18
ROOM AIR CONDITIONERS TROUBLESHOOTING
CAUTION: Review Safe Servicing Practices in
the front of this manual before attempting
diagnostic procedures and repairs.
AIR CONDITIONER VOLTAGE LIMITS
E
T
A
L
P
E
M
A
N
G
N
I
T
A
R
M
U
M
I
N
I
M
M
U
M
I
X
A
M
C
A
V
5
1
1
C
A
V
5
.
3
0
1
C
A
V
5
.
6
2
1
C
A
V
0
3
2
C
A
V
7
0
2
C
A
V
3
5
2
0
3
2
/
8
0
2
C
A
V
5
.
7
9
1
C
A
V
3
5
2
AIR CONDITIONER VOLTAGE LIMITS
Low voltage is a common cause of trouble in the operation
of any room air conditioner.
Improper voltage may cause one or more of the following
problems:
1. Unit will not start.
2. Compressor motor cycling on motor protector.
3. Premature failure of motor protector.
4. Blown fuses.
5. Premature failure of compressor or fan motor.
6. Noticable dimming of lights when air conditioner is
running.
7. Evaporator icing. Low voltage may reduce fan speed
resulting in inadequate air flow over evaporator, thereby
allowing it to ice up.
HIGH VOLTAGE
High voltage can be equally troublesome, causing motors
to overheat, cycle on their protectors, or break down
electrically. This problem can only be solved by the power
company.
ELECTRONIC CONTROL
This control is not repairable. If any component in the
control is defective, the entire control must be replaced.
IMPORTANT NOTICE:
Repair or replace any
malfunctioning line voltage component before testing
or replacing the electronic control.
DO NOT
assume a
service problem is directly caused by the electronic
control system. A line voltage component (including
power cord and wiring) that has opened, shorted,
grounded or otherwise malfunctioned, may have created
a service problem.
Low voltage can also be the direct result of inadequately
wired circuits, extension cords, or loose fuses and
connections to the power supply. Voltage may also be a
general condition in the area (a responsibility of the power
company).
All units will start and run on the minimum voltage stated
in the chart to the left, and will perform satisfactorily if the
voltage remains constant. Low voltage caused by defective
wiring will not remain constant under load.
To test for low voltage, use a reliable meter with sufficient
capacity to measure the required voltage. Take
measurements at the electric power entry point and at the
electric outlet serving the air conditioner. Take readings
with the unit off, while the unit is starting, and again while
the unit is running. The lowest reading should not drop
below the lowest value listed in the chart.
SYMPTON
POSSIBLE CAUSE
Fan motor will not run.
1. No power.
2. Power supply cord.
3. Selector switch.
4. Energy saving switch (if applicable).
5. Electronic control (if applicable).
6. Wire disconnected or connection loose.
7. Capacitor. (Discharge capacitor before testing.)
8. Defective fan motor windings.
9. Will not rotate. Fan blade hitting shroud or blower
wheel hitting scroll. (Motor cycles on overload.)
Fan motor runs intermittently.
1. Cycle on motor protector.
