Ingersoll-Rand Thermo King CRR DF MPC2000, Maintenance Manual

Page: 66 / 165

Microprocessor Controller
65
Initiating a Manual Defrost
With the unit On/Off switch ON:
1. Press the DEFROST key.
• If the unit operating conditions allow a manual defrost (e.g. evaporator coil temperature is less
than 10 C [50 F]), the unit enters defrost as the Defrost LED turns ON.
• If unit operating conditions do NOT allow defrost, the LCD message display shows “DEFROST
NOT ACTIVATED”.
2. The defrost cycle automatically terminates.
Displaying Alternate Controlling (Supply or Return) Air
Sensor Temperature
The controller can show either the supply or return air temperature in the LED Display. With the
unit On/Off switch ON and the controller showing the standard LED Display:
1. Check the indicator LEDs to determine which sensor temperature (supply air or return air) currently
appears in the right display. This is the controlling sensor (return air sensor at setpoints of -10 C [14 F]
and below).
2. To view the supply air temperature, press and hold the SUP/RET key. The controller will show the
supply air temperature as long as the SUP/RET key is depressed.
3. The display then returns to the return air temperature when the SUP/RET key is released.
Displaying Alternate Fahrenheit (F) or Celsius (C)
Temperature
The controller can display temperatures in Fahrenheit or Celsius. With the unit On/Off switch
ON and the controller showing a standard LED Display:
1. Press and hold the C/F key. The controller will show the LED display temperature in the alternate
temperature scale (Fahrenheit or Celsius) from the temperatures shown on the display as long as the
C/F key is depressed.
2. The display then returns to the original display when the C/F key is released.
NOTE: To change the default temperature scale display, see “Changing the Temperature Display
Value (C/F)” under MISC. FUNCTIONS in the Menu Operating Instructions section in this chapter.
Menu Operating Instructions
NOTE: To view the controller’s menu or download data when external power is disconnected from the
unit, press a special key: C/F key, SUP/RET key, DEFROST key or SETPOINT key. The controller
LCD display will appear using 12 Vdc battery power.