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CAUTION
PRECAUTIONS IN THIS MANUAL.
• ONLY FOR AUTHORIZED SERVICE PERSONNEL.

1. PREFACE ...................................................................................................................................................3
1.1 FEATURES.....................................................................................................................................................3
1.2 SPECIFICATIONS .........................................................................................................................................3
1.3 LOCATIONS OF CONTROLS .......................................................................................................................4
1.4 SAFETY PRECAUTIONS ..............................................................................................................................4
1.5 INSULATION RESISTANCE TEST ................................................................................................................4
2. DISASSEMBLY INSTRUCTIONS ................................................................................................5
2.1 MECHANICAL PARTS ..................................................................................................................................5
2.1.1 FRONT GRILLE ....................................................................................................................................5
2.1.2 CABINET................................................................................................................................................5
2.1.3 CONTROL BOARD................................................................................................................................5
2.2 AIR HANDLING PARTS ................................................................................................................................6
2.2.1 AIR GUIDE UPPER ..............................................................................................................................6
2.2.2 ORIFICE, TURBO FAN AND FAN .........................................................................................................6
2.2.3 MOTOR ..................................................................................................................................................7
2.2.4 AIR GUIDE.............................................................................................................................................7
2.3 ELECTRICAL PARTS ....................................................................................................................................7
2.3.1 OVERLOAD PROTECTOR ...................................................................................................................7
2.3.2 COMPRESSOR .....................................................................................................................................8
2.3.3 CAPACITOR ..........................................................................................................................................8
2.3.4 THERMOSTAT .......................................................................................................................................8
2.3.5 ROTARY SWITCH..................................................................................................................................8
2.3.6 POWER CORD .....................................................................................................................................9
2.4 REFRIGERANT CYCLE ................................................................................................................................9
2.4.1 CONDENSER .......................................................................................................................................9
2.4.2 EVAPORATOR ....................................................................................................................................10
2.4.3 CAPILLARY TUBE ..............................................................................................................................10
3. INSTALLATION ....................................................................................................................................12
3.1 SELECT THE BEST LOCATION .................................................................................................................12
3.2 HOW TO INSTALL .......................................................................................................................................12
4. TROUBLESHOOTING GUIDE ....................................................................................................
4.1 OUTSIDE DIMENSIONS..............................................................................................................................15
4.2 PIPING SYSTEM ........................................................................................................................................16
4.3 TROUBLESHOOTING GUIDE ....................................................................................................................17
15
5. CIRCUIT DIAGRAM ...........................................................................................................................22
6. EXPLODED VIEW ..............................................................................................................................23
7. SERVICE PARTS LIST ....................................................................................................................24

1-1. PREFACE
This service manual provides various service information, including the mechanical and electrical parts, etc.
This room air conditioner was manufactured and assembled under a strict quality control system.
The refrigerant is charged at the factory. Be sure to read the safety precautions prior to servicing the unit.
1.1 FEATURES
• DESIGNED FOR COOLING ONLY
• POWERFUL AND INCREDIBLE COOLING
• TOP-DOWN CHASSIS FOR THE SIMPLE INSTALLATION AND SERVICE
• BUILT-IN ADJUSTABLE THERMOSTAT
• WASHABLE ONE-TOUCH FILTER
• COMPACT SIZE
1.2 SPECIFICATIONS
MODELS
ITEMS
COOLING CAPACITY (BTU/h) 5,100
POWER SUPPLY (Phase, V, Hz) 1ø, 115V, 60HZ
INPUT (W) 475
OPERATING CURRENT (AMP.) 4.4
REFRIGERANT CONTROL CAPILLARY TUBE
REFRIGERANT CHARGE (R-22) 280g (9.9 oz)
INSIDE FAN TURBO FAN
OUTSIDE FAN PROPELLER FAN WITH SLINGER RING
AIR DISCHARGE 2-WAY (RIGHT AND LEFT)
CHASSIS TOP-DOWN
PROTECTOR
TEMPERATURE CONTROL THERMOSTAT
ROTARY SWITCH
• OVERLOAD PROTECTOR FOR COMPRESSOR
• INTERNAL PROTECTOR FOR FAN MOTOR
5 STEP (LOW FAN, HIGH FAN, OFF, HIGH COOL, LOW COOL)
RADS-51B
FAN MOTOR 6 POLES, 16W
—3—

