vwr.com I Instruction manual VWR
®
ULT Freezer 352/528 Eco Premium 02/2022
Page 54/86
15.4 Required actions in case of an alarm
Only qualified service personnel authorized by VWR must perform repair.
Repaired chambers must comply with the VWR quality standards.
15.4.1 Safety controller temperature alarm
The selected temperature value of the safety controller was exceeded.
The alarm occurs immediately.
•
Alarm message “Safety controller”, collective alarm icon
•
Audible alarm (buzzer)
•
Switching the zero-voltage relay alarm output
Actions:
•
Check whether the outer door was open for a long time or is not closed properly. Close the door if
necessary. With open door there can be additional door open alarm.
•
Check the setting of the safety controller (chap. 12). The limit temperature should be approx. by 15 K
above the temperature set point. If necessary, adjust the relevant value.
•
Check whether samples were inserted into the freezer that may release heat.
•
Check the ambient conditions. Protect the freezer from direct sunlight. Ensure sufficient ventilation
around the installation location to prevent any buildup of heat in the chamber.
•
If these points do not reveal the source of the fault, it may be that the chamber is faulty. Please contact
Avantor Services.
15.4.2 Temperature tolerance range alarm (too high and too low temperature)
The tolerance range alarm becomes valid only after the setpoint has been reached.
When the actual temperature value leaves the tolerance range, the alarm occurs after the defined delay
time (chap. 14). Factory setting: 60 minutes.
•
Alarm message “Temp. range”, collective alarm icon
•
Audible alarm (buzzer)
•
Switching the zero-voltage relay alarm output
Actions:
•
Factory setting is +/- 5 K.
•
Use the actual temperature displayed on the controller to verify whether the temperature alarm threshold
has been breached, i.e., too cold or too warm.
Temperature too low (under temperature alarm):
•
Input of large quantities of samples which were precooled with liquid nitrogen. Reset the alarm with the
OK button
.
•
Possible cause: Continuous operation of the refrigeration machine after failure of one or several tem-
perature sensors (chap. 15.4.5). In addition, there is continuous operation alarm. Contact Avantor Ser-
vices.