Contents
DC Inverter MULTI-SYSTEM AIR Conditioner
Safety Precautions
Prohibit
Table of Contents
Appendix a
Semi-Concealed Type
Wall Mounted Type
Operating Range
Outdoor Unit CU-3KS19NBU
Unit Specifications
Indoor Unit CS-MKS9NKU ×
Duct Less Type Rated
Indoor Unit
Outdoor Unit
208V
CU-4KS24NBU
BTU/h/W Compressor Locked Rotor Amperes
20,600
CU-4KS31NBU
Indoor Unit CS-MKS9NKU 4units Outdoor Unit CU-4KS31NBU 1unit
24,200
Outdoor Unit
Major Component Specifications
Outdoor Unit CU-4KS24NBU
Outdoor Unit CU-4KS31NBU
CU-3KS19NBU CU-4KS24NBU CU-4KS31NBU
Other Component Specifications
Dimensional Data
Unit inchmm 852-0-0010-20500-0
Unit inchmm 852-0-0010-20600-0
Insulation of Refrigerant Tubing
Refrigerant Flow Diagram
Indoor unit
Outdoor unit
Indoor unit Outdoor unit
1/4 Strainer Header Sub Main Compressor Accumulator
Outdoor Unit CU-3KS19NBU Indoor Unit CS-MKS7NKU ×
Temperature Charts
Temperature Charts CU-3KS19NBU
Outdoor Unit CU-3KS19NBU Indoor Unit CS-MKS9NKU ×
Outdoor Unit CU-3KS19NBU Indoor Unit CS-MKS12NKU ×
Cooling Characteristics
Outdoor Unit CU-3KS19NBU Indoor Unit CS-MKS18NKU ×
Outdoor Unit CU-3KS19NBU Indoor Unit CS-MKS9NB4U ×
Outdoor Unit CU-3KS19NBU Indoor Unit CS-MKS12NB4U ×
Outdoor Unit CU-3KS19NBU Indoor Unit CS-KS18NB4UW ×
Outdoor Unit CU-4KS24NBU Indoor Unit CS-MKS7NKU ×
Temperature Charts CU-4KS24NBU
Outdoor Unit CU-4KS24NBU Indoor Unit CS-MKS9NKU ×
Outdoor Unit CU-4KS24NBU Indoor Unit CS-MKS12NKU ×
Outdoor Unit CU-4KS24NBU Indoor Unit CS-MKS18NKU ×
Outdoor Unit CU-4KS24NBU Indoor Unit CS-MKS24NKU ×
Outdoor Unit CU-4KS24NBU Indoor Unit CS-MKS9NB4U ×
Outdoor Unit CU-4KS24NBU Indoor Unit CS-MKS12NB4U ×
Outdoor Unit CU-4KS24NBU Indoor Unit CS-KS18NB4UW ×
Temperature Charts CU-4KS31NBU
Outdoor Unit CU-4KS31NBU Indoor Unit CS-MKS9NKU ×
Outdoor Unit CU-4KS31NBU Indoor Unit CS-MKS12NKU ×
Outdoor Unit CU-4KS31NBU Indoor Unit CS-MKS18NKU ×
Outdoor Unit CU-4KS31NBU Indoor Unit CS-MKS24NKU ×
Outdoor Unit CU-4KS31NBU Indoor Unit CS-MKS9NB4U ×
Outdoor Unit CU-4KS31NBU Indoor Unit CS-MKS12NB4U ×
Outdoor Unit CU-4KS31NBU Indoor Unit CS-KS18NB4UW ×
Indoor Outdoor
Cooling Capacity
CS-MKS12NB4U ×
Power Supply 230V Single Phase 60Hz Cooling Capacity
CS-MKS9NKU ×
CS-KS18NB4UW + CS-MKS12NB4U + CS-MKS12NB4U
30,600 BTU/h
CS-MKS9NB4U ×
Cooling Capacity Low Ambient
15,180 18,570
19,250 25,420 19,410
19,360 24,830 19,520
24,260 30,760
22,560 28,790 22,730
Outdoor Unit CU-3KS19NBU 8FA2-5251-11800-1
Electric Wiring Diagrams
Outdoor Unit CU-4KS24NBU 8FA2-5251-11600-1
Outdoor Unit CU-4KS31NBU 8FA2-5251-11400-1
Explanation of Functions
Functions
Cool
DRY
Fluctuation fan
Low Ambient Cooling Operation
Current Control
Protective Functions
Description of function
Automatic frequency control
Current control
Compressor Temperature Control
Low Start Current
Precautions before Performing Inspection or Repair
Troubleshooting Before Calling for Service
Display of the Error Monitor Lamps
