Operation
14 Installation and Operation Manual
Thermo Scientific Cryogenic Storage Freezers
6.3.5 Alarm Test
To test the warm alarm, complete the following steps:
1. Press and hold the Alarm Test pad. The digital temperature display
indicates rising temperature. When the temperature reaches the warm
alarm value, the alarm sounds.
Note:
The temperature of the refrigerated space does not change during this
procedure. Only the sensor is heated.
2. Release the Alarm Test pad, the sensor and display return to cabinet
temperature in a few minutes.
You can press the Audio Silence pad to silence the alarm but the alarm will
ring back in five to seven minutes. You can silence the alarm in this manner
as many times as necessary until the sensor cools below the warm alarm
temperature. The alarm quits automatically when the sensor cools below the
warm alarm value.
Note:
There is a limit on the alarm test feature. The alarm test will not
commence if the warm alarm setpoint is more than 15 degrees warmer than the
operating temperature setpoint.
6.4 Frame Heater
Switch
Cryogenic chest freezers (-140° and -150°C) have a frame heater switch
which can be used to prevent or remove condensation near the freezer
compartment lid. The switch is located in back of the unit near the top
center, to the right of the junction box. Turning the switch to the up
position heats up the frame around the lid.
Heating the frame has no effect on interior cabinet temperature. You can
turn on the switch whenever there is condensation near the lid.
