The warm air thermostat is a device combination consisting of three individual devices in a housing with protection class IP40 and the functions of a temperature controller, temperature monitor and a fixed safety temperature limiter. The switch head is attached with two screws through the lower part of the housing. With the help of a screwdriver, the desired switch-off temperature of the temperature controller and temperature monitor can be individually set on a scale inside after removing the housing cover. The temperature controller and temperature monitor are characterized by a high switching point accuracy of +/-4 K in the upper third of the scale. The safety temperature limiter has a switching point accuracy of +0/-5 K and is fixed at the factory. A decisive advantage is that no additional auxiliary power is required for temperature measurement. The electrical connection is made to a terminal block that is mounted on a circuit board. The device can directly switch a maximum permissible switching capacity of AC 230 Volt / 10 A. The temperature controller has a switching difference (hysteresis) of approx. 14 K, the switching difference of the temperature monitor is approx. 6 K. After the set target value is reached, the microswitches of the two devices switch over and after the switch-off temperature falls below the value of the switching difference, they automatically return to the original state. When the set temperature is reached, the safety temperature limiter opens the switching path and locks. The switch can only be manually unlocked again once the temperature has cooled down by approx. 10 K. The thermostat's holding tube is made of copper and has an installation length of approx. 220 mm and a diameter of approx. 10 mm. The three measuring sensors are also made of copper, each have a diameter of 4 mm and protrude approx. 2/3 from the holding tube. This allows the air temperature to be optimally recorded. The housing cover is made of polycarbonate, the housing
