Carrier 38MBR series User manual

Specifications subject to change without notice.
TABLE of CONTENTS
PAGE
SA\FETY CONSIDERATIONS ...................................................... 1
INTRODUCTION............................................................................ 1
MODEL / SERIAL NUMBER NOMENCLATURES .................... 2
WIRING ........................................................................................... 3
CONNECTION DIAGRAM............................................................ 3
WIRING DIAGRAMS..................................................................... 4
REFRIGERATION CYCLE DIAGRAM........................................ 8
REFRIGERANT LINES .................................................................. 9
SYSTEM EVACUATION AND CHARGING ............................... 10
SYSTEM VACUUM AND CHARGE ............................................ 10
ELECTRONIC FUNCTIONS ......................................................... 11
POINT CHECK FUNCTION .......................................................... 14
TROUBLESHOOTING ................................................................... 16
DIAGNOSTIC GUIDES.................................................................. 17
DIAGNOSIS AND SOLUTION...................................................... 18
DISASSEMBLY INSTRUCTIONS SIZE 36.................................. 47
DISASSEMBLY INSTRUCTIONS SIZE 48-58 ............................ 53
SA\FETY 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
coil cleaning. 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 a
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 the 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.
INTRODUCTION
This service manual provides the necessary information to service,
repair, and maintain the 38MBR family of heat pumps. Use the
“TABLE of CONTENTS” on page 1 to locate a desired topic. For
detailed information regarding product specifications refer to product
data documentation.
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.
WA R N I N G
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.
WA R N I N G
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.
CAUTION
Service Manual
38MBR
Outdoor Unit Single Zone Ductless System
Sizes 36 to 58

38MBR: Service Manual
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2
MODEL / SERIAL NUMBER NOMENCLATURES
Table 1 —Unit Sizes
SYSTEM TONS kBTUh VOLTAGE-PHASE OUTDOOR MODEL
3.00 36,000 208/230-1 38MBRQ36A--3
4.00 48,000 208/230-1 38MBRQ48A--3
5.00 58,000 208/230-1 38MBRQ58A--3
OUTDOOR UNIT
38 MB R Q 36 A -- 3
38 = OUTDOOR UNIT
MB = MODEL
VOLTAGE
3 = 208/230-1-60
UNIT TYPE
R= OUTDOOR UNIT
MAXIMUM NUMBER OF FAN COIL UNITS THAT
CAN BE CONNECTED TO THE OUTDOOR UNIT
A= 1:1
NOT USED
SYSTEM TYPE
Q= HEAT PUMP
NOMINAL CAPACITY
36 - 3 TONS
48 - 4 TONS
01 19 V 10001
Week of Manufacture
Year of Manufacture V= ALL MODELS
Sequential Serial Number
Use of the AHRI Certified
TM Mark indicates a
manufacturer’s
participation in the
program For verification
of certification for individual
products, go to
www.ahridirectory.org.

38MBR: Service Manual
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3
WIRING
All wires must be sized per NEC (National Electrical Code) or CEC
(Canadian Electrical Code) and local codes. Use Electrical Data table
MCA (minimum circuit amps) and MOCP (maximum over current
protection) to correctly size the wires and the disconnect fuse or breakers
respectively.
Sizes 36-58 Recommended Connection Method for Power and
Communication Wiring
Power and Communication Wiring:
The main power is supplied to the outdoor unit. The field supplied power
wiring from the outdoor unit to the indoor unit consists of three (3) wires
and provides the power for the indoor unit. Two wires are high voltage
AC power and one is a ground wire. To minimize voltage drop, the
factory recommended wire size is 14/2 stranded with a ground.
Communication Wiring:
A separate shielded stranded copper conductor only, with a 600 volt
rating and double insulated copper wire, must be used as the
communication wire from the outdoor unit to the indoor unit. Please use a
separate shielded 16GA stranded control wire.
CONNECTION DIAGRAM
Fig. 1 — Connection Diagram
NOTES:
1. Do not use thermostat wire for any connection between indoor and outdoor units.
2. All connections between indoor and outdoor units must be as shown. The connections are sensitive to polarity and will generate a fault code.
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
Wires should be sized based on NEC and local codes.
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
Be sure to comply with local codes while running wire from
the indoor unit to the outdoor unit.
Every wire must be connected firmly. Loose wiring may
cause the terminal to overheat or result in unit malfunction. A
fire hazard may also exist. Ensure all wiring is tightly
connected.
No wire should touch the refrigerant tubing, compressor or
any moving parts.
Disconnecting means must be provided and shall be located
within sight and readily accessible from the air conditioner.
Connecting cable with conduit shall be routed through the
hole in the conduit panel.
CAUTION

