Belimo 01DTS-505X Sensor

The Belimo 01DTS-505X is a high-performance low temperature detection sensor, commonly referred to as a freeze stat, designed for critical protection of water and air heaters in commercial HVAC systems. This unit features a manual reset mechanism and a 20ft (6m) copper capillary probe filled with vapor pressure R507 to ensure rapid response times when temperatures drop near the freezing point. Utilizing a single-pole double-throw (SPDT) changeover switch, it provides a reliable frost protection switch signal, rated at 1x SPDT (4 A @ AC/DC 24 V), to trigger a shutdown or alarm before cooling registers sustain damage. Housed in a durable NEMA 4 / IP65 enclosure with a transparent ABS cover, the 01DTS-505X is built for demanding mechanical room environments. Technical setpoints are field-adjustable between 15°F and 60°F (-10°C to 15°C), offering an accuracy of ±0.9°F (±0.5°C) for precise HVAC freeze protection across the entire coil surface.

• Extensive 20ft Capillary: The 6-meter vapor-filled copper probe allows for comprehensive coverage of large cooling coils, effectively eliminating blind spots where localized freezing might occur.
• Reliable Manual Reset: Ensures the system remains offline for inspection following a low-temp trip, preventing short-cycling of equipment under dangerous conditions.
• Rugged Environmental Rating: The NEMA 4 and IP65 certified housing provides superior protection against dust and moisture in mechanical or industrial spaces.
• Universal Switching: The SPDT changeover output integrates seamlessly into various control logic circuits, providing both a common alarm and equipment interlock.

How do I calibrate the setpoint on the 01DTS-505X?
The setpoint is adjusted via a internal scale typically factory-set to 41°F (5°C). Technicians can calibrate the trip point between 15°F and 60°F using the internal adjustment screw; however, if the capillary leaks, the switch will automatically fail-safe to the frost position.

Where should the housing and capillary be installed?
The capillary should be serpentine-mounted across the downstream side of the coil. Crucially, the sensor housing must not be installed in outdoor air; exposure to cold ambient temperatures outside the conditioned duct can cause false trips.

What is the proper wiring for the SPDT switch?
The unit provides a 1x SPDT contact. For standard freeze protection, the "normally closed" contact is typically wired in series with the fan starter or the outside air damper actuator circuit to force a failsafe state upon detection.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.