TECHNICAL & SERVICE MANUAL CS-KS12NB41 & CZ-18BT1U + CU-KS12NK1A CS-KS18NB4UW & CZ-18BT1U + CU-KS18NKU CS-KS18NB4UW & CZ-18BT1U + CU-KS18NKUA DC INVERTER SPLIT SYSTEM AIR CONDITIONER Indoor Model No. Product Code No. Body (Panel) Body (Panel) CU-KS18NKU 1 852 361 18 1 852 361 04 (1 852 361 15) CU-KS12NK1A 1 852 361 16 CS-KS18NB4UW (CZ-18BT1U) 1 852 361 06 (1 852 361 15) CU-KS18NKUA 1 852 361 19 CS-KS12NB41 (CZ-18BT1U) Outdoor Model No. Product Code No.
SAFETY PRECAUTIONS • Before doing repair work, please read the " SAFETY PRECAUTIONS" carefully and fully understand them. • The precautionary items here are divided into " Warning" and " Caution" items. Items in particular which may cause death or serious injury to the service personnel if the work is not performed correctly, are included in the " Warning" table. However, even precautionary items identified as " Caution" also have the potential for serious consequences if not performed correctly.
Warning If refrigerant gas blows off during the work, do not touch the refrigerant gas as it may cause frostbite. Prohibit If refrigerant gas leaks during the work, ventilate the room. If refrigerant gas catches fire, harmful gas may be generated. Do not mix any gas other than the specified refrigerant gas in the refrigerating cycle. If air or other contaminants mix with the gas, pressure will become extremely high in the refrigerating cycle, which may cause a unit breakdown.
Table of Contents Page SAFETY PRECAUTIONS .............................................................................................................. 2 TABLE OF CONTENTS ..................................................................................................................... 4 1. OPERATING RANGE ................................................................................................................... 6 2. SPECIFICATIONS 2-1. Unit Specifications .................................
Page 10. CHECKING ELECTRICAL COMPONENTS 10-1. Measurement of Insulation Resistance ............................................................................... 10-2. Checking Continuity of Fuse on PCB Ass'y ......................................................................... 60 61 11. REFRIGERANT R410A: SPECIAL PRECAUTIONS WHEN SERVICING UNIT 11-1. Characteristics of New Refrigerant R410A ......................................................................... 11-2. Checklist before Servicing ...
1. OPERATING RANGE Models : CS-KS18NB4UW & CZ-18BT1U + CU-KS18NKU Temperature Cooling Indoor Air Intake Temp. Outdoor Air Intake Temp. Maximum 95 °F DB / 71 °F WB 115 °F DB Minimum 67 °F DB / 57 °F WB 67 °F DB Models : CS-KS12NB41 & CZ-18BT1U + CU-KS12NK1A CS-KS18NB4UW & CZ-18BT1U + CU-KS18NKUA Temperature Cooling Indoor Air Intake Temp. Outdoor Air Intake Temp.
2. SPECIFICATIONS 2-1. Unit Specifications 2-1-1.
Indoor Unit Outdoor Unit CS-KS18NB4UW & CZ-18BT1U CU-KS18NKU Indoor Unit (CS-KS18NB4UW & CZ-18BT1U) Dimensions & Weight (Indoor Unit) Unit Dimensions Package Dimensions Weight Height Width Depth Height Width Depth Net Shipping Shipping Volume < 230V > inch (mm) inch (mm) inch (mm) inch (mm) inch (mm) inch (mm) Ib. (kg) Ib. (kg) cu.ft (m3) 12-5/16 (313) 24-19/32 (625) 24-19/32 (625) 41.3 (18.
2-1-2.
Indoor Unit Outdoor Unit CS-KS18NB4UW & CZ-18BT1U CU-KS18NKU Indoor Unit (CS-KS18NB4UW & CZ-18BT1U) Dimensions & Weight (Indoor Unit) Unit Dimensions Package Dimensions Weight Height Width Depth Height Width Depth Net Shipping Shipping Volume < 208V > inch (mm) inch (mm) inch (mm) inch (mm) inch (mm) inch (mm) Ib. (kg) Ib. (kg) cu.ft (m3) 12-5/16 (313) 24-19/32 (625) 24-19/32 (625) 41.3 (18.
