Mitsubishi Electric MSZ-D30NA Service Manual page 18

8-9. EMERGENCY/TEST OPERATION
In case of test run operation or emergency operation, use the emergency operation switch on the front of the indoor unit.
Emergency operation is available when the remote controller is missing or has failed, or when 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 speed 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 Med.
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 case of latter normal operation will start.
NOTE : Do not press the emergency operation switch during normal operation.
E.O.
SW
8-10. 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.
8-11. 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 or remove
the batteries.
OBH501D
Emergency operation switch
Press RESET button gently using
a fine-tipped object.
Operation mode
Set temperature
Fan speed
Horizontal vane
The operation mode is indicated by the Operation
Indicator lamp as following
Operation Indicator lamp
(MSZ type)
E.O.
EMERGENCY COOL
SW
EMERGENCY HEAT
STOP
(MSY type)
EMERGENCY COOL
STOP
18
HEAT
COOL
(MUZ)
75°F (24°C) 75°F (24°C)
Med. Med.
Auto Auto
Lit
↓
Not lit
↓
↓