38MBR: Service Manual
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4
WIRING DIAGRAMS
Size 36K
Fig. 2 — Wiring Diagram Size 36K
Table 2 — Wiring Diagram Size 36K Codes
CODE PART NAME
CN1~CN2 Input: 230VAC High voltage
CN5~CN6 Output: 230VAC High voltage
P-1 Connection to the earth
CN10~CN44 Output: 230VAC High voltage Chassis Crankcase Heater
CN4~CN40 Output: 230VAC High voltage Compressor Crankcase Heat
CN3~CN22 Output: 230VAC High voltage
CN43 Output: Pin3~Pin2, Pin4~Pin2 (230 VAC High voltage) For AC FAN
CN41~CN42 Output To AC FAN Capacitor
CN34 Output:-24VDC-24VDC
CN33 Input: Pin 1 (0-5VDC),Pin 2 (5VDC) Discharge Temperature Sensor
CN8 Input: Pin3, Pin4 (5VDC),Pin2 (0VDC),Pin1,Pin5 (0-5VDC) T3 & T4
CN9 Input: Pin2, Pin4 (0VDC),Pin1,Pin3 (0-5VDC) H/L Pressure Switch
CN20 Output: Pin1-Pin4: Pulse waveform(0-12VDC),Pin5, Pin6 (12VDC)
CN7 Output: Pin1 (12VDC),Pin2 (5VDC),Pin3 (EARTH)
COMP
FM1
MAIN BOARD
U
V
W
L
DRIVER BOARD
7
7
YELLOW
Applicable to the units
adopting DC motor only
CN52
CN6
SV
4-WAY1
BLUE
HEAT_D
HEAT_Y
OPTIONAL
3
BLACK
RED
BLUE
BLUE
YELLOW
BLACK
EEV
CN20
M
5
CN5
CN2
CN1
P-1
Y/
G
L1 L2
(1)L1 (2)L2
RED
L-PRO
T3
T4
H-PRO
TP
CN33
CN8
CN9
CN41
CN42
CN43
CN3
CN22
CN4
CN10
CN7
CN44
CN40
BLUE
BLUE
BLUE
RED
BLACK
BLACK
RED
CN51
CN53 CN54
RED
CN55
CN19
3
Y/G
Y/G
U VW
BLUE
KCALBKCALB
RED
BLACK
MAIN POWER
SUPPLY
TO INDOOR UNIT
POWER SUPPLY
CN34
XT1
TO INDOOR COMM. BUS
XT2
S1
S2
NOTE
shielded wire.
Please use 2-core
YELLOW
GRAY
2
LANOITPOLANOITPO
OPTIONAL

38MBR: Service Manual
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5
WIRING DIAGRAMS (CONT)
Size 36K
Table 3 — Wiring Diagram Size 36K Codes
Table 4 — Wiring Diagram Sizes 09K, 12K, 18K (208-230V)
OUTDOOR UNIT PFC & IPM BOARD
CODE PART NAME
CN53~CN54 Input: 230VAC High voltage
CN55 Output: Pin1 (12VDC),Pin2 (5VDC),Pin3 (EARTH)
CN19 Pin1~Pin3: Connect to FAN voltage among phases 0~200VAC
U~V~W Connect to compressor voltage among phases 0~200VAC
CN51~CN52 CN51~EARTH,CN52~EARTH Output: 224-380VDC High voltage
CODE PART NAME CODE PART NAME
COMP COMPRESSOR LPFC INDUCTOR
CAP1 FAN MOTOR CAPACITOR L-PRO LOW PRESSURE SWITCH
HEAT CRANKCASE HEATING H-PRO HIGH PRESSURE SWITCH
FM1 OUTDOOR DC FAN SV 4-WAY VALVE
FAN1 OUTDOOR AC FAN T3 CONDENSER TEMPERATURE SENSOR
EEV ELECTRONIC EXPANSION VALVE T4 OUTDOOR AMBIENT TEMPERATURE SENSOR

38MBR: Service Manual
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6
WIRING DIAGRAMS (CONT)
Sizes 48K and 58K
Fig. 3 — Wiring Diagram Sizes 48K and 58K
Table 5 — Wiring Diagram Sizes 48K and 58K Codes
CODE PART NAME
CN1~CN3 Input: 230VAC High voltage
P7~P8 Output: 230VAC High voltage to IDU
P5,P6,P9 Connection to the earth
CN22 Output:-24VDC-24VDC for IDU Communication
CN17~CN18 Output: 230VAC High voltage 4 way valve
CN19~CN20 Output: 230VAC High voltage Chassis Crankcase Heater
CN24~CN25 Output: 230VAC High voltage Compressor Crankcase Heater
CN2~CN4 Output: 230VAC High voltage to AC CURRENT DETECTOR
CN12 Input: Pin1 (0-5VDC),Pin2 (5VDC) Heatsink Temperature Sensor
CN8 Input: Pin1 (0-5VDC),Pin2 (5VDC) Compressor Top Sensor (PAIQI)
CN9 Input: Pin3,Pin4 (5VDC),Pin2 (0VDC),Pin1,Pin5 (0-5VDC) the ambient sensor and pipe sensor
CN10 Input: Pin2, Pin4 (0VDC),Pin1,Pin3 (0-5VDC) for the H/L pressure switch
CN15 Output: Pin1-Pin4: Pulse waveform (0-12VDC),Pin5, Pin6 (12VDC) EEV
CN6 Output: Pin1-Pin6: Pulse waveform (0-5VDC), Pin7, Pin9 (0VDC) Pin8 (0-5VDC), Pin10 (5VDC)
IPM & PFC BOARD
MAIN BOARD
WIRING DIAGRAM (OUTDOOR UNIT)
CN15
A
ELECTRONIC
EXPANSIVE
VA LV E A
CN12
TH
CN10
RED
ORP-L
H-PRO
CN9
T4
T3
TNEIBMAROSNES
PMETEPI
PROSNES.
D
12
3
4
5
CN36
P5
CN19
CN20
CN28
CN24
CN25
CN31
CN17
FAN1
CN18
HEAT_D
OPTIONAL
HEAT_Y
OPTIONAL
SV
4-WAY
BLUE
RED
BLUE
CN4
CN2
CN3
CN1
COMP
UVW
Y/G
Ferrite bead
CH2
CN6
CN9
10
3
CN1
CN2
L
YELLOW
YELLOW
U
V
W
BLUE
BLACK
RED
WIHTE
/RED
BLACK
RED
BLACK
Ferrite bead
CH1
CT1
DCFAN2 DCFAN1
Y/G
Y/G
DC MOTOR
DRIVER BOARD
CON1
FAN1
CN1
FAN2
3
3
P6
2
CN6 CN3
Y/G
BLACK
TO INDOOR COMM. BUS
XT2
WOLLEY
YARG
S1
S2
NOTE
shielded wire.
Please use 2-core
2
L2
L1
MAIN POWER SUPPLY
XT1
TO INDOOR UNIT
(1)L1
Y/G
XT2
OPTIONAL
N
L
P9
P7
P8
CN22
RED
BLUE
/BLACK
CN8
PAIQI
ORANGE
ORANGE
RED
BLACK
CH2
Ferrite bead
Ferrite bead
Ferrite bead
CH2
CH2
~
~
~
Ferrite bead
Ferrite
bead
Notes:
This symbol indicates the element
is optional, the actual shape prevails.
(2)L2
(1)N (2)N
CN34
CN32
CN27
YELLOW

