Mitsubishi Electric PUZ-A24NHA User Manual

SERVICE MANUAL
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
SPLIT-TYPE, AIR CONDITIONERS
CONTENTS
1. TECHNICAL CHANGES·································2
2. REFERENCE MANUAL··································2
3. SAFETY PRECAUTION··································3
4. FEATURES ·····················································6
5. SPECIFICATIONS···········································7
6. DATA ·······························································9
7. OUTLINES AND DIMENSIONS····················13
8. WIRING DIAGRAM·······································16
9. WIRING SPECIFICATIONS ··························20
10. REFRIGERANT SYSTEM DIAGRAM ··············23
11. TROUBLESHOOTING···································26
12. EASY MAINTENANCE FUNCTION··············81
13. FUNCTION SETTING····································84
14. MONITORING THE OPERATION DATA BY THE REMOTE CONTROLLER ············92
15. DISASSEMBLY PROCEDURE ···················102
16. PARTS LIST ················································117
17. RoHS PARTS LIST ·····································126
No.OC367
REVISED EDITION-C
R410A
June 2007
[model names]
PUZ-A18NHA
PUZ-A24NHA
PUZ-A30NHA
PUZ-A36NHA
PUZ-A42NHA
PUZ-A18NHA-BS
PUZ-A24NHA-BS
PUZ-A30NHA-BS
PUZ-A36NHA-BS
PUZ-A42NHA-BS
PUY-A12NHA
PUY-A18NHA
PUY-A24NHA
PUY-A30NHA
PUY-A36NHA
PUY-A42NHA
PUY-A12NHA-BS
PUY-A18NHA-BS
PUY-A24NHA-BS
PUY-A30NHA-BS
PUY-A36NHA-BS
PUY-A42NHA-BS
[Service Ref.]
PUZ-A18NHA
PUZ-A24NHA
PUZ-A30NHA
PUZ-A36NHA
PUZ-A42NHA
PUZ-A18NHA-BS
PUZ-A24NHA-BS
PUZ-A30NHA-BS
PUZ-A36NHA-BS
PUZ-A42NHA-BS
PUY-A12NHA PUY-A12NHA
1
PUY-A18NHA PUY-A18NHA1
PUY-A24NHA PUY-A24NHA1
PUY-A30NHA PUY-A30NHA1
PUY-A36NHA PUY-A36NHA1
PUY-A42NHA
PUY-A12NHA
1-BS
PUY-A18NHA
1-BS
PUY-A24NHA
1-BS
PUY-A30NHA
1-BS
PUY-A36NHA
1-BS
PUY-A42NHA-BS
NOTE:
• This manual describes only
service data of the outdoor
units.
• RoHS compliant products
have <G> mark on the spec
name plate.
• For servicing RoHS compliant
products, refer to the RoHS
PARTS LIST.
PUZ-A24/30/36NHA
PUY-A24/30/36NHA
Revision:
• “9-2. SEPARATE INDOOR
UNIT/OUTDOOR UNIT
POWER SUPPLIES” is
deleted in REVISED
EDITION-C.
• Some descriptions have
been modified.
• Please void OC367 REVISED
EDITION-B.
Outdoor unit
OC367C--1.qxp 07.6.20 0:56 PM Page 1

Mitsubishi Electric PUZ-A24NHA Specifications

General

Refrigerant	R410A
Indoor Unit Weight	37 lbs
Outdoor Unit Weight	130 lbs
Phase	1
Power Supply	220-240 V
Indoor Unit Dimensions (H x W x D)	295 x 800 x 223 mm
Voltage (V)	208/230
Indoor Unit Dimensions (WxHxD)	800 x 295 x 223 mm
Outdoor Unit Dimensions (WxHxD)	765 x 550 x 285 mm

Summary

Technical Changes

Reference Manual

Indoor Unit Reference

Details regarding indoor unit models and their service references.

Technical Data Book Reference

Manual number for the technical data book.

Safety Precautions

General Safety Instructions

General safety instructions to follow before starting work.

R410A Refrigerant Cautions

Specific safety precautions for handling R410A refrigerant.

