Unifit. Cool (03/07)
Thru-the-Wall Series
Service and Parts
Manual
—2—
1. PREFACE
1.1 SAFETY PRECAUTIONS ...............................2
1.2 INSULATION RESISTANCE TEST.................2
1.3 SPECIFICATIONS ..........................................3
1.4 FEATURES.....................................................5
1.5 CONTROL LOCATIONS.................................5
2.
DISASSEMBLY INSTRUCTIONS
2.1 MECHANICAL PARTS....................................6
2.1.1 FRONT GRILLE.....................................6
2.1.2 CABINET................................................6
2.1.3 CONTROL BOX.....................................6
2.2 AIR HANDLING PARTS..................................7
2.2.1
ORIFICE, HEATER ASSY AND TURBO FAN
.........7
2.2.2 FAN........................................................7
2.2.3 SHROUD................................................8
2.3 ELECTRICAL PARTS.....................................8
2.3.1 MOTOR..................................................8
2.3.2 COMPRESSOR.....................................8
2.3.3 CAPACITOR..........................................8
2.3.4 POWER CORD......................................9
2.3.5 THERMISTOR .......................................9
2.4 REFRIGERATION CYCLE.................................10
2.4.1 CONDENSER......................................10
2.4.2 EVAPORATOR....................................10
2.4.3 CAPILLARY TUBE...............................10
3.
TROUBLESHOOTING GUIDE
3.1 OUTSIDE DIMENSIONS...............................13
3.2 PIPING SYSTEM ..........................................13
3.3 TROUBLESHOOTING GUIDE......................14
4. SCHEMATIC DIAGRAM
4.1 CIRCUIT DIAGRAM......................................1
5. EXPLODED VIEW..................................
6. REPLACEMENT PARTS LIST.......2
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 SAFETY PRECAUTIONS
1. When servicing the unit, turn off the air conditioner
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 the unit, make an insulation
resistance test to protect the customer from being
exposed to shock hazards.
1.2
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 & 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.
4. The value should be over 1MΩ.
CONTENTS
—3—
1.3 SPECIFICATIONS
Buyer Model US10D10B-A US10D30B-A US12D10B-A US12D30B-A
PERFORMANCE
BTU performance (Cooling)
9,800 10,000/9,800 11,500 11,500/11,200
BTU performance (Heating)
EER
9.8 9.8/9.8 9.8 9.8/9.8
COP
Dehumid. ( Pts/Hr)
3.2 3.2 3.8 3.8
Dry Air Flow (CFM)
285 285 290 290
dBA Level (Indoor / Outdoor)
54/61 54/61 55/62 55/62
Electrical Ratings
Voltage / 60 Hz
115 230/208 115 230/208
Watts (Cooling)
1,000 1,020/1,000 1,170 1,170/1,140
Watts (Heating)
Rated Amps (Cooling)
9.2 4.7/5.1 10.4 5.3/5.7
Rated Amps (Heating)
Features
Thermostat Control
Thermistor Thermistor Thermistor Thermistor
Air Diflection
4-Way 4-Way 4-Way 4-Way
Remote controller
Yes Yes Yes Yes
Auto swing
NO NO NO NO
Auto Restart
Yes Yes Yes Yes
Energy saver fuction
Yes Yes Yes Yes
Timer
24Hr,On/Off 24Hr,On/Off 24Hr,On/Off 24Hr,On/Off
Filter Alarm Function
Yes Yes Yes Yes
Sleep
- - - -
Fan Speed: Cooling(Heating)
3 3 3 3
Fan Only
3 3 3 3
Compressor
ROTARY ROTARY ROTARY ROTARY
In Door Fan Type
TURBO TURBO TURBO TURBO
Type Air Discharge
Top Top Top Top
Outdoor Vent / Exhaust
Yes Yes Yes Yes
Rear grille
Yes Yes Yes Yes
Chassis Type
XB XB XB XB
Others
Carton Height(inch)
17 13/32 17 13/32 17 13/32 17 13/32
Width
27 23/32 27 23/32 27 23/32 27 23/32
Depth
22 13/32 22 13/32 22 13/32 22 13/32
Demension Height(inch)
14 13/32 14 13/32 14 13/32 14 13/32
Width
24 24 24 24
Depth
20 3/32 20 3/32 20 3/32 20 3/32
Net Weight(lbs.)
