Chapter
6
© SP Industries, Inc.
200-31974-999 Rev. 009
52
Base
Unit
Controls
When the ThermoJet is powered, the System Controller continuously monitors the incoming air
pressure. So long as the inlet pressure remains above 75 psig, the ThermoJet will provide up to
20 SCFM for air temperatures below 100°C and up to 15 SCFM for air temperatures above
100°C. The operator must manually reduce the airflow to achieve higher temperatures.
NOTE:
If the incoming air pressure drops low enough to inhibit proper performance, the
system will power down and set off a “Low Air Pressure” alarm.
The base unit houses the refrigeration system, the air filtering/drying system and most of the
high-voltage electrical components. Initial installation and maintenance/service call are the only
time that the THJ80 base unit controls, switches, gauges and indicators need to be accessed.
Access to the base unit internals is not needed during normal operations.
NOTE:
The base unit contains no user serviceable components. Contact your authorized
FTS service representative for repairs.
The Emergency Mechanical Off button, located on the left front corner of the ThermoJet top,
immediately shuts off system power. It should be used as a safety switch, not as an on/off switch.
Normal shutdowns should be performed via the PLC / touch screen.
Air Delivery Assembly
The air delivery assembly (Fig. 40) heats the refrigerated air, just before it exits the nozzle and
impinges on the DUT or into a custom test apparatus. The air delivery assembly is comprised of
an air channel, thermal insulating materials, heater, thermocouples, and a protective outer jacket.
Figure 40 – ThermoJet Head
In addition to providing thermal insulation, the generous layering of
insulation (Fig. 41) also protects the other components of the air
delivery assembly from physical wear and tear.
Figure 41 – Cross-sectional View of Head
A
IR
F
LOW
