LG LP121CEM-Y8 Svc Manual Download Page 38

Page: 38 / 48

- 38 -

LGE Internal Use Only

5.1 OUTSIDE DIMENSIONS

1,066mm (42")

505mm (20")

406mm (16")

5.2 PIPING SYSTEM

Following is a brief description of the important components and their functions in the refrigeration system.

Refer to Figure 62 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

LIQUID OUTLET

HIGH PRESSURE VAPOR

LIQUID PEFRIGERANT

LOW PRESSURE VAPOR

ROOM AIR CONDITIONER

EVAPORATOR COILS

CONDENSER COILS

CYCLE OF REFRIGERATION

Figure 62

5. Troubleshooting Guide

Summary of Contents for LP121CEM-Y8

Page 1: ... Air Conditioner SVC MANUAL MODEL LP121CEM Y8 CAUTION Before Servicing the unit read the safety precautions in General SVC manual Only for authorized service personnel Internal Use Only http biz lgservice com ...

Page 2: ...ter washable anti fungus Plasma Filter Steps Fan Cool Heat Airflow Direction Control up down Airflow Direction Control left right Remote Controller Type Setting Temperature Range Cooling Heating Auto Operation Micom Control Panel Touch Type Timer Air Discharge Air Ventilation Defrost Control Hot Start Look Cabinet Type Chassis Type Special Function Model LP121CEM Y8 3 28 3 37 11300 11500 3 1 3 5 1...

Page 3: ...tes to have a time of equalizing the refrigerant pressures for optimizing cycling Fan Only Setting High Low The fan can run at HIGH or LOW speed without COOLING or HEATING to provide air circulation and ventilation Indoor Fan Speed Selections High Low The fan can run at HIGH or LOW speed for either COOLING or HEATING Two Fan motors The unit has two fan motors to provide quiet operation and maximum...

Page 4: ...es on control panel from 50 F to 90 F Temperature limits help to prevent overheating and overcooling and reduce energy costs Condensate Drain Valve The unit has a condensate drain valve to prevent water from collecting or freezing in the basepan Quick Heater Recovery The unit is designed to operate the electric heater to warm the room to the temperature set point as soon as heat pump cycle is on i...

Page 5: ...high speed fan operation LOW HEAT Heating with the low speed fan operation HIGH HEAT Heating with the high speed fan operation VENTILATION The ventilation lever is located to the lower left side of the unit The ventilation lever must be in the CLOSE position in order to maintain the best cooling conditions When fresh air is necessary in the room set the ventilation lever to the OPEN position The d...

Page 6: ...C 54 F 12 2 C 72 F 22 2 C Temperature Temperature Temperature Limit 1 Limit 2 Limit 3 Lowest Temp Highest Temp Lowest Temp Highest Temp Cooling Operation Heating Operation 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 gri...

Page 7: ...truction in this manual for the Remote Wall Thermostat 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...

Page 8: ...nto place This Room Air Conditioner PTAC discharges air from the top of the unit through reversible 2 position discharge grille louvers The unit is shipped from the factory with the discharge grille louvers at an angle of 40 off vertical In the alternate position the louvers will be at an angle of 15 off vertical To adjust air direction remove the front grille Remove the 4 screws that fasten the d...

Page 9: ...o section 2 1 1 2 Remove the two screws which fasten the control box See Figure 2 3 Pull the control box from the Air guide 4 Remove the control box cover See Figure 3 5 Disconnect wire housings on the control box 6 Pull the control box assembly out from the unit See Figure 4 7 Re install the components by referring to the removal procedure Figure 2 Figure 3 Figure 4 ...

Page 10: ...Refer to section 2 1 2 3 Remove the 4 screws which fasten the Evaporator See Figure 5 4 Remove the top cover assembly net steel brace See Figure 6 5 Remove the 6 screws which fasten the Air guide 6 Pull the Air guide assembly out from the unit See Figure 7 7 Remove the 2 screws which fasten the electric heater in the left hand side 8 Pull the electric heater towards left for a while and then lift ...

