead wire options, and optional certifications to accommodate specific installation requirements:

• Probe Lengths: Available in 4", 6", 8", 12", and 18" configurations. The insertion length (Ref A) corresponds directly to the probe size with tolerances of ± 0.13" for shorter probes and ± 0.25" for longer probes.
• Probe Construction: Features a 0.250" (6.35mm) diameter sheath made from 304 Stainless Steel, utilizing ACI's double encapsulation process with thermally conductive epoxy to eliminate moisture effects and increase thermal response time.
• Lead Wire Options:
  • Standard Wire: Etched Teflon (PTFE) colored leads rated MIL-W-16878/4 (Type E). Suitable for indoor/outdoor wet locations and resistant to oil, moisture, acids, oils, and abrasion. Lead lengths are 14" (35.6 cm) for 4", 6", and 8" probes; 24" (61cm) for 12" and 18" probes.
  • Plenum Wire: CL2P FEP (Fluorinated Ethylene Propylene) cable available in 6 ft, 10 ft, or 20 ft lengths. Rated TYPE CL2P - TYPE CMP with UL/C(UL) listing E130356 ROHS.
• Electrical Connection: Two non-polarity sensitive wires (Silver Plated Copper for standard; Tinned Copper for plenum).
• Certifications & Options: CE, RoHS2, and WEEE compliant. Optional NIST Certificates are available.

Key Product Differences

The primary variation within the series is defined by probe length (4" through 18") and lead wire type (Standard Etched PTFE vs. Plenum Rated CL2P). The model number structure follows the format A/BALCO/PO/<Probe Length>/<Lead Wire Option>/<NIST>. For example, a 4" probe with standard leads is ordered as A/BALCO-PO-4", while a plenum-rated version may include suffixes such as -20'CL2P. Accessories available for this series include silicone-free thermal grease in 2 oz and 16 oz containers to assist with heat transfer during installation.