38MBR: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
7
WIRING DIAGRAMS (CONT)
Sizes 48K and 58K
Table 6 — Wiring Diagram Sizes 48K and 58K Codes
Table 7 — Wiring Diagram Sizes 48K and 58K Codes
Table 8 — Wiring Diagram Sizes 48K and 58K Codes
OUTDOOR UNIT PFC & IPM BOARD
CODE PART NAME
CN1~CN6 Output:224-380VDC High voltage to DIODE MODULE
CN2~CN3 Output:224-380VDC High voltage to PFC INDUCTOR
U~V~W Connection to compressor voltage among phases 0~200VAC
CN9 Input:Pin1-Pin6: Pulse waveform (0-5VDC),Pin7, Pin9 (0VDC) Pin8 (0-5VDC),Pin10 (5VDC)
FAN1 Output: Pin1~Pin2: High voltage (224-380VDC), Pin4 (0-15VDC) Pin5 (0-5.6VDC), Pin6:Pulse waveform (0-15VDC)
OUTDOOR UNIT DC MOTOR DRIVER BOARD
CODE PART NAME
CON1 Output:Pin1~Pin2:High voltage (224-380VDC)
CN1 Input: Pin4: Pulse waveform (0-15VDC),Pin3 (0-6.5VDC) Pin2 (0VDC),Pin1 (15VDC)
FAN1 Pin1-Pin3: Connect to FAN voltage among phases 0~200VAC
FAN2 Pin1-Pin3: Connect to FAN voltage among phases 0~200VAC
CODE PART NAME
COMP COMPRESSOR
CAP1,CAP2 FAN MOTOR CAPACITOR
CT1 AC CURRENT DETECTOR
DDIODE MODULE
EEV ELECTRONIC EXPANSION VALVE
FM1,FM2 OUTDOOR DC FAN
FAN1,FAN2 OUTDOOR AC FAN
HEAT CRANKCASE HEATING
H-PRO HIGH PRESSURE SWITCH
LPFC INDUCTOR
L-PRO LOW PRESSURE SWITCH
KM AC CONTACTOR
SV 4-WAY VALVE
TP EXHAUST TEMPERATURE SENSOR
T3 CONDENSER TEMPERATURE SENSOR
T4 OUTDOOR AMBIENT TEMPERATURE SENSOR
TH HEATSINK TEMPERATURE SENSOR
PAIQI COMPRESSOR TOP SENSOR (GAS PIPE SENSOR)
CH 1
CH 2
CH 3
FERRITE BEAD

38MBR: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
8
REFRIGERATION CYCLE DIAGRAM
Fig. 4 — Refrigerant Cycle Diagram
LIQUID SIDE
GAS SIDE
HEAT
EXCHANGE
(EVAPORATOR)
HEAT
EXCHANGE
(CONDENSER)
Compressor
2-WAY VALVE
3-WAY VALVE
4-WAY VALVE
COOLING
HEATING
T2B Evaporator
temp. sensor
outlet
T1 Room temp.
sensor
T3 Condenser
temp. sensor
T5 Discharge
temp. sensor
T4 Ambient
temp. sensor
ROODTUOROODNI
T2 Evaporator
temp. sensor
middle
Electronic
expansion valve
CAPILIARY TUBE

38MBR: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
9
REFRIGERANT LINES
General Refrigerant Line Sizing
1. The outdoor units are shipped with a full charge of R410A refrigerant. All charges, line sizing, and capacities are based on runs of 25ft. (7.6 m). For runs
over 25 ft. (7.6 m), consult the long-line applications section for the proper charge adjustments.
2. The minimum refrigerant line length between the indoor and outdoor units is 10 ft. (3 m).
3. Refrigerant lines should not be buried in the ground. If it is necessary to bury the lines, not more than 36in (914 mm) should be buried. Provide a
minimum 6in (152 mm) vertical rise to the service valves to prevent refrigerant migration.
4. Both lines must be insulated. Use a minimum of 1/2in. (12.7 mm) thick insulation. Closed-cell insulation is recommended in all long-line applications.
5. Special consideration should be given to isolating interconnecting tubing from the building structure. Isolate the tubing so vibration or noise is not
transmitted into the structure.
IMPORTANT: Both refrigerant lines must be insulated separately.
Table 9 displays the following maximum lengths allowed.
Table 9 — Piping and Refrigerant
• The charge amount listed in Table 9 is for piping runs up to 25 ft. (7.6 m).
• For piping runs greater than 25 ft. (7.6 m), add refrigerant up to the allowable length as specified in Table 10.
Long Line Applications,:
1. No change in line sizing is required.
2. Add refrigerant per Table 10.
Table 10 — Additional Charge Table Per Zone
System Size 36K 48K 58K
PIPING
Min. Piping Length ft (m) 10(3) 10(3) 10(3)
Standard Piping Length ft (m) 25(7.5) 25(7.5) 25(7.5)
Max. outdoor-indoor height difference (OU higher than IU) ft (m) 98(30) 98(30) 98(30)
Max. outdoor-indoor height difference (IU higher than OU) ft (m) 98(30) 98(30) 98(30)
Max. Piping length with no additional refrigerant charge ft (m) 26(8) 26(8) 26(8)
Max. Piping Length ft (m) 213(65) 213(65) 213(65)
Additional refrigerant charge
(between Standard - Line Lengths Max piping length) Oz/ft (g/m) 0.32 (30) 0.32 (30) 0.32(30)
Gas Pipe (size-connection type) in (mm) 5/8(16) 5/8(16) 3/4(19)
Liquid Pipe (size-connection type) in (mm) 3/8(9.52) 3/8(9.52) 3/8(9.52)
REFRIGERANT Refrigerant Type -- R410A R410A R410A
Charge Amount Lbs (kg) 6.72(3.05) 9.26(4.2) 10.19(4.62)
UNIT SIZE
TOTAL LINE LENGTH FT. ADDITIONAL CHARGE OZ/FT. (M)
MIN. MAX. >10-25
(3-8)
>25-213
(8-65)
36
10 213 None 0.3248
58

