Process Control; Ambient Temperature Sensor Selection - Full Gauge VC-108 Log Manual

12. PROCESS CONTROL

The refrigeration process control takes into account the temperatures measured in the ambient sensors (S1 or S4) and in the evaporator sensor (S2):
- The ambient sensor is used to control the temperature inside the F2.01 equipment and to detect the end of a defrost process F3.15;
- The evaporator sensor serves to detect the end of the defrost process (F3.14), to allow the start of a manual defrost cycle (F3.12) and to control the
F3.22 and F3.23 fan actuation.
Note: The condenser (S3) and drawer (S5-S10) sensors do not influence the thermal process control.
12.1 Selection of Ambient Temperature Sensor:
The equipment provides two sensors for measuring ambient temperature:
- S1: Sensor located inside a capsule containing glycerol, to simulate the thermal behavior of the stored vaccines;
- S4: Sensor in direct contact with the air inside the equipment cabinet.
Only one of these sensors is used for control, according to parameter F3.41 - Selection of ambient temperature sensor for control. Based on this
parameter, the following logic is respected:
- If F3.41 = S1 (Glycerol):
- The S1 temperature is used for process control, display and alarms.
- If F3.41 = S4 (Air):
- The S4 temperature is used for process control;
- The S1 temperature is used for display and alarms.
If the sensor selected in F3.41 fails, the other sensor is used as backup, for process control, display and alarms.
Attention: When sensor S4 is not enabled, i.e., F3.47 - Sensor S4 (ambient 2 - air) indication offset = Off, parameter F3.41 is ignored. In this
configuration, sensor S4 also cannot function as a substitute in case of failure of sensor S1.
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