JUMO 60.5051 Explosion-protected surface-mounting thermostat, ATH-EXx Operating Manual - Manual (Page 19)

19
5 Settings
5.2 Resetting the TB or STB limiter
If the temperature at the probe goes above the limit that has been set, the
electrical circuit 1-4 is opened and remains mechanically locked out. When the
critical temperature has fallen to about 9-15% below the set limit, the TB or
STB can be reset manually.
✱ Open the housing.
➩ "Opening the surface-mounting thermostat", page 9
✱ Press the reset arm ( 2 ) in the direction of the arrow.
➩ "( 2 ) reset arm", page 18
5.3 Self-monitoring (fail-safe)
5.3.1 Response to a fracture of the measuring system
5.3.2 Response to low temperature
On the STW or STB, in the event of a fracture of the measuring system (leakage)
the circuit 1-4 will remain permanently open.
On the STB, the microswitch is also mechanically and permanently locked out.
If the probe temperature of approx. -30°C (-60°C for the TZ 679) of the STW
and STB is gone below, the power circuit is opened.
When the temperature rises above the minimum probe temperature, the STW
resets itself automatically. The STB requires a manual reset.
➩ "Resetting the TB or STB limiter", page 19