38MBR: Service Manual
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10
SYSTEM EVACUATION AND CHARGING
Refrigerant tubes and indoor coil should be evacuated using the
recommended deep vacuum method of 500 microns. The alternate triple
evacuation method may be used if the following procedure is followed.
Always break a vacuum with dry nitrogen.
SYSTEM VACUUM AND CHARGE
Using Vacuum Pump
1. Completely tighten the flare nuts (A, B, C, D, E). Fully open all circuits
service valves. Connect the manifold gage charge hose to the charge
port of the low side Master service valve to evacuate all circuits at the
same time (see Fig. 5).
2. Connect charge hose to vacuum pump.
3. Fully open the low side of manifold gage (see Fig. 6).
4. Start vacuum pump
5. Evacuate using the triple evacuation method.
6. After evacuation is complete, fully close the low side of manifold gage
and stop operation of vacuum pump.
7. The factory charge contained in the outdoor unit is good for up to
25ft. (8 m) of line length. For refrigerant lines longer than 25ft. (8
m), add refrigerant as specified in “Additional Charge Table Per
Zone” on page 9.
8. Disconnect charge hose from charge connection of the low side service
valve.
9. Securely tighten caps of service valves.
Fig. 5 — Service Valve
Fig. 6 — Manifold
Deep Vacuum Method
The deep vacuum method requires a vacuum pump capable of pulling a
vacuum of 500 microns and a vacuum gage capable of accurately measuring
this vacuum depth. The deep vacuum method is the most positive way of
assuring a system is free of air and liquid water (see Fig. 7).
Fig. 7 — Deep Vacuum Graph
Triple Evacuation Method
The triple evacuation method should be used. Refer to Fig. 8 and proceed
as follows:
1. Pump system down to 500 MICRONS of mercury and allow pump to
continue operating for an additional 15 minutes. Unit must maintain 500
microns or less for 30 minutes or more to ensure a dry system.
2. Close service valves and shut off vacuum pump.
3. Connect a nitrogen cylinder and regulator to system and open until
system pressure is 2 psig.
4. Close service valve and allow system to stand for 10 minutes. During
this time, dry nitrogen will be able to diffuse throughout the system
absorbing moisture.
5. Repeat this procedure as indicated in Fig. 8. System will then be free of
any contaminants and water vapor.
Fig. 8 — Triple Evacuation Method
Final Tubing Check
IMPORTANT: Check to be certain factory tubing on both
indoor and outdoor unit has not shifted during shipment.
Ensure tubes are not rubbing against each other or any sheet
metal. Pay close attention to feeder tubes, making sure wire ties
on feeder tubes are secure and tight.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
Never use the system compressor as a vacuum pump.
CAUTION
Outdoor Unit Indoor Unit
Refrigerant
Service Valve
Low Side
High Side
A
B
C
D
Manifold Gage
500 microns
Low side valve High side valve
Charge hose
Charge hose
Vacuum pump
Low side valve
500
MINUTES
01234567
1000
1500
LEAK IN
SYSTEM
VACUUM TIGH
T
TOO WET
TIGHT
DRY SYSTEM
2000
MICRONS
2500
3000
3500
4000
4500
5000
CHECK FOR TIGHT, DRY SYSTEM
(IF IT HOLDS DEEP VACUUM)
EVACUATE
BREAK VACUUM WITH DRY NITROGEN
WAIT
EVACUATE
RELEASE CHARGE INTO SYSTEM
BREAK VACUUM WITH DRY NITROGEN
EVACUATE
WAIT

38MBR: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
11
ELECTRONIC FUNCTIONS
Abbreviation
• T1: Indoor room temperature
• T2: Coil temperature of indoor heat exchanger middle
• T2B: Coil temperature of indoor heat exchanger outlet
• T3: Coil temperature of condenser
• T4: Outdoor ambient temperature
• T5: Compressor discharge temperature
• Td: Target temperature
Main Protection
Three Minute Delay for Compressor Restart
Less than a 1 minute delay for the initial start-up and a 3 minute delay for
subsequent starts.
Compressor Top Temperature Protection
The unit stops working when the compressor top temp. protector cuts off,
and restarts after the compressor top temp. protector restarts.
Compressor Discharge Temperature Protection
When the compressor discharge temp. increases, the running frequency is
limited per the following rules:
• Compressor discharge temp. T5>239°F(115°C) for 5s, compressor
stops and restarts up until T5<194°F (90°C)
• 110<T5<239°F(115°C), decrease the frequency to the lower level
every 2 minutes.
• 221°F(105°C)<T5<230°F(110°C), keep running at the current
frequency.
• T5<221°F(105°C), no limit for frequency.
Fan Speed is Out of Control
When the indoor fan speed remains low (lower than 300RPM) for 50s,
the indoor fan shuts off and restarts 30s later. If the protection mode
engages 3 times when the fan motor restarts continuously, the unit stops
and the LED displays the failure.
When the outdoor fan speed remains low (lower than 100RPM) or too
high (higher than 1500RPM) for 60s, the unit stops and the LED displays
the failure. The malfunction clears 30s later.
Inverter Module Protection
The inverter module has a protection function for current, voltage and
temperature. If any of these protections engage, the corresponding code
displays on the indoor unit and the unit stops working.
Indoor Fan Delayed Open Function
When the unit starts up, the louver is active immediately and the indoor
fan opens 10s later. If the unit is running in the HEATING mode, the
indoor fan is controlled also by the anti-cold wind function.
Compressor Preheating Functions
Preheating Permitting Condition:
If T4<37.4°F(3°C) and the machine connects to power supply newly
within 5 seconds or if T4<37.4°F(3°C) and the compressor has stopped
for over 3 hours, the compressor heating cable will work.
Preheating Mode:
A weak current flow through the compressor coil from the compressor
wiring terminal, then the compressor is heated without operation.
Preheating Release Condition:
If T4=41°F(5°C) or the compressor starts running, the preheating
function stops.
Condenser High Temperature T3 Protection:
• 131°F(55°C)<T3<140°F(60°C), the compressor frequency decreases
to the lower level until to F1 and then runs at F1. If
T3<129.2°F(54°C), the compressor keeps running at the current
frequency.
• T3<125.6°F(52°C), the compressor does not limit the frequency and
resumes the former frequency.
• T3>140°F(60°C) for 5 seconds, the compressor stops until
T3<125.6°F(52°C).
Evaporator Low Temperature T2 Protection:
• T2<32°F(0°C), the compressor stops and restarts when
T2=41°F(5°C).
• 32°F(0°C) ≦T2<39.2°F(4°C), the compressor frequency is limited
and decreases to the lower level
• 39.2°F(4°C)=T2<44.6°F(7°C), the compressor retains the current
frequency
• T2>44.6°F(7°C), the compressor frequency is not limited.
Operation Modes and Functions
FAN Mode
1. Outdoor fan and compressor stop
2. Temperature setting function is disabled and no setting temperature
appears.
3. Indoor fan can be set to high/med/low/auto
4. The louver operates same as in the COOLING mode.
5. Auto fan
Fig. 9 — FAN Mode
a
b
c
d
e
T1
°C
10.8
°F (6.0°C)
9°F (5.0°C)
7.2°F (4.0°C)
6°F (3.0°C)
1.8°F (1.0°C)
H
(H-L)*0.75+L
(H-L)*0.5+L
(H-L)*0.25+L
L

