KBF-LQC (E5.2) 12/2010
page 63/106
11.3 Temperature safety device class 3.3 (DIN 12880) (option)
With the option over/under temperature protective device (temperature safety device class 3.3 acc. to
DIN 12880) the unit is equipped with two additional safety devices (class 3.1 and class 3.2). The combi-
nation of the safety devices is regarded as a safety device class 3.3.
The temperature safety device, class 3.3, serves to protect the climatic chamber, its environment and the
contents against forbidden temperature excesses. Please observe the guideline BGI/GUV-I on safe work-
ing in laboratories (formerly BGR/GUV-R 120 or ZH 1/119 laboratory guidelines issued by the employers’
liability insurance association) (for Germany).
With
safety device class 3.1
a maximum value for the temperature is set that the unit will not exceed
due to the regulatory function of the safety device class 3.1. This protection against excessively high
temperatures can, for example, serve to protect the climatic chamber, its environment and the material
under treatment from excess temperatures.
With
safety device class 3.2
a minimum value for the temperature is set that the unit will not fall below
due to the regulatory function of the safety device class 3.2. This protection against excessively low tem-
peratures can, for example, serve to protect sensitive loads from undercooling.
Both safety devices are functionally and electrically independent of the temperature control system. If an
error occurs, they perform regulatory function.
Safety devices class 3.1 (14) and class 3.2 (15) are located in the left lateral control panel.
With option temperature safety device class 3.3, the safety controller (chap. 11.2) must be set
to limit 100 °C /
212°F
.
(15)
(14)
Excess
temperature
Set-point
Insufficient
temperature
W
X
CONFIG
HAND
VIEW->
EXIT
W
08:43:55 20.09.02
TEMP
°C
40.0
36.8
HUMID
%rH
65.0
58.6
(1)
Figure 20: Temperature safety device class 3.3
11.3.1 Temperature safety device class 3.1
If you turn the control knob (14) to its end-stop (position 10), the safety de-
vice class 3.1 protects the appliance. If you set it to a temperature a little
above the set-point temperature, it protects the charging material.
If the safety device class 3.1 has taken over control, identifiable by the red
alarm lamp (14a) lighting up, the message “TEMP ALARM” on the controller
display, and the buzzer, proceed as follows:
•
Reset the buzzer with RESET key on the controller
•
Disconnect the unit from the power supply
•
Have examined and rectified the cause of the fault by an expert
•
Start up the unit again as described in chap. 5.
(14a)
(14)
