Mars Comfort-Aire VMH Series User manual

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Service Manual
VMH Series
Inverter Multi Zone Ductless Mini-Split
Model
A-VMH18DU-1
A-VMH28TU-1
A-VMH36QU-1
A-VMH48PU-1

Service Manual - VMH 18/28/36/48 Series
2
CONTENTS
1. Indoor Unit Combination......................................................................................................................................... 4
2. Dimension Of Outdoor Unit .................................................................................................................................... 7
3. Refrigerant Cycle Diagram....................................................................................................................................... 9
4. Installation Details .................................................................................................................................................12
4.1 Wrench torque sheet for installation ...............................................................................................................12
4.2 Connecting the cables ...................................................................................................................................... 12
4.3 Pipe length and the elevation........................................................................................................................... 12
4.4 First-Time Installation.......................................................................................................................................12
4.5 Adding Refrigerant after Long-Term System Operation...................................................................................14
4.6 Procedure when servicing the indoor unit refrigeration circuit....................................................................... 14
4.7 Evacuation after servicing the outdoor unit refrigeration circuit ....................................................................15
5. Electronic Function ................................................................................................................................................17
5.1 Abbreviation .....................................................................................................................................................17
5.2 Electric Control Working Environment............................................................................................................. 17
5.3 Main Protection................................................................................................................................................ 17
5.4 Control and Functions ...................................................................................................................................... 19
6. Wiring Diagrams.....................................................................................................................................................24
7. Troubleshooting.....................................................................................................................................................45
7.1Safety................................................................................................................................................................. 45
7.2Indoor Unit Error Display...................................................................................................................................46
7.3 Outdoor Unit Display ........................................................................................................................................48
7.4 Diagnosis and Solution .....................................................................................................................................54
7.5 Trouble Criterion of Main Parts......................................................................................................................111
8. Disassembly Instructions .....................................................................................................................................121
A-VMH18DU-1.............................................................................................................................................. 121
A-VMH18DU-1.............................................................................................................................................. 121

Service Manual - VMH 18/28/36/48 Series
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A-VMH28TU-1 ..............................................................................................................................................135
A-VMH36QU-1, A-VMH48PU-1................................................................................................................. 143
A-VMH36QU-1, A-VMH48PU-1................................................................................................................. 150

Service Manual - VMH 18/28/36/48 Series
4
1. Indoor Unit Combination
Multi DC Outdoor
Unit
Nominal
capacity
Suggested
Combination Limit
A-VMH18DU-1 5.2kW
6+6
None
6+9
6+12
9+9
9+12
12+12
Multi DC Outdoor
Unit
Nominal
capacity
Suggested Combination Limit
Two units Three units
A-VMH28TU-1 7.8kW
6+12 6+6+6 6+12+12
None
6+18
6+6+9
6+12+18
9+9
6+6+12
9+9+9
9+12
6+6+18
9+9+12
9+18
6+9+9
9+9+18
12+12
6+9+12
9+12+12
12+18
6+9+18
12+12+12
18+18
A-VMH28TU-1 7.8kW
6+12
6+6+6
6+9+18
None
6+18
6+6+9
6+12+12
9+9
6+6+12
9+9+9
9+12
6+6+18
9+9+12
9+18
6+6+24
9+9+18
9+24
6+9+9
9+12+12
12+12
6+9+12
12+12+12
12+18
12+24
18+18

