Midea V4+R Series User manual

Commercial Air Conditioners
Service
Manual
R410A
iOS Version Android Version
Midea CAC After-service Application
iOS Version
Midea CAC News Application
Add.: Midea Headquarters Building, 6 Midea Avenue, Shunde, Foshan, Guangdong, China
Postal code: 528311
Tel: [phone] Fax: [phone]
cac.midea.com global.midea.com
Note: Product specifications change from time to time as product improvements and
developments are released and may vary from those in this document.
Commercial Air Conditioner Division
Midea Group

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CONTENTS
CONTENTS
Part 1 General Information............................................................................ 3
Part 2 Component Layout and Refrigerant Circuits ................................... 11
Part 3 Control ............................................................................................... 23
Part 4 Field Settings..................................................................................... 37
Part 5 Diagnosis and Troubleshooting......................................................... 41

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Part 1 - General Information
Part 1
General Information
1 Indoor and Outdoor Unit Capacities .................................................. 4
2 External Appearance ............................................................................. 6
3 Outdoor Unit Combinations .................................................................. 9
4 Combination Ratio .............................................................................. 10

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1Indoor and Outdoor Unit Capacities
1.1 Indoor Units
Table 1-1.1: Standard indoor unit abbreviation codes
Abbreviation
code
Type
Abbreviation
code
Type
Q1
One-way Cassette
T1
High Static Pressure Duct
Q2
Two-way Cassette
W
Wall-mounted
Q4-C
Compact Four-way Cassette
DL
Ceiling & Floor
Q4
Four-way Cassette
F
Floor Standing
T3
Low Static Pressure Duct
Z
Console
T2
Medium Static Pressure Duct
Table 1-1.2: Indoor unit capacity range
Capacity
Capacity
index
Q1
Q2
Q4-C
Q4
T3
T2
T1
W
DL
F
Z
kW
HP
1.8
0.6
18
18
—
—
—
18
—
—
—
—
18
—
2.2
0.8
22
22
22
22
—
22
22
—
22
—
22
22
2.8
1
28
28
28
28
28
28
28
—
28
—
28
28
3.6
1.25
36
36
36
36
36
36
36
—
36
36
36
36
4.5
1.6
45
45
45
45
45
45
45
—
45
45
45
45
5.6
2
56
56
56
—
56
56
56
—
56
56
56
—
7.1
2.5
71
71
71
—
71
71
71
71
71
71
71
—
8.0
3
80
—
—
—
80
—
80
80
80
80
80
—
9.0
3.2
90
—
—
—
90
—
90
90
90
90
90
—
10.0
3.6
100
—
—
—
100
—
—
—
—
—
—
—
11.2
4
112
—
—
—
112
—
112
112
—
112
—
—
14.0
5
140
—
—
—
140
—
140
140
—
140
—
—
16.0
6
160
—
—
—
—
—
—
160
—
160
—
—
20.0
7
200
—
—
—
—
—
—
200
—
—
—
—
25.0
9
250
—
—
—
—
—
—
250
—
—
—
—
28.0
10
280
—
—
—
—
—
—
280
—
—
—
—
40.0
14
400
—
—
—
—
—
—
400
—
—
—
—
45.0
16
450
—
—
—
—
—
—
450
—
—
—
—
56.0
20
560
—
—
—
—
—
—
560
—
—
—
—
1.2 Heat recovery ventilator
Table 1-1.3: Heat recovery ventilator capacity range
Model
HRV-200
HRV-300
HRV-400
HRV-500
HRV-800
HRV-1000
HRV-1500
HRV-2000
Capacity (m3/h)
200
300
400
500
800
1000
1500
2000