Unit Features

Chargeless System

Pre-charged refrigerant system for simplified installation.

Specifications Overview

Data and Performance

Refrigerant Charge Data

Table showing refrigerant charge amounts based on piping length.

Compressor Technical Data

Technical specifications for the compressor unit.

Outlines and Dimensions

Foundation Bolt Installation

Instructions for securing the unit with foundation bolts.

Piping and Wiring Directions

Information on routing piping and wiring connections.

Outdoor Unit Installation Space

Guidelines for required clearance around the outdoor unit.

Wiring Diagrams and Symbols

Wiring Diagram Symbols

List of symbols used in the wiring diagrams.

M-NET Adapter Information

Information about the M-NET adapter and its components.

Service Cautions

Important safety warnings before performing service.

Wiring Specifications

Indoor Unit Power Supply from Outdoor Unit

Wiring specifications for power supply from outdoor to indoor units.

M-NET Wiring Method

M-NET Wiring Points to Notice

Important considerations for M-NET wiring to prevent noise and ensure proper function.

Incorrect M-NET Grounding Example

Illustrates an incorrect method for grounding the M-NET shield wire.

Correct M-NET Grounding Examples

Shows correct methods for single spot grounding of M-NET shield wire.

Address Settings Regulations

M-NET Address Setting Procedure

Procedure for setting the M-NET address on outdoor units for central control.

Refrigerant Address Setting

Method for setting refrigerant addresses for multiple refrigerant circuits.

Address Regulations for Grouped Systems

Guidelines for setting addresses in grouped systems.

Refrigerant System Diagrams

Troubleshooting Guide

Refrigerant Collecting (Pump Down)

Procedure for collecting refrigerant before unit movement or servicing.

Test Run Start and Finish

Steps for starting and completing a test run for system verification.

General Troubleshooting Steps

General troubleshooting guidelines based on error code display.

Test Run Checkpoints

Important checks to perform before and during a test run.

Test Run Mode Symptoms

Troubleshooting symptoms displayed on the remote controller during test run.

Inferior Phenomena (Error Codes)

List of error codes and their corresponding phenomena for diagnosis.

Self-Diagnosis Procedures

Steps for initiating and interpreting self-diagnosis results.

Problem Diagnosis During Operation

Procedure for checking errors when a problem occurs during operation.

Self-Diagnosis During Maintenance

How to recall error history during maintenance or service.

Remote Controller Diagnosis

Steps to diagnose issues with the remote controller itself.

Wireless Remote Malfunction Diagnosis

Procedure for diagnosing malfunctions using a wireless remote controller.

Self-Diagnosis Action Table: Power On

Table detailing actions for power-on abnormalities.

Self-Diagnosis Action Table: During Operation

Table detailing actions for abnormalities detected during unit operation.

Troubleshooting Inferior Phenomena: Remote Controller

Troubleshooting steps when the remote controller display is blank.

Troubleshooting Inferior Phenomena: PLEASE WAIT Display

Steps for when 'PLEASE WAIT' is continuously displayed on the remote controller.

Troubleshooting Inferior Phenomena: Operation Display Issue

Diagnosing issues when the operation display appears briefly then disappears.

Diagnosis Flow: Persistent PLEASE WAIT

Flowchart to diagnose persistent 'PLEASE WAIT' display on the remote controller.

Diagnosis Flow: No Remote Display (Scenario 1)

Flowchart to diagnose when nothing is displayed on the remote controller (scenario 1).

Diagnosis Flow: No Remote Display (Scenario 2)

Flowchart to diagnose when nothing is displayed on the remote controller (scenario 2).

Diagnosis Flow: No Remote Display (Scenario 3)

Flowchart to diagnose when nothing is displayed on the remote controller (scenario 3).

Customer Support: Unit Not Operating

Troubleshooting steps when the unit does not operate at all.

Customer Support: Remote Controller Issues

Common issues and responses related to the remote controller.

Customer Support: Insufficient Cooling/Heating

Troubleshooting steps when cooling or heating is insufficient.

Customer Support: Unusual Sounds

Explanations for various sounds heard from the air conditioner.

