LG LM-2421C2L/A2L Service Manual
LG LM-2421C2L/A2L Service Manual

LG LM-2421C2L/A2L Service Manual

Multi type room air conditioner

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Multi Type Room Air Conditioner

SERVICE MANUAL

MODEL: LM-2421C2L/A2L
LM-3022C3L/A3L

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Summary of Contents for LG LM-2421C2L/A2L

  • Page 1: Service Manual

    Multi Type Room Air Conditioner SERVICE MANUAL MODEL: LM-2421C2L/A2L LM-3022C3L/A3L...
  • Page 2: Table Of Contents

    Contents Functions............................3 Product Specifications ........................ 4 Dimensions............................6 Refrigeration Cycle Diagram....................... 9 Wiring Diagram........................... 11 Operation Details ........................12 Display Function/Self-diagnosis Function ................14 Installation ..........................15 Operation ............................ 31 Disassembly of the parts (Indoor Unit)..................32 2-way, 3-way Valve ........................34 Cycle Troubleshooting Guide ....................38 Electronic Parts Troubleshooting Guide .................
  • Page 3: Functions

    Functions I nd oor Un it Remote Controller Operation ON/OFF by Remote controller Operation ON/OFF Sensing the Room Temperature • Room temperature sensor (THERMISTOR) Operation Mode Selection Room temperature control Cooling Operation Mode ( Soft Dry Operation Mode ( • Maintains the room temperature in accordance with the Setting Temp.
  • Page 4: Product Specifications

    Product Specifications(Cooling Only) 1. LM-2421C2L/A2L Operation A or B unit A + B unit Unit Item Cooling Capacity Btu/h(kcal/h) 17,000(4,270) 24,000(6,050) Moisture Removal 1.6 x 2 Power Source ø, V, Hz 1Ø, 220, 60HZ Indoor Air Circulation /min Outdoor Indoor...
  • Page 5 2. LM-3022C3L/A3L Operation A-Unit B or C-Unit A+B or C A+B+C Unit Item 14,000(4,000) 14,000(4,000) 22,000(6,000) 22,000(5,800) 20,000(7,300) Cooling Capacity Btu/h(kcal/h) Moisture Removal 1Ø, 220V, 60Hz Power Source ø, V, Hz Indoor 8.8 + 7.8 7.8 + 7.8 8.8 + 7.8 + 7.8 Air Circulation /min Outdoor...
  • Page 6: Dimensions

    Dimensions 1. Indoor Unit Tubing hole cover Left rear piping Right rear piping Installation plate LM-2421C2L/A2L MODEL LM-3022C3L/A3L - 6 -...
  • Page 7: Outdoor Unit

    2. Outdoor Unit 2-1. LM-2421C2L/A2L Gas side 3-Way valve Liquid side 2-Way valve MODEL LM-2421C2L LM-2421A2L 76.5 - 7 -...
  • Page 8 2-2. LM-3022C3L/A3L Gas side 3-way valve Liquid side 2-way valve MODEL LM-3022C3L LM-3022A3L 76.5 - 8 -...
  • Page 9: Refrigeration Cycle Diagram

    Refrigeration Cycle Diagram 1. LM-2421C2L/A2L ø12.7 ø12.7 COMP 3-WAY Valve (A Unit) (B Unit) ø6.35 ø6.35 Max. Max. Solenoid Valve Pipe Size (Diameter : inch) piping length piping elevation Capillary Liquid Cooling 1/2" 1/4" 10~15 - 9 -...
  • Page 10 2. LM-3022C3L/A3L ø12.7 COMP ACCUMUIATOR ø12.7 ø12.7 3-WAY Valve (A Unit) (B Unit) (C Unit) ø6.35 ø6.35 ø6.35 2-WAY Valve Max. Max. Solenoid Valve Pipe Size (Diameter : inch) piping length piping elevation Capillary Liquid Cooling 1/2" 1/4" 10~15 - 10 -...
  • Page 11: Wiring Diagram

    Wiring Diagram(Cooling Only) 1-1. Indoor Unit (LM-2421C2L/A2L, LM-3022C3L/A3L) FORCED MAIN PCB OPERATION AUTO RESTART REMOTE CONTROL MOTOR THERMISTOR STEP SH-CAPA. MOTOR FUSE AC250V/T2A CN-DISP1 PILLAR 1 ( L ) 2 ( N ) TERMINAL DISPLAY PCB ASM TO OUTDOOR UNIT...
  • Page 12: Operation Details