Page 11: ...ve the 4 screws which fasten the indoor motor and the earth wire See Figure 10 6 Remove the supports on both sides 7 Pull the cross flow fan out from the air guide 8 Re install the components by referring to the removal procedure 2 2 3 AXIAL FAN 1 Remove the brace 2 Remove the 4 screws which fasten the condenser with the shroud and the basepan See Figure 11 3 Remove the condenser sideways carefull...

Page 12: ...charge the refrigerant system using a refrigerant recovery system If there is no valve to attach the recovery system install one such as a WATCO A 1 before venting the refrigerant Leave the valve in place after servicing the system 2 Disconnect the 3 leads from the compressor 3 After purging the unit completely unbraze the suction and discharge tubes at the compressor connections 4 Remove the 3 nu...

Page 13: ...rring 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 an exact replacement part The special cord means the cord which has the same specification marked on the supply cord fitted to the unit 2 3 6 P C B 1 Remove the escutcheon 2 Remove the two knobs 3 Remove the 2 screws which fasten P C B ...

Page 14: ...Discharge the refrigerant completely 3 Remove the control box assembly Refer to section 2 1 2 4 Remove the 4 screws which fasten the evaporator at the left side and the right side 5 Move the evaporator sideward carefully and then unbraze the interconnecting tube at the evaporator connectors 6 Remove the evaporator 7 Re install the components by referring to notes See Figure 20 2 4 3 CAPILLARY TUBE...

Page 15: ...ylinder See Figure 21 B 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 c...

Page 16: ...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 21 A Pulling Vacuum Figure 21 B Charging A B EXTERNAL VACUUM PUMP A CHARGING CYLINDER LOW HI B C ...

Page 17: ...e 3 To improve unit energy efficiency it is recommended the change of outside grille for an unit protection and an addition of a plastic rear grille This is optional 4 Insulation strip prevents the exhaust air from re entering from either side of condenser space which may decrease the cooling efficiency of condenser 406 mm 16 1 066 mm 42 349 mm 13 3 4 505 mm 20 42 13 3 4 16 1 1 2 TYP 1 2 6 21 36 1...

Page 18: ...awings in this manual The case may be installed flush with the finished indoor wall Mounting an outdoor grille or louver section to the building face may cause a space between the outdoor coil and the louver section Air splitters aligned with the ends of the outdoor coil must be installed between the outdoor coil inlet and outlet air streams Gaps between the outdoor coil and the louver section may...

Page 19: ...ase should be at least flush with the finished wall for line cord installations and permanent connection installations when no sub base is used and should project into the room at least 2 3 8 when a sub base is used If the minimum exterior dimensions are not met refer to page 20 The outside edge of the wall case should extend at least 1 4 beyond the outside wall This is necessary for proper caulki...

Page 21: ...ASE OUTDOOR GRILLE CAULK CAULK 1 4 MIN POWER SUPPLY CONDUIT WALL RECEPTACLE BY OTHERS FINISHED FLOOR OR TOP OF CARPET Caulk around perimeter of wall case all four sides where it joins the building Interior and Exterior CAULK 1 4 CAULK LINTEL ROOM CABINET 2 MIN MOUNTING SCREWS BY INSTALLER WALL CASE OUTDOOR GRILLE SIDE CHANNEL 3 MIN 5 MAX 1 5 16 FINISHED FLOOR OR TOP OF CARPET SUB BASE RAK204 CAULK...

Page 22: ...ee Figure 24 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 Figure 25 3 Slide the unit into the wall sleeve and secure with 6 screws through the unit flange holes See Figure 26 4 Reinstall the front grille by hooking the top over the unit top then pushing it in at the bottom See Figure 27 Figure 24 Figure 25 Figure 26 Figure 27 ...

Page 23: ...r supply requirements 3 3 1 ELECTRICAL DATA FOR 230 208V MODEL 3 3 2 ELECTRICAL SAFETY IMPORTANT GROUNDING INSTRUCTIONS The air conditioner has a three prong grounding plug on its power supply cord which must be plugged into properly grounded three prong wall receptacle for your protection against possible shock hazard FUSE Use a time delay fuse or circuit breaker Refer to the nameplate for proper...

