Temperature Safety Devices; Over Temperature Protective Device Class 2 (Thermal Switch); Overtemperature Safety Controller Class 2; Safety Controller Mode - Binder VDL Series Operating Manual

14.

Temperature safety devices

14.1 Over temperature protective device class 2 (thermal switch)

The chamber is equipped with an internal temperature safety device class 2.0 acc. to DIN 12880:2007. It
serves to protect the chamber and prevent dangerous conditions caused by major defects of the cham-
ber. It is electrically independent of the controller (bimetallic switch).
When the fixed temperature of 330 °C is measured at the thermal switch, the overtemperature protective
device turns off the heating. This is the equivalent to an inner chamber temperature of 270 °C uo to
300 °C.
The alarm message "Overtemperature" is displayed on the controller.
If the overtemperature protective device has turned off the heating, proceed as follows:
• Confirm the alarm message on the controller.
• Disconnect the power supply (pull the power plug) and let the chamber cool down
• If appropriate, have an expert examine and rectify the cause of the fault.
• Restart the chamber.
As soon as the inner chamber temperature after restart is below the defined cut-off temperature of the
overtemperature protective device of 230 °C, the heating is released again.
14.2

Overtemperature safety controller class 2

The chambers are regularly equipped with an electronic overtemperature safety controller (temperature
safety device class 2 – temperature limiter) acc. to DIN 12880:2007). The safety controller protects the
chamber, its environment and the charging material against exceeding the maximum permissible tempe-
rature. The safety device class 2 is electrically independent of the temperature controller and turns off the
chamber permanently.
In the event of a fault in the temperature controller, the safety controller turns off the vacuum drying oven
permanently, i.e. until manual alarm reset. This condition (state of alarm) is indicated visually and additio-
nally with an audible alert if the buzzer is enabled (chap. 16.4.1). You can turn off the buzzer with the OK
button / Confirm icon. The alarm persists until the chamber cools down below the configured safety con-
troller value.
Please observe the DGUV guidelines 213-850 on safe working in laboratories, issued by the employers'
liability insurance association (for Germany).
Check the setting regularly and adjust it following changes of the set-point or charge.
The temperature safety device only activates after the set-point has been reached once.

14.2.1 Safety controller mode

You can set the safety controller mode to "Limit" or "Offset".
• Limit: Limit value, 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 value 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.
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