Classic Air Conditioners MRHNC24AS - User Manual

RevisionA:1403100001,Contentupdated.
ModelNumbers:
MWNC09S/MRNC09AS,MWHNC09S/MRHNC09AS,MWHNC09SA/MRHNC09ASA
MWNC12S/MRNC12AS,MWHNC12S/MRHNC12AS,MWH NC12SA/MRHNC12ASA
MWNC18S/MRNC18AS,MWHNC18S/MRHNC18AS,
MWNC24S/MRNC24AS,MWHNC24S/MRHNC24AS
COMFORT SERIES DC INVERTER AIR
CONDITIONER
SERVICE MANUAL
Mono DC
Table of Contents
1. Precaution
2. Part Names And Functions
3. Specification
4. Dimension
5. Refrigerant Cycle Diagram
6. Wiring Diagram
7. Installation Details
8. Operation Characteristics
9. Electronic Function
10. Troubleshooting
11. Disassembly Instructions
WARNING
 Installation MUST conform with local building codes or, in the absence of local codes, with the
National Electrical Code NFPA70/ANSI C1-1993 or current edition and Canadian Electrical
Code Part1 CSA C.22.1.
 The information contained in the manual is intended for use by a qualified service technician
familiar with safety procedures and equipped with the proper tools and test instruments
 Installation or repairs made by unqualified persons can result in hazards to you and others.
 Failure to carefully read and follow all instructions in this manual can result in equipment
malfunction, property damage, personal injury and/or death.
 This service is only for service engineer to use.

Summary

Precaution

Safety Precaution

Instructions to prevent user injury and property damage during operation.

Warning

Safety warnings related to installation, electrical work, and product handling.

Part Names And Functions

Part names of Indoor;Outdoor units

Functions of Indoor;Outdoor units

Wiring Diagram

Installation Details

Installation for the first time

Outlines procedures for initial installation, including leak testing and evacuation.

Adding the refrigerant after running the system for many years

Re-installation while the indoor unit need to be repaired

Re-installation while the outdoor unit need to be repaired

Operation Characteristics

Electronic Function

Main Protection

Details various protection mechanisms and delays for compressor and fan operation.

Troubleshooting

Indoor Unit Error Display

Lists error codes displayed on the indoor unit and their corresponding LED status.

Outdoor unit error display

Describes the LED indicator on the outdoor PCB and its behavior during standby, operation, and faults.

EEPROM parameter error diagnosis and solution(E0;F4)

Indoor; outdoor units communication diagnosis and solution(E1)

Zero crossing detection error diagnosis and solution(E2)

Fan speed has been out of control diagnosis and solution(E3)

Open circuit or short circuit of temperature sensor diagnosis and solution(E5)

Refrigerant Leakage Detection diagnosis and solution(EC)

IPM malfunction or IGBT over-strong current protection diagnosis and solution(P0)

Troubleshooting for IPM or IGBT over-current protection faults.

Over voltage or too low voltage protection diagnosis and solution(P1)

Diagnoses and resolves issues related to over/under voltage protection.

High temperature protection of compressor top diagnosis and solution(P2)

Troubleshooting for compressor top high temperature protection.

Inverter compressor drive error diagnosis and solution(P4)

Troubleshooting for inverter compressor drive errors.

Classic Air Conditioners MRHNC24AS Specifications