Operator’s Manual: ThermoJet
Chapter 5: Display Screens
© SP Industries, Inc.
200-31974-999 Rev. 009
47
F. Defrost –
While in IDLE mode, from the Utilities Screen (Fig. 16), select the “Defrost” button
and the screen depicted below will open. This screen reminds the operator to protect the DUT
from possible moisture contamination by moving the head away from the test site before starting
the defrost cycle. If “Yes” is pressed the defrost cycle will start, the Manual screen will reappear
and the status window will display “Defrost”.
The Defrost function removes any moisture (ice) that may have built up within the heat
exchanger. It should only be required in the event the supplied air is not within system specified
parameters or in the event of an air dryer malfunction. The entire Defrost function normally takes
less than fifteen minutes to complete. Indications that a system defrost may be required include
degraded low temperature performance and/or degraded air flow.
Figure 34 – Defrost Screen
To run the Defrost function:
1. Before starting the defrost cycle, terminate any test program that may be underway.
2. Raise the pneumatic head assembly and move the shroud away from the test site. Point the
nozzle away from personnel or equipment.
NOTE:
The purpose of the Defrost is to remove ice (moisture) from the heat exchanger.
Moisture will be blown out of the exit nozzle during the Defrost function!
3. Press the Defrost button on Utilities Screen. Then press “Yes” on the Defrost Screen.
4. The system will enter the Defrost Mode and return to the Manual Mode Screen. The status
window will display “Defrosting”.
5. When the defrost function is complete the controller will automatically return the user to the
Manual screen in IDLE Mode.
Since the 2nd stage compressor shuts off during the Defrost cycle, it will take an additional 10 to
15 minutes for the ThermoJet to re-establish its maximum low temperature capacity; however,
testing at elevated temperatures can begin immediately.
Defrost Screen