77 77 80 80
Shipplin
g Weig
ht(lbs.)
8
7 87 90 90
Stuffing Quantity (40ft)
339 339 339 339
—5—
24
24
—6—
2.1 MECHANICAL PARTS
2.1.1 FRONT GRILLE
1. Open the inlet grille downward.
2. Remove the screw which fastens the front grille.
3. Pull the front grille from the right side.
4. Remove the front grille. (See Fig. 1)
5. Re-install the component by referring to the
removal procedure.
2.1.2 CABINET
1. After disassembling the FRONT GRILLE, remove
the 6 screws which fasten the cabinet at the both
sides and the top. (See Fig. 2)
Keep these for later use.
2.1.3 CONTROL BOX
1. Remove the front grille. (Refer to section 2.1.1)
2. Remove the screw which fasten the control
box. (See Fig. 3)
3. Pull the control box from the barrier.(See Fig.3)
4. Discharge the capacitor by placing a 20,000 ohm
resistor across the capacitor terminals.
5. Disconnect two wire housings in the control box.
6. Pull the control box forward completely.
7. Re-install the components by referring to the
removal procedure. (See Fig. 3)
(Refer to the circuit diagram found on page 19 in
this manual and on the control box.)
2. DISASSEMBLY INSTRUCTIONS
— Prior to disassembling the unit, make sure that the POWER is off and the power cord is unplugged from the
wall receptacle.
Figure 1
Figure 2
Figure 3
Figure 7
—7—
2.2 AIR HANDLING PARTS
2.2.1 ORIFICE, AND TURBO FAN
1. Remove the front grille. (Refer to section 2.1.1)
2. Remove the cabinet. (Refer to section 2.1.2)
3. Remove the 2 screws which fasten the
evaporator at the left side and the right side.
(See Fig. 4)
4. Move the evaporator to the side carefully.
5. Remove the orifice. (See Fig. 5)
8. Using handheld pliers, remove the clamp which
secures the turbo fan. (See Fig. 6)
9. Remove the turbo fan with pliers or your hand,
without touching blades. (See Fig. 7)
10. Re-install the components by referring to the
removal procedures, above.
2.2.2 FAN
1. Remove the cabinet. (Refer to section 2.1.2)
2. Remove the brace.
(Refer to section 2.2.1)
3. Remove the 7 screws which fasten the condenser.
4. Move the condenser to the side carefully.
5. Using handheld pliers, remove the clamp which
secures the fan.
6. Remove the fan. (See Fig. 8)
7. Re-install the components by referring to the
removal procedures, above.
Figure 4
Figure 5
Figure 6
Figure 8
—8—
2.2.3 SHROUD
1. Remove the fan. (Refer to section 2.2.2)
2. Remove the shroud. (See Fig. 9)
3. Re-install the components by referring to the
removal procedures, above.
2.3 ELECTRICAL PARTS
2.3.1 MOTOR
1. Remove the cabinet. (Refer to section 2.1.2)
2. Remove the clamp cord and disconnect the wire
housing in control box. (Refer to section 2.1.3)
3. Remove the turbo fan. (Refer to section 2.2.2)
4. Remove the fan. (Refer to section 2.2.2)
5. Remove the 4 or 2 screws which fasten the motor.
(See Fig. 10)
6. Remove the motor.
7. Re-install the components by referring to the
removal procedures, above.
2.3.2 COMPRESSOR
1. Remove the cabinet. (Refer to section 2.1.2)
2. Discharge the refrigerant system using a Freon
TM
Recovery System.
Install a valve for recovery before venting the
Freon. Remove the valve when finished.
3. Disconnect the 3 leads from the compressor.
4. After purging the unit completely, unbraze the
suction and discharge tubes at the compressor
connections.
5. Remove the 3 nuts and the 3 washers which
fasten the compressor. (See Fig. 11)
6. Remove the compressor.
7. Re-install the components by referring to the
removal procedures, above.
2.3.3 CAPACITOR
1. Remove the control box. (Refer to section 2.1.3)
2. Remove the 1 screw
3. Open the control box
4. Disconnect all the leads on the capacitor terminals.
5. Re-install the components by referring to the
removal procedures, above.