Customer Support: Blower Issues

Troubleshooting for issues related to the air conditioner's blower.

Customer Support: Airflow Direction Issues

Troubleshooting for problems with the airflow direction control.

Part Checking Procedures

Thermistor Resistance Checks

Details on checking thermistor resistance values at different temperatures.

Four-Way Valve Solenoid Coil Check

How to measure resistance of the four-way valve solenoid coil.

Compressor Motor Resistance Check

Procedure to measure compressor motor winding resistance.

Linear Expansion Valve Coil Check

Instructions for checking linear expansion valve coil resistance.

DC Fan Motor Check

Steps to check DC fan motor operation and power supply.

Component Feature Charts

Thermistor Feature Chart

Charts providing resistance values for various thermistors at different temperatures.

Linear Expansion Valve Operation (A12, 18)

Linear Expansion Valve Operation Summary

Overview of the linear expansion valve's operation and control signals.

Linear Expansion Valve Pulse Operation

Detailed explanation of linear expansion valve operation based on pulse signals.

Linear Expansion Valve Operation (A24, 30, 36, 42)

Linear Expansion Valve Operation Summary

Overview of the linear expansion valve's operation and control signals.

Linear Expansion Valve Pulse Operation

Detailed explanation of linear expansion valve operation based on pulse signals.

Linear Expansion Valve Coil Handling (A12, 18)

Linear Expansion Valve Coil Composition

Describes the separable parts of the linear expansion valve.

How to Detach the Coil

Steps for safely detaching the coil from the linear expansion valve.

How to Attach the Coil

Steps for safely attaching the coil to the linear expansion valve.

Linear Expansion Valve Coil Handling (A24, 30, 36, 42)

Linear Expansion Valve Coil Composition

Describes the separable parts of the linear expansion valve.

How to Detach the Coil

Steps for safely detaching the coil from the linear expansion valve.

How to Attach the Coil

Steps for safely attaching the coil to the linear expansion valve.

Emergency Operation Procedures

Conditions for Emergency Operation

Conditions under which emergency operation is possible.

Emergency Operation Checks and Cautions

Important checks and warnings for emergency operation.

Performing Emergency Operation

Step-by-step instructions to perform emergency operation.

Releasing Emergency Operation

Procedure to stop and reset emergency operation.

Test Point Diagrams

Outdoor Controller Circuit Board Test Points

Diagram showing test points on the outdoor controller circuit board.

Outdoor Noise Filter Circuit Board Diagram

Diagram of the outdoor noise filter circuit board with connection points.

Outdoor Power Circuit Board Diagram

Diagram of the outdoor power circuit board with test points and connections.

Function of Switches, Connectors, and Jumpers

Function of Switches (DIP, Push)

Explanation of the functions of various switches (DIP, Push).

Function of Connectors and Select Switches

Details on functions of connectors and model select switches.

Special Functions

Explanation of special functions like low-level sound priority and demand control.

Easy Maintenance Function

Maintenance Mode Operation Method

How to use the maintenance mode for checking operation data.

Function Setting

Unit Function Setting via Remote Controller

How to set unit functions using the remote controller.

Selecting Functions (Wired Remote Controller)

Step-by-step guide to selecting functions via wired remote controller.

Selecting Functions (Wireless Remote Controller)

Operating instructions for selecting functions with a wireless remote controller.

Remote Controller Function Selection Details

Detailed explanation of various function settings available via remote controller.

Monitoring Operation Data

How to Monitor Operation Data

Guide on monitoring operation data using the remote controller.

Request Code List for Operation Data

List of available request codes for monitoring operation data.

Disassembly Procedure

Operating Procedures for Disassembly

Step-by-step instructions for disassembling the unit.

Disassembly Photos and Illustrations

Visual guide illustrating disassembly steps.

Parts List (Non-RoHS Compliant)

Structural Parts List

List of structural parts for specific models.

Functional Parts List

List of functional parts for specific models.

RoHS Parts List (RoHS Compliant)

Functional Parts List (RoHS Compliant)

List of RoHS compliant functional parts for specific models.