1.3 LOCATIONS OF CONTROLS
1.4 SAFETY PRECAUTIONS
1. When servicing, set the ROTARY SWITCH to
Off and unplug the power cord.
2. Observe the original lead dress.
If a short circuit is found, replace all parts which
have been overheated or damaged by the short circuit.
3. After servicing, make an insulation resistance test
to prevent the customer from being exposed to
shock hazards.
1.5
INSULATION RESISTANCE TEST
1. Unplug the power cord and connect a jumper
between 2 pins (black and white).
2. The grounding conductor (green or green and yellow) is to be open.
3. Measure the resistance value with an ohm meter
between the jumpered lead and each exposed
metallic part on the equipment at all position
[except Off] of the ROTARY SWITCH.
4. The value should be over 1 MΩ.
CAUTION : After switching the air conditioner from Cool to Off or Fan, wait at least 3 minutes before switching it
back to Cool.
On/Off Timer
Fan/Cool/Dry
• Everytime you push this button, it will toggle between
COOL, FAN, and DRY.
Power
Temperature Setting
• This button can automatically control the temperature
of the room. The temperature can be set within a range of
60°F to 86°F by 1°F.
Select the lower number for lower temperature of the room.
Fan Speed
Energy Saver
The fan stops when the compressor stops cooling.
• Approximately every 3 minutes the fan will turn on and
check the room air to determine if cooling is needed.
Each press of the button cycles through the options in this
order: 1 Hour → 2 Hours → 3 Hours → 4 Hours → 5 Hours
→ 6 Hours → 7 Hours → 8 Hours → 9 Hours → 10 Hours →
11 Hours → 12 Hours → CANCEL.
The set temperature will be raised 2°F after 30 minutes
and again after another 30 minutes.
Each press of the button cycles through the options in this
order: 1 Hour → 2 Hours → 3 Hours → 4 Hours → 5 Hours
→ 6 Hours → 7 Hours → 8 Hours → 9 Hours → 10 Hours →
11 Hours → 12 Hours → CANCEL.
• To turn the unit ON, push the button. To turn the unit OFF,
push the button again.
• This button takes priority over any other buttons.
• When the unit is first powered up, it defaults to settings of
High Cool at 72°F.
• Pressing the Fan Speed button toggles between Low and
High speeds.
- Stopping Operation
- Stopping Operation

—5—
2. DISASSEMBLY INSTRUCTIONS
2.1 MECHANICAL PARTS
2.1.1 FRONT GRILLE
1. Pull the inlet grille forward.
2. Remove the screw securing the Front Grille. (Fig. 3)
3. Push the grille up from the bottom and pull the top of
the grille away from the case to lift the top tabs out of
their slots. (Fig. 4)
4. Carefully position the grille, bottom first, and snap back
into place.
5. Reposition the screw that secures the front grille
2.1.2 CABINET
1. Disconnect the unit from the power source.
2. Remove the front grille. (Refer to section 2.1.1)
3. Remove 9 screws that secure the cabinet to the
base pan and condenser. (See Figure 3)
4. Lift the cabinet from the unit.
5. Re-install by referring to the procedures above.
2.1.3 CONTROL2.1.3 CONTROL PANEL
2. Remove the front grille. (Refer to Section 2.1.1)
3. Remove the cabinet. (Refer to Section 2.1.2)
4. Remove 1 screws that secure the control board to
base pan and air guide. (See Figure 4)
5. Pull the control 5. Pull the control panel toward yourself.
the fan motor and compressor. (See Figure 5)
7. Re-install components by referring to procedures
above. (Refer to wiring diagram on page 23 in this
manual or inside control board.)
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
NOTE : Controls, wires, and capacitor are now
accessible for servicing. Discharge the
capacitor before ser vicing. See step
2.3.3 on page 8 for procedures.

—6—
2.2 AIR HANDLING PARTS
2.2.1 AIR GUIDE UPPER
1. Disconnect the unit from the power source.
2. Remove the front grille. (Refer to Section 2.1.1)
3. Remove the cabinet. (Refer to Section 2.1.2)
4. Remove the control board.
(Refer to Section 2.1.3)
5. Remove 2 screws that secure the air guide upper
to air guide lower. (See Figure 6)
6. Lift air guide upper upward.
7. Re-install by referring to the procedures above.
2.2.2 ORIFICE, TURBO FAN AND FAN
1. Disconnect the unit from the power source.
2. Remove the front grille. (Refer to Section 2.1.1)
3. Remove the cabinet. (Refer to Section 2.1.2)
4. Remove the control board.
(Refer to Section 2.1.3)
5. Remove the air guide upper.
(Refer to Section 2.2.1)
6. Remove 2 screws that secure the base pan to
condenser. (See Figure 7)
7. Remove screw that secures the shroud to
channel of condenser.
8. Press the snap area of shroud with your thumbs.
This allows you to remove it from the condenser.
9. Lift the compressor upward with the evaporator
and condenser. (See Figure 7)
10. Remove the orfice by pushing the snap area of
the air guide blower. (See Figure 8)
11. Remove the clamp springs which are clamped to
the boss of fan and turbo fan by hand plier. (See
Figure 9)
12. Pull the fan and turbo fan outward.
13. Remove the shroud.
14. Re-install by referring to the procedures above.
Figure 6
Figure 7
Figure 8
Figure 9