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Part 1 - General Information
1.3 Outdoor Units
Table 1-1.4: Outdoor unit capacity range
Capacity
8HP
10HP
12HP
14HP
16HP
Model
(MDV-*W/D2RN1T(C))
252(8)
280(10)
335(12)
400(14)
450(16)
Capacity
18HP
20HP
22HP
24HP
26HP
28HP
30HP
32HP
Model
(MDV-*W/D2RN1T(C))
532(18)
560(20)
615(22)
680(24)
730(26)
800(28)
850(30)
900(32)
Outdoor unit 1
8HP
10HP
10HP
10HP
10HP
14HP
14HP
16HP
Outdoor unit 2
10HP
10HP
12HP
14HP
16HP
14HP
16HP
16HP
Capacity
34HP
36HP
38HP
40HP
42HP
44HP
46HP
48HP
Model
(MDV-*W/D2RN1T(C))
960(34)
1010(36)
1065(38)
1130(40)
1200(42)
1250(44)
1300(46)
1350(48)
Outdoor unit 1
10HP
10HP
10HP
10HP
14HP
14HP
14HP
16HP
Outdoor unit 2
10HP
10HP
12HP
14HP
14HP
14HP
16HP
16HP
Outdoor unit 3
14HP
16HP
16HP
16HP
14HP
16HP
16HP
16HP
Capacity
50HP
52HP
54HP
56HP
58HP
60HP
62HP
64HP
Model
(MDV-*W/D2RN1T(C))
1432(50)
1460(52)
1515(54)
1580(56)
1650(58)
1700(60)
1750(62)
1800(64)
Outdoor unit 1
8HP
10HP
10HP
10HP
14HP
14HP
14HP
16HP
Outdoor unit 2
10HP
10HP
12HP
14HP
14HP
14HP
16HP
16HP
Outdoor unit 3
16HP
16HP
16HP
16HP
14HP
16HP
16HP
16HP
Outdoor unit 4
16HP
16HP
16HP
16HP
16HP
16HP
16HP
16HP
Notes:
1. The full model names can be obtained by substituting the asterisk in the model name format given in the left-hand column of the table above
with the shortened model names given in the table. For example, the model name for the 40HP model is MDV-1130(40)W/D2RN1T(C)).
2. The combinations of units shown in the table are factory-recommended. Other combinations of units are also possible.

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2External Appearance
2.1 Indoor Units
Table 1-2.1: Standard indoor unit appearance
One-way Cassette
Two-way Cassette
Q1
Q2
Compact Four-way Cassette
Four-way Cassette
Q4-C
Q4
Low Static Pressure Duct
Medium Static Pressure Duct
T3
T2
High Static Pressure Duct
Wall-mounted
T1
W
Ceiling & Floor
Floor Standing
DL
F
Console
Z

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Part 1 - General Information
2.2 Heat Recovery Ventilator
Table 1-2.2: Heat recovery ventilator appearance
Heat Recovery Ventilator
2.3 Outdoor Units
2.3.1 Single units
Table 1-2.3: Single outdoor unit appearance
8/10/12/14/16HP
2.3.2 Combinations of units
Table 1-2.4: Combination outdoor unit appearance
18/20/22/24/26/28/30/32HP
34/36/38/40/42/44/46/48HP
50/52/54/56/58/60/62/64HP

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2.4 MS boxes
Table 1-2.5: MS box appearance
Model name
Appearance
Max. number of
downstream indoor
units
MS01/N1-C
4
MS02/N1-C
8
MS04/N1-C
16
MS06/N1-C
24
MS02E/N1-C
1
MS04E/N1-C
1

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Part 1 - General Information
3Outdoor Unit Combinations
Table 1-3.1: Outdoor unit combinations
System capacity
Number
of units
Modules1
Outdoor branch joint kit2
kW
HP
8
10
12
14
16
25.2
8
1
●
—
28.0
10
1
●
33.5
12
1
●
40.0
14
1
●
45.0
16
1
●
53.2
18
2
●
●
FQZHW-02SB
56.0
20
2
●●
61.5
22
2
●
●
68.0
24
2
●
●
73.0
26
2
●
●
80.0
28
2
●●
85.0
30
2
●
●
90.0
32
2
●●
96.0
34
3
●●
●
FQZHW-03SB
101.0
36
3
●●
●
106.5
38
3
●
●
●
113.0
40
3
●
●
●
120.0
42
3
●●●
125.0
44
3
●●
●
130.0
46
3
●
●●
135.0
48
3
●●●
143.2
50
4
●
●
●●
FQZHW-04SB
146.0
52
4
●●
●●
151.5
54
4
●
●
●●
158.0
56
4
●
●
●●
165.0
58
4
●●●
●
170.0
60
4
●●
●●
175.0
62
4
●
●●●
180.0
64
4
●●●●
Notes:
1. The combinations of units shown in the table are factory-recommended. Other combinations of units are also possible.
2. For systems with two or more outdoor units, outdoor branch joints (sold separately) are required.

