Nickel-Strap-On

Supported Applications

The ACI Nickel Strap-On Series is a single-point Nickel RTD temperature sensor built around a 1.5" square copper plate, with the sensing element encapsulated on the back of the plate to improve thermal conductivity between a pipe and the sensor. It is designed for use with electronic controllers in commercial heating and cooling building-management systems.

Because it clamps to the outside of a pipe, the Strap-On is the practical choice for retrofit applications where an immersion-style sensor cannot be inserted into the line. For best results the pipe should be cleaned with an emery cloth before mounting, thermal grease is recommended between the plate and pipe, and the sensor should be insulated from ambient air. As with all such sensors, its wiring must never run in a conduit carrying line voltage.

Operating Conditions & Performance

The sensor is a Nickel RTD with a positive-temperature-coefficient (PTC) curve, a nominal output of 1000 Ohms at 21.1°C and Red/Red leads. It conforms to DIN 43760 with a temperature coefficient of 6370 ppm/°C and covers a sensing range of -40°C to 130°C.

Accuracy is ±1.52°C at -40°C, ±0.4°C at 0°C, ±0.17°C at 21.1°C, ±0.56°C at 54.4°C and ±1.25°C at 121°C. Response time is 8 Seconds nominal, self-heating is 0.3°C/mW in still air with a maximum operating current of 5 mA, and long-term stability is ±0.05% after 1000 Hours at 150°C.

Leads are 22 AWG (0.65 mm) etched-Teflon colored wires, and the foam insulation is a Neoprene/EPDM/SBR polymer rated UL94-HF1. Operating humidity is 10 to 95% RH non-condensing, storage is rated -40 to 85°C, and the series is CE, RoHS2 and WEEE compliant.

Configuration Options

Variants differ by the pipe-size configuration and the enclosure, which set both the range of pipe the clamp fits and the environmental protection:

• S configuration — Strap-On for 1.25" to 4" pipe sizes.
• S10 configuration — Strap-On for 2" to 10" pipe sizes.
• -GD Galvanized — galvanized steel, -40 to 93°C, NEMA 1 (IP 10).
• -PB Plastic box — ABS plastic, -30 to 85°C, UL94-HB, plenum rated.
• -4X enclosure — polystyrene, -40 to 70°C, UL94-V2, NEMA 4X (IP 66) weatherproof.

Enclosure choice also sets the housing size; the plastic box (-PB) measures 121.55 mm x 91.44 mm, the galvanized enclosure (-GD) measures 106.68 mm x 59.06 mm, and the NEMA 4X enclosure (-4X) measures 93.98 mm x 64.77 mm. A NIST-traceable calibration certificate is available as an option.

Key Product Differences

Models follow the scheme A/1K-NI-<configuration>-<enclosure>-<NIST>. The lineup includes:

• A/1K-NI-S-GD — galvanized enclosure for 1.25" to 4" pipe.
• A/1K-NI-S-PB — plastic enclosure for 1.25" to 4" pipe.
• A/1K-NI-S-4X — NEMA 4X enclosure for 1.25" to 4" pipe.
• A/1K-NI-S-GD-NIST — galvanized enclosure with NIST certificate.
• A/1K-NI-S10-GD — galvanized enclosure for the larger 2" to 10" pipe range.

Accessories include A/HOSE CLAMP-2-5" and A/HOSE CLAMP-2-12" quick-release stainless-steel hose clamps for larger-diameter pipes, plus NSG heat-transfer paste in 2 oz and 16 oz sizes.