2-1-3.
Indoor Unit Outdoor Unit CS-KS12NB41 & CZ-18BT1U CU-KS12NK1A Indoor Unit (CS-KS12NB41 & CZ-18BT1U) Dimensions & Weight (Indoor Unit) Unit Dimensions Package Dimensions Weight Height Width Depth Height Width Depth Net Shipping Shipping Volume inch (mm) inch (mm) inch (mm) inch (mm) inch (mm) inch (mm) Ib. (kg) Ib. (kg) cu.ft (m3) 12-5/16 (313) 24-19/32 (625) 24-19/32 (625) 41.3 (18.
2-1-4.
Indoor Unit Outdoor Unit CS-KS18NB4UW & CZ-18BT1U CU-KS18NKUA Indoor Unit (CS-KS18NB4UW & CZ-18BT1U) Dimensions & Weight (Indoor Unit) Unit Dimensions Package Dimensions Weight Height Width Depth Height Width Depth Net Shipping Shipping Volume < 230V > inch (mm) inch (mm) inch (mm) inch (mm) inch (mm) inch (mm) Ib. (kg) Ib. (kg) cu.ft (m3) 12-5/16 (313) 24-19/32 (625) 24-19/32 (625) 41.3 (18.
2-1-5. Indoor Unit Outdoor Unit CS-KS18NB4UW & CZ-18BT1U CU-KS18NKUA Features Electrical Rating Performance Voltage Rating 208V Single-Phase 60Hz Cooling 17,500 ( 4,000 to 17,500 ) 5.15 ( 1.2 to 5.15 ) 10,600 6,900 341 (579) / 294 (500) / 253 (430) 4.89 187 to 253 9.1 ( 1.2 to 9.1 ) 1,860 ( 250 to 1,860 ) 98 9.41 16 17.5 15 Microprocessor / I.C.
Indoor Unit Outdoor Unit CS-KS18NB4UW & CZ-18BT1U CU-KS18NKUA Indoor Unit (CS-KS18NB4UW & CZ-18BT1U) Dimensions & Weight (Indoor Unit) Unit Dimensions Package Dimensions Weight Height Width Depth Height Width Depth Net Shipping Shipping Volume < 208V > inch (mm) inch (mm) inch (mm) inch (mm) inch (mm) inch (mm) Ib. (kg) Ib. (kg) cu.ft (m3) 12-5/16 (313) 24-19/32 (625) 24-19/32 (625) 41.3 (18.
2-2. Major Component Specifications 2-2-1. Indoor Unit Indoor Unit (Body) CS-KS12NB41 Control PCB Part No. Controls Control Circuit Fuse CB-CS-KS12NB4U Microprocessor 250V 3A Fan Type Q'ty ... Dia. and Length Turbo 1 ... D12-5/8 / L5-3/4 (D322/L147) inch (mm) Fan Motor Type Model ... Q'ty No. of Poles Rough Measure RPM (Cool) Rating Voltage / Nominal Output Coil Resistance Ohm (Ambient Temp.
Indoor Unit (Body) CS-KS18NB4UW Control PCB Part No. Controls Control Circuit Fuse CB-CS-KS18NB4U Microprocessor 250V 3A Fan Type Q'ty ... Dia. and Length Turbo 1 ... D12-5/8 / L5-3/4 (D322/L147) inch (mm) Fan Motor Type Model ... Q'ty No. of Poles Rough Measure RPM (Cool) Rating Voltage / Nominal Output Ohm Coil Resistance (Ambient Temp. 68 °F (20 °C)) Safety Device Type Over- Current Protection Over- Heat Protection Run Capacitor Micro F VAC DC Motor SIC-62FW-D866-2 ...
2-2-2. Outdoor Unit Outdoor Unit CU-KS18NKU Control PCB Part No. Controls Control Circuit Fuse CB-CU-KS18NKU Microprocessor 250V 25A Compressor Type Compressor Model / Nominal Output Pints (cc) Compressor Oil ... Amount Coil Resistance (Ambient Temp. 68 °F (20 °C)) Ohm DC Twin Rotary (Hermetic) C-6RVN93H0M / 1,050W FV50S ... 0.74 (350) R - S : 0.482 S - T : 0.482 T - R : 0.482 Safety Device CT (Peak current cut-off control) Compressor Discharge Temp.
