Chromalox IntelliTrace ITAS, Installation Manual, Page: 7 / 110

3
Theory of Operation
The set-up of the individual and global circuit parameters is explained in the Temp/Load Set-up sections of this
manual. This Theory of Operation overview is intended to give a quick summary of how it all works together.
• Each circuit of the system may be enabled (active) or disabled (inactive). A disabled loop will have no
output and will not map into the common alarm. It will display “Circuit #” and “Disabled” text above
the process temperature. Alarms for disabled circuit will not be monitored or displayed on the screen.
• Each circuit of the system may use unique individual control parameters or the control parameters may
be alike. The Global Settings function facilitates this action.
• The GFEP and Load current are automatically and continuously being calculated. The horizontal orange
bar indicates the average output current for that circuit. The GFEP current value is not displayed on
the screen but its value is compared to the GFEP setpoint. A GFEP alarm condition will occur when
the GFEP current value exceeds the GFEP setpoint value.
• If a ground fault that exceeds the GFEP setpoint value is detected during normal operation and “Trip”
button on the Load Setpoints screen is checked, the output of the defective circuit is set to 0% and
that circuit goes into an alarm condition. If “Trip” button is not selected, the operation of that circuit
continues and that circuit goes into alarm condition. The GFEP alarm may be either Latching or Non-
Latching.
• During extended periods of time where the output of all circuits are off, such as during warmer sea-
sons, the Auto Cycle feature may be engaged. This feature initiates power to each circuit and checks
for alarms. Each output is tested for one minute within the desired Auto Cycle Interval. The Auto Cycle
feature may be disabled by setting the Auto Cycle Interval time to “0 Hours”.
• To limit inrush current on the overall system, a proprietary Soft Start algorithm is applied during sys-
tem start-up. This will ONLY occur while the operation mode is set to AUTO. The Soft Start program
will increment output % by 1% every 1 second until the desired temperature is reached or the output
% achieves 100%. After the Soft Start program completes its cycle, the Control Mode of the system
will either be PID or ON/OFF Control Mode, depending what was selected by the user. The Soft Start
Program will not function if the control mode is set to Manual.
• Centralized control of multiple ITAS or ITLS panels is accomplished via the ISC-IntelliTrace Supervisory
Controller.