—7—
2.2.3 MOTOR
1. Disconnect the unit from the power source.
2. Remove the front grille. (Refer to Section 2.1.1)
3. Remove the cabinet. (Refer to Section 2.1.2)
4. Remove the control board.
(Refer to Section 2.1.3)
5. Remove the air guide upper.
(Refer to Section 2.2.1)
6.
Remove the compressor, turbo fan, fan and
shroud. (Refer to
Section
2.2.2)
7.
Remove 2 screws that secure the motor to the
motor. (See Figure 10)
8. Remove the motor.
9.
Re-install by referring to the procedures above.
2.2.4 AIR GUIDE
1. Disconnect the unit from the power source.
2. Remove the front grille. (Refer to Section 2.1.1)
3. Remove the cabinet. (Refer to Section 2.1.2)
4. Remove the control board.
(Refer to Section 2.1.3)
5. Remove the air guide upper.
(Refer to Section 2.2.1)
6.
Remove the compressor, turbo fan, fan and
shroud. (Refer to
Section
2.2.2)
7.
Remove the motor. (Refer to
Section
2.2.3)
8. Remove 2 screws that secure the air guide to the
base pan. (See Figure 11)
9. Push the air guide backward and lift it upward.
(See Figure 11)
10. Re-install by referring to the procedures above.
2.3 ELECTRICAL PARTS
2.3.1 OVERLOAD PROTECTOR
1. Remove the front grille and cabinet.
(Refer to Section 2.1)
2. Remove the nut which fastens the terminal cover.
3. Remove the terminal cover.
4. Remove all the leads from the overload protector.
5. Remove the overload protector.
6. Re-install the components by referring to the
removal procedure above.
(See Figure 12 and 13)
Figure 10
Figure 12
Figure 13
Figure 11

—8—
2.3.2 COMPRESSOR
1. Remove the front grille and cabinet.
(Refer to Section 2.1)
2. Discharge the refrigerant by using a refrigerant
recovery system.
3. Remove the overload protector.
(Refer to Section 2.3.1)
4. After discharging the unit completely, unbrace the
suction and discharge pipes at the compressor
connections.
5. Remove 3 nuts which fasten the compressor.
6. Remove the compressor.
7. Re-install by referring to the removal procedure
above. (See Figure 14)
2.3.3 CAPACITOR
1. Remove the cabinet. (Refer to Section 2.1.2)
2. Remove the control panel.
(Refer to Section 2.1.3)
3. Discharge the capacitor by placing a 20 KΩ
resistor across the capacitor terminals.
4. Remove the screw which fastens the capacitor
clamp.
5. Remove all the leads of capacitor terminals.
6. Re-install the components by referring to the
removal procedure above. (See Figure 15)
2.3.4 THERMISTOR
1. Remove the cabinet. (Refer to Section 2.1.2)
2. Remove the control panel.
(Refer to Section 2.1.3)
3. Disconnect the thermistor terminals from main
P.W.B assembly.
4. Remove the thermistor.
5. Re-install the components by referring to the
removal procedure above. (See Figure 16)
2.3.5 CONTROL BOARD
1. Remove the cabinet. (Refer to Section 2.1.2)
2. Remove the control panel.
(Refer to Section 2.1.3)
3. Pull the control board forward and pull out it.
4. Remove 2 lead wire terminals.
5. Re-install the components by referring to the
removal procedure above. (See Figure 17)
Figure 14
Figure 15
Figure 16
Figure 17

