website http://www.lgservice.com LG LG Room Air Conditioner SERVICE MANUAL CAUTION • BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. • ONLY FOR AUTHORIZED SERVICE PERSONNEL.
CONTENTS 2.4.1 CONDENSER ......................................14 2.4.2 EVAPORATOR ....................................14 2.4.3 CAPILLARY TUBE...............................14 1. PREFACE 1.1 SPECIFICATIONS ..........................................3 1.2 FEATURES AND BENEFITS ..........................4 1.3 CONTROL LOCATIONS .................................6 1.4 ADDITIONAL CONTROLS..............................7 3. INSTALLATION 3.1 HOW TO INSTALL THE UNIT ......................17 3.
1.1 SPECIFICATIONS Cooling / Electric Heater Model Name Cooling(Btu/h) Cooling Watts(W) EER Electric Heat (Btu/h) Electric Heat Amps(A) Min Circuit Protection (Amps) LP120CEM 11800/11500 1055/1025 11.2/11.2 - - 20 Cooling / Heat Pump / Electric Model Name Cooling(Btu/h) Cooling Watts(W) EER Electric Cycle Heat (Btu/h) COP Electric Heat (Btu/h) Electric Heat Min Circuit Amps(A) Protection (Amps) LP090HEM 9300/9000 800/775 11.6/11.6 8200/8000 3.4/3.4 11900/9900 3.2/3.
1.2 features Unit Features The PTAC has many features, some of which are different than those found on conventional PTAC units. The servicer must be familiar with these features in order to properly service the unit. • Highly featured Micom controls using IIR (infinite impulse response) IIR function can make Micom controls maximize and keep the comfort conditions to sense the small changes in temperature per second.
• Outdoor Air Temperature Switchover The unit is designed to control the electric heater interfacing with the outdoor temperature. When the outdoor temperature falls to 20˚F below, it makes the compressor be off and the electric heater be turned on until the outdoor temperature is above 25˚F. This will effectively change the Unit from heat pump mode to total electric resistance heat.
1.3 CONTROL LOCATIONS • OPERATION ELECTRIC HEATING MODEL COOLING ONLY MODEL TEMPERATURE CONTROL Set the Thermostat control to the desired temperature mark 5 (the mid-point is a good starting position). If the room temperature is not satisfactory after a reasonable time, adjust the control to a cooler or warmer setting, as appropriate. OPERATION MODE SELECTOR OFF: Turns air conditioner off. LOW FAN: Low speed fan operation without cooling. HIGH FAN: High speed fan operation without cooling.
1.4 ADDITIONAL CONTROLS • REMOVING THE FRONT GRILLE Additional controls are available after removing the front grille and option cover of control box. To remove the front grille, pull out the bottom of front grille and then lift up. To replace the front grille, place the tabs over the top of the unit and push the bottom of front grille until the clips snap into place. • ADDITIONAL CONTROLS The additional controls are located behind the option cover of control box.
• REMOTE/LOCAL CONTROL When remote/local switch #1 is on, it allow the unit to operate by the control of Remote Wall Thermostat. The unit control by knobs are not available. • ENERGY SAVER The energy saver switch #2 is on. This switch is set at continuous fan to provide continuous fan operation in cool or heat modes. When the switch is off the continuous fan allows continuous circulation of room air and make the more balanced temperature of the room.
2. DISASSEMBLY INSTRUCTIONS — Before the following disassembly, POWER SWITCH is set to OFF and disconnected the power cord. 2.1 MECHANICAL PARTS 2.1.1 FRONT GRILLE 1. Remove the front grille. (See Fig. 1) 2. To remove the front grille, pull out the bottom of the front grille and then lift up. Re-install the component by referring to the removal procedure. 3. To replace the front grille, place the tabs over the top of the unit and push the bottom of front grille until the clips snap into place.
2.1.2 CONTROL BOX (Half-Disassembly) 1. Remove the front grille. (Refer to section 2.1.1) 2. Remove the three screw which fasten the control box. (See Fig. 2) 3. Pull the control box from the barrier. (See Fig.2) 4. Discharge the capacitor by placing a 20,000 ohm resistor across the capacitor terminals. 5. Disconnect three 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.
2.2 AIR HANDLING PARTS 2.2.1 HEATER ASSEMBLY AND CROSS FLOW FAN 1. Remove the front grille. (Refer to section 2.1.1) 2. Remove the control box assembly. (Refer to section 2.1.3) 3. Remove the 3 screws which fasten the net steel. (See Fig. 4) 4. Remove the 3 screws which fasten the electric heater assembly. (Electric heater model only) (See Fig.4). Figure 4 5. Loosen the hexagon screw with the Hex-wrench (See Fig.5) Figure 5 6. Remove the 4 screws which fasten the indoor motor and the earth wire.
