Surface-mounted thermostat ATHs-70 60/60001522

Thermostats control and monitor thermal processes. The devices of the ATH type series are available as TR temperature controller, TW temperature monitor, TB temperature limiter, STW (STB) safety temperature monitor and as STB safety temperature limiter.

In the event of disturbances, the STB-type puts the monitored system in a condition of safe operation.

Built-on thermostats operate on the principle of liquid expansion; a microswitch is used as an electrical switching device.

Switching function:

TR temperature controller and TW temperature monitor

If the temperature at the temperature sensor exceeds the set point, the microswitch is activated through the transmission mechanism and the circuit is opened or closed. If the temperature falls below the set point (by the switching difference), the microswitch is put back to its initial position.

Restart lock-out: 

withthe TB temperaturelimiterandtheSTBsafetytemperaturelimiter

If the temperature at the temperature sensor exceeds the set limit value, the circuit will open and the microswitch will be locked mechanically.

After falling below the danger temperature by about 10% of the full scale (about 15% if the limit value is set by >+350°C), the microswitch can be unlocked mechanically.

Self-monitoring with the STB safety temperature limiter and STW (STB)safety temperature monitor

Failure of the measuring system, i.e. a leakage of the expansion liquid, causes the pressure under the diaphragm of the STB and STW (STB) to drop, thus permanently opening the circuit. Unlocking is no longer possible.

If the sensor cools down to a temperature below about - 20°C, the circuit will also open. If the temperature rises above about -20°C, STB must first be manually deactivated by pressing the reset button. Switching on will take place automatically.