Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 89

8-4. The following symptoms do not represent product failure
Symptom
Even the cooling (heating) operation selection button is
pressed, the indoor unit cannot be operated.
Display: "Cooling (Heating)" blinks
The auto vane runs freely.
Display: Normal display
Fan setting changes during heating.
Display: Normal display
Fan stops during heating operation.
Display: "Heat Defrost
Fan does not stop while operation has been stopped.
Display: Light is off
No setting of fan while start SW has been turned on.
Display: "Heat Standby
Indoor unit remote controller shows "Please Wait" indicator
for about 2 minutes when turning ON power supply.
Display: "Please Wait" blinks
Drain pump does not stop while unit has been stopped.
Display: Light is off
Drain pump continues to operate while unit has been
stopped.
Display: —
8-5. Internal switch function table
■ SWU1 and SWU2
0 0
SWU2 SWU1
(tens digit) (ones digit)
Bit When to set
Rotary switch Before turning the power ON
■ SW1: Digital display switch
Initial setting
ON
OFF
1 2 3 4 5 6 7 8
The black square (■) indicates a switch position.
Bit When to set
1-8 Any time
■ SW2: Function switch
Initial setting
ON
OFF
1 2 3 4 5 6
The black square (■) indicates a switch position.
OCH800A_89
"
"
Purpose
To display outdoor unit's information to the LED on outdoor multi controller circuit board.
Refer to "Outdoor unit information display".
Cause
The indoor unit cannot cool (heat) if other indoor units are
heating (cooling).
Because of the control operation of auto vane, it may
change over to horizontal blow automatically from the
downward blow in cooling because the downward blow
operation has been continued for 1 hour. At defrosting in
heating, hot adjusting and thermostat OFF, it automatically
changes over to horizontal blow.
Ultra-low speed operation is commenced at thermostat
OFF. Light air automatically change over to set value by
time or piping temperature at thermostat ON.
The fan stops during defrosting.
Fan runs for 1 minute after stopping to exhaust residual
heat (only in heating).
Ultra-low speed operation for 5 minutes after SW ON or
until piping temperature reaches 95°F (35°C). Then low
speed operates for 2 minutes and operates at the normal
set air volume. (Hot adjust control)
The system is in the process of startup. Operate remote
controller again after "Please Wait" disappears.
After a stop of cooling operation, unit continues to operate
drain pump for 3 minutes and then stops.
Unit continues to operate drain pump if drainage is gener-
ated, even during a stop.