Siemens Building Technology 357-0001 Stat

The Siemens 357-0001 TH 357 Limitem is a high-performance pneumatic low limit thermostat designed for precision air temperature monitoring in commercial air handling units. This gradual-direct acting controller utilizes a liquid-filled, 8-foot averaging bulb to sense temperature fluctuations across a duct cross-section, providing a proportional pneumatic signal to downstream dampers or valves. With an operating range of 35° to 145° F, it is frequently specified as a freeze protection or discharge air temperature control in unit ventilators and HVAC systems. The robust two-valve design significantly reduces bleed air consumption, ensuring maximum efficiency of the pneumatic plant. Field adjustments are streamlined via adjustable sensitivity settings ranging from 1/3 to 3.5 psi/°F, allowing technicians to fine-tune the 357-0001 to meet specific system dynamics. The 3/32-inch diameter sensing element is paired with a 6-inch capillary and included mounting bracket for a fast, reliable installation in high-velocity air streams.

Key Benefits:

• Averaging Sensing Element: The 8-foot liquid-filled bulb compensates for temperature stratification in large ducts, preventing nuisance trips.
• Compressed Air Efficiency: The dual-valve construction minimizes constant air waste, lowering the demand on your pneumatic compressor.
• Rapid Thermal Response: Engineered for quick reaction to temperature shifts, protecting coils from freezing or overheating.
• Direct Acting Reliability: Standard DA pneumatic signal output simplifies integration with common actuators and controllers.
• Proven Field Durability: A legacy Siemens Building Technology component known for operating in ambient case temperatures up to 180°F.

Common Questions:

How do I adjust the sensitivity on the 357-0001?
The sensitivity is mechanical. Locate the sensitive spring and move it to the corresponding slot (1/3 to 3.5 psi/°F) to match the required control response for your specific AHU application.

Can this be used for low-limit freeze protection?
Yes, the 8-foot averaging bulb makes this specific model ideal for freeze-stat applications where it monitors air temperature leaving the heating coil to prevent freezing conditions.

What is the maximum supply pressure for this unit?
Typical operating supply pressure should not exceed 30 psi. Most standard 20 psi pneumatic systems are perfectly suited for this controller.

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.