Thanks to its impact-resistant housing with high-quality plastic cover and die-cast aluminum base, the 1-pole mechanical surface-mounted thermostat is very robust and can also be used under harsh conditions. The measuring system used works according to the liquid expansion principle and can be used without problems up to a maximum permissible sensor temperature of 230 °C. The smooth round sensor made of copper has a diameter of 6 mm and a sensor length of approx. 85 mm. The thermostat's long-distance line is also made of copper and can be laid flexibly, provided a bending radius of 5 mm is observed. The maximum permissible ambient temperature on the housing (protection class IP54) is 80 °C. With the help of a screwdriver, the desired switch-off temperature can be easily set on a scale inside after removing the housing cover. If the temperature at the temperature sensor exceeds the set limit, the circuit is opened and the microswitch is mechanically locked. Once the temperature falls below the danger temperature by approx. 10% of the scale range, the microswitch can be unlocked manually. The safety temperature limiter is characterized by a high switching point accuracy of +0/-5% in the upper third of the scale. If the measuring system is destroyed, the circuit is permanently opened and unlocking is then no longer possible. If the sensor cools down to a temperature below approx. -20 °C, the circuit is also opened; only when the temperature rises above approx. -20 °C can the STB be unlocked manually using the restart button. A decisive advantage is that no additional auxiliary power is required for temperature measurement. The electrical connection is made via screw terminals directly on the built-in microswitch, which can directly switch a maximum permissible switching capacity of AC 230 volts / 10 A. The safety temperature limiter can be used very flexibly and is used both in the heating and cooling systems and in the refrigeration systems.