38MBR: Service Manual
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12
COOLING Mode
Outdoor Fan Running Rules
Fig. 10 — Outdoor Fan Running Rules
In the COOLING mode, the indoor fan runs all the time and the speed
can be selected as high, medium, low and auto. The indoor fan is
controlled as shown in Fig. 11.
Fig. 11 — Indoor Fan Table
The AUTO Fan function under the COOLING mode acts (see Fig. 12).
Fig. 12 —AUTO Fan function under the COOLING Mode
HEATING Mode
Outdoor Fan Running Rules
Fig. 13 — Outdoor Fan Running Rules
Indoor Fan Running Rules
When the compressor is on, the indoor fan can be set to high/med/low/
auto. And the anti-cold wind function has the priority. The indoor fan is
controlled as shown in Fig. 14.
Fig. 14 — Indoor Fan Running Rules
AUTO Fan action in HEATING mode
Fig. 15 — AUTO Fan action in HEATING mode
A DC_FAN_HI_SPD_ADD
B DC_FAN_MID_SPD_ADD
C DC_FAN_MIN_SPD_ADD
D DC_FAN_SLOW_SPD_ADD
E DC_FAN_SSLOW_SPD_ADD
28 (82.4°F)
19 (66.2°F)
17 (62.6°F)
26 (78.8°F)
25 (77°F)
23 (73.4°F)
22 (71.6°F)
20 (69°F)
A
B
C
D
E
A
DD
DD
D
D
D
D
D
D
D
D
D
D
D
_
A
A
A
A
D
D
D
D
D
D
D
DD
D
D
_
A
DD
DD
D
D
D
D
DD
D
D
D
D
P
D
_
A
A
A
A
D
D
D
D
D
DD
D
D
D
D
D
S
P
D
_
A
A
A
A
A
A
A
A
A
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
Setting
Fan Speed
Actual
Fan Speed
H+(H+=H+G)
AH（=H）
B
C
M+(M+=M+Z)
D M(M=M)
E
F
L+(L+=L+D)
G L(L=L)
H
I
T1-Td °F (°C)
L
L-(L-=L-D)
H
H-（H-=H-G)
M
M-(M-=M-Z)
4.5(40.1)
3.0(37.4)
1.5(34.7)
4.5(40.1)
3.0(37.4)
1.5(34.7)
4.5(40.1)
3.0(37.4)
1.5(34.7)
a
b
c
d
6.0°C(13°F)
T1-Td
e
H
(H-L)*0.75+L
(H-L)*0.5+L
(H-L)*0.25+L
L
5.0°C(11.0°F)
4.0°C(8°F)
2.5°C(5°F)
1.0°C(2°F)
T4
E
D
C
B
A DC_FAN_HI_SPD_ADD
DC_FAN_MID_SPD_ADD
DC_FAN_MIN_SPD_ADD
DC_FAN_SLOW_SPD_ADD
DC_FAN_SSLOW_SPD_ADD
59°F(15°C)
5
5.4°F(13°C
)
53.6°F(12°C)
50°F(10°C)
6
9.8°F(21°C
)
6
6.2°F(19°C
)
64.4°F(18°C)
60.8°F(16°C)
Setting Fan
Speed
H（=H）
H+(H+=H+G)
M(M=M)
M+(M+=M+Z)
L(L=L)
L+(L+=L+D)
H-（H-=H-G)
M-(M-=M-Z)
L-(L-=L-D)
T1-Td+34.7°F(1.5°C)
L
H
M
-3
°F(-1.5°C)
-6°F(-3.0°C)
-10°F(-4.5°C)
Actual Fan
Speed
-3°F(-1.5°C)
-6°F(-3.0°C)
-10°F(-4.5°C)
-3°F(-1.5°C)
-6°F(-3.0°C)
-10°F(-4.5°C)
0°F(0.0°C)
T
1-Td+3°F(1.5°C)
L
(H+-L)*0.2+L
(H+-L)*0.4+L
(H+-L)*0.6+L
H+
(H+-L)*0.8+L
-2°F(-1°C)
-4°F(-2°C)
-6°F(-3°C)
-8°F(-4°C)
-11.0°F(-5°C)
-13°F(-6°C)
-15°F(-6.5°C)

