Lauda RA 12, Operating Instructions Manual, Page: 31 / 52

7/2022 Alpha 31 / 52
7.11.2 Overtemperature and low level protection

The units are designed for operation only with non-flammable liquids to
DIN EN 61010-2-010.

The overtemperature cut-off point is activated close above 105 °C and can
not be changed.



If the bath temperature rises above the overtemperature cut-off point or the
liquid level is too low (

6.2):
1. Alarm sounds as dual-tone signal.
2.
SAFE
for overtemperature cut-off point appears in the display.
3. The red LED above the fault triangle flashes.

Heater switches off on all poles;

Pump and refrigerating unit are switched off electronically.
 Rectify cause of fault.

Wait until the bath temperature has cooled below the cut-off point.
Unlock the thermostat (

7.11.4).
7.11.3 Overtemperature and low level protection testing
Every 6 month or before the unit is running unattended for longer periods this protection should be tested.
Therefore:

Remove the heat transfer liquid of the thermostat (

6.2).

Turn on thermostat and set the set temperature to a value a couple degrees
above ambient temperature.



The heater of the thermostat will now start heating. Attention the heater will
get very hot. Don't touch it at any time.

Wait about 45 seconds until the protection device will shut off the heater and
the pump and the alarm
SAFE
will appear.

If it takes more then 45 seconds for the overtemperature protection to get
triggered immediately cut out the power manually and have the equipment
checked by the LAUDA Service or the local service organization.

Refill the heat transfer liquid (

6.2).

Unlock (reset) the alarm (

7.11.4).
 Shut off the control head and turn it on again. The alarm must have disap-
peared now.
Overtemperature alarm
S A F E
Overtemperature alarm
S A F E