Outdoor Unit CU-KS12NK1A Control PCB Part No. Controls Control Circuit Fuse CB-CU-KS12NK1A Microprocessor 125V 25A Compressor Type Compressor Model / Nominal Output Pints (cc) Compressor Oil ... Amount Coil Resistance (Ambient Temp. 68 °F (20 °C)) Ohm DC Rotary (Hermetic) G4C090LU1ER / 900W FV50S ... 0.68 (320) U - V : 0.81 V - W : 0.81 W - U : 0.81 Safety Device CT (Peak current cut-off control) Compressor Discharge Temp.
Outdoor Unit CU-KS18NKUA Control PCB Part No. Controls Control Circuit Fuse CB-CU-KS18NKUA Microprocessor 250V 25A Compressor Type Compressor Model / Nominal Output Pints (cc) Compressor Oil ... Amount Coil Resistance (Ambient Temp. 68 °F (20 °C)) Ohm DC Twin Rotary (Hermetic) C-6RVN93H0M / 1,050W FV50S ... 0.74 (350) R - S : 0.482 S - T : 0.482 T - R : 0.482 Safety Device CT (Peak current cut-off control) Compressor Discharge Temp.
2-3. Other Component Specifications Indoor Unit CS-KS12NB41 & CZ-18BT1U CS-KS18NB4UW & CZ-18BT1U Outdoor Unit CU-KS18NKU CU-KS12NK1A CU-KS18NKUA • Indoor heat exchanger sensor (Model:PT2M-51H-S3) • Compressor temp sensor (CU-KS12NK1A...Model:DTN-TKS274Y TH2) (CU-KS18NKU , CU-KS18NKUA...
7-23/32 1-27/32 1 2 3 4 5 6 7 8 1-3/32 2-3/32 Less than 31/32 22-5/8 (575) 5-9/16 3-5/8 1-25/32 25/32 7 2 2 1 2 Less than 31/32 Fresh air intake duct connection port (dia. 3-7/8") Suspension bolt hole (4 - 1/2" x 1-1/8" hole) Power supply port Drain tube connection port VP20 (outer dia. 1") Refrigerant tubing (gas tube) dia. 1/2" (flared) Refrigerant tubing (liquid tube) dia.
Outdoor Unit CU-KS12NK1A 21-3/16 3-19/32 15/32 :1 5/ 16 12-7/16 10-7/16(265) 28-11/32 (720) 11-13/32 2ID 3-19/32 Wide tube service valve dia.3/8" (9.52) 2-1/8 21-9/16 (548) Narrow tube service valve dia.1/4" (6.
Outdoor Unit CU-KS18NKU CU-KS18NKUA 23-15/16 5-11/32 32 3/ 13-5/32 11-7/32 (285) 34-21/32 (880) 12-7/32 2ID :2 Wide tube service valve dia.1/2" (12.70) 2-17/32 6-17/32 23/32 2-5/32 26-3/8 (670) Narrow tube service valve dia.1/4" (6.
4. REFRIGERANT FLOW DIAGRAM 4-1. Refrigerant Flow Diagram CS-KS12NB41 & CZ-18BT1U Outdoor Unit CU-KS12NK1A Outdoor unit Wide tube Wide tube service valve Accumulator Muffler O.D. 3/8" (9.52 mm) Heat exchanger Heat exchanger High pressure switch H.P. Compressor Indoor unit Strainer Indoor Unit Narrow tube Electric expansion valve Narrow tube service valve M Muffler O.D. 1/4" (6.
CS-KS18NB4UW & CZ-18BT1U Outdoor Unit CU-KS18NKU CU-KS18NKUA Outdoor unit Wide tube Wide tube service valve Accumulator Muffler O.D. 1/2" (12.7mm) Heat exchanger Heat exchanger High pressure switch H.P. Compressor Indoor unit Strainer Indoor Unit Narrow tube Electric expansion valve Narrow tube service valve M O.D. 1/4" (6.
