The Model TC140 is a Digital Temperature Controller which features an independent count-up timer. The controller uses a Type K thermocouple and is microprocessor controlled. The regulation temperature can be set in one degree increments within specified limits. Hysteresis, Offset and Fahrenheit or Celsius are selected via front panel switches. The HEAT ON light indicates output relay activation. Actual sensed temperature is normally shown on the digital display. The control has diagnostic messages for open probe and memory failure.
Operating Logic: The timer function is started by pressing the TIME START button. The digital display will then alternate between probe temperature and elapsed time in hours and minutes. The timer function is cancelled by pressing the TIME START button again.
Setting Regulation Point: Press the TEMP button momentarily. The display will flash SET and PNT briefly then flash the setpoint value. The and buttons can now be used to adjust the temperature regulating setpoint. Press the TEMP button again to cause the control to regulate to the new setpoint.
Setting Hysteresis: The turn-on and turn-off temperature around a setpoint can be separately adjusted to ±20°F. Press and hold the , and TEMP buttons for .5 second. The display will alternate between ON and the turn-on value. The and buttons can now be used to change this value. Press the TEMP button again and the OFF value will be displayed. The and buttons can now be used to change the OFF value. Pressing the TEMP button again will return the control to normal operation and will store the new settings. The hysteresis is set to -1°F, +0°F as shipped from the factory.
Setting Offset: The displayed value can be changed by ±20°F. relative to actual sensed temperature value. This feature corrects for disparity of location of the probe and the volumetric center of the heating chamber. Press and hold the TIME and TEMP buttons, then also press and hold the and buttons. After one second the display will flash OFF and SET briefly then will flash the offset value. At this point, the and buttons can be used to adjust the offset. Pressing the TEMP button programs the control for the new value. The offset is set to 0 as shipped from the factory.
Diagnostic Messages: An open probe will cause the digital display to show PROB and will disable the output until input voltage is removed and re-applied. If a memory loss or failure occurs, the digital display will show FAIL and the output will be disabled. Input voltage should be removed and re-applied. If the FAIL message is gone, recheck programmed parameters and resume operation. If the FAIL message reappears, contact the factory for service.