Danfoss RT 3 Industrial Thermostat (017-501466) | −25 / +15 °C, Capillary Sensor, SPDT, IP66

The Danfoss RT 3 (code 017-501466) is a mechanical thermostat with capillary tube sensor made for heavy-duty industrial applications. It switches its single-pole contact (SPDT) according to the sensor temperature and the value on the setting scale. It is used in cold rooms, process cooling, heating circuits and marine installations, either for temperature control or as a safety/alarm limiter.

Heavy-Duty Industrial and Marine Thermostat

The RT series is a family regarded as a standard in the field for its simplicity and long life: high repeatability, high accuracy, all major marine approvals and safety integrity level SIL 2 according to IEC 61508. The housing is IP66-protected; it can be mounted without an enclosure in damp and dusty environments.

Technical Specifications (Official Danfoss Data Sheet)

• Model: Danfoss RT 3 | Code: 017-501466
• Setting Range: −25 … +15 °C
• Differential: 2.8 – 10 K (at lowest setting) · reset differential 1 – 4 K
• Contact: SPDT (single pole double throw), automatic reset
• Sensor: Coiled type, 2 m capillary tube, max. sensor temperature 150 °C
• Protection Class: IP66 | Safety: SIL 2 (IEC 61508)
• Dimensions: Housing 110 × 127 × 74 mm · mounting hole spacing 83 × 100 mm (Ø5 / Ø8.5) — official dimension drawing in the 2nd image
• Capillary Variants: 2 m (017-501466) · 5 m (017-501666) · 8 m (017-501766)

• 🔧 Immerse the sensor at least 50 mm — shallow immersion shifts the reading toward ambient temperature and the thermostat cuts out early.
• Do not kink the capillary tube sharply and do not cut it; if the charge leaks, the element must be replaced completely.
• For immersion mounting with a sensor pocket, Danfoss pockets 017-437066 (brass) / 017-436966 (stainless) are used.