2.2.3 SHROUD 1. Remove the fan. (Refer to section 2.2.2) 2. Remove the screw which fastens the shroud. 3. Remove the shroud. (See Fig. 8) 4. Re-install the component by referring to the removal procedure, above. 2.3 ELECTRICAL PARTS 2.3.1 OUTDOOR MOTOR 1. Remove the clamp cord and disconnect a wire housing in control box. (Refer to section 2.1.2) 2. Remove the fan. (Refer to section 2.2.2) 3. Remove the 2 screws which fasten the motor. (See Fig. 9) 4. Remove the motor. 5.
2.3.5 POWER CORD 1. Remove the control box. (Refer to section 2.1.2) 2. Disconnect the grounding screw from the control box. 3. Disconnect 2 receptacles. 4. Remove a screw which fastens the clip cord. 5. Separate the power cord from the control box. (See Fig. 12) 6. Re-install the component by referring to the removal procedure, above. (Use only one ground-marked hole for ground connection.) 7. If the supply cord of this appliance is damaged, it must be replaced by the special cord.
2.4 REFRIGERATION CYCLE CAUTION Discharge the refrigerant system using FreonTM Recovery System. If there is no valve to attach the recovery system, install one (such as a WATCO A-1) before venting the FreonTM. Leave the valve in place after servicing the system. 2.4.1 CONDENSER 1. Remove the brace and the shroud. (Refer to section 2.2.2) 2. Remove the 4 screws which fasten the shroud. (Refer to section 2.2.2) 3. Push forward the shroud and remove the 2 screws which fasten the condenser with the basepan. 4.
NOTES — Replacement of the refrigeration cycle. 1. When replacing the refrigeration cycle, be sure to discharge the refrigerant system using a FreonTM recovery System. If there is no valve to attach the recovery system, install one (such as a WATCO A-1) before venting the FreonTM. Leave the valve in place after servicing the system. 2. After discharging the unit completely, remove the desired component, and unbraze the pinch-off tubes. 3.
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.
3. INSTALLATION Dimension of air conditioner 3.1 HOW TO INSTALL THE UNIT 1,066mm(42") CAUTION • There are sharp edges that can cause serious cuts. • When lifting the air conditioner, it is HEAVY. Use 2 peoples to lift. 406mm (16") For existing sleeve, you should measure the wall sleeve dimensions. You can install the new air conditioner according to these installation instructions to achieve the best performence.
3.2 SUGGESTED TOOL REQUIREMENTS SCREWDRIVER(+, -), RULER, KNIFE, HAMMER, PENCIL, LEVEL 3.2.1 PREPARATION OF SLEEVE 2 1 4 1 SLEEVE HARDWARE R O O 1 R O O D N I ASSEMBLE THE WALL SLEEVE • Raise the sleeve side panels to upright position as shown on the right. I Q’TY 1 1 4 1 1 N NAME OF PARTS SLEEVE LOWER SLEEVE UPPER SCREW OUTDOOR GRILLE DRAIN KIT D NUMBER • Place sleeve upper on top of side panels. • Fasten the four screws as shown on the right.
3.2.3 UNIT INSTALLATION 1. Remove the shipping screw from the ventilation door. (See Fig. 17) Figure 17 2. Remove the front gille by pulling it out at the bottom to release it, then lift it up along the unit top front. (See Fig. 18) Figure 18 3. Slide the unit into the wall sleeve and secure with 6 screws through the unit flange holes. (See Fig. 19) Figure 19 4. Reinstall the front grille by hooking the top over the unit top, then pushing it in at the bottom. (See Fig.
3.3 ELECTRICAL REQUIREMENTS 3.3.1 ELECTRICAL DATA (FOR 230/208V MODEL) CAUTION 1. Do not use an extension cord with this unit. 2. When the unit is in the OFF position, the power supply to the electrical controls. 3. Disconnect the power to the unit before servicing the unit. 4. Remove the power cord from the wall receptacle. 5. Remove or turn off the protective device (fuses or circuit breaker).
4. PERFORMANCE DATA Air Conditioner Performance Data Voltage (V) Cooling Data Cooling Capacity (Btu/h) Cooling Amps (A) Cooling Power (W) EER (Btuh/Watt) Moisture Removal (Pts/h) 208 LP120CEM 230 208 230 11,500 4.8 1025 11.0 11,800 5.2 1055 11.0 3.3 3.3 300 330 290 290 320 350 280 310 Airflow Indoor CFM (Wet) @0.3ESP (Hi) Indoor CFM (Wet) @0.3ESP (Lo) Indoor CFM (Dry) @0.3ESP (Hi) Indoor CFM (Dry) @0.