—9—
2.3.6 POWER CORD
1. Disconnect the unit from source of power.
2. Remove the front grille. (Refer to Section 2.1.1)
3. Remove the cabinet. (Refer to Section 2.1.2)
4. Remove a screw that secures control board to
base pan. (Refer to Section 2.1.3)
5. Pulls the control board toward you.
6. Disconnect the 2 receptacles and remove the
grounding screw.
7. Remove a screw securing the clip with cord to the
control board.
8. Pull the power cord.
9. Re-install by referring to procedures above.
2.4 REFRIGERANT CYCLE
2.4.1 CONDENSER
1. Remove the cabinet. (Refer to Section 2.1.2)
2. Discharge the refrigerant by using a refrigerant
recovery system.
3. Remove the air guide. (Refer to Section 2.2.1)
4. Remove 2 screws which fasten the condenser.
5. After discharging the refrigerant completely,
unbraze the interconnecting tube at the
condenser connections.
6. Remove the condenser.
7. Re-install by referring to the procedures above.
Figure 18
Figure19

2.4.2 EVAPORATOR
1. Remove the cabinet.
2. Discharge the refrigerant by using a refrigerant
recovery system.
3. Remove the air guide upper. (Refer to Section
2.2.1)
4. After discharging the refrigerant completely,
unbraze the interconnecting tube at the condenser
connections.
5. Remove the evaporator.
6. Re-install by referring to the procedures above.
2.4.3 CAPILLARY TUBE
1. Remove the cabinet.
2. Discharge the refrigerant by using a refrigerant
recovery system.
3. Remove the air guide upper. (Refer to Section
2.2.1)
4. After discharging the refrigerant completely,
unbraze the interconnecting tube of the capillary
tube.
5. Remove the capillary tube.
6. Re-install by referring to the procedures above.
NOTES
Replacement of the refrigeration cycle.
1. When replacing the refrigerating cycle, be sure to
discharge the refrigerant by using a refrigerant
recovery system.
2. After discharging the unit completely, remove the
desired components, and unbraze the pinch-off
tubes.
3. Solder service valves into the pinch-off tube ports,
leaving the valves open.
4. Solder the pinch-off tubes with service valves.
5. After completing the above procedures, the valve
must be closed and left in place on the system for
any subsequent procedures.
6. Evacuate as follows:
6-1. Connect the vacuum pump, as illustrated in
figure 21A.
6-2. Start the vacuum pump. Slowly open manifold
valves A and B with two full turns counterclockwise and leave the valves closed.
The vacuum pump is now pulling through
valves A and B up to valve C by means of
manifold and the entire system.
CAUTION : If high vacuum equipment is used,
just crack valves A and B for a few minutes, then
open slowly with the two full turns counterclock-
wise. This will keep oil from foaming and being
drawn into the vacuum pump.
6-3. Operate the vacuum pump for 20 to 30 min-
utes, until 600 micron vacuum is obtained.
Close valves A and B and observe vacuum
gauge for a few minutes.
A rise in pressure would indicate a possible
leak or moisture remaining in the system.
With valves A and B closed, stop the vacuum
pump.
6-4. Remove the hose from the vacuum pump and
place it on the charging cylinder. See figure
23B. Open valve C.
Discharge the line at the manifold connection.
6-5. The system is now ready for final charging.
7. Recharge as follows:
7-1. Refrigeration cycle systems are charged from
the high-side. If the total charge cannot be put
in the high-side, the balance will be put in the
suction line through the access valve which is
installed as the system is opened.
7-2. Connect the charging cylinder as shown in fig-
ure 21B. With valve C open, discharge the
hose at the manifold connection.
7-3. Open valve A and allow the proper charge to
enter the system. Valve B is still closed.
7-4. If more charge is required, the high-side will
not take it. Close valve A.
7-5. With the unit running, open valve B and add
the balance of the charge.
a. Do not add the liquid refrigerant to the low-
side.
b. Watch the low-side gauge, allow pressure to
rise to 30 lbs.
c. Turn off valve B and allow the pressure to
drop.
d. Repeat steps b. and c. until the balance of
the charge is in the system.
7-6. When the unit is operating correctly, use the
pinch-off tool with the unit still running and
clamp on the pinch-off tube. Using a tube cutter, cut the pinch-off tube about 2 inches from
the pinch-off tool. Use sil-fos solder and solder
the pinch-off tube closed. Turn off the unit,
allow setting for a while and then test the leakage of the pinch-off connection.
—10—