Figure 9
Figure 10
Figure 11
Figure 12
—9—
2.3.4 POWER CORD
1. Remove the control box. (Refer to section 2.1.3)
2. Unfold the control box. (Refer to section 2.3.3)
3. Disconnect the grounding screw from the Base
pan.
4. Disconnect 2 receptacles.
5. Remove a screw which fastens the clip cord.
6. Pull the power cord. (See Fig. 13)
7. Re-install the components by referring to the
removal procedure, above.
(Use only one ground-marked hole, , for ground
connection.)
8. If the supply cord of this appliance is damaged, it
must be replaced with the factory-authorized and
specified cord.
2.3.5 ELECTRONIC CONTROL BOARD
1. Remove the control box. (Refer to section 2.1.3)
2. Unfold the control box. (Refer to section 2.3.3)
3. Disconnect all the leads of Electronic control board
terminals.
4. Remove the Electronic control board. (See Fig. 14)
5. Re-install the components by referring to the
removal procedures, above.
Figure 13
Figure 14
—10—
2.4 REFRIGERATION CYCLE
2.4.1 CONDENSER
1. Remove the cabinet. (Refer to section 2.1.2)
2. Remove the brace.
(Refer to section 2.2.1)
3. Remove the 7 screws which fasten the condenser.
4. After discharging the refrigerant completely into a
Freon
TM
Recovery System, unbraze the
interconnecting tube at the condenser
connections.
5. Remove the condenser.
6. Re-install the components by referring to the notes
– on pages 11-13. (See Fig. 15)
2.4.2 EVAPORATOR
1. Remove the cabinet. (Refer to section 2.1.2)
2. Discharge the refrigerant completely – into a
Freon
TM
Recovery System.
3. Remove the 2 screws which fasten the evaporator
at the left side and the right side.
4. Move the evaporator to the side carefully and then
unbraze the interconnecting tube at the evaporator
connectors.
5. Remove the evaporator.
6. Re-install the components by referring to the notes
– on pages 11-13. (See Fig. 16)
2.4.3 CAPILLARY TUBE
1. Remove the cabinet. (Refer to section 2.1.2)
2. After discharging the refrigerant completely – into
a Freon
TM
Recovery System, unbraze the
interconnecting tube at the capillary tube.
3. Remove the capillary tube.
4. Re-install the components by referring to the notes
– on page 11-13.
Figure 15
Figure 16
Discharge the refrigerant system using a Freon
TM
Recovery System.
Install a valve for the recovery, before venting
the Freon, remove the valve when finished.
CAUTION
—11—
— Replacement of the refrigeration cycle.
1. When replacing refrigeration components, be sure
to discharge the refrigerant system using a Freon
TM
recovery System.
Install a valve for the recovery, before venting the
Freon, remove the valve when finished.
2. After discharging the unit completely, remove the
desired component, 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. Evacuate as follows.
1) Connect the vacuum pump, as illustrated Fig.
17A.
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 the manifold
and entire system.
3) Operate the vacuum pump for 20 to 30 minutes,
until 600 microns of 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.
4) Remove the hose from the vacuum pump and
place it on the charging cylinder. See Fig. 17B.
Open valve C.
Discharge the line at the manifold connection.
5) The system is now ready for final charging.
6. Recharge as follows :
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 you
installed as the system was opened.
2)
Connect the charging cylinder as shown in Fig. 17B.
With valve C open, discharge the hose at the
manifold connection.
3) Open valve A and allow the proper charge to
enter the system. Valve B is still closed.
4) If more charge is required, and the high-side will
not
take it. Close valve A.
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 pressure to drop.
d. Repeat steps B and C until the balance of the
charge is in the system.
6) When satisfied the unit is operating correctly,
use the pinch-off tool with the unit still running
and clamp on to 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
pinch-off tube closed. Turn off the unit, allow it to
set for a while, and then test for leakage add the
pinch-off connection.
NOTES
If high vacuum equipment is used, just crack
valves A and B for a few minutes, then open
slowly with the two full turns counterclockwise.
This will keep oil from foaming and being
drawn into the vacuum pump.