    Operation Details 1. MAIN UNIT FUNCTION • DISPLAY Operation Indicator • On while in appliance operation, off while in appliance pause • Flashing while in disconnection or short in Thermistor (3 sec off / 0.5 sec on) Soft Dry Indicator •...
  • Page 13 Auto Restarting Operation • When the power is restored after a sudden power failure while in appliance operation, the mode before the power failure is kept on the memory and the appliance automatically operates in the mode on the memory. •...
  • Page 14: Display Function/Self-Diagnosis Function

    Display Function Cooling Model Operation Indicator • Operation Timer Indicator • Timer Mode Soft Dry Indicator • Soft Dry Mode Outdoor Unit Operation DOOR • Outdoor Unit Operating or not Self-diagnosis Function Error Indicator • The function is to self-diagnoisis airconditioner and express the troubles identifically if there is any trouble. •...
  • Page 15: Installation

    Installation (1) Installation of Indoor, Outdoor unit 1) Selection of the best location Front 1. Indoor unit There should not be any heat source or steam • Left near the unit. • There should not be any obstacles to prevent Rear left the air circulation.
  • Page 16 2) Indoor Unit Installation The mounting wall should be strong and solid enough to protect it from the vibration. Installation Plate 1. Mount the installation plate on the wall with four Type "A" screws. (If mounting the unit on the concrete wall, consid- er using anchor bolts.) marking-off line Type "A"...
  • Page 17 (2) Piping and Drainage of Indoor Unit 1) Preparation of pipings Pipe cutter 1. Cut the pipes and the cable. • Use the accessory piping kit or the pipes purchased locally. Slanted Rough • Measure the distance between the indoor and the outdoor unit.
  • Page 18 2) Connection of Pipings Installation plate 1. Remove the installation plate • Pull the two '∆' marked portion of bottom of the chassis and pull the installation plate out of chas- sis. Pull 2. Route the drain hose and the indoor tubing. Pull For right rear piping 3.
  • Page 19 5. Bend the tubing as shown in the figure and bind the pipings, the connecting cables and the drain hose altogether. • Make a small loop for easy connection later. 6. Tape the tubing, drain hose and the connecting cable. Be sure that drain hose locates at the lowest side of the bundle.
  • Page 20 For left rear pipings Drain hose 3. Route the indoor tubing with the drain hose to the piping hole as desired position. Tubing holder • To remove the holder, press the bottom of the chassis near the holder upwards and the tab is Pull clear of its hole.
  • Page 21 7. Indoor unit installation • Hook the indoor unit onto the upper position of installation plate. (Engage the two hooks of the Connecting rear top of the indoor unit with the upper edge of cable the installation plate.) Ensure the hooks are properly seated on the installation plate by moving it in left and right.
  • Page 22 10. Set the pipings and the connecting cable to the back of the chassis with the tubing holder. • Hook the edge of tubing holder to tap on chas- sis and push the bottom of tubing holder to be engaged in the bottom of chassis. 11.
  • Page 23 (3) Connecting Pipings and the cable to Outdoor unit 1) Connecting the pipings to the Outdoor unit 1. Align the center of the pipings and sufficiently tighten the flare nut with fingers. 2. Finally, tighten the flare nut with torque wrench until the wrench clicks.
  • Page 24 2) Connection of the cable Terminal block 1. Remove the cover control from the unit by loosening the screw. Over 5mm Connect the wires to the terminals on the control board Holder for individually as the following. power supply cord •...
  • Page 25 (4) Checking the Drainage and Pipe forming 1) Checking the Drainage 1. Remove the Grille from the cabinet • Set the up-and-down air direction louver to open position(horizontally) by finger pressure. • Remove the securing screws. • To remove the Grille, pull lower the left and right side of the grille toward you (slightly tilted) Pull the right and and lift it straight upward.
  • Page 26 • Ensure that the color of the wires of outdoor unit and the terminal No. are the same as those of indoor unit respectively. • LM-2421C2L/A2L Terminal on the OUTDOOR UNIT 1(L) 2(N) 1(L)
  • Page 27 3) Form the pipings 1. Wrap the connecting portion of indoor unit with the Insulation material and secure it with two Plastic Bands(for the right pipings). • If you want to connect an additional drain hose, Taping the end of the drain-outlet should keep distance from the ground.(Do not dip it into water, and fix Drain hose it on the wall to avoid swinging in the wind.)
  • Page 28 (5) Air Purging of the Pipings and indoor unit The air which contains moisture remaining in the is refrigeration cycle may cause a malfunction on the compressor. 1. Confirm that both the liquid side valve and the gas side valve are set to the closed position. 2.
  • Page 29 (6) Maximum Length of Pipe and Freon Extra Charge Charge amount per 1m Maximum Length & Height(m) STANDARD Charge am't(g) Model LENGTH(m) per 1m LM-2421C2L LM-3022C3L B(Length) INDOOR UNIT A(Height) INDOOR UNIT OUTDOOR UNIT INDOOR UNIT Preventive function of cable mis-connection This product has a preventive function of cable mis-connection.
  • Page 30 (7) Test running 1) Connection of power supply 1. Connect the power supply cord to the inde- Battery Cover pendent power supply. 2. Prepare the remote control. • Insert two batteries provided. Remove the battery cover from the remote con- troller.
  • Page 31: Operation