—11—
Equipment needed: Vacuum pump, charging cylinder, manifold gauge, brazing equipment, pinch-off tool capable
of making a vapor proof seal, leak detector, tubing cutter, hand tools to remove components and service valve.
B
A
B
A
B
A
COMPOUND GAUGE
SEE INSETS
BELOW
CAPILLARY TUBE
EVAPORATOR
(LOW PRESSURE SIDE)
COMPRESSOR
CONDENSER
(HIGH PRESSURE SIDE)
EXTERNAL VACUUM PUMP
LO HI
CHARGING CYLINDER
MANIFOLD
GAUGE
C
Figure 21A-Pulling Vacuum Figure 21B-Charging

—12—
3. INSTALLATION
This air conditioner is designed with a button-down
chassis so it can be easily installed in a window.
3.1 SELECT THE BEST LOCATION
1. To prevent vibration and noise, make sure the unit is
installed securely and firmly.
2. Install the unit where the sun does not shine directly
on the unit.
3. The outside of the cabinet must extend outward for at
least 10" and there should be no obstacles, such as a
fence or wall, within 20" from the back of the cabinet
because it will prevent heat radiation of the condenser.
Restriction of outside air will greatly reduce the cooling
efficiency of the air conditioner.
4. Install the unit slanted slightly so the back is slightly lower than the front (about 1/
4"). This will force
condensed water to the outside.
5. Install the unit with the bottom about 30"~60"
above the floor level.
3.2 HOW TO INSTALL
3.2.1 WINDOW REQUIREMENTS
NOTE: All supporting parts should be secured to fir m
wood, masonry, or metal.
1. This unit is designed for installation in standard double hung windows with actual opening widths of 22" to
36". The upper and lower sash must open sufficiently
to allow a clear vertical opening of 13" from the bottom of the sash to the window stool.
2.If storm window presents interference, fasten a 2" wide
wood strip to the inner window sill across the full
width of the sill. The wood strip should be thick
enough to raise the height of the window sill so that
the unit can be installed without interference by the
storm window frame. See Figure. 24. Top of wood
strip should be approximately 3/4" higher than the
storm window frame (STORM WINDOW FRAME) or
wood strip (OUTDOORS) to help condensation to
drain properly to the outside.
3.
Install a second wood strip (approximately 6" long by
11/2" wide and same thickness as first strip) in the center of the outer sill flush against the back off the inner
sill. This will raise the L bracket as shown Figure. 24.
4. If the distance between STORM WINDOW FRAME
and WOOD STRIP MOUNTED ON TOP OF INNER
SILL is more than 1", two of wood strip are not necessary.
ABOUT / "
Over 20"
HEAT
RADIATION
FENCE
AWNING
OUTSIDE
INSIDE
COOLED AIR
30"-60"
1
4
Figure 22
Figure 23
Figure 24
All side louvers of the cabinet must remain
exposed on the outdside of the structure.
CAUTION
OUTDOORSINDOORS
INNER
SILL
OUTER
SILL
INNER
SILL
WOOD STRIP MOUNTED
ON TOP OF INNER SILL
WOOD STRIP
FOR
L
BRACKET
3/4"
CLEARANCE
1" MAX.
STORM
WINDOW
FRAME
OUTDOORSINDOORS
OUTER
SILL

—13—
Installation
3.2.2 BEFORE INSTALLATION
1. Inser t the guide panels into the guides of the air condi-
tioner. Fasten the curtains to the unit with screws (TYPE
A) as shown Figure. 25.
2.
Cut the adhesive-backed seal strip (TYPE D) to the window
width.
Remove the backing from the seal strip and attach the seal
strip to the underside of the bottom window. (
Figure
. 26)
3.2.3 NOW START INSTALLATION
1. LOCATING UNIT IN WINDOW
Open the window and mark center line on the center of
the inner sill, as shown in Figure. 27.
2. ATTACH L BRACKET
a. Install the L brackets behind the inner window sill, with
the short side of bracket as shown.
Use the 2 screws (TYPE A) provided.
b. The bracket helps to hold unit securely in place. Be
sure to place bracket edge flush against back of inner
sill. See Figure. 27.
TYPE B: 4EA
(WOOD SCREW)
HARDWARE
TYPE A: 11EA
(SHORT SCREW)
TYPE C: 3EA
(L BACKET)
TYPE E: 1EA
(SASH SEAL)
(Not adhesive backed)
TYPE D: 1EA
(SEAL STRIP)
(Adhesive backed)
TYPE F: 2EA
(GUIDE PANEL)
10mm
16mm
During the following step, hold unit firmly until
window sash is lowered to top channel behind
side panel frames. Personal injury or property
damage may result if unit falls from window.
CAUTION
ROOM SIDE
CENTER LINE
INNER SILL
SEAL STRIP
(TYPE D)
TYPE A
TYPE A
Figure 25
Figure 26
Figure 27