CAUTION
—12—
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, Service
valve.
A
COMPOUND GAUGE
EVAPORATOR
(LOW PRESSURE SIDE)
COMPRESSOR
CAPILLARY TUBE
CONDENSER
(HIGH PRESSURE SIDE)
SEE INSETS
BELOW
MANIFOLD
GAUGE
B
Figure 17A-Pulling Vacuum
Figure 17B-Charging
A
B
EXTERNAL
VACUUM PUMP
A
CHARGING
CYLINDER
LOW
HI
B
C
—13—
3. TROUBLESHOOTING GUIDE
3.1 OUTSIDE DIMENSIONS
20-
3
/32"
(499mm)
24"
(610mm)
14-
13
/
32
"
(366mm)
CONDENSER COILS
EVAPORATOR COILS
FAN
MOTOR
: REFRIGERANT FLOW
TURBO FAN
CAPILLARY TUBE
COMPRESSOR
3.2 PIPING SYSTEM
Following is a brief description of the important components and their functions in the refrigeration system.
Refer to Fig. 18 to follow the refrigeration cycle and the flow of the refrigerant in the cooling cycle.
MOTOR
COMPRESSOR
OIL
(LIQUID REFRIGERANT)
CAPILLARY TUBE
OUTSIDE COOLING
AIR FOR REFRIGERANT
PASS THROUGH
SUCTION LINE
COOL LOW PRESSURE VAPOR
COOLED
AIR
COMPLETE LIQUID
BOIL OFF POINT
LIQUID
PRESSURE
DROP
ROOM AIR HEAT LOAD
VAPOR INLET
HOT
DISCHARGED
AIR
LIQUID OUTLET
HIGH PRESSURE VAPOR
LIQUID REFRIGERANT
LOW PRESSURE VAPOR
ROOM AIR CONDITIONER
SLIOC RESNEDNOCSLIOC ROTAROPAVE
CYCLE OF REFRIGERATION
Figure 18
—14—
3.3 TROUBLESHOOTING GUIDE
In general, possible trouble is classified in two causes.
One is called Starting Failure which is caused from an electrical defect, and the other is Ineffective Air Conditioning
caused by a defect in the refrigeration circuit and/or improper application.
Unit is running but cooling is ineffective
Ineffective Cooling
Check outdoor coil
(heat exchanger) & the fan
operation.
Check gas leakage.
Repair gas leak.
Replacement of unit if the
unit is beyond repair.
Satisfactory operation with
temperature difference of
inlet & outlet air ; 18-26°F
Check heat load increase.
Unexpected residue
Overloaded Circuit
Check inside gas pressure.
Adjusting of refrigerant
charge
Malfunction of compressor
Replacement of
compressor
Check cold air circulation
for smooth flow.
Dirty indoor coil
(Heat exchanger)
Malfunction of fan
Clogged air filter
Obstruction at air outlet
Correct above troubles
Check for a clog in
refrigeration circuit.
Repair for a clog in
refrigeration circuit.
—15—
Fails to Start
Check circuit breaker
and fuse.
Check control board
Only fan fails to start.
Improper wiring.
Defect of fan motor
capacitor.
Irregular motor resistance
( ).
Irregular motor insulation
( ).
Replacement of fan motor
Regular but fails to start
Replacement of compressor
(locking of rotor, metal)
Improper thermostat setting
Loose terminal connection.
Improper wiring
Irregular motor resistance ( )
Irregular motor insulation ( )
Replacement of compressor
(Motor damaged)
Drop in power voltage.
Check capacitor.
Replacement.
Only compressor fails to
start.
Defective compressor
capacitor.
Check power source.
Check control switch
setting.
—16——16—
COMPLAINT CAUSE REMEDY
Check voltage at outlet. Correct if none.
Check voltage to rotary switch. If none, check
power supply cord. Replace cord if circuit is open.
Check switch continuity. Refer to wiring diagram
for terminal identification. Replace switch if
defective.
Connect wire. Refer to wiring diagram for terminal
identification. Repair or replace loose terminal.
Test capacitor.
Replace if not within ±10% of manufacturer's
rating. Replace if shorted, open, or damaged.
Fan blade hitting shroud or blower wheel hitting
scroll. Realign assembly.