    Operation Name and Function-Remote Control Remote Control Signal trasmitter OPERATION DISPLAY Transmits the signals Displays the operation conditions. to the room air conditioner. CHAOS SWING BUTTON Used to stop or start louver movement and set the desired up/down airflow direction. TEMP.
  • Page 32: Disassembly Of The Parts (Indoor Unit)

    Disassembly of the parts (Indoor unit) Warning : Disconnect the unit from power supply before mak- ing any checks. Be sure the power switch is set to “OFF”. To remove the Grille from the Chassis. • Set the up-and-down air discharge louver to open position (horizontally) by finger pressure.
  • Page 33 2. To remove the Control Box. • Remove securing screws. • Pull the control box out from the chassis care- fully. 3. To remove the Discharge Grille. • Pull the discharge grille out from the chassis carefully. 4. To remove the Evaporator. •...
  • Page 34: 2-Way, 3-Way Valve

    2-way, 3-way Valve 2-way Valve (Liguid Side) 3-way Valve (Gas Side) Valve cap Open position Hexagonal wrench (4mm) Flare nut Closed position Flare nut Open position Closed position piping piping Service Service connection connection port cap port To outdoor unit To outdoor unit Works Shaft position...
  • Page 35: Pumping Down

    (1) Pumping down Liquid side Indoor unit Outdoor unit Close 2-Way valve Gas side Open 3-Way valve manifold gauge Low-handle Hi- handle (CLOSE) (CLOSE) Procedure • 6. Operate the air conditioner at the cooling cycle 1. Confirm that both the gas side and liquid side and stop it when the gauge indicates 1kg/cm valves are set to the open position.
  • Page 36 (2) Evacuation (All amount of refrigerant leaked) Liquid side Indoor unit Outdoor unit Close 2-Way valve Gas side Open 3-Way valve manifold gauge Vacuum pump Low- handle Hi- handle (OPEN) (CLOSE) • Procedure 1. Confirm that both the liguid side valve and gas side valve are set to the opened position.
  • Page 37: Gas Charging

    (3) Gas Charging (After Evacuation) Liquid side Indoor unit Outdoor unit Close 2-Way valve Gas side Open 3-Way valve manifold gauge Charging cylinder Low-handle Hi- handle (OPEN) Check valve (CLOSE) • Procedure 1. Connect the gauge to the charging cylinder. 4.
  • Page 38: Cycle Troubleshooting Guide

    Cycle Troubleshooting Guide Trouble analysis • Check temperature difference between intake and discharge air and operating current. Temp. difference : approx. 0°C All amount of refrigerant leaked out. Current : less than 80% of Check refrigeration cycle. rated current Temp. Difference Refrigerant leakage Temp.
  • Page 39 When product is operating normally, but there is no cool air from all three indoor unit. Check as follows.(LM-3022C3L) No cool air from all three indoor unit Compressor is operating normally. Outdoor unit is clogged by extraneous substances. Remove it and turn off Main Power Source. Check refrigerant pressure (Suction pressure is usually 4.5~6.0kg/cm at normal condition.
  • Page 40: Electronic Parts Troubleshooting Guide

    Electronic Parts Troubleshooting Guide 1. Product does not operate at all. (* Refer to Electronic Control Device drawing and Schematic diagram.) Turn off Main Power (After 10 seconds) Turn on Main Power Does "beeping" sound is made from the Indoor Unit? Primarily, the operating condition of Micom is OK.
  • Page 41 2. The product is not operate with the remote control. Turn on Main Power While the compressor has been stopped, the compressor does not operate owing to the delaying function for 3 minutes after stopped. When the compressor stopped Indoor Fan is driven by a low speed. At this point the wind speed is not controlled by the remote controller.
  • Page 42 3. When cooling does not operate Turn on Main Power Operate "Cooling Mode( )" by setting the desired temperature of the remote controller is less than one of the indoor temperature by 1°C at least. When in Air Circulation Mode, Compressor/Outdoor Fan is stopped. Check the sensor for indoor temperature is attached as close as to be effected by the temperature of Heat Exchanger(EVA).
  • Page 43: When Indoor Fan Does Not Operate