5. PERFORMANCE DATA 5-1. Temperature Charts Indoor Unit CS-KS12NB41 & CZ-18BT1U Outdoor Unit CU-KS12NK1A Cooling Characteristics (RH : 46%, Indoor fan speed : High fan) (60Hz, 115V) Low pressure at wide tube service valve psig(MPaG) (1) Low pressure performance chart Lo Fan Hi Fan 131 (0.9) ) 6°F (30°C ir Temp.8 Indoor A °C) 80°F (27 °C) 75°F (24 102 (0.7) 73 (0.5) 77 86 (30) (25) 95 (35) 104 (40) Outdoor inlet air DB temp.
Indoor Unit CS-KS18NB4UW & CZ-18BT1U Outdoor Unit CU-KS18NKU or CU-KS18NKUA Cooling Characteristics (RH : 46%, Indoor fan speed : High fan) (60Hz, 230V) Low pressure at wide tube service valve psig(MPaG) (1) Low pressure performance chart Lo Fan 131 (0.9) Hi Fan ) 6°F (30°C ir Temp.8 Indoor A °C) 80°F (27 °C) 75°F (24 102 (0.7) 73 (0.5) 77 86 (30) (25) 95 (35) 104 (40) Outdoor inlet air DB temp.
5-2. Cooling Capacity Indoor Unit : CS-KS12NB41 & CZ-18BT1U Outdoor Unit : CU-KS12NK1A Power Supply : 115V Single Phase 60Hz < Cooling Capacity > RATING CAPACITY: INDOOR ENT. TEMP. oF (oC) WB 59 (15.0) 63 (17.2) 67 (19.4) 71 (21.7) 75 (23.9) 11,900 BTU/h DB AIR FLOW RATE: OUTDOOR AMBIENT TEMP. oF (oC) 235 CFM 65 (18.3) 75 (23.9) 85 (29.4) 95 (35.0) 105 (40.6) 115 (46.1) TC CI 8,350 0.79 8,570 0.93 8,800 1.06 8,930 1.16 9,210 1.25 7,830 1.07 6,340 7,210 8,120 8,350 8,350 12,230 0.
Indoor Unit : CS-KS18NB4UW & CZ-18BT1U Outdoor Unit : CU-KS18NKU or CU-KS18NKUA Power Supply : 230V Single Phase 60Hz < Cooling Capacity > RATING CAPACITY: 17,500 BTU/h INDOOR ENT. TEMP. oF (oC) WB 59 (15.0) 63 (17.2) 67 (19.4) 71 (21.7) 75 (23.9) DB 72 76 80 84 88 72 76 80 84 88 72 76 80 84 88 72 76 80 84 88 76 80 84 88 AIR FLOW RATE: 341 CFM OUTDOOR AMBIENT TEMP. oF (oC) 65 (18.3) 75 (23.9) 85 (29.4) 95 (35.0) 105 (40.6) 115 (46.1) TC CI 12,260 1.15 12,550 1.34 12,830 1.
5-3. Cooling Capacity (Low Ambient) Indoor Unit : CS-KS12NB41 & CZ-18BT1U Outdoor Unit : CU-KS12NK1A Power Supply : 115V Single Phase 60Hz < Cooling Capacity (Low Ambient) > RATING CAPACITY: 11,900 BTU/h AIR FLOW RATE: INDOOR ENT. TEMP. oF (oC) WB 59 (15.0) 63 (17.2) 67 (19.4) 71 (21.7) 75 (23.9) OUTDOOR AMBIENT TEMP. oF (oC) DB 72 76 80 84 88 72 76 80 84 88 72 76 80 84 88 72 76 80 84 88 76 80 84 88 235 CFM 0 (-17.8) 5 (-15.0) 15 (-9.4) 25 (-3.9) 35 (1.7) 45 (7.2) 55 (12.
Indoor Unit : CS-KS18NB4UW & CZ-18BT1U Outdoor Unit : CU-KS18NKUA Power Supply : 230V Single Phase 60Hz < Cooling Capacity (Low Ambient) > RATING CAPACITY: 17,500 BTU/h AIR FLOW RATE: INDOOR ENT. TEMP. oF (oC) WB 59 (15.0) 63 (17.2) 67 (19.4) 71 (21.7) 75 (23.9) OUTDOOR o o AMBIENT TEMP. F ( C) DB 72 76 80 84 88 72 76 80 84 88 72 76 80 84 88 72 76 80 84 88 76 80 84 88 341 CFM 0 (-17.8) 5 (-15.0) 15 (-9.4) 25 (-3.9) 35 (1.7) 45 (7.2) 55 (12.8) TC CI 13,400 0.69 13,430 0.
