Midea DLCERAH12AAJ

Specifications subject to change without notice.
DLCERA
SERVICE MANUAL
Outdoor Unit Single Zone Ductless System − Sizes 09 to 24
TABLE OF CONTENTS
PAGE
SAFETY CONSIDERATIONS 1.............................
INTRODUCTION 1.......................................
MODEL/SERIAL NUMBER NOMENCLATURES 2.............
SPECIFICATIONS 3.......................................
DIMENSIONS 5.........................................
CLEARANCES 8.........................................
ELECTRICAL DATA 9....................................
WIRING 9...............................................
CONNECTION DIAGRAMS 10.............................
WIRING DIAGRAM 10....................................
REFRIGERATION CYCLE DIAGRAMS 14....................
REFRIGERANT LINES 15.................................
SYSTEM EVACUATION AND CHARGING 16.................
ELECTRONIC FUNCTIONS 17.............................
TROUBLESHOOTING 21..................................
OUTDOOR UNIT DIAGNOSTIC GUIDES 22..................
PCB DIAGRAMS 23......................................
DIAGNOSIS AND SOLUTION 25...........................
DISASSEMBLY INSTRUCTIONS 46.........................
APPENDIX 69...........................................
SAFETY CONSIDERATIONS
Installing, starting up, and servicing air−conditioning equipment can be
hazardous due to system pressures, electrical components, and
equipment location (roofs, elevated structures, etc.).
Only trained, qualified installers and service mechanics should install,
start−up, and service this equipment.
Untrained personnel can perform basic maintenance functions such as
cleaning coils. All other operations should be performed by trained
service personnel.
When working on the equipment, observe precautions in the literature
and on tags, stickers, and labels attached to the equipment.
Follow all safety codes. Wear safety glasses and work gloves. Keep
quenching cloth and fire extinguisher nearby when brazing. Use care in
handling, rigging, and setting bulky equipment.
Read this manual thoroughly and follow all warnings or cautions included
in literature and attached to the unit. Consult local building codes and
National Electrical Code (NEC) for special requirements. Recognize safety
information. This is the safety−alert symbol
!
!
. When you see this symbol
on the unit and in instructions or manuals, be alert to the potential for
personal injury. Understand these signal words: DANGER, WARNING,
and CAUTION.
These words are used with the safety−alert symbol. DANGER
identifies the most serious hazards which will result in severe personal
injury or death. WARNING signifies hazards which could result in
personal injury or death. CAUTION is used to identify unsafe practices
which may result in minor personal injury or product and property
damage. NOTE is used to highlight suggestions which will result in
enhanced installation, reliability, or operation.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing, modifying, or servicing system, main
electrical disconnect switch must be in the OFF
position. There may be more than 1 disconnect switch.
Lock out and tag switch with a suitable warning label.
EXPLOSION HAZARD
Failure to follow this warning could
result in death, serious personal injury,
and/or property damage.
Never use air or gases containing
oxygen for leak testing or operating
refrigerant compressors. Pressurized
mixtures of air or gases containing
oxygen can lead to an explosion.
!
WARNING
CAUTION
!
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Do not bury more than 36 in. (914 mm) of refrigerant pipe
in the ground. If any section of pipe is buried, there must be
a 6 in. (152 mm) vertical rise to the valve connections on
the outdoor units. If more than the recommended length is
buried, refrigerant may migrate to the cooler buried section
during extended periods of system shutdown. This causes
refrigerant slugging and could possibly damage the
compressor at start−up.
INTRODUCTION
This Service Manual provides the necessary information to service, repair,
and maintain the outdoor units. Section 2 of this manual has an appendix
with data required to perform troubleshooting. Use the Table of Contents
to locate a desired topic.

Midea DLCERAH12AAJ Specifications

General

Energy Efficiency Ratio (EER)	3.21
Power Supply	220-240V, 50Hz
Refrigerant	R32
Net Weight (Indoor Unit)	10 kg
Net Weight (Outdoor Unit)	28 kg
Type	Split System
Capacity	12000 BTU/h
Cooling Capacity	12000 BTU/h
Noise Level (Indoor)	40 dB
Operating Temperature (Cooling)	18°C to 43°C

Summary

Safety Considerations

Electrical Shock Hazard

Details hazards and precautions for electrical shock, emphasizing potential for severe injury or death.

