Temperaturrelæer

Temperaturrelæer are devices that monitor temperature and control an electrical output when a set temperature is reached. They can be electromechanical or electronic and are used to protect equipment, regulate processes, and ensure safe operation in heating, cooling, and other temperature-dependent systems. In Danish technical contexts, they encompass both simple thermostats and more advanced protection relays found in industrial settings.

There are several main types. Mechanical or thermal relays use a bimetal strip that bends with temperature changes to open or close contacts. Electronic temperature relays rely on sensors such as thermistors, RTDs (resistance temperature detectors), or thermocouples, often with digital or microprocessor-based control. Some relays offer multiple setpoints, adjustable differential (hysteresis), time delays, and alarms. Outputs may be simple relay contacts (normally open or normally closed), transistor or triac outputs, or solid-state relays for higher reliability and fast switching.

Operation typically involves sensing the process temperature with a connected sensor, comparing it to a configured setpoint, and actuating the output when the threshold is reached. Features may include manual reset, remote sensing, and status indicators. They are widely used for motor protection (thermal overload), process temperature control, ovens and furnaces, refrigeration and HVAC systems, and other applications where maintaining or limiting temperature is essential.

Standards and installation considerations include safety approvals, environmental ratings, and appropriate mounting. Proper selection depends on the sensor type, required accuracy, switching load, and the operating temperature range.