6. ELECTRICAL DATA 6-1. Electrical Characteristics Indoor Unit CS-KS12NB41 & CZ-18BT1U Outdoor Unit CU-KS12NK1A Cooling Indoor Unit Fan Motor Performance at Rating conditions Rating conditions: Running amp. Power input Indoor air temperature: Outdoor air temperature: A W 0.21 18 Outdoor Unit Fan Motor + Compressor 115V Single-phase 60Hz 12.39 1,242 80 °F (26.7 °C) DB / 67 °F (19.4 °C) WB 95 °F (35 °C) DB 34 Complete Unit 12.
Indoor Unit CS-KS18NB4UW & CZ-18BT1U Outdoor Unit CU-KS18NKU Cooling < 230V > Indoor Unit Fan Motor Performance at Rating conditions Rating conditions: Running amp. Power input Indoor air temperature: Outdoor air temperature: A W 0.15 22 Outdoor Unit Fan Motor + Compressor 230V Single-phase 60Hz 8.15 1,838 8.3 1,860 80 °F (26.7 °C) DB / 67 °F (19.
2 3 36 WHT RED BLK AC1 AC2 SI FM FERRITE CORE DP DRAIN PUMP 1 3 1 3 DP 3P (BLU) 3P (RED) GRN/YEL CONTROLLER 1 2 3 4 5 6 1 2 3 4 5 6 DCM 6P (BLU) 6P (WHT) RED FAN MOTOR BLK WHT YEL BLU BOX 1 2 3 4 5 6 7 1 2 3 4 5 6 7 PWM/POW 7P (RED) SERIAL 1 1 2P (WHT) 2 2 GRN RED WHT BRN RED ORG YEL PNK BLU VLT BOX 1 2 3 4 5 6 7 1 2 3 4 5 6 7 PWM/POW 7P (RED) 1 1 SERIAL 2 2 2P (WHT) IND LAMP ASSY 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 1 2 3 4 RC 4P (WHT) FLAP (R) 1 2 3 4 5 6 1 2 3 4 5
Outdoor Unit CU-KS12NK1A 8FA2-5251-12300-2 37
Outdoor Unit CU-KS18NKU CU-KS18NKUA REACTANCE BLK WHT WHT w w w w L2 E2 E1 E CONTROLLER BLK RED BLU YEL WHT ACIN2 w WHT SI-A w RED 1 2 BLK 5 WHT 6 N L POWER SUPPLY 1 2 3 4 5 1 2 3 4 5 HIGH PRESSURE SWITCH BLK 1 1 2 2 BLK 2P-CONNECTOR (BLK) MV0 MAGNETIC COIL FAN MOTOR WHT WHT GND 4 GND 1 2 3 4 5 6 7 1 2 3 4 5 6 7 FM *ELEC SYSTEM ASSY BLK ORG RED YEL BLK GRY BLK RED BLU YEL WHT 1 2 3 4 5 1 2 3 4 5 7P-CONNECTOR (WHT) MV0 1 2 3 4 5 6 7 YEL DCFM 1 2 3 4 1 2 3 4 YEL COIL
7. MAINTENANCE Tab 7-1. Address Setting of the Remote Controller The address can be set in order to prevent interference between remote controllers when two indoor units are installed near each other. The address is normally set to "A." To set a different address, it is necessary to change the address on the second remote controller. Fig. 1 NOTE Once changed, you cannot restore the original address setting of the air conditioner. (1) Switch on the power source.
7-2. Disconnecting and Connecting Positive Connector for Outdoor Unit One of the two types of connectors illustrated at left is used. Their basic structure is the same for each. How to Disconnect Hold the resin connector cover, and pull the connector off. You cannot disconnect the connector by pulling the wire since it is locked inside. Always hold the cover to disconnect. (See illustration at left.) For the connector without the resin cover, push the lock in the direction of "2" while pulling it off.