38MBR: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
13
Defrosting Mode
If any one of the following conditions are met, AC enters the DEFROSTING mode. After the compressor starts and continues to run, mark the
minimum value of T3 from the 10th minute to 15th minute as T30.
Fig. 16 — Defrosting Chart

38MBR: Service Manual
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14
Evaporator Coil Temperature Protection
Fig. 17 — Evaporator Coil Temperature Protection
Off: Compressor stops
Decrease: Decrease the running frequency to the lower level
Hold: Keep the current frequency
Resume: No limitation for frequency
Auto Mode
This mode can be chosen with remote controller and the setting
temperature can be changed between 62.6~86F(17~30C).
In AUTO mode, the machine either selects COOLING, HEATING or
FAN-Only mode according to T (T=T1-Ts).
The indoor fan runs in the AUTO Fan mode of the relevant mode.
The louver operates same as in relevant mode. If the machine switches
mode between heating and cooling, the compressor will continue to stop
for 15 minutes and then choose a mode according to T1-Ts. If the setting
temperature is modified, the machine selects a running function once
again.
DRYING Mode
DRYING mode works the same as COOLING mode in BREEZE
speed. All protections are active and the same as that in the COOLING
mode.
Auto-Restart Function
The indoor unit is equipped with an auto-restart function, which is carried
out through an auto-restart module. In case of a sudden power failure, the
module memorizes the setting conditions before the power failure. The
unit resumes the previous operation setting (not including sleep function)
automatically after 3 minutes when power returns.
POINT CHECK FUNCTION
Press the remote controller LED DISPLAY or LED or MUTE three
times, and then press AIR DIRECTION or SWING three times in ten
seconds (the buzzer rings for two seconds). The air conditioner enters the
information enquiry status.
The user can press the LED DISPLAY or AIR DIRECTION to check
the next or front item's information. When the air conditioner enters the
enquiry information status, it displays the code name in 2 seconds. Refer
to Table 11 for details.
Table 11 — Enquiry Information
When the air conditioner enters the information enquiry status, the LED
displays the code value within 25 seconds (see Table 12 on page 15).
ΔT=T1-Ts Running Mode
ΔT≥2F(1 ℃)Cooling Mode
-2°F(-1 ℃)<ΔT<3(2°F1 ℃)Fan-only Mode
ΔT≤-1 ℃(-2°F) Heating Mode
TEstop
T2
Resume
Off
Decrease
TEdown
TEH2
Hold
ENQUIRY
INFORMATION DISPLAYING CODE MEANING
T1 T1 T1 temp.
T2 T2 T2 temp.
T3 T3 T3 temp.
T4 T4 T4 temp.
T2B Tb T2B temp.
TP TP TP (T5) temp.
TH TH TH temp.
Targeted Frequency FT Targeted Frequency
Actual Frequency Fr Actual Frequency
Indoor Fan Speed IF Indoor Fan Speed
Outdoor Fan Speed OF Outdoor Fan Speed
EXV Opening Angle LA EXV Opening Angle
Compressor
Continuous
Running Time
CT
Compressor
Continuous
Running Time
Compressor
Stop Issues ST Compressor Stop Issues

38MBR: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
15
Enquiry Information
Table 12 — Enquiry Information
ENQUIRY INFORMATION DISPLAY VALUE MEANING REMARK
T1,T2,T3,T4, T2B,TP,TH,
Targeted Frequency,
Actual Frequency
- 1F,- 1E,- 1d,- 1c,- 1
b,- 1A - 25,- 24,- 23,- 22,- 21,- 20 1. All the displaying temperature is
actual value.
2. Temperature is _C no matter the
remote.
3. T1,T2,T3,T4,T2B display range:-
25~ 70,
4. TP display range:- 20~ 130.
5. Frequency display range:
0~159HZ.
6. If the range, it displays the
maximum value or minimum
value.
- 19—99 - 19—99
A0,A1,A9 100,101,109
b0,b1,b9 110,111,119
c0,c1,c9 120,121,129
d0,d1,d9 130,131,139
E0,E1,E9 140,141,149
F0,F1,F9 150,151,159
Indoor fan speed/
Outdoor fan speed
0OFF
1,2,3,4 Low speed, Medium speed, High
speed, Turbo For some big capacity motors
14- FF
Actual fan speed = Display value
turns to decimal value and then
multiply 10. The unit is RPM.
For some small capacity motors
the display value is 14- FF
(hexadecimal), the corresponding
fan speed range is from 200- 2550
RPM.
EXV opening angle 0- FF
Actual EXV opening value = Display
value turns to decimal value and then
multiply 2.
Compressor continuous
running time 0- FF 0- 255 minutes
If the actual value exceeds the
range, it displays the maximum
value or minimum value.
Compressor stop causes 0- 99 For a detailed meaning, please
consult with an engineer Decimal display
Reserve 0- FF

