LG LT143CNR Service Manual Download Page 1

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ROOM AIR CONDITIONER

SERVICE MANUAL

CAUTION

- BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
- ONLY FOR AUTHORIZED SERVICE

MODEL:

LT143CNR

Summary of Contents for LT143CNR

Page 1: ...ROOM AIR CONDITIONER SERVICE MANUAL CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL ONLY FOR AUTHORIZED SERVICE MODEL LT143CNR ...

Page 2: ...NT PARTS LIST 28 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 ...

Page 3: ...DIMESION inch W x H x D mm SLEEVE DEPTH inch WITH FRONT GRILLE mm 1Ø 230 208V 60Hz 13 000 12 600 1 530 1 480 7 0 7 5 8 5 8 5 510g 18 0OZ 26 7 DB 19 4 WB 35 DB 23 9 WB 2 ROW 12STACKS 2ROW 17STACKS L BENDING TYPE LOUVERED FINTYPE TURBO FAN PROPELLER TYPE FAN WITH SLINGER RING 3 3 6 POLES ELECTRIC THERMISTOR VERTICAL LOUVER RIGHT LEFT HORIZONTAL LOUVER UP DOWN TOP DOWN EXTERNAL OVERLOAD PROTECTOR INT...

Page 4: ...operation TIMER SHUT OFF TIME You will usually use shut off time while you sleep If unit is running use Timer to set number of hours until shut off For your sleeping comfort once Time is set the Temperature setting will raise 2 F after 30 min and once again after another 30 min Push Timer button to advance setting from 1Hour 2Hours 12Hours maximum START TIME If unit is off use Timer to set number ...

Page 5: ...OX 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 pr...

Page 6: ...e 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 sideways 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 MOD E TIM ER POW ER FAN SPE ED Fan Ener gy Save r ...

Page 7: ...nTM Recovery System If there is no valve to attach the recovery system to install one such as a WATCO A 1 before venting the FreonTM Leave the valve in place after servicing the system 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 compresso...

Page 8: ...e 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 THERMISTOR 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 thermistor terminals 4 Remove the thermistor See Fig 14 5 Re install the components by r...

Page 9: ...Move the evaporator sideward 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 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 FreonTM Recovery System unbraze the interconnecting tube at the capillary tube 3 R...

Page 10: ...ifold 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 a...

Page 11: ...or 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 ...

Page 12: ...sonal injury property damage or product damage due to the weight of this device and sharp edges that may be exposed Air conditioners covered in this manual pose an excessive weight hazard Two or more people are needed to move and install the unit To prevent injury or strain use proper lifting and carrying techniques when moving unit Carefully inspect location where air conditioner will be installe...

Page 13: ...of wall sleeve 1 2 3 4 5 6 1 4 Wall Sleeve FRONT UNIT SHIM PLACEMENT UNIT INSTALLATION 1 high 3 4 High Shim 6 6 FIG 19 Installing the FRIEDRICH USC sleeve ensures optional performances of the unit If you decide to keep the existing wall sleeve you have to redirect the louvers at the back of the wall sleeve Refer to FIG 23 on p15 The use of pliers is recommended If you DO NOT redirect you run the r...

Page 14: ...emove the backing from the Around Insulation strip 671 8 x 13 8 x 25 32 and attach that to the inside front of the sleeve as shown below FIG 20 Around Insulation 9 1 2 6 Indoor Outdoor FIG 22 or Bracket Bracket FIG 21 Fasten the screws and the bracket 1 2 3 4 5 Wall Trim 2 ea FIG 23 Air conditioners covered in this manual pose an excessive weight hazard Two or more people are needed to move and in...

Page 15: ...it from leaving the sleeve Remove the backing from the Vertical Insulation strip 159 16 x 13 8 x 13 8 and attach that to the inside right of the sleeve as shown below Remove the backing from the Around Insulation strip 671 8 x 13 8 x 25 32 and attach that to the inside front of the sleeve as shown below If the depth of your existing wall sleeve is less than or equal to 18 skip to step 7 Otherwise ...

Page 16: ... conditioners covered in this manual pose an excessive weight hazard Two or more people are needed to move and install the unit To prevent injury or strain use proper lifting and carrying techniques when moving unit When handling the air conditioner be careful to avoid cuts from sharp metal fins on front and rear coils Make sure air conditioner does not fall during removal If unit does not operate...

Page 17: ...e pressed into the square holes of the rear flanges Fasten the bracket to the upside of the wall sleeve using the washer screw The bracket prevents the unit from leaving the sleeve Remove the backing from the Horizontal Insulation strip 237 32 x 13 8 x 13 16 and attach that to the inside right of the sleeve as shown below Remove the backing from the Around Insulation strip 5927 32 x 13 8 x 13 8 an...

Page 18: ... conditioner does not fall during removal If unit does not operate after installation check to be sure the circuit interrupter has not been tripped Refer to the Troubleshooting guide for reset procedure CAUTION Parts and Installation PROCEDURE C CONTINUED To achieve rearward slope for unit draining remove the backing from the 1113 16 shim strips and attach them as shown below in Fig 37 The higher ...

Page 19: ...ir functions in the refrigeration system Refer to Fig 41 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 LIME COOL LOW PRESSURE VAPOR COOLED AIR COMPLETE LIQUID BOIL OFF POINT LIQUID PRESSURE DROP ROOM AIR HEAT LOAD VAPOR INLET HOT DISCHARGED AIR LI...

Page 20: ...heck gas leakage Repair gas leak Replacement of unit if the unit is beyond repair Satisfactory operation with temperature difference of inlet outlet air 44 6 50 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 Hea...

Page 21: ...lation 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 sour...

Page 22: ...bearings if motor shaft will not rotate replace the motor Check voltage See limits on page 27 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 ...

Page 23: ...n Check the position of knob If not at the coldest setting advance the knob to this setting and restart unit Check continuity of the thermostat Replace thermostat 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 ov...

Page 24: ...se 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 of 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 ...

Page 25: ... 26 5 SCHEMATIC DIAGRAM 5 1 CIRCUIT DIAGRAM MODEL BG 101A LT1010CR LT121CSG LT1210CR LT0810CR LT080CSG BG 81A LT1030CR LT1230CR BG 123A LT1430CR ...

Page 26: ...00 147582 1 147581 135303 152302 147582 2 135312 349480 352113 552113 W48602 354210 731273 E C B 567480 267110 W0CZZ 249950 238310 237200 A C 264110 MO E D M I T R E W O P R E N A F D E E P S Fa n y g r e n E r e v a S Co ol Timer P M E T F F1 LOW F2 MED F3 HIG H 132100 130900 559011 268711 2 268711 1 435301 ...

Page 27: ...P No 3828A20294T February 2007 Printed in China ...

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