Page 24: ...les Figure 29 3 Install the new door assembly with the key lock by bowing the door with both hands and aligning the door hinge pins with their bracket in the front Figure 30 Important Note Personal Risk Hazard Underwriter s Laboratories Inc listed For institutional use only where supervisory monitoring is available Any other use may increase the risk of personal injury or property damage Note The ...

Page 25: ...note it on the delivery receipt Unit must be stored in its original shipping carton in a dry secure place prior to its installation and use Installation The installation and servicing of the equipment referred to in this booklet should be performed by qualified experienced technicians WARNING Hazardous Voltage Disconnect all electric power including remote disconnects before servicing Follow prope...

Page 26: ... fig 34 Then install one of the three rubber elbows ref fig 38 at the inlet of the spraying tube and through the rubber grommet 10 Place the top cover assembly back into the unit 11 Install tube 1 and tube 2 ref fig 38 on the pump assembly using the rubber elbows as shown in fig 35 12 Position pump assembly to the basepan as shown in fig 36 and fasten the pump bracket to the basepan using the thre...

Page 27: ...ntrol barrier as shown in fig 39 15 Assembly the unit back following the reverse order of disassembly NOTE All tube should be inserted into rubber elbows by at least 1 2 inch 27 Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only Figure 38 Pump assembly Tube 1 Tube 2 Rubber elbows 3 Spraying Tube Figure 40 Figure 39 ...

Page 28: ...om the sleeve These items may be removed from inside of the building Note The sleeve stiffener must be taken out before the rear sleeve enclosure panel can be removed from the sleeve 2 Prepare the stamped aluminum grille for installation on the sleeve by inserting the six 6 plastic grommets into the square holes located near the outer edges of all four sides of the grille With the grille positione...

Page 29: ...wer before servicing could result in death or serious injury Important Note The unit OFF switch does not disconnect all electrical power to this unit Receiving Upon receipt of the product inspect the shipping carton for signs of visible damage Report any damage or shortage to the carrier and note it on the delivery receipt The product must be stored in its original shipping carton in a dry secure ...

Page 30: ... A on the back of blank off plate C and secure the assembly to the left rear of wall sleeve with sheet metal screws provided See Figure 45 for finished left hand side installation If the unit chassis is to be installed right away install the condenser grille to wall sleeve with hardware provided See condenser grille installation instructions If the unit chassis will not be installed right away rep...

Page 31: ...ted to the drain system inside of the building Install the two blank off plates C and gaskets A on the outdoor portion of the wall sleeve as shown in Figure 46 These components may be installed after the sleeve is secured in the wall opening just prior to the installation of the condenser grille and chassis Leveling Legs Part No AYLL101 Description Leveling legs are designed to provide extra front...

Page 32: ...side to side Provide a slight slope one quarter bubble in the sight glass toward the outside Check the level again after the unit has been installed Adjust the legs as needed Installation on Wall Sleeve 1 Drill four 1 8 inch diameter holes in the wall sleeve two on each side using the leveling legs as a template Caulk around screws to prevent water leaks 2 Attach the legs to the wall sleeve using ...

Page 33: ...to ensure the power can not be inadvertently energized Failure to disconnect power before servicing could result in death or serious injury Important Note The unit OFF switch does not disconnect all electrical power to this unit CAUTION Use Copper Conductors Only Unit terminals are not designed to accept other types of conductors Failure to use copper conductors may result in equipment damage Impo...

Page 34: ...the red lead from the wire assembly 2 Connect the black lead to the center terminal of the fuse holder 3 Connect the white lead to the common C terminal on the capacitor 4 Connect the ground wire to the partition panel where the ground wire on the power cord was located Use the supplied green ground screw 5 Connect the white lead of the wire assembly at the junction box to the white lead of the fi...