3. INST ALL THE AIR CONDITIONER IN THE WINDO W
a. Carefully lift the air conditioner and slide it into the
open window. Make sure the bottom guide of the air
conditioner drops into the notches of the
L bracket. See Figure. 28.
IMPORTANT :
When the air conditioner drops into the L bracket, the air
conditioner will be centered in window opening as shown in
Figure. 29.
b. While steadying the air conditioner, carefully bring the
window sash down behind the upper guide of the air
conditioner, as shown in Figure. 30.
4. SECURE THE GUIDE PANELS
Extend the guide panels (TYPE F) to fill the window
opening using 4 screws (TYPE B) to secure them, as
shown in Figure. 31.
5. INSTALL THE SASH SEAL AND SASH LOCK
a. Cut the sash seal (TYPE E) to the window width. Stuff
the sash seal between the glass and the window to
prevent air and insects from getting into the room, as
shown in Figure. 31.
b . F asten the L bracket using a (TYPE A) screw, as
shown in Figure. 31.
6. Window installation of room air conditioner is now
completed. See ELECTRICAL DATA for attaching
power cord to electrical outlet.
—14—
OUTSIDE
INSIDE
L
BRACKET
OUTER SILL
SHORT SIDE
INNER SILL
TYPE A
8"
8"
CENTER LINE
SEAL
WINDOW FRAME
BOTTOM
GUIDE
ABOUT
1/4"
L
BRACKET
UPPER GUIDE
CENTER LINE
DRAIN PIPE
DRAIN CAP
hang push
SASH SEAL
(TYPE E)
L BRACKET
TYPE A
Figure 28
Figure 29
Figure 30
Figure 31
TYPE B

REMOVAL FROM WINDOW
Tur n the air conditioner off, disconnect the power cord, remove the L bracket and the screws installed through the top and bottom of the guide panels, and save for reinstallation later. Close the guide panels. Keeping a firm grip on the air conditioner,
raise the sash, and carefully tilt the air conditioner backward, draining any condensate water. Lift the air conditioner from the
window and remove the sash seal from between the windows.
4. TROUBLESHOOTING GUIDE
4.1 OUTSIDE DIMENSIONS (unit: mm [in])
370 (14 9/16")
312 (12 1/4")
370 (14 9/16")
312 (12 1/4")
29 (1
5
/32")
120 (4 3/4")
27.5 (1
3
/32")
42 (1 21/32")
42 (1 21/32")
155(6
3/32
")
12
(0.4
1/16
")
22.5(0.8
3/32
")
346 (13
5
/8
")
472 (18 9/16")
472 (18 9/16")

—16—
4.2 PIPING SYSTEM
Figure 32 is a brief description of the important components and their function in what is called the refrigeration
system. This will help you to understand the refrigeration cycle and the flow of the refrigerant in the cooling cycle.
COOLED
AIR
HOT
DISCHARGED
AIR
MOTOR
COMPRESSOR
ROOM AIR HEAT LOAD
CAPILLARY TUBE
(LIQUID REFRIGERANT)
LIQUID OUTLET
VAPOR INLET
COMPLETE LIQUID
BOIL OFF POINT
SUCTION LINE
COOL LOW PRESSURE VAPOR
LIQUID
PRESSURE
DROP
DISCHARGE
LINE
NOT HIGH PRESSURE
VAPOR
OUTSIDE COOLING
AIR FOR REFRIGERANT
PASS THROUGH
EVAPORATOR COILS CONDENSER COILS
ROOM AIR CONDITIONER
CYCLE OF REFRIGERATION
HIGH PRESSURE VAPOR
LIQUID REFRIGERANT
LOW PRESSURE VAPOR
OIL
CONDENSER COILS
FAN
CAPILLARY
MOTOR
TUBE
TURBO FAN
EVAPORATOR
COILS

—17—
4.3 TROUBLESHOOTING GUIDE
In general, possible trouble is classified in two kinds.
The one is called Starting Failure which is caused by an electrical defect. The other is Ineffective Air Con-
ditioning caused by a defect in the refrigeration circuit and improper application.
Unit is running but cooling is ineffective.
Ineffective Cooling
Satisfactory operation
with temperature
difference of inlet & outlet
air: 55~59°F (13~15°C)
Replacement of unit if
the unit is beyond repair.
Check outdoor coil
(heat exchanger) and
fan operation.
Check heat load
increase.
Check cold air
circulation for smooth
flow.
Check gas leakage.
Clean condenser.
Not on separate circuit
Check inside gas
pressure.
Adjust refrigerant
charge.
Malfunction of
compressor.
Replacement of
compressor.
Check clogging in refrigeration circuit.
Repair clogging in
refrigeration circuit.
Dirty indoor coil
(heat exchanger)
Repair gas leak.
Malfunction of fan.
Clogging of air filter.
Obstruction at air outlet.
Remove obstruction.

