Balco-Strap-On

Supported Applications

The ACI Balco Strap-On Series features a 1.5" square copper plate with the sensor encapsulated to the back side of the plate to improve thermal conductivity between the pipe and the sensor when an immersion-style sensor cannot be inserted into the pipe. It is purpose-built for retrofit applications, where a Balco RTD must be added to existing piping without breaking into the line.

Designed for use with electronic controllers in commercial heating and cooling systems, each sensor uses a silver-plated copper plate and a Neoprene/EPRDM/SBR Polymer foam interface. It clamps directly to the pipe, making it ideal for hydronic supply and return lines, chilled-water piping, and similar surface-temperature measurement points. Certifications include CE, RoHS2, and WEEE.

Operating Conditions & Performance

The Balco RTD element has a PTC (Positive Temperature Coefficient) curve with a sensor output of 1000 Ohms nominal at 70°F (21.1°C) and a sensor accuracy of +/- 1% at that reference. The temperature coefficient is 4618 ppm/°C over 0-100°C, and sensor stability is +/- 0.05% after 1000 Hours @ 150°C (302°F). Response time to a 63% step change is 8 Seconds nominal, and maximum operating current is 5 mA.

The sensor connects through two non-polarity-sensitive, 22 AWG (0.65mm) Etched Teflon (PTFE) colored leads. The storage temperature range is -40 to 85°C (-40 to 185°F) and the operating humidity range is 10 to 95% RH, non-condensing. The standard Strap-On configuration fits pipe sizes from 32mm to 100mm, while the S10 configuration extends coverage from 50mm to 250mm. The foam interface carries UL94-HF1, MIL-R-6130C, and FMVSS-302 flammability ratings.

Configuration Options

The three catalog variants share the same Balco RTD sensing element and 1.5" copper plate, differing only in enclosure — which in turn sets the operating temperature range, flammability rating, and environmental protection.

• A/BALCO-S-GD uses a Galvanized Steel enclosure rated -40 to 93°C (-40 to 200°F), NEMA 1 (IP 10). It is the heaviest at 0.37kg and measures 106.68mm x 59.06mm (front view).
• A/BALCO-S-PB uses an ABS Plastic enclosure rated -30 to 85°C (-22 to 185°F), UL94-HB, Plenum Rated. It weighs 0.18kg and measures 121.55mm x 91.44mm (front view).
• A/BALCO-S-4X uses a NEMA 4X (IP 66) weatherproof plastic enclosure rated -40 to 70°C (-40 to 158°F). It weighs 0.25kg and measures 64.77mm x 93.98mm (front view).

All enclosures accept an adjustable clamp (2"-5") and can be ordered with an optional NIST Certificate (3 Points).

Key Product Differences

• A/BALCO-S-GD (Item #114910) — Balco, Strap-On, Galvanized Enclosure.
• A/BALCO-S-PB (Item #124210) — Balco, Strap-On, Plastic Enclosure.
• A/BALCO-S-4X (Item #137376) — Balco, Strap-On, NEMA 4X Plastic Enclosure.

The part number encodes sensor series (A/), model series (BALCO), configuration (S for 1.25" to 4" pipe, or S10 for 2" to 10" pipe), enclosure (GD, PB, or 4X), and an optional NIST selection. Accessories include the A/HOSE CLAMP-2-5" (Item #142630) and A/HOSE CLAMP-2-12" (Item #142631) quick-release worm-gear hose clamps, plus NSG Heat Transfer Paste (Item #102595).