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TECHNICAL & SERVICE MANUAL
OUTDOOR UNIT : CU-3KE19NBU
CU-4KE24NBU
CU-4KE31NBU
DC INVERTER MULTI-SYSTEM AIR CONDITIONER
Capacity at 230V Outdoor Model No. Product Code No.
19,100 BTU/h CU-3KE19NBU 1 852 361 27
23,200 BTU/h CU-4KE24NBU 1 852 361 28
30,600 BTU/h CU-4KE31NBU 1 852 361 29
< Applicable Indoor Units >
CU-3KE19NBU
Wall mounted type
CS-MKE7NKU
CS-MKE9NKU
CS-MKE12NKU
CS-MKE18NKU
CS-MKE24NKU
Semi-concealed type
CS-MKE9NB4U & CZ-18BT1U
CS-MKE12NB4U & CZ-18BT1U
CS-KE12NB4UW & CZ-18BT1U
CU-
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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
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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." Prohibit When th
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Table of Contents Page SAFETY PRECAUTIONS .............................................................................................................. 2 TABLE OF CONTENTS ...................................................................................................................... 4 APPLICABLE INDOOR UNITS ..................................................................................................... 6 1. OPERATING RANGE .........................................
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Page 9. REFRIGERANT R410A: SPECIAL PRECAUTIONS WHEN SERVICING UNIT 9-1. Characteristics of New Refrigerant R410A ......................................................................... 88 9-2. Checklist before Servicing ................................................................................................... 89 9-3. Tools Specifically for R410A ................................................................................................ 90 9-4. Tubing Installat
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APPLICABLE INDOOR UNITS Wall Mounted Type Indoor Unit CS-MKE7NKU CS-MKE9NKU CS-MKE12NKU CS-MKE18NKU CS-MKE24NKU Multi-Outdoor Unit 3-Room CU-3KE19NBU YES YES YES YES NO 4-Room CU-4KE24NBU YES YES YES YES YES 4-Room CU-4KE31NBU YES YES YES YES YES Semi-Concealed Type CS-MKE9NB4U CS-MKE12NB4U CS-KE12NB4UW Indoor Unit & & & CZ-18BT1U CZ-18BT1U CZ-18BT1U Multi-Outdoor Unit 3-Room CU-3KE19NBU YES YES YES 4-Room CU-4KE24NBU YES YES YES 4-Room CU-4KE31NBU YES YES YES 6
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1. OPERATING RANGE Temperature Indoor Air Intake Temp. Outdoor Air Intake Temp. Maximum 95 °F DB / 71 °F WB 115 °F DB Cooling Minimum 67 °F DB / 57 °F WB 14 °F DB Maximum 80 °F DB / 67 °F WB 75 °F DB / 65 °F WB Heating Minimum – DB / – WB – DB / 0 °F WB 7
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2. SPECIFICATIONS 2-1. Unit Specifications Outdoor Unit CU-3KE19NBU Indoor Unit CS-MKE9NKU × 2 Duct Less Type Rated < 230V > Type 3-Room Multi Outdoor Unit Number of Connectable Indoor Units 3 Number of Operatable Indoor Units 3 Voltage Rating 230V Single-Phase 60Hz Cooling Heating Total Capacity BTU/h 17,000 ( 6,800 to 18,600 ) 23,200 ( 7,800 to 24,800 ) kW 5.00 ( 1.90 to 5.45) 6.80 ( 2.30 to 7.30) Sensible Capacity 14,300 - BTU/h Latent Capacity BTU/h 2,700 - 3 3 Air Circulation (High) ft /