Service Manual - VMH 18/28/36/48 Series
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Multi DC Outdoor Unit Nominal capacity Suggested Combination Limit
Two units Three units Four units
A-VMH36QU-1 10.5kW
6+18 6+6+12 9+9+12 6+6+6+6 6+9+9+18
None
6+24
6+6+18
9+9+18
6+6+6+9
6+9+9+24
9+18
6+6+24
9+9+24
6+6+6+12
6+9+12+12
9+24
6+9+12
9+12+12
6+6+6+18
6+9+12+18
12+12
6+9+18
9+12+18
6+6+6+24
6+12+12+12
12+18
6+9+24
9+12+24
6+6+9+9
6+12+12+18
12+24
6+12+12
9+18+18
6+6+9+12
9+9+9+9
18+18
6+12+18
12+12+12
6+6+9+18
9+9+9+12
18+24
6+12+24
12+12+18
6+6+9+24
9+9+9+18
24+24
6+18+18
12+12+24
6+6+12+12
9+9+12+12
6+18+24
12+18+18
6+6+12+18
9+9+12+18
9+9+9
6+6+12+24
9+12+12+12
6+9+9+9
12+12+12+12
6+9+9+12
A-VMH36QU-1 10.5kW
6+18 6+6+12 9+9+9 6+6+6+6 6+9+9+12
None
6+24
6+6+18
9+9+12
6+6+6+9
6+9+9+18
6+30
6+6+24
9+9+18
6+6+6+12
6+9+9+24
9+18
6+6+30
9+9+24
6+6+6+18
6+9+12+12
9+24
6+9+12
9+9+30
6+6+6+24
6+9+12+18
9+30
6+9+18
9+12+12
6+6+6+30
6+12+12+12
12+12
6+9+24
9+12+18
6+6+9+9
6+12+12+18
12+18
6+9+30
9+12+24
6+6+9+12
9+9+9+9
12+24
6+12+12
9+18+18
6+6+9+18
9+9+9+12
12+30
6+12+18
12+12+12
6+6+9+24
9+9+9+18
18+18
6+12+24
12+12+18
6+6+12+12
9+9+12+12
18+24
6+12+30
12+12+24
6+6+12+18
9+9+12+18
18+30
6+18+18
12+18+18
6+6+12+24
9+12+12+12
24+24
6+18+24
6+9+9+9
12+12+12+12

Service Manual - VMH 18/28/36/48 Series
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Multi DC
Outdoor Unit
Nominal
capacity
Suggested Combination
Limit
Two
units
Three units Four units Five units
A-VMH48PU-1 14kW
9+24 6+6+24 9+12+18 6+6+6+18 6+9+18+30 6+6+6+6+9 6+6+12+12+12
None
9+30
6+6+30 9+12+24
6+6+6+24
6+12+12+12
6+6+6+6+12
6+6+12+12+18
9+36
6+6+36 9+12+30
6+6+6+30
6+12+12+18
6+6+6+6+18
6+6+12+12+24
12+24
6+9+24 9+12+36
6+6+6+36
6+12+12+24
6+6+6+6+24
6+6+12+18+18
12+30
6+9+30 9+18+18
6+6+9+18
6+12+12+30
6+6+6+6+30
6+9+9+9+9
12+36
6+9+36 9+18+24
6+6+9+24
6+12+18+18
6+6+6+6+36
6+9+9+9+12
18+18
6+12+18 9+18+30
6+6+9+30
6+12+18+24
6+6+6+9+9
6+9+9+9+18
18+24
6+12+24 9+18+36
6+6+9+36
9+9+9+9
6+6+6+9+12
6+9+9+9+24
18+30
6+12+30 9+24+24
6+6+12+12
9+9+9+12
6+6+6+9+18
6+9+9+9+30
18+36
6+12+36 9+24+30
6+6+12+18
9+9+9+18
6+6+6+9+24
6+9+9+12+12
24+30
6+18+18 12+12+12
6+6+12+24
9+9+9+24
6+6+6+9+30
6+9+9+12+18
24+36
6+18+24
12+12+18
6+6+12+30
9+9+9+30
6+6+6+9+36
6+9+9+12+24
30+30
6+18+30
12+12+24
6+6+12+36
9+9+9+36
6+6+6+12+12
6+9+9+18+18
6+18+36
12+12+30
6+6+18+18
9+9+12+12
6+6+6+12+18
6+9+12+12+12
6+24+24
12+12+36
6+6+18+24
9+9+12+18
6+6+6+12+24
6+9+12+12+18
6+24+30
12+18+18
6+6+18+30
9+9+12+24
6+6+6+12+30
6+9+12+12+24
9+9+18
12+18+24
6+6+24+24
9+9+12+30
6+6+6+18+18
6+12+12+12+12
9+9+24
12+18+30
6+9+9+12
9+9+18+18
6+6+6+18+24
6+12+12+12+18
9+9+30
12+24+24
6+9+9+18
9+9+18+24
6+6+9+9+9
9+9+9+9+9
9+9+36
18+18+18
6+9+9+24
9+12+12+12
6+6+9+9+12
9+9+9+9+12
9+12+12
18+18+24
6+9+9+30
9+12+12+18
6+6+9+9+18
9+9+9+9+18
6+9+9+36
9+12+12+24
6+6+9+9+24
9+9+9+9+24
6+9+12+12
9+12+12+30
6+6+9+9+30
9+9+9+12+12
6+9+12+18
9+12+18+18
6+6+9+12+12
9+9+9+12+18
6+9+12+24
9+12+18+24
6+6+9+12+18
9+9+9+12+24
6+9+12+30
12+12+12+12
6+6+9+12+24
9+9+12+12+12
6+9+12+36
12+12+12+18
6+6+9+12+30
9+9+12+12+18
6+9+18+18
12+12+12+24
6+6+9+18+18
9+12+12+12+12
6+9+18+24
12+12+18+18
6+6+9+18+24
12+12+12+12+12

