Mitsubishi Electric NTXMMX A AA Series Service Manual page 21

8-12. EMERGENCY/TEST OPERATION
In the case of test run operation or emergency operation, use the emergency operation switch on the right side of the
indoor unit. Emergency operation is available when the remote controller is missing or has failed, or the batteries in the
remote controller are running down. The unit will start and OPERATION INDICATOR lamp will light up.
The first 30 minutes of operation is the test run operation. This operation is for servicing. The indoor fan runs at High
speed and the temperature control does not work.
After 30 minutes of test run operation, the system shifts to EMERGENCY COOL/HEAT MODE with a set temperature of
75°F(24°C). The fan speed shifts to Medium.
The coil frost prevention works even in the test run or the emergency operation.
In the test run or emergency operation, the horizontal vane operates in VANE AUTO ( ) mode.
Emergency operation continues until the emergency operation switch is pressed once or twice or the unit receives any
signal from the remote controller. In the latter case normal operation will start.
NOTE: Do not press the emergency operation switch during normal operation.
Remote control receiving section
Emergency operation switch
Operation indicator lamp
8-13. 3-MINUTE TIME DELAY OPERATION
When the system turns OFF, compressor will not restart for 3 minutes as 3-minute time delay function operates to protect
compressor from overload.
8-14. Changing temperature indication (°F/°C)
• The preset unit is °F.
• °F → °C: Press RESET button while the TEMPERATURE buttons are pressed.
• °C → °F: Press RESET button while the TEMPERATURE buttons are pressed.
OBHT802B
Operation mode COOL/HEAT
Set temperature 75°F(24°C)
Fan speed Medium
Horizontal vane Auto
The operation mode is indicated by the Operation
Indicator lamp as following
Operation Indicator lamp
EMERGENCY COOL
↓
EMERGENCY HEAT
↓
STOP
21
Lit
Not lit
Press RESET button gently
using a thin instrument.