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4Combination Ratio
Table 1-4.1: Indoor and outdoor unit combination ratio limitations
Type
Minimum combination ratio
Maximum combination ratio
V4+R Series outdoor units
50%
130%
Table 1-4.2: Combinations of indoor and outdoor units
Outdoor unit capacity
Sum of capacity indexes of connected indoor units
Maximum number of
connected indoor units
kW
HP
Capacity index
25.2
8
252
126 to 327.6
13
28.0
10
280
140 to 364
16
33.5
12
335
167.5 to 435.5
20
40.0
14
400
200 to 520
23
45.0
16
450
225 to 585
26
53.2
18
532
266 to 691.6
29
56.0
20
560
280 to 728
33
61.5
22
615
307.5 to 799.5
36
68.0
24
680
340 to 884
39
73.0
26
730
365 to 949
43
80.0
28
800
400 to 1040
46
85.0
30
850
425 to 1105
50
90.0
32
900
450 to 1170
53
96.0
34
960
480 to 1248
56
101.0
36
1010
505 to 1313
59
106.5
38
1065
532.5 to 1384.5
63
113.0
40
1130
565 to 1469
64
120.0
42
1200
600 to 1560
125.0
44
1250
625 to 1625
130.0
46
1300
650 to 1690
135.0
48
1350
675 to 1755
143.2
50
1432
716 to 1861.6
146.0
52
1460
730 to 1898
151.5
54
1515
757.5 to 1969.5
158.0
56
1580
790 to 2054
165.0
58
1650
825 to 2145
170.0
60
1700
850 to 2210
175.0
62
1750
875 to 2275
180.0
64
1800
900 to 2340
Combination ratio =
Sum of capacity indexes of the indoor units
Capacity index of the outdoor units

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Part 2 - Component Layout and Refrigerant Circuits
Part 2
Component Layout and
Refrigerant Circuits
1Layout of Functional Components ....................................................... 12
2Piping Diagrams .................................................................................. 14
3Refrigerant Flow Diagrams .................................................................. 16

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1Layout of Functional Components
MDV-252(8)W/D2RN1T(C) / MDV-280(10)W/D2RN1T(C) / MDV-335(12)W/D2RN1T(C)
Figure 2-1.1: MDV-252(8)W/D2RN1T(C) / MDV-280(10)W/D2RN1T(C) / MDV-335(12)W/D2RN1T(C) top view
Figure 2-1.2: MDV-252(8)W/D2RN1T(C) / MDV-280(10)W/D2RN1T(C) / MDV-335(12)W/D2RN1T(C) front view
Electronic
expansion valve
Solenoid valve
Solenoid valve
Solenoid valve
Electronic
expansion valve
DC fan motor
Four-way valve
Four-way valve
Four-way valve
High pressure sensor
Outdoor ambient
temperature sensor
High pressure switch
Unloading valve
DC fan motor
Solenoid valve
Solenoid valve
Solenoid valve
Low pressure switch
DC inverter compressor

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Part 2 - Component Layout and Refrigerant Circuits
MDV-400(14)W/D2RN1T(C) / MDV-450(16)W/D2RN1T(C)
Figure 2-1.3: MDV-400(14)W/D2RN1T(C) / MDV-450(16)W/D2RN1T(C) top view
Figure 2-1.4: MDV-400(14)W/D2RN1T(C) / MDV-450(16)W/D2RN1T(C) front view
Electronic
expansion valve
Solenoid valve
Solenoid valve
Electronic
expansion valve
High pressure switch
High pressure sensor
DC fan motor
Four-way valve
Four-way valve
Four-way valve
Outdoor ambient
temperature sensor
DC fan motor
Unloading valve
Low pressure switch
DC inverter compressor
High pressure switch
DC inverter compressor