38MBR: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
16
TROUBLESHOOTING
This section provides the required flow charts to troubleshoot problems
that may arise.
NOTE: Information required in the diagnoses can be found in the
wiring diagrams.
Required Tools:
The following tools are needed when diagnosing the units:
• Digital multimeter
• Screw drivers (Phillips and straight head)
• Needle-nose pliers
• Refrigeration gauges
Recommended Steps
1. Refer to the diagnostic hierarchy charts below and determine the
problem at hand.
2. Go to the chart listed in the diagnostic hierarchy and follow the steps in
the chart for the selected problem.
For the ease of service, the systems are equipped with diagnostic code
display LED's on both the indoor and outdoor units. The outdoor
diagnostic display is on the outdoor unit board and is limited to very few
errors. The indoor diagnostic display is a combination of flashing LED's
on the display panel on the front of the unit. If possible always check the
diagnostic codes displayed on the indoor unit first.
The diagnostic codes for the indoor and outdoor units are listed in the
following pages.
Problems may occur that are not covered by a diagnostic code, but are
covered by the diagnostic flow charts. These problems are typical air
conditioning mechanical or electrical issues that can be corrected using
standard air conditioning repair techniques.
For problems requiring measurements at the control boards, note the
following:
1. Always disconnect the main power.
2. When possible check the outdoor board first.
3. Start by removing the outdoor unit top cover.
4. Reconnect the main power
5. Probe the outdoor board inputs and outputs with a digital multi-meter
referring to the wiring diagrams.
6. Connect the red probe to hot signal and the black probe to the ground or
negative.
7. Note that some of the DC voltage signals are pulsating voltages for
signal. this pulse should be rapidly moving at all times when there is a
signal present.
8. If it is necessary to check the indoor unit board you must start by
disconnecting the main power.
9. Next remove the front cover of the unit and then control box cover.
10. Carefully remove the indoor board from the control box, place it face
up on a plastic surface (not metal).
11. Reconnect the main power and repeat steps 5, 6, and 7.
12. Disconnect main power before reinstalling board to avoid shock hazard
and board damage.

38MBR: Service Manual
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17
DIAGNOSTIC GUIDES
Table 13 — Indoor Unit Error Display
O (light) X (off) ☆(flash)
Table 14 — Error Display on Two Way Communication Wired Controller
OPERATION LAMP TIMER LAMP DISPLAY LED STATUS SOLUTION
☆ 1 time X E0 Indoor unit EEPROM parameter error Page 20
☆ 2 times X E1 Communication malfunction between indoor and outdoor units Page 22
☆ 4 times X E3 Fan speed is operating outside of the Normal Range Page 25
☆ 5 times X E4 Indoor room temperature sensor (T1) malfunction Page 26
☆ 6 times X E5 Evaporator coil temperature sensor (T2) malfunction Page 26
☆ 7 times X EC Refrigerant leakage detection Page 27
☆ 8 times X EE Water-level alarm malfunction Refer to Indoor Unit
Service Manual
☆ 1 time O F0 Current overload protection Page 21
☆ 2 times O F1 Outdoor ambient temperature sensor (T4) malfunction Page 26
☆ 3 times O F2 Condenser coil temperature sensor (T3) malfunction Page 26
☆ 4 times O F3 Compressor discharge temperature sensor (T5) malfunction Page 26
☆ 5 times O F4 Outdoor unit EEPROM parameter error Page 20
☆ 6 times O F5 Outdoor fan speed malfunction Page 25
☆ 7 times O F6 Indoor coil outlet pipe sensor (Located on outdoor unit low pressure valve) Refer to Indoor Unit
Service Manual
☆ 8 times O F7
Communication malfunction between the cassette optional lift panel and the unit
Refer to Indoor Unit
Service Manual
☆ 9 times O F8 Cassette optional lift panel malfunction Refer to Indoor Unit
Service Manual
☆ 10 times O F9 Cassette optional lift panel not closed Refer to Indoor Unit
Service Manual
☆ 1 time ☆P0 Inverter module (IPM) malfunction Page 28
☆ 2 times ☆P1 Over-voltage or under-voltage protection Page 31
☆ 3 times ☆P2 Compressor top high temperature protection (OLP) Page 32
☆ 4 times ☆P3 Low ambient temperature cut off in HEATING mode Refer to Indoor Unit
Service Manual
☆ 5 times ☆P4 Compressor drive malfunction Page 33
☆ 6 times ☆P5 Indoor units mode conflict Refer to Indoor Unit
Service Manual
☆ 7 times ☆P6 Low pressure protection Refer to Indoor Unit
Service Manual
☆ 8 times ☆P7 Outdoor IPM temperature sensor error Page 34
DISPLAY LED STATUS SOLUTION
F0 Communication error between wired controller and indoor unit Page 21
F1 The cassette faceplate is abnormal Page 26
E1 Communication malfunction between indoor and outdoor units Page 22
E2 Indoor room temperature sensor (T1) malfunction Refer to Indoor Unit Service Manual
E3 Evaporator coil temperature sensor (T2) malfunction Refer to Indoor Unit Service Manual
E5 Outdoor ambient temperature sensor (T4) malfunction Page 26
E5 Condenser coil temperature sensor (T3) malfunction Page 26
E5 Compressor discharge temperature sensor (T5) malfunction Page 26
E7 Indoor unit EEPROM parameter error Refer to Indoor Unit Service Manual
E8 Indoor fan speed malfunction Refer to Indoor Unit Service Manual
EF Refrigerant leak detection Refer to Indoor Unit Service Manual
EE Water-level alarm malfunction Refer to Indoor Unit Service Manual
ED Outdoor unit EEPROM parameter error Refer to Indoor Unit Service Manual
ED Outdoor fan speed malfunction Refer to Indoor Unit Service Manual
EB Inverter module (IPM) malfunction Refer to Indoor Unit Service Manual
EF Other malfunction

38MBR: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
18
DIAGNOSIS AND SOLUTION
Outdoor Unit Error Display
Table 15 — Diagnostic Guide for Outdoor Units
NO. PROBLEMS ERROR CODE SOLUTION
1 Communication malfunction between indoor and outdoor units E1 Page 22
2 Current overload protection F0 Page 21
3 Outdoor ambient temperature sensor (T4) malfunction F1 Page 26
4 Condenser coil temperature sensor (T3) malfunction F2 Page 26
5 Compressor discharge temperature sensor (T5) malfunction F3 Page 26
6 Outdoor unit EEPROM parameter error F4 Page 20
7 Outdoor fan speed malfunction F5 Page 25
8 Inverter module (IPM) malfunction P0 Page 27
9 Over-voltage or under-voltage protection P1 Page 31
10 Compressor top high temperature protection (OLP) P2 Page 32
11 Low ambient temperature cut off in HEATING mode P3 Refer to Indoor Unit Service Manual
12 Compressor drive malfunction P4 Page 33
13 High temperature protection of indoor coil in HEATING mode J0 Page 35
14 Outdoor temperature protection of outdoor coil in COOLING J1 Page 36
15 Temperature protection of compressor discharge J2 Page 37
16 PFC module protection J3 Page 38
17 Communication malfunction between control board and IPM board J4 Page 39
18 High pressure protection J5 Page 40
19 Low pressure protection J6 Page 41
20 Outdoor IPM module temperature sensor malfunction P7 Page 34
21 AC voltage protection J8 Page 42

