High temperature limit switch – principle of operation

When the set limiting temperature (including hysteresis) in the temperature limiter is reached, the reset button is released, which switches the system into a safe state. The purpose is to protect the heating equipment from overheating.

The normal operating state of the system can only be restored manually or with a tool, e.g. a screwdriver setting. This is to ensure that the installation has been checked after the safety threshold has been exceeded and that any fault that led to overheating has been rectified.

Temperature limiter switch – standard

The switching characteristics of temperature limit switch are defined in DIN EN 14597 for the use of safety devices in heating installations. One of its most important requirements is that, once the limit temperature is exceeded, the devices must fulfil their control or switching functions within the set time parameters.

JUMO safety temperature limiters comply with DIN EN 14597.

How to connect temperature limit switches?

Heating systems usually use a combination of several closed-loop and open-loop controllers together with a safety temperature limiter. Safety temperature monitors and thermostats and temperature controllers are usually connected to this device.

JUMO safety temperature limiters and monitors

At JUMO you will find universal STB temperature limitersas well as application-specific temperature limiters.

Our product range includes:

• JUMO safetyM STB/STW universal temperature limiter/monitor with LCD display. The device can also be used in applications that comply with the new Machinery Directive 2006/42/EC.

• Safety temperature limiter for potentially explosive atmospheres JUMO safetyM STB/STW Ex with intrinsically safe input

• Safety temperature limiter for DIN rail mounting (e.g. in control cabinets) JUMO heatTHERM-AT / heatTHERM-DR

  Safety thermostats

• Safety thermostat STB for installation in devices up to 500°C of the JUMO EM series. Maximum capillary length up to 5000 mm. Equipped with a changeover contact spdt. Adjustment by means of a screwdriver.

• Safety thermostat with capillary JUMO ATH

Contact us and visit our site for additional information and more details.