—18—
Fails to Start
Improper thermostat
setting
Loose terminal
connection
Improper wiring
Check of power source.
Drop of power voltage.
Capacitor check.
Replacement.
Check of control switch
setting.
Compressor fails only to
start.
Defect of compressor
capacitor.
Replacement of compressor
(Motor damaged).
Irregular motor insulation (Ω)
Irregular motor resistance (Ω)
Check of circuit breaker
and fuse.
Gas leakage of feeler
bulb of thermostat.
Check control switch.
Fan only fails to start.
Improper wiring.
Defect of fan motor
capacitor.
Replacement of fan motor.
Regular but fails to start.
Replacement of compressor.
(Locking of piston, metal.)
Irregular motor
resistance (Ω)
Irregular motor
insulation (Ω)

—19—
ROOM AIR CONDITIONER VOLTAGE LIMITS
NAME PLATE RATING MINIMUM MAXIMUM
115V ± 10% 103.5V 126.5V
COMPLAINT CAUSE REMEDY
Fan motor will not run. No power Check voltage at outlet. Correct if none.
Power supply cord Check voltage to rotary switch. If none, check
power supply cord. Replace cord if circuit is
open.
Rotary switch Check switch continuity. Refer to wiring diagram
for terminal identification. Replace switch if
defective.
Wire disconnected or Connect wire. Refer to wiring diagram for
connection loose terminal identification. Repair or replace loose
terminal.
Capacitor (Discharge Test capacitor.
capacitor before testing.) Replace if not within ±10% of manufacturer's
rating. Replace if shorted, open, or damaged.
Will not rotate Fan blade hitting shroud or blower wheel hitting
scroll. Re-align assembly.
Units using slinger ring condenser fans must
have 0.22~0.25 inch clearance to the base.
If necessary, shim up the bottom of the fan motor
with mounting screw(s).
Check fan motor bearings; if motor shaft will not
rotate, replace the motor.
Fan motor runs. Revolves on overload Check voltage. See limits on this page.
If not within limits, call an electrician.
Test capacitor.
Check bearings. Does the fan blade rotate
freely?
If not, replace fan motor.
Pay attention to any change from high speed to
low speed. If the speed does not change,
replace the motor.

—20—
COMPLAINT CAUSE REMEDY
Fan motor noise. Fan If cracked, out of balance, or partially missing,
replace it.
Blower If cracked, out of balance, or partially missing,
replace it.
Loose set screw Tighten it.
Worn bearings If knocking sounds continue when running or
loose, replace the motor. If the motor hums or
noise appears to be internal while running,
replace motor.
Compressor will not run, Voltage Check voltage. See the limits on the preceding
fan motor runs. page. If not within limits, call an electrician.
Wiring Check the wire connections; if loose, repair or
replace the terminal. If the wires are discon-
nected, refer to wiring diagram for identification,
and replace the wires. Check the wire connections;
If not according to the wiring diagram, correct
the connections.
Rotary Check for continuity, refer to the wiring diagram
for terminal identification. Replace the switch if
the circuit is open.
Thermostat Check the position of knob. If not at the coldest
setting, advance the knob to this setting and
restart the unit.
Check the continuity of the thermostat. Replace
the thermostat if the circuit is open.
Capacitor (discharge Check the capacitor.
capacitor before Replace if not within ±10% of manufacturer’s
servicing.) rating, replace if shorted, open, or damaged.
Compressor Check the compressor for open circuit or
ground. If open or grounded, replace the
compressor.
Overload
Check the compressor overload if externally mounted.
Replace if open. (If the compressor temperature is
high, remove the overload, cool, and retest.)
Compressor cycles on Voltage Check the voltage. See the limits on the
overload. preceding page. If voltage is not within these limits,
call an electrician.
Overload Check overload, if externally mounted.
Replace if open. (If the compressor temperature
is high, remove the overload, cool, and retest.)