7-3. Disassembly Procedure To avoid electrical shock hazard, be sure to disconnect power before WARNING attempting to disassemble the unit. When a footstool, etc. is used for disassembling the indoor unit, be careful not to fall down. If you fall down, you might be injured seriously. 7-3-1. Remove the air intake grill. (1) Slide the 2 latches each to the corresponding arrow direction. (Fig. 1 and Fig. 2) Open downward the air intake grill located on the latch side.
7-3-3. Remove the ceiling panel. (1) Open the clamp (4 locations) and remove the 2 lead wires from the clamps. (Fig. 6) (2) Remove the 4 screws fixing the corner cover (at 3 locations) and indicator cover (at 1 location). (Fig. 6) (3) Press the center 1 of the cover and remove the cover with the section 2 pulled down. (Fig. 7) (4) Remove the strap (3 locations) from the hook on the ceiling panel. (Fig. 8) There is no strap on the indicator cover.
7-3-4. Remove the indoor air temperature sensor. (1) Disconnect the connector CN08 (ROOM 2P) in the control box and remove the indoor air temperature sensor. (Fig. 10) Indoor air temperature sensor CN08 Fig.10 7-3-5. Remove the power box and control box. (1) Remove a screw and remove the terminal cover. (Fig. 11) (2) Remove the 2 screws and remove the power box cover. (Fig. 11) (3) Disconnect the power lines (No. 1 and No. 2) / signal line (No. 3) and ground cable from the terminals in the power box.
(4) Disconnect the connector CN07 (DP 2P) in the power box. (Fig. 13) Remove a screw and disconnect the ground cable. (Fig. 13) (5) Disconnect the connector CN03 (DCM 6P) in the power box. (Fig. 14) (6) Remove the 4 screws and remove the power box. (Fig. 14) (7) Disconnect the connectors CN06 (FS 3P) and CN09 (COIL-1 2P) in the control box. (Fig. 15) (8) Remove the 2 screws and remove the control box. (Fig. 15) Screw Ground cable 1 2 3 CN07 Fig.13 Screw Screw Screw Screw CN03 Fig.
NOTE For the removal of the following components, perform any work after removing the indoor unit (main body) from the ceiling. Main body lower section Heat exchanger sensor Drain pump Float switch Turbo fan Fan motor Heat exchanger 1. Perform the work after draining the water to prevent the water leakage from the drain pan. • Put a bucket, etc., under the drain cap and remove the drain cap to drain the water. (Fig. 16) 2.
7-3-7. Remove the heat exchanger sensor. (1) Remove the heat exchanger sensor from the sensor holder. (Fig. 19) Heat exchanger sensor Holder Fig.19 7-3-8. Remove the drain pump and float switch. (1) Remove the 2 screws (Fig. 20) (2) Loosen the clamp and disconnect the drain hose from the drain pump. (Fig. 20) (3) Remove the drain pump from the main body upper section. (Fig. 20) (4) Remove a nut and remove the float switch. (Fig. 21) Screw Drain pump Float switch Nut Drain hose Clamp Fig.20 Fig.
7-3-9. Remove the turbo fan and fan motor. (1) Remove a nut and remove the turbo fan. (Fig. 22) (2) Remove the 2 screws and 3 nuts, and remove the fan motor. (Fig. 23) Turbo fan Screw Nut Nut Fan motor Fig.22 Fig.23 7-3-10. Remove the heat exchanger. (1) Remove the 3 screws. (Fig. 24) (2) Remove the 3 screws. (Fig. 25) (3) Remove the heat exchanger from the main body upper section with the heat exchanger lifted. Heat exchanger Screw Screw Main body upper section Screw Fig.24 Fig.
8. FUNCTIONS 8-1. Operation Functions Emergency operation SENSOR DRY Emergency operation is available when the remote controller malfunctions, has been lost, or otherwise cannot be used. During DRY operation, the system adjusts the room temperature and fan speed according to the conditions in the room, in order to maintain a comfortable room environment. To operate the system, press the OPERATION button, which is also used as the receiver, below the unit display.
