43

A7 -- Fuse Chart

Unit Size Fuse Rating (Amps/Volts)
Indoor Outdoor Outdoor
009 --- 3.15A/250V 2A/250V
012 --- 3.15A/250V 2A/250V
018 3.15A/250V 3.15A/250V ---
024 3.15A/250V 3.15A/250V ---
The 3.15A fuses protect the board against the indoor or outdoor fan motors.
The 2A fuses protect the board against a Class II circuit board failure.

A8 -- Indoor Unit Diagnostic Guides

9K & 12K Units

Operation
Lamp
Timer
Lamp Failure Mode Diagnostic
Chart
lXIndoor fan speed has been out of control for over 1 minute 1
lOn Indoor room temp. or evaporator sensor is open circuit or short circuited 2
XlCompressor over---current protection has been activated four times 3
On lEPROM error* ---
l l Indoor unit communication error (Illuminates simultaneously) 4

18K & 24K Units

Opera-
tion
Lamp
Timer
Lamp
Defrosting
Lamp
Auto
Lamp Failure Mode Diagnostic
Chart
l l l l Over --- current protection of the compressor occurs four times 3
XlX X Indoor room temp. sensor is open circuit or short circuited 2
lX X X Temp. sensor on indoor evaporator is open circuit or short circuited 2
X X lXTemp. sensor on outdoor condenser is open circuit or short circuited (not
cooling only modes) 2
X X l l Outdoor unit protects (outdoor temp. sensor, phase order, etc.) 5
XlXlEPROM error* ---
X X X lIndoor unit communication error 6
l=Flashing
X=Off
* = Replace Indoor Board
A07545a
A07544
A07546a
Model size 009 Model size 012 Model size 018--024*
Infrared signal receptor
OPERATION TIMER
PRE-DEF
AUTO
ECON
TIMER OPERATION
PRE-DEF
Infrared signal recepto
r
*PRE--DEF light will illuminate when the unit is running in FAN ONLY mode on Cooling Only units.
AUTO
TIMER
PRE.-DEF.
OPERATION

Fig. 34 – LED Display Panel

A9 -- Outdoor Unit Diagnostic Guides

Flashing
Times after 2
Second Off
Failure Mode Diagnostic
Chart
5Communication failure 4or6
2Condenser temperature sensor failure 2
1Other indoor failure –

If the unit is operating normally, the LED light on the outdoor board is lit continuously. If there is a failure, the LED light will flash a specific

number of times. Refer to the Outdoor Unit Diagnostic table above to determine failure.

38/40MVC, MVQ