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Outdoor Unit CU-3KE19NBU Indoor Unit CS-MKE9NKU × 3 < 230V > Type 3-Room Multi Outdoor Unit Number of Connectable Indoor Units 3 Number of Operatable Indoor Units 3 Voltage Rating 230V Single-Phase 60Hz Cooling Heating Total Capacity BTU/h 18,600 ( 9,800 to 18,600 ) 24,800 ( 11,600 to 24,800 ) kW 5.45 ( 2.90 to 5.45 ) 7.30 ( 3.40 to 7.30 ) Sensible Capacity 15,800 - BTU/h Latent Capacity BTU/h 2,800 - 3 3 Air Circulation (High) ft /min (m /h) 1,707 (2,900) 1,707 (2,900) Available Voltage Range
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Outdoor Unit CU-3KE19NBU Indoor Unit CS-MKE9NKU × 3 < 208V > Type 3-Room Multi Outdoor Unit Number of Connectable Indoor Units 3 Number of Operatable Indoor Units 3 Voltage Rating 208V Single-Phase 60Hz Cooling Heating Total Capacity BTU/h 18,600 ( 9,800 to 18,600 ) 24,800 ( 11,600 to 24,800 ) kW 5.45 ( 2.90 to 5.45 ) 7.30 ( 3.40 to 7.30 ) Sensible Capacity 15,800 - BTU/h Latent Capacity BTU/h 2,800 - 3 3 Air Circulation (High) ft /min (m /h) 1,707 (2,900) 1,707 (2,900) Available Voltage Range
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Outdoor Unit CU-4KE24NBU Indoor Unit CS-MKE7NKU × 2 + CS-MKE9NKU Duct Less Type Rated < 230V > Type 4-Room Multi Outdoor Unit Number of Connectable Indoor Units 4 Number of Operatable Indoor Units 4 Voltage Rating 230V Single-Phase 60Hz Cooling Heating Total Capacity BTU/h 22,400 ( 8,500 to 23,200 ) 27,200 ( 10,200 to 29,200 ) kW 6.60 ( 2.50 to 6.80 ) 8.00 ( 3.00 to 8.60 ) Sensible Capacity 18,800 - BTU/h Latent Capacity BTU/h 3,600 - 3 3 Air Circulation (High) ft /min (m /h) 1,707 (2,900) 1,70
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Outdoor Unit CU-4KE24NBU Indoor Unit CS-MKE9NKU × 3 < 230V > Type 4-Room Multi Outdoor Unit Number of Connectable Indoor Units 4 Number of Operatable Indoor Units 4 Voltage Rating 230V Single-Phase 60Hz Cooling Heating Total Capacity BTU/h 23,200 ( 9,800 to 23,200 ) 29,200 ( 11,600 to 29,200 ) kW 6.80 ( 2.90 to 6.80 ) 8.60 ( 3.40 to 8.60 ) Sensible Capacity 19,600 - BTU/h Latent Capacity BTU/h 3,600 - 3 3 Air Circulation (High) ft /min (m /h) 1,707 (2,900) 1,707 (2,900) Available Voltage Range
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Outdoor Unit CU-4KE24NBU Indoor Unit CS-MKE9NKU × 3 < 208V > Type 4-Room Multi Outdoor Unit Number of Connectable Indoor Units 4 Number of Operatable Indoor Units 4 Voltage Rating 208V Single-Phase 60Hz Cooling Heating Total Capacity BTU/h 23,200 ( 9,800 to 23,200 ) 29,200 ( 11,600 to 29,200 ) kW 6.80 ( 2.90 to 6.80 ) 8.60 ( 2.90 to 8.60 ) Sensible Capacity 19,600 - BTU/h Latent Capacity BTU/h 3,600 - 3 3 Air Circulation (High) ft /min (m /h) 1,707 (2,900) 1,707 (2,900) Available Voltage Range
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Outdoor Unit CU-4KE31NBU Indoor Unit CS-MKE7NKU × 3 + CS-MKE9NKU Duct Less Type Rated < 230V > Type 4-Room Multi Outdoor Unit Number of Connectable Indoor Units 4 Number of Operatable Indoor Units 4 Voltage Rating 230V Single-Phase 60Hz Cooling Heating Total Capacity BTU/h 29,000 ( 9,800 to 29,000 ) 30,600 ( 11,600 to 32,000 ) kW 8.50 ( 2.90 to 8.50 ) 9.00 ( 3.40 to 9.40 ) Sensible Capacity 24,400 - BTU/h Latent Capacity BTU/h 4,600 - 3 3 Air Circulation (High) ft /min (m /h) 1,942 (3,300) 1,94