Explosion Hazard

Explains explosion risks, particularly when using oxygen for leak testing, and necessary safety measures.

Equipment Damage Hazard

Outlines precautions to prevent equipment damage or improper operation, such as regarding refrigerant pipe burial.

Specifications - Cooling Only

Cooling Only Electrical Specifications

Specifications - Heat Pump

Heat Pump Electrical Specifications

Electrical Data

Electrical Data - Cooling Only

Table of electrical parameters (MCA, MOCP, RLA, FLA, Rated HP) for cooling-only units.

Electrical Data - Heat Pump

Table of electrical parameters (MCA, MOCP, RLA, FLA, Rated HP) for heat pump units.

Wiring Guidelines

Recommended Power and Communication Wiring

Connection Diagrams

115 V Indoor Unit Connection Diagram

230 V Indoor Unit Connection Diagram

Wiring Diagrams

Wiring Diagram - 12 K (115 V)

Wiring Diagrams (Continued)

Wiring Diagram - 09 K, 12 K (208-230 V)

Outdoor Wiring Diagram - 18 K-24 K (Heat Pump)

Outdoor Wiring Diagram - 18 K-24 K (Cooling Only)

Refrigeration Cycle Diagrams

Heat Pumps Refrigeration Cycle Diagram

Diagram illustrating the refrigeration cycle, including components for heat pump models.

Refrigerant Lines

General Refrigerant Line Sizing Guidelines

Piping and Refrigerant Information Table

System Evacuation and Charging

Deep Vacuum Method Procedure

Procedure for achieving a deep vacuum in the system using a vacuum pump and gauge.

Triple Evacuation Method Procedure

Step-by-step guide for the triple evacuation process using vacuum and nitrogen.

Electronic Functions

Main Protection Features

Details on compressor restart delay, temperature protection, fan speed control, and inverter module protection.

Refrigerant Leakage Detection

Function to detect refrigerant leaks in cooling mode to prevent compressor overload.

Evaporator Coil Temperature Protection

Evaporator Coil Protection Actions

Actions taken by the system based on evaporator coil temperature readings (Off, Decrease, Hold, Resume).

Refrigerant Leak Detection

Refrigerant Leak Detection Function

Function that detects refrigerant leaks in cooling mode and displays 'EC'.

Troubleshooting Safety

Capacitor Discharge Safety

Important safety note regarding discharging high-voltage capacitors before troubleshooting.

Electrolytic Capacitors Identification

Identification and caution for high-voltage electrolytic capacitors on the PCB.

Capacitor Discharge Position

Procedure and diagram showing the correct position for discharging capacitors.

Outdoor Unit Diagnostic Guides

Diagnostic Codes and LED Status

Table correlating operation/timer lamps with display codes (E, F, P) and LED status for diagnostics.

PCB Diagrams

PCB Diagram - 12 k (115 V)

Schematic of the Printed Circuit Board (PCB) for the 12K 115V outdoor unit.

PCB Diagram - 09 k-12 k (208-230 V)

PCB Diagrams (Continued)

PCB Diagram - 18 k-24 k (208-230 V)

LED Codes for Troubleshooting

Table of LED codes indicating unit problems and their corresponding meanings.

Diagnosis and Solution - EEPROM Error

EEPROM Parameter Error Diagnosis (E0 F4)

Troubleshooting steps for EEPROM parameter errors, including supposed causes and solutions.

EEPROM Chip Location

Diagnosis and Solution - Communication Error

IndoorOutdoor Communication Error (E1)

Troubleshooting for communication errors between indoor and outdoor units, including wiring and PCB checks.

Test DC Voltage Procedure

Procedure to measure DC voltage between specific ports for troubleshooting.

Diagnosis and Solution - Voltage and Reactor Tests

Test DC Voltage

Detailed steps to test DC voltage using a multimeter at L2 and S ports.

Test Reactor Resistance

Procedure to test the resistance of the reactor, noting normal values.

Diagnosis and Solution - Zero Crossing Error

Zero Crossing Detection Error (E2)

Troubleshooting steps for errors related to abnormal zero crossing signal feedback.

Diagnosis and Solution - Fan Speed Error

Fan Speed Out of Control (E3 F5)

Troubleshooting steps for errors where indoor fan speed is too low or out of control.

Diagnosis and Solution - Fan Motor Checks

DC Fan Motor Voltage InputOutput

Procedure to check DC fan motor voltage inputs and outputs from the PCB.