Trouble Diagnosis by Error Monitor Lamps
Location of the Error Monitor Lamps
Checking the outdoor unit
Work procedure Check items unit operation
Checking the Outdoor System
Trouble Diagnosis of Each Part
Problems of Each Part and Inspection Points
Outdoor control circuit board
Inspection Points for Each Part
Fuse
Compressor
CU-3KS19NBU MV0 MV1 MV2 CU-4KS24NBU MV3 CU-4KS31NBU
Electric expansion valve
Refrigerant gas pressure
Branch tubing temperature sensor
Breaker
Diagnostic results
Diagnostic procedure
Remedy for symptom 3 to
Trouble Diagnosis of Fan Motor
What is New Refrigerant R410A?
Characteristics of New Refrigerant R410A
Characteristics
Components mixing proportions
Checklist before Servicing
Tools Specifically for R410A
Tubing Installation Procedures
Case of Compressor Malfunction
Procedure for Replacing Compressor
Example
Amount in the charging cylinder is less than 20%
To prevent the composition
R410A from changing
Recharging
Case Refrigerant is Leaking
Welding leaking points
Charging Additional Refrigerant
When Tubes are Extended
Retro-Fitting Existing Systems
Use of Existing Units
852-6-4190-581-00-1
For Outdoor Unit
Contents
Please Read Before Starting
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Fins of the outdoor unit. You may get injured
General
For ceiling-mounted cassette units
Installation Site Selection
For wall-mounted units
H1, H2, H3, H4
Connecting indoor unit for CU-4KS24NBU
Connecting Indoor Units
Connecting indoor unit for CU-3KS19NBU
815.88mm Locally purchased
Connecting indoor unit for CU-4KS31NBU
CS-MKS24NKU
It is recommended to use baffle plates
Baffle Plate for the Outdoor Unit
Front
Back
Air Discharge Baffle
Air Intake Baffle
Precautions for installation
CU-3KS19NBU
Outer Dimensions of Outdoor Unit
CU-4KS24NBU
CU-4KS31NBU
Never install only a single indoor unit
Diagram of Outdoor Unit Installation
Use of the Flaring Method
Installation Process
Flaring Procedure with a Flare Tool
Tubing Connections
To 0.5 mm Adjust so that the amount of tube
To prevent heat loss and wet floors due to dripping of con
Insulation of Refrigerant Tubing
For wall-mounted units
For ceiling-mounted cassette units
Air Purging with a Vacuum Pump for Test Run
Finishing the Installation
Air Purging
Adapter manual, and use the adapter correctly
External diameter of service port R410A 5/16
Pump-down procedure
What is pump-down?
Pump Down
If pump-down is not possible
Recommended Wire Length and Diameter
Wiring Instructions
General Precautions on Wiring
Disconnect switch may be required by national or local codes
For Outdoor Unit For solid core wiring or F-cable
How to connect wiring to the terminal
For stranded wiring
For Indoor Unit
Indoor unit D
Wiring Instructions for the Outdoor Unit
Indoor unit B
Indoor unit C
Performing a test run
Checking tubing and wiring
Test Run
Installation Check Sheet
Connecting a Home Automation Device
DC1111-0