EB 5206 EN
5
Design and principle of operation
2 Design and principle of oper-
ation
The thermostats are equipped with a
changeover contact. When the thermostat is
triggered, the connection between connec-
tions 1 and 2 are interrupted and the con-
nections 1 and 4 are connected (see Fig. 5
on page 14).
Safety temperature monitor (STM)
A snap-action switch in the STM is triggered
when the temperature at the temperature
sensor rises above the adjusted set point.
When the temperature falls below the set
point by approximately 8 K, the switch re-
turns to its original position.
The contact opens or closes when the tem-
perature at the temperature sensor falls be-
low –20 °C. It automatically closes or opens
again when the temperature at the tempera-
ture sensor rises above –20 °C.
The STM is triggered when the capillary tube
breaks.
Temperature regulator (TR)
The snap-action switch is triggered when the
temperature at the temperature sensor rises
above the adjusted set point. When the tem-
perature falls below the set point by approxi-
mately 4 K, the switch returns to its original
position.
Safety temperature limiter (STL)
The snap-action switch is triggered and
locked when the temperature at the tempera-
ture sensor rises above the adjusted set
point. When the temperature falls below the
set point by approximately 10 %, the
snap-action switch can be unlocked manual-
ly.
The contact opens or closes when the tem-
perature at the temperature sensor falls be-
low –20 °C. It automatically closes or opens
again when the temperature at the tempera-
ture sensor rises above –20 °C.
The contact opens or closes when the system
fails. It is not possible to unlock the device.
2.1 Typetesting
The thermostats are tested by the German
Technical Inspectorate (TÜV) according to
DIN EN 14597.
Type
DIN register number
5343
STW1209
5344
TR1208
5345
STB1207
Summary of Contents for EB 5206 EN Series
Page 23: ...EB 5206 EN 23...