Indoor AC Fan Motor Voltage Check

Procedure to measure voltage for the indoor AC fan motor to diagnose PCB issues.

Diagnosis and Solution - Temperature Sensor Errors

Temperature Sensor Diagnosis (E4 E5 F1 F2 F3)

Troubleshooting steps for open circuit or short circuit of temperature sensors.

Diagnosis and Solution - Refrigerant Leakage

Refrigerant Leakage Detection Diagnosis (EC)

Troubleshooting steps for refrigerant leakage detection, including sensor and system checks.

Diagnosis and Solution - Overload Current Protection

Overload Current Protection Diagnosis (F0)

Troubleshooting steps for overload current protection, including power, blockage, and compressor checks.

Diagnosis and Solution - IPM Malfunction

IPM Malfunction or Over-Strong Current Protection (P0)

Troubleshooting for IPM or IGBT over-current protection, checking wiring, IPM, fan, and compressor.

Diagnosis and Solution - Voltage Protection

Over Voltage or Too Low Voltage Protection (P1)

Troubleshooting steps for over voltage or too low voltage protection, checking power, reactor, and IPM.

Diagnosis and Solution - Compressor Top Temperature Protection

High Temperature Protection of Compressor Top (P2)

Troubleshooting steps for compressor top high-temperature protection, checking airflow and OLP.

Diagnosis and Solution - Inverter Compressor Drive Error

Inverter Compressor Drive Error (P4)

Troubleshooting for inverter compressor drive errors, checking wiring, IPM, fan, and compressor.

Diagnosis and Solution - Temperature Sensor Checking

Temperature Sensor Resistance Check

Procedure to check resistance values of various temperature sensors (T1-T5) using a tester.

Diagnosis and Solution - Compressor Checking

Compressor Winding Resistance Check

Procedure to measure winding resistance of the compressor using a tester.

Diagnosis and Solution - IPM and Fan Motor Checks

IPM Continuity Check

Procedure to measure IPM continuity resistance between specified terminals.

Fan Motor Resistance Check

Procedure to measure the resistance of fan motor windings.

Disassembly Instructions - 12 K (115 V)

Panel Plate Removal

Side Panel Removal

Disassembly Instructions - 12 K (115 V) (Continued)

Fan Assembly Removal

Fan Motor Removal

Electrical Parts Removal - Compressor Connector

Four-Way Valve Removal

Electrical Parts Removal - Sensor Connectors

Ground Wires and Control Box Removal

Compressor Removal

Disassembly Instructions - 9-12 K (208-230 V)

Panel Plate Removal (9-12 K 208-230 V)

Side Panel Removal (9-12 K 208-230 V)

Disassembly Instructions - 9-12 K (208-230 V) (Continued)

Fan Assembly Removal (9-12 K 208-230 V)

Fan Motor Disconnection and Removal

Four-Way Valve Removal (9-12 K 208-230 V)

Electrical Parts - Compressor Connectors

Compressor Removal (9-12 K 208-230 V)

Disassembly Instructions - 18 K (208-230 V)

Panel Plate Removal (18 K 208-230 V)

Side Panel Removal (18 K 208-230 V)

Disassembly Instructions - 18 K (208-230 V) (Continued)

Fan Assembly Removal (18 K 208-230 V)

Fan Motor Disconnection and Removal (18 K 208-230 V)

Electric Heaters and Ground Screw Removal

Four-Way Valve Removal (18 K 208-230 V)

Electrical Parts - Compressor and Reactor Connectors

Wire Removal and Control Box Removal

Compressor Removal (18 K 208-230 V)

Disassembly Instructions - 24 K (208-230 V)

Panel Plate Removal (24 K 208-230 V)

Side Panel Removal (24 K 208-230 V)

Disassembly Instructions - 24 K (208-230 V) (Continued)

Fan Assembly Removal (24 K 208-230 V)

Fan Motor Disconnection and Removal (24 K 208-230 V)

Electrical Parts - Compressor Connector

Pressure Switch Connector Disconnection

Four-Way Valve Removal (24 K 208-230 V)

Electronic Expansion Valve Wire Disconnection

Electrical Parts - Four Way Valve Wires

Compressor Removal (24 K 208-230 V)

Electrical Parts - Sensor Connector Disconnection

Ground Wire and Control Box Removal