Carrier 38MAQB18-3 User Manual

38MAQ
Outdoor Unit Single Zone Ductless System
Sizes 09 to 30
Service Manual
TABLE OF CONTENTS
PAGE
SAFETY CONSIDERATIONS 1.........................
INTRODUCTION 1...................................
MODEL/SERIAL NUMBER NOMENCLATURES 2.........
SPECIFICATIONS 3...................................
DIMENSIONS 4.....................................
CLEARANCES 7.....................................
PERFORMANCE 6...................................
ELECTRICAL DATA 8................................
WIRING 8...........................................
CONNECTION DIAGRAMS 9..........................
WIRING DIAGRAMS 10...............................
FAN AND MOTOR SPECIFICATIONS 15.................
REFRIGERANT COIL SPECIFICATIONS 16..............
REFRIGERATION CYCLE DIAGRAMS 17................
REFRIGERANT LINES 18.............................
SYSTEM EVACUATION AND CHARGING 19.............
ELECTRONIC FUNCTION 20..........................
TROUBLESHOOTING 21..............................
DIAGNOSTIC GUIDES 23.............................
DIAGNOSIS AND SOLUTION 29.......................
APPENDIX 46.......................................
DISASSEMBLY INSTRUCTIONS 52.....................
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.

Carrier 38MAQB18-3 Specifications

General

Refrigerant	R-410A
Compressor Type	Inverter
Cooling Capacity	18000 BTU/h
HSPF Rating	10.0
Voltage	208-230V
Sound Level (dB)	52 dB
Power Supply	208-230V, 60Hz

Summary

SAFETY CONSIDERATIONS

General Safety Precautions

Details hazards, PPE, and signal words.

Electrical Shock Hazard Warning

Warning about disconnecting power before servicing to prevent electrical shock.

Explosion Hazard Warning

Warning against using oxygen for leak testing or operating refrigerant compressors.

CLEARANCES

ELECTRICAL DATA

System Electrical Specifications

Table detailing voltage, MCA, MOCP, RLA, and FLA for different unit sizes.

WIRING

Wiring Recommendations

Guidelines for sizing wires, using appropriate conductors, and connection methods.

CONNECTION DIAGRAMS

115V System Wiring Diagram

Illustrates power and communication connections for 9K and 12K 115V units.

208/230V System Wiring Diagram

Shows connections for 9K to 30K units operating on 208/230V.

WIRING DIAGRAMS

Outdoor Unit 9K & 12K 115V Wiring

WIRING DIAGRAMS (CONTINUED)

Outdoor Unit 9K & 12K 208/230V Wiring

Outdoor Unit 18K 208/230V Wiring

Outdoor Unit 24K 208/230V Wiring

Outdoor Unit 30K 208/230V Wiring

FAN AND MOTOR SPECIFICATIONS

REFRIGERANT COIL SPECIFICATIONS

REFRIGERATION CYCLE DIAGRAMS

Heat Pump Refrigerant Cycle Diagram

Illustrates the refrigerant flow for heat pump operation, including key components and sensors.

REFRIGERANT LINES

General Refrigerant Line Sizing Guidelines

Piping and Refrigerant Information Table

SYSTEM EVACUATION AND CHARGING

Deep Vacuum Method

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

Triple Evacuation Method

Step-by-step guide for alternate triple evacuation method using nitrogen.

TROUBLESHOOTING

Required Tools for Diagnosis

Troubleshooting Steps and Procedures

General steps, including checking diagnostic codes, wiring, and using a multimeter.

DIAGNOSTIC GUIDES

Indoor Unit Diagnostic Error Codes

Table mapping operation/timer lamp flashes to specific error codes and statuses.

Outdoor Unit Error Display Sizes 09-12 (115V)

LED1 Status Interpretation

Outdoor Unit Error Display Sizes 09-12 (208-230V)

LED Status Interpretation (208-230V)

Outdoor Unit Error Display Size 18

Error Codes and LED Indicators

Table detailing error codes, LED status (Green/Red), and IU Display messages.

Outdoor Unit Error Display Size 24

LED1 Status for Size 24

Outdoor Unit Error Display Size 30

LED1 Status for Size 30

DIAGNOSIS AND SOLUTION

EEPROM Parameter Error (E0/F4) Diagnosis

Troubleshooting steps for EEPROM parameter errors, including PCB replacement.

Indoor/Outdoor Communication Error (E1) Diagnosis

Troubleshooting flowchart for communication errors between indoor and outdoor units.

Testing DC Voltage and Reactor Resistance

Guides on using a multimeter to test DC voltage and reactor resistance.

Zero Crossing Detection Error (E2) Diagnosis

Troubleshooting for zero crossing detection errors related to PCB or connections.

Fan Speed Control Error (E3/F5) Diagnosis

Troubleshooting steps for issues with indoor fan speed control.

DC Fan Motor Voltage Input/Output Checks

Procedures for checking DC fan motor voltages for 220-240V and 115V systems.

Temperature Sensor Circuit Errors (E4/E5/F1/F2/F3)

Troubleshooting for open/short circuits in temperature sensors.

Refrigerant Leakage Detection (EC) Diagnosis

Troubleshooting steps for refrigerant leakage detection errors.

Overload Current Protection (F0) Diagnosis

Troubleshooting for overload current protection, checking power supply and blockages.

IPM Malfunction/Over-Current Protection (P0) Diagnosis

Troubleshooting for IPM malfunction and over-current protection issues.

Over Voltage/Low Voltage Protection (P1) Diagnosis

Troubleshooting for over/under voltage protection, checking power supply and reactor.

Compressor High Temperature Protection (P2) Diagnosis

Troubleshooting for compressor high-temperature protection, checking airflow and refrigerant.

Inverter Compressor Drive Error (P4) Diagnosis

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

Compressor Checking

Compressor Winding Resistance Measurement

IPM Continuity Check

Digital Tester Measurement of IPM