—21—
COMPLAINT CAUSE REMEDY
Compressor cycles on Fan motor If not running, determine the cause. Replace if
overload. required.
Condenser air flow Remove the cabinet, inspect the interior surface
restriction of the condenser. If restricted, clean carefully
with a vacuum cleaner (do not damage fins) or
brush. Clean the interior base before
re-assembling.
Condenser fins If the condenser fins are closed over a large
(damaged) area on the coil surface, head pressures will
increase, causing the compressor to cycle.
Straighten the fins or replace the coil.
Capacitor Test the capacitor.
Wiring Check the terminals. If loose, repair or replace.
Refrigeration system Check the system for a restriction.
Insufficient cooling Air filter If restricted, clean or replace.
Unit undersized Determine if the unit is properly sized for the
area to be cooled.
Excessive noise Blower or fan Check the set screw, or clamp. If loose or miss-
ing, correct. If the blower or fan is hitting scroll
or barrier, rearrange the air handling parts.
Copper tubing Remove the cabinet and carefully rearrange the
tubing not to contact the cabinet,
compressor, shroud, and barrier.

1
2
6
7
5
3854AR2330A
COMP.
MOTOR
ROCKER SWITCH
YL BR
THERMOSTAT
OLP
BRRBL
RD
BK
OR(BR)
CAPACITOR
F
H
C
YL
ROTARY SWITCH
2H
L
M
BK
BR
RD
BL
BK
POWER INPUT
BK(BR)
(Plain)
WH(BL)
(Ribbed)
GN(GN/YL)
RD
BL
YL
OR(BR)
4
6
8
1
3
5
7
BL
RD
BK
BR
WIRING DIAGRAM
SYNC. M.
S
C
3
4
Q'TY
PER SET
1
1
1
1
1
1
1
LOCATION
NO.
1
2
3
4
5
6
7
DESCRIPTION
POWER CORD ASSY
FAN MOTOR
COMPRESSOR
ROTARY SWITCH
THERMOSTAT
CAPACITOR
OVERLOAD PROTECTOR
2H00677P
4681A10016C
2520
UCAA003
2H00154H
2H01109H
0CZZA20005B
6750U-L050A
PART NO.

RADS - 51B
W48602 3H02932B CLAMP,SPRING
R
Description
130410 3041A20036G BASE ASSEMBLY,WELD
130910 3091AR6055M CABINET ASSEMBLY,SINGLE
135312 3531A20087D GRILLE ASSEMBLY,FRONT
135313 3530A10039H GRILLE,INLET
147581 4520AR3191A LINK
147582-1 5990AR3190C LOUVER,VERTICAL
147582-2 5990AR3190D LOUVER,VERTICAL
149980 4998AR1608A SHROUD
152302 5231AR2148A FILTER,AIR
237200 3720A20017A PANEL,CONTROL R
238310 3831A10001F ESCUTCHEON
249950 ABQ30999202 CASE ASSEMBLY,CONTROL
263230 6323A20003S THERMISTOR,NTC
264110 6411A20056A POWER CORD ASSEMBLY
267110 6711A20066C REMOTE CONTROLLER ASSEMBLY
268711-1 PCB ASSEMBLY,MAIN
EBR39266506
268711-2 6871A20432B PCB ASSEMBLY,DISPLAY
346811 4681A10016N MOTOR ASSEMBLY,AC,SINGLE
349480 4948A10016B ORIFICE
352111 5211AR3332N TUBE ASSEMBLY,CAPILLARY
352113 5211A10129A TUBE ASSEMBLY,DISCHARGE
352115 5211A10063E TUBE ASSEMBLY,EVAPORATOR(IN)
35211A 5211A10062G TUBE ASSEMBLY,SUCTION
352380 5238A20013A GUIDE,AIR
352390 5239A30003G GUIDE ASSEMBLY,AIR
354210 5421A20016L EVAPORATOR ASSEMBLY,FIRST
359012 5900A10005B FAN,TURBO
550140 5040AR4195A DAMPER,COMPRESSOR
554030 5403A20009R CONDENSER ASSEMBLY,FIRST
554160 2520UABC2JA COMPRESSOR SET,KOREA
559011 5901A20011B FAN ASSEMBLY,AXIAL
567502 6750U-L050A OVERLOAD PROTECT
731273 3127A20074A INSTALL PART ASSEMBLY,SINGLE
749740 5210AR3196C GUIDE
W0CZZ 0CZZA20005B
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R

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