Thermo Scientific 3907 Operating Manual page 36

| Handling and Control
Chapter 8
|
8-4 Model 3907 & 3948
If an overtemp condition occurs, the alarm can only be silenced by raising the overtemp
safety thermostat setting. However, the cause of the problem must be determined and
corrected before normal operation under the main temperature controller is resumed.
Humidity Alarm
Humidity
Controller
Indicator lights
Indicators and Controls
Figure 8-5
Undertemp Safety Control, Indicator Light and Audible Alarm (Figure 8-5)
The undertemp safety thermostat should be set slightly lower than the operating
temperature of the environmental chamber. In the event of an undertemp condition, the
undertemp safety thermostat will:
Activate the audible alarm and the overtemp indicator light.

Interrupt power to the refrigeration system and maintain the environmental

chamber'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.
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 8-5).
Temperature Controller
Cool Indicator Heat Indicator
Overtemp &
Undertemp
Controls
Thermo Scientific