HIGH POWER NIGHT SETBACK This function acts to raise the power but keeps the AC system in the same operating mode. This function is set with the HIGH POWER button on the remote controller. (It can be set regardless of the temperature and fan speed settings.) When NIGHT SETBACK operation is set, the temperature and fan speed settings will be adjusted automatically to allow comfortable sleep. When NIGHT SETBACK operation is set, " mark" appears on the remote controller.
8-2. Protective Functions Compressor discharge temperature control Freeze prevention This function controls the operation frequency to prevent the compressor discharge temperature from rising more than a specified temperature. Indoor heat exchanger temperature °F(°C) During COOL or DRY operation, freezing is detected and operation is stopped when the temperature of the indoor heat exchanger matches the conditions below. 1.
9. TROUBLESHOOTING (BEFORE CALLING FOR SERVICE) 9-1. Precautions before Performing Inspection or Repair After checking the self-diagnostics monitor, turn the power OFF before starting inspection or repair. High-capacity electrolytic capacitors are used inside the outdoor unit controller (inverter). They retain an electrical charge (charging voltage DC 310V) even after the power is turned OFF, and some time is required for the charge to dissipate.
(1) Self-diagnostics Lamps INDOOR UNIT OPERATION button OPERATION lamp TIMER lamp HIGH POWER lamp REMOTE CONTROL receiver Since the indications cover various units, the corresponding parts listed below may not be present in some models. .... OFF INDICATION ON INDOOR UNIT OPERATION TIMER HIGH POWER CODE S01 S02 DIAGNOSIS CONTENTS .... ON POSSIBLE MALFUNCTION (1) OPEN OR SHORT CIRCUIT IN SENSOR ROOM TEMP. SENSOR TROUBLE (2) POOR CONTACT AT CONNECTOR OR OPEN CIRCUIT AT TERMINAL PRESS-FIT LOCATION.
(2) If the self-diagnostics function fails to operate Check the indoor unit. • No indicators illuminate and the indoor fan does not rotate. • Check the power voltage. Blown Is the fuse blown? Normal Replace the circuit board or the fuse. Replace the controller. 9-3. Checking the Indoor and Outdoor Units (1) Checking the indoor unit No. 1 Control Use the remote controller to operate the unit in "TEST run" mode.
(3) Serial Communication Error Identification Procedure If the lamps on the main body show the following conditions after the completion of self-diagnostics, a communication error between the indoor unit and outdoor unit might be considered. In such a case, identify the breakdown section by using the following procedure. Refer to "Method of Self-Diagnostics" for the self-diagnostics procedure.
( Continued from the previous page A. ) A ( Continued from the previous page B. ) B Is the voltage of about DC22V to 24V given between the terminals 2 and 3 on the indoor unit terminal strip (Serial Communication Line) ? (Fig. 2) Yes No Defect in the indoor unit P.C. board Defect or connection error in the inter-unit cable Outdoor Unit 1. Turn OFF the power and wait until the power lamp (LED) of the outdoor unit controller is turned OFF. 2.
(3-2) Condition: E12 Troubleshooting Serial Communication Outdoor Unit 1 2 3 4 5 6 Power 1. Turn off the power and wait until the power lamp (LED) of the outdoor unit controller is turned OFF. 2. Disconnect the cable from the terminal 3 on the Outdoor unit terminal strip. (Fig. 6) 1 2 3 Indoor Unit Fig. 6 1. Turn ON the power and operate the system using the remote controller or the operation button on the indoor unit. 2. Perform the self-diagnosis five seconds after the operation start.
9-4. Trouble Diagnosis of Fan Motor 9-4-1. Indoor Fan Motor This indoor DC fan motor contains an internal control PCB. Therefore, it is not possible to measure the coil resistance, and the following procedure should be used to check the motor. To perform diagnosis, operate the unit in cooling mode with indoor fan speed "High". Next, make sure that the indoor unit receive the signals from the remote controller when the ON/OFF operation button is pressed.
9-4-2. Outdoor Fan Motor This outdoor DC fan motor contains an internal control PCB. Therefore, it is not possible to measure the coil resistance, and the following procedure should be used to check the motor. Perform the trouble diagnosis by Test Run mode described on Installation Instructions. Important: (A) Turn OFF the power before connecting or disconnecting the motor connectors.