Cooling Wattage - Air Conditioners Model Temperature Outdoor Air Dry Bulb LP120CEM Return Air Wet Bulb Rating Wattage 100 95 90 85 80 85 80 75 70 65 60 55 85 80 75 70 65 60 55 85 80 75 70 65 60 55 85 80 75 70 65 60 55 85 80 75 70 65 60 55 Total Wattage Input Min Max 1045 1090 1050 1055 1060 1055 1050 1045 1030 1000 1005 1005 1005 1000 990 980 950 950 955 950 950 940 930 895 900 905 900 895 890 880 850 850 850 850 850 940 830 1180 1180 1180 1180 1180 1175 1160 1125 1130 1135 1130 1125 1120 1105 1
Cooling Wattage - Heat Pumps Model Temperature Outdoor Air Return Air Dry Bulb Wet Bulb Rating Wattage 100 95 90 85 80 85 80 75 70 65 60 55 85 80 75 70 65 60 55 85 80 75 70 65 60 55 85 80 75 70 65 60 55 85 80 75 70 65 60 55 LP090HM* LP120HEM Total Wattage Input Min Max Total Wattage Input Min Max 810 850 1120 1145 830 835 835 835 830 820 810 785 790 795 790 785 780 770 745 750 750 750 745 735 720 700 705 705 705 700 690 680 655 660 660 660 655 650 635 935 940 940 940 935 925 915 890 890 890
Cooling change of temperature - Air Conditioners Room Air Dry Bulb 90 85 80 75 70 Room Air Wet Bulb LP120CEM Temperature Across Indoor Coil (∆ T) Rating Btu/h Rating CFM 85 80 75 70 80 75 70 65 75 70 65 60 70 65 60 55 65 60 55 Min 11700 300 1 9 18 26 5 13 21 29 9 15 23 29 10 15 21 26 9 13 18 Max 12000 330 5 13 22 30 10 18 25 33 13 20 26 33 15 20 25 30 13 17 21 Cooling Change of Temperature - Heat Pumps Room Air Room Air Dry Wet Bulb Bulb 90 85 80 75 70 Rating Btu/h Rating CFM 85 80 75 70 80 7
Heating Change of Temperature - Heat Pumps Room Air Dry Bulb 50 45 40 35 Room Air Wet Bulb Rating Btu/h Rating CFM 85 80 75 70 65 85 80 75 70 65 85 80 75 70 65 85 80 75 70 65 Model LP090HEM LP120HEM Temperature Across Temperature Across Indoor Coil (∆ T) Indoor Coil (∆ T) Min 8200 260 24 25 26 28 28 22 23 24 24 25 20 21 22 23 24 17 18 19 20 21 Max 8400 290 27 28 29 30 30 24 25 26 27 28 22 23 24 24 25 20 21 22 23 24 Min 10900 330 27 28 29 31 31 24 25 26 27 28 23 23 24 25 26 21 22 23 23 24 Max 11200
5. TROUBLESHOOTING GUIDE 5.1 OUTSIDE DIMENSIONS 406mm(16") 1,066mm(42") 406mm(16") 505mm(20") 5.2 PIPING SYSTEM Following is a brief description of the important components and their functions in the refrigeration system. Refer to Fig. 21 to follow the refrigeration cycle and the flow of the refrigerant in the cooling cycle.
5.3 TROUBLESHOOTING GUIDE In general, possible trouble is classified in two causes. The 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 improper application. Unit is running but cooling is ineffective Ineffective Cooling Check of cold air circulation for smooth flow. Check of outdoor coil (heat exchanger) & the fan operation. Dirty indoor coil (Heat exchanger) Check gas leakage.
Fails to Start Check of power source. Check of circuit breaker and fuse. Check of control switch setting. Gas leakage of feeler bulb of thermostat Check of control switch. Only compressor fails to start. Only fan fails to start. Improper wiring. Drop of power voltage. Improper thermostat setting Defect of fan motor capacitor. Defect of compressor capacitor. Loose terminal connection. Check capacitor. Irregular motor resistance ( ). Irregular motor insulation ( ). Improper wiring Replacement.
COMPLAINT Fan motor will not run. CAUSE REMEDY 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 connection loose Connect wire. Refer to wiring diagram for terminal identification. Repair or replace loose terminal.
COMPLAINT Compressor will not run, but fan motor runs. CAUSE REMEDY Voltage Check voltage. See the limits on the preceding. page. If not within limits, call an electrician. Wiring 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. Rotary Check for continuity, refer to the wiring diagram for terminal identification.
COMPLAINT Compressor cycles on overload. Insufficient cooling or heating Excessive noise. REMEDY CAUSE Voltage Check the voltage. See the limits on the preceding page. If not within 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.) Fan motor If not running, determine the cause. Replace if required. Condenser air flow restriction Remove the cabinet.
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8. REPLACEMENT PARTS LIST A B C D E F PART NO. LOCATION NO.
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