Units using slinger ring condenser fans must
have
1
/
4
to
5
/
16
inch clearance to the base. If it is
hitting the base, 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.
Check voltage. See limits on page 17. 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.
Check grommets; if worn or missing, replace them.
If cracked, out of balance, or partially missing,
replace it.
If cracked, out of balance, or partially missing,
replace it.
Tighten it.
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.
No power
Power supply cord
Rotary switch
Wire disconnected or
connection loose
Capacitor (Discharge
capacitor before testing.)
Will not rotate
Cycles on overload.
Grommets
Fan
Turbo fan
Loose set screw
Worn bearings
Fan motor will not run.
Fan motor runs
intermittently
Fan motor noise.
—17—
NAME PLATE RATING MINIMUM MAXIMUM
115V 103.5V 126.5V
208/230V 187V 253V
COMPLAINT CAUSE REMEDY
Check voltage. See the limits on the preceding.
page. If not within limits, call an electrician.
Check the wire connections, if loose, repair or
replace the terminal. If wires are off, refer to wiring
diagram for identification, and replace. Check wire
locations. If not per wiring diagram, correct.
Check for continuity, refer to the wiring diagram
for terminal identification. Replace the switch if
circuit is open.
Check the capacitor.
Replace if not within ±10% of manufacturers
rating. Replace if shorted, open, or damaged.
Check the compressor for open circuit or
ground. If open or grounded, replace the
compressor.
Check the compressor overload, if externally
mounted. Replace if open. (If the compressor
temperature is high, remove the overload, cool it,
and retest.)
Voltage
Wiring
Rotary
Capacitor (Discharge
capacitor before
servicing.)
Compressor
Overload
Compressor will not run,
but fan motor runs.
ROOM AIR CONDITIONER VOLTAGE LIMITS
—18—
COMPLAINT CAUSE
REMEDY
Check the voltage. See the limits on the preced-
ing page. If not within limits, call an electrician.
Check overload, if externally mounted.
Replace if open. (If the compressor temperature
is high, remove the overload, cool, and retest.)
If not running, determine the cause. Replace if
required.
Remove the cabinet. Inspect the interior surface
of the condenser; if restricted, clean carefully
(do not damage fins). Clean the interior base before
reassembling.
If condenser fins are closed over a large area
on the coil surface, head pressures will increase,
causing the compressor to cycle. Straighten the
fins or replace the coil.
Test capacitor.
Check the terminals. If loose, repair or replace.
Check the system for a restriction.
If restricted, clean or replace.
Close if open.
Determine if the unit is properly sized for the area to
be cooled.
Check the set screw or clamp. If loose or missing,
correct. If the blower or fan is hitting air guide,
rearrange the air handling parts.
Remove the cabinet and carefully rearrange tubing
not to contact cabinet, compressor, shroud, and
barrier.
Voltage
Overload
Fan motor
Condenser air flow
restriction
Condenser fins
(damaged)
Capacitor
Wiring
Refrigerating system
Air filter
Exhaust damper door
Unit undersized
Blower or fan
Copper tubing
Compressor cycles
on overload.
Insufficient cooling or
heating
Excessive noise.
—19—
4. SCHEMATIC DIAGRAM
4.1 CIRCUIT DIAGRAM
(SMPS)
MEZ64403901
250V/T2A
(250V/T3.15A)
*MODEL:US08E10
*MODEL:US10E10，US12D10，US12D30，US14D30 ,US10E30
(SMPS)
MEZ62420710
250V/T2A
(250V/T3.15A)
—27 —
5. EXPLODED VIEW
•
554160
359012
352380
346811
554031-1
149980
352115
35211A
130410
435300-1
147582-1
147581
135303
152302
147582-2
135312
349480
352113
552113-1
W48602
354210
731273
E
C
B
567480
267110
W0CZZ
249950
238310 237200
A
264110
MO ED
M I
T
R E
W O P
R E
N A
F
D E
E P S
F
an
y
g r e
n E
r e v
a
S
C
ool
Ti
me
r
P M E T
'
F
F
1L O
W
F
2MED
F3H
I
GH
132100
130900
559011
268711-2
268711-1
552113-2
554031-2
435300-2
349600
550140
552111