9-5. Noise Malfunction and Electromagnetic Interference An inverter A/C operates using pulse signal control and high frequencies. Therefore, it is susceptible to the effects of external noise, and is likely to cause electromagnetic interference with nearby wireless devices. A noise filter is installed for ordinary use, preventing these problems. However, depending on the installation conditions, these effects may still occur. Please pay attention to the points listed below.
10. CHECKING ELECTRICAL COMPONENTS 10-1. Measurement of Insulation Resistance Ground wire Clip The insulation is in good condition if the resistance exceeds 1M ohm. Probe 10-1-1. Power Supply Cord Insulation tester Clamp the grounding wire of power cord with the lead clip of the insulation resistance tester and measure the resistance by placing a probe on either of the two power wires. (Fig. 1) Then also measure the resistance between the grounding and other power terminals. (Fig. 1) Fig.
10-2. Checking Continuity of Fuse on PCB Ass'y Fuse Remove the PCB Ass'y from the electrical component box. Then pull out the fuse from the PCB Ass'y. (Fig. 5) Check for continuity using a multimeter as shown in Fig. 6. PCB Ass'y Fig. 5 Fuse Fig.
11. REFRIGERANT R410A: SPECIAL PRECAUTIONS WHEN SERVICING UNIT 11-1. Characteristics of New Refrigerant R410A 11-1-1. What is New Refrigerant R410A? R410A is a new refrigerant that contains two types of pseudo-non-azeotropic refrigerant mixture. Its refrigeration capacity and energy efficiency are about the same level as the conventional refrigerant, R22. 11-1-2. Components (mixing proportions) HFC32 (50%) / HFC125 (50%) 11-1-3.
11-2. Checklist before Servicing Use a clutch-type flare tool for R410A or the conventional flare tool. Note that sizes of the resultant flares differ between these two tools. Where a conventional flare tool is used, make sure to observe A Specification (amount of extrusion) by using the flare spacer. Specification A Diameter of tube D Flare tool for R410A Conventional flare tool (for R22) Dia.3/8" (9.52 mm) 0 to 0.0196" 0.0472" Dia.1/2" (12.7 mm) (0 to 0.5 mm) (1.2 mm) Dia.1/4" (6.35 mm) Dia.
11-3. Tools Specifically for R410A For servicing, use the following tools for R410A Tool Distinction Tool Name Gauge manifold Charging hose Gas leak detector Refrigerant cylinder Charging cylinder Refrigerant recovery unit Tools specifically for R410A Vacuum pump with anti-reverse flow (*1) (Solenoid valve-installed type, which prevents oil from flowing back into the unit when the power is off, is recommended.) Vacuum pump (*2)...can be used if the following adapter is attached.
11-5. In Case of Compressor Malfunction CAUTION Should the compressor malfunction, be sure to make the switch to a replacement compressor as quickly as possible. Use only the tools indicated exclusively for R410A. Specifically for R410A." See "11-3. Tools 11-5-1. Procedure for Replacing Compressor (1) Recovering refrigerant Any remaining refrigerant inside the unit should not be released to the atmosphere, but recovered using the refrigerant recovery unit for R410A.
(5) Recharging Configuration and characteristics of cylinders Be sure to charge the specified amount of refrigerant in liquid state using the service port of the wide tube service valve. The proper amount is listed on the unit's nameplate. Valve When the entire amount cannot be charged all at once, charge gradually while operating the unit in Cooling Operation. CAUTION Liquid Never charge a large amount of liquid refrigerant at once to the unit. This may cause damage to the compressor.
11-6. In Case Refrigerant is Leaking CAUTION Never attempt to charge additional refrigerant when refrigerant has been leaking from the unit. Follow the procedure described below to locate points of leaks and carry out repairs, then recharge the refrigerant. (1) Detecting Leaks Use the detector for R410A to locate refrigerant leak points.
11-7. Charging Additional Refrigerant 11-7-1. When Tubes are Extended Observe the proper amount of refrigerant as stated in this service manual or the installation manual that came with the indoor unit. Charge additional refrigerant in liquid state only. CAUTION Never charge additional refrigerant if refrigerant is leaking from the unit. Follow instructions given in "11-6. In Case Refrigerant is Leaking" and completely carry out repairs. Only then should you recharge the refrigerant. 11-8.