Binder MK 115, Operating Manual

Page: 70 / 159

MK / MKT (E5) 03/2019 page 70/158
12. Temperature safety devices
12.1 Over temperature protective device (class 1)
The chamber is equipped with an internal temperature safety device, class 1 acc. to DIN 12880:2007. It
serves to protect the chamber and prevents dangerous conditions caused by major defects.
If the actual temperature exceeds the nominal temperature by approx. 20 °C, the over temperature protec-
tive device permanently turns off the chamber. The user cannot restart the chamber again. The protective
cut-off device is located internally. Only a service specialist can replace it. Therefore, please contact an
authorized service provider or BINDER Service.
12.2 Overtemperature safety controller class 2
The chambers are regularly equipped with an electronic overtemperature safety controller (temperature
safety device class 2 according to DIN 12880:2007). The safety controller is functionally and electrically
independent of the temperature control system and serves to protect the chamber, its environment and
the contents from exceeding the maximum permissible temperature.
With option temperature safety device class 3.3 (chap. 12.3), the safety controller is not used.
In this case it must be set to the maximum temperature.
Please observe the DGUV guidelines 213-850 on safe working in laboratories (formerly BGI/GUV-I 850-0,
BGR/GUV-R 120 or ZH 1/119, issued by the employers’ liability insurance association) (for Germany).
When the entered safety controller set-point is reached, the overtemperature safety controller turns off the
heating, fan, and refrigeration system. This condition (state of alarm) is indicated visually and additionally
with an audible alert if the buzzer is enabled (chap. 11.4). The alarm persists until the chamber cools
down below the configured safety controller setpoint and the alarm is manually reset.
Check the setting regularly and adjust it following changes of the set-point or charge.
The safety controller only activates after the set-point has been reached once.
12.2.1 Safety controller modes
You can select between “Limit (absolute)” and “Offset (relative)” safety controller mode
•
Limit: Absolute maximum permitted temperature value
This setting offers high safety as a defined temperature limit will not be exceeded. It is important to
adapt the safety controller set-point after each modification of the temperature set-point. Otherwise, the
limit could be too high to ensure efficient protection, or, in the opposite case, it could prevent the con-
troller from reaching an entered set-point outside the limit range.
•
Offset: Maximum overtemperature above any active temperature set point. The maximum tempera-
ture changes internally and automatically with every set-point change.
This setting is recommended for program operation. It is important to check the safety controller set-
point and safety controller mode occasionally, as it does not offer a fix, independent limit temperature
value, which would never be exceeded.