18
/// Setting the safety temperature
Safety circuit
The adjustable safety circuit prevents the temperature of the heating bath from getting too high
as a result of:
- a controller error,
- the rotating/pressing knob having been accidentally turned�
Once the safety temperature has been reached, the device switches off permanently�
Furthermore, dry running of the heating bath is detected� The device switches off permanently�
The dry running function detects both accidental heating of the heating bath without liquid and
dry running caused by water evaporation starting at a set temperature of 60 °C� The error message
E26 appears and the heating bath is switched off permanently� To remedy this error, see “Error
codes”�
When the safety circuit is set, an upper temperature limit between 50 and 190 °C is defined�
�
Silicone oils as tempering media
When increased safety is not necessary the temperature of the safety circuit stays at 190 °C�
Temperature of the tempering medium rises to a maximum of 190 °C in the case of an error�
Then the safety circuit switches the heating bath permanently off�
�
Demineralised water as the tempering medium
When increased safety is not necessary, the adjustment knob of safety circuit stays all the way
to the right� As long as there is any demineralised water in the heating bath, the temperature
of the tempering medium rises to a maximum of 100 °C, in the case of an error� If the water is
evaporated completely, the temperature of the tempering medium rises to a maximum of 190
°C� Then the safety circuit switches off the heating bath permanently�
�
Temperature-sensitive or easily flammable media in the rotary evaporator
When the pre-set bath temperature may not be exceeded under any circumstances set the
safety temperature as described below�
Adjusting the safety temperature
- Set the desired safety temperature by turning the rotating/pressing knob within the 5 seconds of
the “SAFE TEMP�“ appearing on the display after the device is switched on� (Fig� 5)
Checking the safety circuit
- The safety circuit has to be checked by the user once a year�
- Fill the heating bath with 1 liter of water as tempering medium�
- Set the safety temperature to 100 °C�
- Set the set temperature to 80 °C�
- Start the heating function by pressing the rotating/pressing knob�
- When the set temperature is reached, turn the heating bath off and on again at the mains
switch�
- Set the safety temperature to 70 °C�
- The medium temperature is thus 10 K above the safety temperature, the safety circuit trips, the
display shows E24� (Fig� 7)