    4. When indoor Fan does not operate. Turn off Main power Check the connection of CN-FAN or CN-MOTOR Check the Fan Motor Check the Fuse(AC250V/T2A) Check the related circuit of indoor Fan Motor. • The pin of Micom, and the part for driving SSR •...
  • Page 44: When Vertical Louver Does Not Operate

    5. When Vertical Louver does not operate. • Confirm that the Vertical Louver is normally geared with the shaft of Stepping Motor. • If the regular torque is detected when rotating the Vertical Louver with hands Normal • Check the connecting condition of CN-U/D Connector •...
  • Page 45: Communication Error

    6. Outdoor unit does not operate at all. Check Outdoor Unit PCB Board Operation Check in Outdoor Items Content Remedy • Power Transformer - About AC220V/240V ± 10% - Check the power voltage (Outdoor unit) • Replace Trans - About AC14 ± 3V - Input Voltage - Output Voltage •...
  • Page 46: Electronic Control Device

    Electronic Control Device 1. Indoor (LM-2421C2L/A2L, LM-3022C3L/A3L) MAIN P.C.B ASSY 2. Outdoor (LM-2421C2L/A2L, LM-3022C3L/A3L) MAIN P.C.B ASSY 3. DISPLAY P.C.B ASSY - 46 -...
  • Page 47: Schematic Diagram

    Schematic Diagram 1. Indoor (LM-2421C2L/A2L, LM-3022C3L/A3L) - 47 -...
  • Page 48 2. Outdoor 2-1. LM-2421C2L/A2L - 48 -...
  • Page 49 2-2. LM-3022C3L/A3L - 49 -...
  • Page 50: Exploded View And Replacement Parts List

    Exploded View & Replacement Parts List 1. Indoor Unit (LM-2421C2L/A2L, LM-3022C3L/A3L) - 50 -...
  • Page 51 Parts List(Indoor Unit) LOCATION No. PART No. DESCRIPTION REMARKS SUB PART No. 131410 3141A20003B CHASSIS ASSY 135311 3531A10023A GRILLE ASSY, DISCHARGE(INDOOR) 135312 3531A10052J GRILLE ASSY, FRONT(INDOOR) 135314 3531A10054E GRILLE ASSY, INLET SUB 146811 4681AR2727H MOTOR ASSY, STEP 152302 5230A20004A FILTER(MECH), A/C 159901 5990A30006B VANE, HORIZONTAL...
  • Page 52 2. Outdoor Unit • LM-2421C2L/A2L - 52 -...
  • Page 53 Parts List(LM-2421C2L/A2L) PART No. LOCATION No. DESCRIPTION REMARKS LM-2421C2L LM-2421A2L 263230 3Q35015E 3Q35015E THERMISTOR ASSY 430411 3041A30003H 3041A30003H BASE ASSY, WELD(OUTDOOR) 435511 3551A30028M 3551A30028M COVER ASSY, CONTROL(OUTDOOR) 435512 3H03266K 3H03266K COVER ASSY, TOP(OUTDOOR) 437212 3720AP0003F 3720AP0003F PANEL ASSY, REAR 447910...
  • Page 54 • LM-3022C3L/A3L - 54 -...
  • Page 55 Parts List(LM-3022C3L/A3L) PART No. LOCATION No. DESCRIPTION REMARKS LM-3022C3L LM-3022A3L 263230 3Q35015E 3Q35015E THERMISTOR ASSY 268716 6871A20031R 6871A20031R PWB(PCB) ASSY, MAIN(OUTDOOR) 430411 3041A30003K 3041A30003K BASE ASSY, WELD(OUTDOOR) 435511 3551AP7042V 3551AP7042V COVER ASSY, CONTROL(OUTDOOR) 435512 3H03266K 3H03266K COVER ASSY, TOP(OUTDOOR) 437212 3720AP0003F 3720AP0003F PANEL ASSY, REAR...
  • Page 56 January, 2002 P/No: 3828A20023G Printed in Korea...

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Lm-3022c3l/a3l

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