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Operating mode B
The heating function is switched off.
The target value is set to 20 °C or the most recent tempera-
ture setting.
The controller tempering medium is set to water or the most
recent medium setting.
The heating function must be restarted following a power
failure.
The following settings are possible/adjustable:
- the target value setting,
- the controller tempering medium.
The safety circuit is set to the most recently set value and
cannot be adjusted.
When the device is switched on at the mains switch, B ap-
pears.
Operating mode C
The heating function is switched on or off depending on the
last selected setting.
The last target value set in mode B applies.
The setting controller tempering medium set before the de-
vice was last switched off in mode B applies.
The following settings cannot be adjusted:
- the target value,
- the safety circuit,
- the controller tempering medium.
When the device is switched on at the mains switch, C ap-
pears.
Switching operating modes
Switch the device off at the mains switch.
Sequence A, B, C, A etc.
The operating mode setting appears on the display when st-
.
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 "Temperature" rotating 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 target temperature of 60 °C. The er-
ror message E 26 appears and the heating bath is switched off
permanently. To remedy this error, see the section entitled "Error
message".
When the safety circuit is set, an upper temperature limit bet-
1. 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 error. Then the safety circuit switches
the heating bath permanently off.
2. 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 tempera-
ture of the tempering medium rises to a maximum of 100 °C
in the case of 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.
3. Temperature-sensitive or easily fl ammable media in the
rotary evaporator
When the pre-set bath temperature may not be exceeded
under any circumstances set the safety circuit as described
below.
Adjusting the safety circuit
Checking the safety circuit
The safety circuit has to be checked by the user once a year.
Fill the heating bath with 1 litre of water as tempering me-
dium.
Set the safety temperature to 100° C.
Set the target temperature to 80° C.
When the target temperature is reached, turn the heating
bath off and on again at the main switch.
Set the safety temperature to 70° C.
The medium temperature is thus 10 K above the safety tem-
perature, the safety circuit trips, the LC display shows E 24,
Control of the medium temperature
The medium temperature is limited by the set safety tempera-
ture. The medium temperature is controlled by means of a PID
controller. The medium temperature is measured by the PT 1000
temperature sensor and is heated up as quickly as possible wit-
hout overshooting to the set temperature.
The PID controller adapts to the different tempering media and
ensures optimum temperature control with minimum tempera-
ture drift and fl uctuation.
Optimum control is only achieved when the medium is mixed
using a rotating evaporator piston.
Set the desired medium temperature between room tempe-
temperature setting is the safety temperature minus 10 °C.
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