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2Piping Diagrams
MDV-252(8)W/D2RN1T(C) / MDV-280(10)W/D2RN1T(C) / MDV-335(12)W/D2RN1T(C)
Figure 2-2.1: MDV-252(8)W/D2RN1T(C) / MDV-280(10)W/D2RN1T(C) / MDV-335(12)W/D2RN1T(C) piping diagram
MDV-400(14)W/D2RN1T(C) / MDV-450(16)W/D2RN1T(C)
Figure 2-4.2: MDV-400(14)W/D2RN1T(C) / MDV-450(16)W/D2RN1T(C) piping diagram
Solenoid valve SV2
Solenoid
valve SV4
High
pressure
sensor
DC inverter
compressor
Pressure release
valve
Oil balance stop valve
Solenoid valve SV5
ST3
EXV-B
High pressure
switch
Low pressure switch
Oil
separator
EXV-A
ST1
ST2
Heat exchanger 1
Heat exchanger 2
Liquid stop valve
Low pressure gas stop valve
High pressure gas stop valve
Gas balance stop valve
Accumulator
ST3
Liquid stop valve
Low pressure gas stop valve
High pressure gas stop valve
Gas balance stop valve
Oil balance stop valve
Low pressure switch
Pressure release
valve
High pressure
switch
High
pressure
sensor
Oil
separator
DC inverter
compressor
DC inverter
compressor
Heat exchanger 2
Heat exchanger 1
ST1
ST2
EXV-A
EXV-B
Accumulator
Solenoid valve SV5
Solenoid valve SV2
Solenoid valve SV4

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Part 2 - Component Layout and Refrigerant Circuits
Key components:
1. Oil separator:
Separates oil from gas refrigerant pumped out of the compressor and quickly returns it to the compressor. Separation
efficiency is up to 99%.
2. Accumulator:
Stores liquid refrigerant and oil to protect compressor from liquid hammering.
3. Electronic expansion valve (EXV):
Controls refrigerant flow and reduces refrigerant pressure.
4. Four-way valve ST1:
Controls refrigerant flow direction of the left heat exchanger. When closed, the left heat exchanger functions as a
condenser; when open, the left heat exchanger functions as an evaporator.
5. Four-way valve ST2:
Controls refrigerant flow direction of the right heat exchanger. When closed, the right heat exchanger functions as a
condenser; when open, the right heat exchanger functions as an evaporator.
6. Four-way valve ST3:
When the system is in total cooling mode, ST3 is open. When the system is in total heating mode or mixed mode, ST3
is closed.
7. Solenoid valve SV2:
Protects the compressor. If compressor discharge temperature rises above 100°C, SV2 opens and sprays a small
amount of liquid refrigerant to cool the compressor. SV2 closes again once the discharge temperature has fallen
below 90°C.
8. Solenoid valve SV4:
Returns oil to the compressor. In single outdoor unit systems: opens once the compressor has run for 200 seconds
and closes 600 seconds later. In systems with multiple outdoor units: each unit's SV4 opens for 3 minutes every 20
minutes.
9. Solenoid valve SV5:
Enables fast defrosting. During defrosting operation, opens to shorten the refrigerant flow cycle and quicken the
defrosting process. Closed in cooling mode.
10. High and low pressure switches:
Regulate system pressure. When system pressure rises above the upper limit or falls below the lower limit, the high or
low pressure switches turn off, stopping the compressor. After 10 minutes, the compressor restarts.

