Temperature Switches

Temperature Switches

Temperature switches are instruments designed for safe monitoring of process temperatures by providing discrete switching actions at configured setpoints. Depending on the model and configuration, they can be selected with one or two switch outputs, or with a switch output combined with a standardized analog output, enabling both alarm/interlock functions and continuous indication from a single device. A range of process connections supports flexible mounting across industrial services.

At the measuring point, the switch couples a temperature sensing element with electronics that evaluate the measured value against setpoint and hysteresis parameters. This enables direct activation of alarms, fans, heaters, shutdown relays, or permissives without requiring continuous controller scan logic for the basic protective function. Where local indication is provided, the device can also serve as a convenient field reference during maintenance and commissioning.

The core benefits are simplicity and determinism. A hard-wired switch output reduces complexity for basic protective functions, shortens wiring runs by consolidating outputs, and can improve response in applications where immediate local action is preferred. Compact construction and easy commissioning are emphasized as hallmarks of modern switch technology, supporting cost-effective expansion of temperature monitoring coverage.

Temperature switches integrate cleanly into automation and safety architectures as discrete inputs to PLC/DCS/SIS, and the optional analog output can provide trending and diagnostics in parallel with the protective setpoint. Selection should consider switching capacity, required approvals, environmental sealing, and the suitability of the process connection and immersion geometry for the expected flow and thermal gradients.

Typical applications include overheating protection for pumps, compressors, motors, and bearing housings; temperature monitoring of heaters and heat tracing circuits; and high/low temperature alarms on utility headers, cooling loops, and HVAC process interfaces. They are also used on packaged equipment to provide an independent, easily verifiable protective layer for critical temperature limits.

Miller Mechanical Specialties, an exclusive authorized representative of sales and service for Endress+Hauser.