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Outdoor Unit CU-4KE31NBU Indoor Unit CS-MKE9NKU × 4 < 230V > Type 4-Room Multi Outdoor Unit Number of Connectable Indoor Units 4 Number of Operatable Indoor Units 4 Voltage Rating 230V Single-Phase 60Hz Cooling Heating Total Capacity BTU/h 30,600 ( 9,800 to 30,600 ) 32,000 ( 11,600 to 32,000 ) kW 9.00 ( 2.90 to 9.00 ) 9.40 ( 3.40 to 9.40 ) Sensible Capacity 25,800 - BTU/h Latent Capacity BTU/h 4,800 - 3 3 Air Circulation (High) ft /min (m /h) 1,942 (3,300) 1,942 (3,300) Available Voltage Range
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Outdoor Unit CU-4KE31NBU Indoor Unit CS-MKE9NKU × 4 < 208V > Type 4-Room Multi Outdoor Unit Number of Connectable Indoor Units 4 Number of Operatable Indoor Units 4 Voltage Rating 208V Single-Phase 60Hz Cooling Heating Total Capacity BTU/h 28,600 ( 9,800 to 28,600 ) 32,000 ( 11,600 to 32,000 ) kW 8.40 ( 2.90 to 8.40 ) 9.40 ( 3.40 to 9.40 ) Sensible Capacity 24,200 - BTU/h Latent Capacity BTU/h 4,400 - 3 3 Air Circulation (High) ft /min (m /h) 1,942 (3,300) 1,942 (3,300) Available Voltage Range
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2-2. Major Component Specifications 2-2-1. Outdoor Unit Outdoor Unit CU-3KE19NBU Control PCB Part No. CB-CU-3KE19NBU Controls Microprocessor Control Circuit Fuse 250V 25A Compressor Type DC Twin Rotary (Hermetic) Compressor Model / Nominal Output 5KD240XAB21 / 1,700W Compressor Oil ... Amount Pints (cc) FV50S ... 1.91 (900) Coil Resistance (Ambient Temp. 68 °F (20 °C)) Ohm U - V : 0.720 V - W : 0.708 W - U : 0.726 Safety Device CT (Peak current cut-off control) Yes Compressor Discharge
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Outdoor Unit CU-4KE24NBU Control PCB Part No. CB-CU-4KE24NBU Controls Microprocessor Control Circuit Fuse 250V 25A Compressor Type DC Twin Rotary (Hermetic) Compressor Model / Nominal Output 5KD240XAB21 / 1,700W Compressor Oil ... Amount Pints (cc) FV50S ... 1.91 (900) Coil Resistance (Ambient Temp. 68 °F (20 °C)) Ohm U - V : 0.720 V - W : 0.708 W - U : 0.726 Safety Device CT (Peak current cut-off control) Yes Compressor Discharge Temp. Control Yes Operation cut-off control in abnormal am
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Outdoor Unit CU-4KE31NBU Control PCB Part No. CB-CU-4KE31NBU Controls Microprocessor Control Circuit Fuse 250V 25A Compressor Type DC Twin Rotary (Hermetic) Compressor Model / Nominal Output 5JD420XAB22 / 3,000W Compressor Oil ... Amount Pints (cc) FV50S ... 2.55 (1,200) Coil Resistance (Ambient Temp. 68 °F (20 °C)) Ohm U - V : 0.435 V - W : 0.441 W - U : 0.452 Safety Device CT (Peak current cut-off control) Yes Compressor Discharge Temp. Control Yes Operation cut-off control in abnormal
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2-3. Other Component Specifications Quantity of Sensor Model No. Sensor Name of sensor CU-3KE19NBU CU-4KE24NBU CU-4KE31NBU Outdoor air temp sensor TKS295B 1 1 1 Outdoor heat exchanger sensor TKS292B 1 1 1 AW / AN sensor TKS292B 1 / 1 1 / 1 1 / 1 BW / BN sensor TKS292B 1 / 1 1 / 1 1 / 1 CW / CN sensor TKS292B 1 / 1 1 / 1 1 / 1 DW / DN sensor TKS292B 0 1 / 1 1 / 1 40 35 30 25 20 15 10 5 0 -4 5 14 23 32 41 50 59 68 (-20)(-15)(-10) (-5) (0) (5) (10) (15) (20) Temperature F ( C) Quantity of Sensor
