BINDER KT 53 - Manual (Page 106)

KT (E6) 09/2013 Page 106/135
17.3 Over- and undertemperature safety controller (temperature safety device
class 3.3) (option)
With this option the chamber is equipped with an electronic over- and undertemperature safety controller.
The combination of overtemperature (class 3.1) and undertemperature (class 3.2) protection is regarded
as a safety device class 3.3 acc. to DIN 12880.
This over- and undertemperature safety controller serves to protect the refrigerated incubator, its
environment and the contents from exceeding the maximum or minimum permissible temperature. 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). The
safety controller is functionally and electrically independent of the temperature control system. If an error
occurs, it performs a regulatory function.
The
overtemperature safety controller set-point is a maximum temperature value, which the unit will
not exceed due to the regulatory function of the safety device. This protection against excessively high
temperatures serves to protect the refrigerated incubator, its environment and the contents. In the case of
an error, the safety controller limits the temperature inside the chamber to the entered safety controller
set-point.
The
undertemperature safety controller set-point is a minimum temperature value, which the unit will
not fall below due to the regulatory function of the safety device. This protection against excessively low
temperatures serves to protect sensitive loads against under cooling. In the case of an error, the safety
controller limits the temperature inside the chamber to the entered safety controller set-point.
Check the setting regularly and adjust it following changes of the set-point or charge.
17.3.1 Safety controller modes
You can select between “Limit (absolute)” and “Offset (relative)” safety controller mode
•
Limit: Absolute maximum or minimum permitted temperature value
Example:
Temperature set point 40 °C
Overtemperature safety controller set-point 45 °C
Undertemperature safety controller set-point 30 °C
This setting offers high safety as a defined temperature limit will not be exceeded or fallen below. It is
important to adapt the safety controller set-point after each modification of the temperature set-point.
Otherwise, the limit could be too big to ensure efficient protection, or, in the opposite case, it could
prevent the controller from reaching an entered set-point outside the limit range.
• Offset: Maximum permitted over- or under temperature above/ below the active temperature set point.
The maximum temperature changes internally and automatically with every set-point change.
Example:
Temperature set point 40 °C
Overtemperature safety controller set-point 5 °C
Undertemperature safety controller set-point 10 °C.
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 limit value, which would not be
exceeded or fallen below.