Service Manual - VMH 18/28/36/48 Series
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2. Dimension Of Outdoor Unit
H
D
A
B
Model Unit W D H W1 A B
A-VMH18DU-1 mm 845 363 702 923 540 350
inch 33.3 14.3 27.6 36.0 21.3 13.8
A-VMH18DU-1 mm 890
342
673
990
663
354
inch 35.04 13.46 26.50 38.98 26.10 13.94
A-VMH28TU-1 mm 946 410 810 1034 673 403
inch 37.2 16.5 31.9 40.6 26.5 15.9
A-VMH36QU-1
A-VMH48PU-1
mm 946 410 810 1034 673 403
inch 37.2 16.5 31.9 40.6 26.5 15.9

Service Manual - VMH 18/28/36/48 Series
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H
W
A
D
W1
B
Model
Unit
W D H W1 A B
A-VMH36QU-1
A-VMH48PU-1
mm 952 415 1333 1060 634 404
inch 37.5 16.3 52.5 41.7 25.0 15.9

Service Manual - VMH 18/28/36/48 Series
9
3. Refrigerant Cycle Diagram
3.1 Refrigeration circuit drawing of A-VMH18DU-1
LIQUID VALVE A
GAS VALVE A
HEAT
EXCHANGE
(EVAPORATOR) HEAT
EXCHANGE
(CONDENSER)
COOLING
HEATING
T2 Evaporator
temp. sensor
middle
T1 Room
temp. sensor
T3
Condenser
temp. sensor
T4 Ambient
temp. sensor
INDOOR OUTDOOR
EXV A
CAPILLARY TUBE
EXV B
LIQUID VALVE B
GAS VALVE B
Compressor
4-WAY VALVE
T5 Discharge
temp. sensor
Accumulator High pressure
switch
Low pressure
switch
T2B-A Evaporator
temp. sensor outlet
T2B-B
T2B-C

Service Manual - VMH 18/28/36/48 Series
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3.3 Refrigeration circuit drawing A-VMH28TU-1
HEAT
EXCHANGE
(EVAPORATOR) HEAT
EXCHANGE
(CONDENSER)
COOLING
HEATING
T2 Evaporator
temp. sensor
middle
T1 Room
temp. sensor
T3
Condenser
temp. sensor
T4 Ambient
temp. sensor
INDOOR OUTDOOR
CAPILLARY TUBE
EXV A
LIQUID VALVE A
GAS VALVE A
EXV B
LIQUID VALVE B
GAS VALVE B
EXV C
LIQUID VALVE C
GAS VALVE C
Compressor
4-WAY VALVE
T5 Discharge
temp. sensor
Accumulator High pressure
switch
Low pressure
switch
T2B-A Evaporator
temp. sensor outlet
T2B-B
T2B-C
3.4 Refrigeration circuit drawing of A-VMH36QU-1
LIQUID VALVE A
GAS VALVE A
HEAT
EXCHANGE
(EVAPORATOR) HEAT
EXCHANGE
(CONDENSER)
COOLING
HEATING
T2 Evaporator
temp. sensor
middle
T1 Room
temp. sensor
T3
Condenser
temp. sensor
T4 Ambient
temp. sensor
INDOOR OUTDOOR
EXV A
CAPILLARY TUBE
EXV B
LIQUID VALVE B
GAS VALVE B
EXV C
LIQUID VALVE C
GAS VALVE C
EXV D
LIQUID VALVE D
GAS VALVE D
Compressor
4-WAY VALVE
T5 Discharge
temp. sensor
Accumulator High pressure
switch
Low pressure
switch
T2B-A Evaporator
temp. sensor outlet
T2B-B
T2B-C
T2B-D