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3Refrigerant Flow Diagrams
Cooling operation
Figure 2-3.1: refrigerant flow during cooling operation
SV2
SV5
SV4
ST3
EXV-B
EXV-A
INV1
ST1 ST2
FAN1
filter
T3 T5
T4
FAN2
filter
filter filter
heat
exchanging
H-PRO
H-LY1
L-PRO
filter
filter
filter
Oil separator
Check
valve
Capillary
tube
Capillary
tube
heat
exchanging
Check valve
Check
valve
Pressure
regulating
valve
INV2
T7C2
Capillary
tube T7C1
Check
valve
filter filter
EXV
filter filter
EXV
filter filter
EXV
FAN
heat
exchanging
FAN
heat
exchanging
FAN
heat
exchanging
Indoor unit Indoor unit Indoor unit
High-Pressure Liquid
High-Pressure Balance
Oil Balance
To other outdoor unit
Cooling Operation
High temperature, high pressure gas
High temperature, high pressure liquid
Low temperature, low pressure gas
Fan ON ON Fan OFF OFF Fan OFF OFF
Indoor unit operation
Thermostat "ON" Thermostat "OFF"
Low Pressure Gas
High-Pressure Gas
Check valve
To other MS unit
MS unit
SV1SV1BSV2SV2BSV3SV3BSV4SV4B
SV7
EXVA
sub-cool
pipe
sub-cool
pipe
sub-cool
pipe
sub-cool
pipe
Cooling Cooling Cooling
Accumulator

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Part 2 - Component Layout and Refrigerant Circuits
Mixed cooling operation
Figure 2-3.2: refrigerant flow during mixed cooling operation
SV2
SV5
SV4
ST3
EXV-B
EXV-A
INV1
ST1 ST2
FAN1
filter
T3 T5
T4
FAN2
filter
filter filter
heat
exchanging
H-PRO
H-LY1
L-PRO
filter
filter
filter
Oil separator
Check
valve
Capillary
tube
Capillary
tube
heat
exchanging
Check valve
Check
valve
Pressure
regulating
valve
INV2
T7C2
Capillary
tube T7C1
Check
valve
filter filter
EXV
filter filter
EXV
filter filter
EXV
FAN
heat
exchanging
FAN
heat
exchanging
FAN
heat
exchanging
Indoor unit Indoor unit Indoor unit
High-Pressure Liquid
High-Pressure Balance
Oil Balance
To other outdoor unit
Mixed Cooling Operation
High temperature, high pressure gas
High temperature, high pressure liquid
Low temperature, low pressure gas
Fan ON ON Fan ON ON Fan ON ON
Indoor unit operation
Thermostat "ON" Thermostat "ON"
Low Pressure Gas
High-Pressure Gas
Check valve
To other MS unit
MS unit
SV1SV1BSV2SV2BSV3SV3BSV4SV4B
SV7
EXVA
sub-cool
pipe
sub-cool
pipe
sub-cool
pipe
sub-cool
pipe
Cooling Cooling Heating
Thermostat "ON"
Accumulator

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Midea V4+R Series Service Manual
Heating operation
Figure 2-3.3: refrigerant flow during heating operation
SV2
SV5
SV4
ST3
EXV-B
EXV-A
INV1
ST1 ST2
FAN1
filter
T3 T5
T4
FAN2
filter
filter filter
heat
exchanging
H-PRO
H-LY1
L-PRO
filter
filter
filter
Oil separator
Check
valve
Capillary
tube
Capillary
tube
heat
exchanging
Check valve
Check
valve
Pressure
regulating
valve
INV2
T7C2
Capillary
tube T7C1
Check
valve
filter filter
EXV
filter filter
EXV
filter filter
EXV
FAN
heat
exchanging
FAN
heat
exchanging
FAN
heat
exchanging
Indoor unit Indoor unit Indoor unit
High-Pressure Liquid
High-Pressure Balance
Oil Balance
To other outdoor unit
Heating Operation
High temperature, high pressure gas
High temperature, high pressure liquid
Low temperature, low pressure gas
Fan ON ON Fan ON OFF Fan ON ON
Indoor unit operation
Thermostat "ON" Thermostat "OFF"
Low Pressure Gas
High-Pressure Gas
Check valve
To other MS unit
MS unit
SV1SV1BSV2SV2BSV3SV3BSV4SV4B
SV7
EXVA
sub-cool
pipe
sub-cool
pipe
sub-cool
pipe
sub-cool
pipe
Heating Heating Heating
Accumulator