38MBR: Service Manual
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19
Table 16 — Outdoor Check Function
NDISPLAY REMARK
00 Normal display
Display running frequency, running state or malfunction code
01 Indoor unit capacity demand code
Actual data*HP*10
If the capacity demand code is higher than 99, the digital display tube displays a single digit and a ten digit. (For example, the
digital display tube displays “5.0” it means the capacity demand is 15. The digital display tube displays “60” it means the
capacity demand is 6.0).
02 Amendatory capacity demand code
03 The frequency after the capacity requirement
transfer
04 The frequency after the frequency limit
05 The frequency of sending to 341 chip
06 Indoor unit evaporator outlet temp.
(HEATING T2，COOLING T2B)
If the temp. is lower than 0 degree, the digital display tube displays “0”. If the temp. is higher than 70 degree, the digital display
tube displays “70”.
07 Condenser pipe temp.(T3)
If the temp. is lower than -9 degree, the digital display tube displays “-9”.If the temp. is higher than 70 degree, the digital
display tube displays “70”. If the indoor unit is not connected, the digital display tube displays: “--”
08 Outdoor ambient temp.(T4)
09 Compressor discharge temp.(T5)
The display value is between 13~129 degree. If the temp. is lower than 13 degrees, the digital display tube displays “13”. If
the temp. is higher than 99 degrees, the digital display tube displays a single digit and a ten digit. (For example, if the digital
display tube displays “0.5”, it means the compressor discharge temp. is 105 degrees. If the digital display tube displays “1.6”,
it means the compressor discharge temp. is 116 degrees).
10 AD value of current
The display value is a hex number.
11 AD value of voltage
12 Indoor unit running mode code
Off:0, Fan only 1,Cooling:2, Heating:3
13 Outdoor unit running mode code Off:0, Fan only 1,Cooling:2, Heating:3, Forced cooling:4
14 EXV open angle
Actual data/4.
If the value is higher than 99, the digital display tube displays a single digit and a ten digit.
For example, if the digital display tube displays “2.0”,it means the EXV open angle is 120×4=480p.).
15 Frequency limit symbol
Bit7 Frequency limit caused by IGBT radiator
The display value is a hex number. For ex., the
digital display tube displays 2A, then Bit5=1,
Bit3=1, Bit1=1.
It represents the frequency limit caused by T4, T3
and current.
Bit6 Frequency limit caused by PFC
Bit5 Frequency limit caused by T4
Bit4 Frequency limit caused by T2
Bit3 Frequency limit caused by T3
Bit2 Frequency limit caused by T5
Bit1 Frequency limit caused by current
Bit0 Frequency limit caused by voltage
16 DC fan motor speed
17 IGBT radiator temp.
The display value is between 30~120 degrees. If the temp. is lower than 30 degrees, the digital display tube displays “30”. If
the temp. is higher than 99 degrees, the digital display tube displays a single digit and a ten digit. (For example, if the digital
display tube displays “0.5”, it means the IGBT radiator temp. is 105 degrees. If the digital display tube displays “1.6”, it means
the IGBT radiator temp. is 116 degrees).
18 Indoor unit number The indoor unit can communicate well with the outdoor unit. General:1, Twins:2
19 Evaporator pipe temp. T2 of1# indoor unit
If the temp. is lower than 0 degree, the digital display tube displays “0”.If the temp. is higher than 70 degrees, the digital
display tube displays “70”. If the indoor unit is not connected, the digital display tube displays: “--”.
20 Evaporator pipe temp. T2 of 2# indoor unit
21 Evaporator pipe temp. T2 of 3# indoor unit
22 1# Indoor unit capacity demand code
Actual data*HP*10
If the capacity demand code is higher than 99, the digital display tube displays a single digit and a tens digit. (For example,
the digital display tube displays “5.0”,it means the capacity demand is 15. If the digital display tube displays “60”,it means the
capacity demand is 6.0). If the indoor unit is not connected, the digital display tube displays: “--”.
23 2# Indoor unit capacity demand code
24 3# Indoor unit capacity demand code
25 Room temp. T1 of 1# indoor unit
If the temp. is lower than 0 degree, the digital display tube displays “0”.If the temp. is higher than 70 degrees, the digital
display tube displays “70”. If the indoor unit is not connected, the digital display tube displays: “--”.
26 Room temp. T1 of 2# indoor unit
27 Average room temp. T1
28 Reason of stop
29 Evaporator pipe temp. T2B of 1# indoor unit
If the temp. is lower than 0 degree, the digital display tube displays “0”.If the temp. is higher than 70 degrees, the digital
display tube displays “70”. If the indoor unit is not connected, the digital display tube displays: “--”.
30 Evaporator pipe temp. T2B of 2# indoor unit

38MBR: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
20
EEPROM Parameter Error - Diagnosis and Solution (E0/F4)
Troubleshooting
EEPROM: A read-only memory whose contents can be erased and reprogrammed using a pulsed voltage. For the location of the EEPROM chip, refer
to the Fig. 18.
Fig. 18 — Outdoor PCB
Figure 18 is for illustration purposes only and may differ from your actual unit.
Error Code E0/F4
Malfunction decision conditions Indoor or outdoor PCB main chip does not receive feedback from EEPROM chip.
Supposed Causes • Installation mistake
•PCBfaulty
Power OFF.
Wait 2 minutes then power ON the unit.
Replace the indoor /outdoor main PCB..
Yes