Thermo Electron 3940 Series, Operating And Maintenance Manual

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Model 3940 Series 2-3 Thermo Electron Corporation
Section 1
Start-Up and Operation
Figure 2-4. Indicators and Controls
Undertemp Safety Control, Indicator Light and Audible Alarm (Fig. 2-4)
The undertemp safety thermostat should be set slightly lower than the
operating temperature of the incubator. In the event of an undertemp
condition, the undertemp safety thermostat will:
• Activate the audible alarm and the undertemp indicator light.
• Interrupt power to the refrigeration system and maintain the incuba-
tor’s cabinet temperature at the undertemp safety control point.
Note
The undertemp control is not directly calibrated. The numbers on
the dial are for reference only.
V
If an undertemp condition occurs, the alarm can only be silenced by
lowering the undertemp safety thermostat setting. However, the cause of
the problem must be determined and corrected before normal operation
under the main temperature controller is resumed.
Audible Humidity Alarm and Indicator Display (Figure 2-4)
The humidity alarm is a function of the humidity controller (Figure 2-
5). When the cabinet humidity goes outside the set parameters of the
controller, L4 indicator on the controller lights, the audible alarm
sounds, and the humidity alarm indicator on the control panel lights.