Page 35: ... servicing of the equipment referred to in this booklet should be performed by qualified experienced technicians WARNING Hazardous Voltage Disconnect all electric power including remote disconnects before servicing Follow proper lockout tagout procedures to ensure the power can not be inadvertently energized Failure to disconnect power before servicing could result in death or serious injury Impor...

Page 36: ...ut tagout procedures to ensure the power can not be inadvertently energized Failure to disconnect power before servicing could result in death or serious injury Important Note The unit OFF switch does not disconnect all electrical power to this unit CAUTION Use Copper Conductors Only Unit terminals are not designed to accept other types of conductors Failure to use copper conductors may result in ...

Page 37: ...ng Access Subbase Box Assembly Low Voltage Compartment 2 13 16 71 mm 11 13 16 300 mm A B F C E D D E Wall Sleeve Outdoor Side Wall Sleeve Inside Edge Back of Flange A 13 3 4 2 3 4 2 5 8 13 7 8 352 mm 3 1 16 78 mm Left End View Concentric Knockouts In Bottom Ground Screw Location Receptacle Provided Inside subbase Accessory Top View Concentric Knockouts In Rear Field Wiring Line Voltage Field Wirin...

Page 38: ...2 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 LIQUID OUTLET HIGH PRESSURE VAPOR LIQUID PEFRIGERANT LOW ...

Page 39: ...g Check of 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 44 6 50 F 7 10 C Check heat load increase Unexpected residue Overloaded Circuit Check of inside gas pressure Adjusting of refrigerant charge Malfunction of compressor Replacement of compres...

Page 40: ...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 of power voltage Check capacitor Replacement Only compressor fails...

Page 41: ... 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 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 Check grommets ...

Page 42: ...tification Replace the switch if circuit is open Check the position of knob If not at the coldest setting advance the knob to this setting and restart unit Check continuity of the thermistor Replace thermistor 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...

Page 43: ...e 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 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 missi...

Page 44: ...d service purposes LGE Internal Use Only 6 Piping Diagrams CAPILLARY TUBE HEAT EXCHANGER EVAPORATOR HEAT EXCHANGER CONDENSER COMPRESSOR Th1 Th2 LOC Description PCB Connector Th1 Thermistor for indoor Air temperature CN IDAT Th2 Thermistor for Evaporator pipe temperature CN IDPT ...

Page 45: ...1 In part A there are 3 types In part B there are 3 types Type 2 Type 3 INDOOR FAN MOTOR INDOOR FAN MOTOR OUTDOOR FAN MOTOR OUTDOOR FAN MOTOR OUTDOOR FAN MOTOR Type 2 BK BL RD OR BR YL BK BL RD OR BR YL BK BL RD OR BR YL BK BL RD OR BR YL BK OR BR YL BK BL RD OR BR YL BL OR BR YL RD OR BR YL BL RD OR BR YL BK RD OR BR YL GN YL INDOOR FAN MOTOR Type 3 BK BL RD OR BR YL BK BL OR BR YL 1 YL YL YL OR ...

Page 46: ...00B Note Please ensure GCSC since the replacement parts may be changed depending upon the buyer s request Please check the correct parts in View RPL Replacement Part List on GCSC GCSC Website http biz lgservice com A 237200 W0CZZB W0CZZA W6640 135511 147901 264110 249941B 149410 238310 249941A 268711B 554160 263230A Thermistor for Indoor Air Temperature Housing color blue 263230B Thermistor for Ev...

Page 47: ... a new one 3 Make sure that the direction of brazing flame is away from the aluminum condenser Follow the above procedure for assembling or disassembling the aluminum condenser 47 Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only CONDENSER OUTDOOR SERVICE REPLACEMENT PROCEDURE Copper pipe Brazing point in assembling or disassembling C...

Page 48: ...P NO MFL42137114 FEBRUARY 2008 ...

Search results

Summary of Contents for LP121CEM-Y8

Reviews:

Related manuals for LP121CEM-Y8

Brands by name

Popular brands

LG LP121CEM-Y8, Svc Manual

Search results

Summary of Contents for LP121CEM-Y8

Reviews:

Related manuals for LP121CEM-Y8

Brands by name

Popular brands