BINDER CB 60 - Manual (Page 91)

CB (E6) 09/2013 Page 91/144
14. Temperature safety devices
14.1 Overtemperature protective device (class 1)
The CO2 incubator is equipped with an internal temperature safety device, class 1 acc. to DIN 12880. It
serves to protect the unit and prevents dangerous conditions caused by major defects.
If the actual temperature exceeds the nominal temperature by approx. 10 °C, the over temperature
protective device permanently turns off the unit. The user cannot restart the device 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.
14.2 Overtemperature safety controller (temperature safety device class 3.1)
The chamber is regularly equipped with an electronic overtemperature safety controller (temperature
safety device class 3.1 according to DIN 12880).
The overtemperature safety controller serves to protect the CO
2
incubator, its environment and the
contents from exceeding the maximum permissible temperature. In the case of an error, it limits the
temperature inside the chamber to the entered safety controller setpoint.
Please observe the guideline BGI/GUV-I 850-0 on safe working in laboratories (formerly BGR/GUV-R 120
or ZH 1/119 laboratory guidelines issued by the employers’ liability insurance association) (for Germany).
Set the safety controller setpoint by approx. 2 °C above the desired temperature setpoint. Recommended
setting: Setpoint type “Offset” with safety controller setpoint 2 °C (factory setting).
The safety controller is functionally and electrically independent of the temperature control system. If an
error occurs, it performs a regulatory function.
Check the setting regularly and adjust it following changes of the setpoint or charge.
During a running sterilization (chap. 18.3) the safety controller is non-functional
14.2.1 Safety controller modes
You can select between “Limit (absolute)” and “Offset (relative)” safety controller mode
•
Limit: Absolute maximum permitted temperature value
Example:
This setting offers high safety as a defined temperature limit will not be exceeded. It is important to
adapt the safety controller setpoint after each modification of the temperature setpoint. Otherwise, the
limit could be too high to ensure efficient protection, or, in the opposite case, it could prevent the
controller from reaching an entered setpoint outside the limit range.
• Offset: Maximum overtemperature above any active temperature setpoint. The maximum temperature
changes internally and automatically with every setpoint change.
It is important to check the safety controller setpoint and safety controller mode occasionally, as it
does not offer a fix, independent limit temperature value, which would never be exceeded.
Example: Desired temperature value 37 °C, desired safety controller value: 39 °C
Possible settings:
Temperature setpoint Safety controller mode Safety controller setpoint
37 °C
Limit (absolute) 39 °C
Offset (relative) 2 °C