Midea M2OC-18HFN1-M User manual

Multi outdoor units
SERVICE MANUAL
Multi zone
CONDENSING UNITS
Revision B: ODMI-C1-1403
Model Numbers:
M2OC-18HFN1-M M3OC-30HRFN1-M
M2OD-18HFN1-M M4OC-36HRFN1-M
M3OD-27HRDN1-M
WARNING
Installation MUST conform with local building codes or, in the absence of local
codes, with the National Electrical Code NFPA70/ANSI C1-1993 or current edition
and Canadian Electrical Code Part1 CSA C.22.1.
The information contained in the manual is intended for use by a qualified service
technician familiar with safety procedures and equipped with the proper tools and
test instruments
Installation or repairs made by unqualified persons can result in hazards to you
and others.
Failure to carefully read and follow all instructions in this manual can result in
equipment malfunction, property damage, personal injury and/or death.
Table of Contents
1. Product Specifications
2. Indoor Unit Combination
3. Suggested Indoor Unit Model Numbers
4. Dimension Of Outdoor Unit
5. Refrigerant Cycle Diagram
6. Installation Details
7. Electronic Function
8. Wiring Diagrams And Electrical Trouble Shooting
9. Disassembly Instructions
10. Exploded View

CONTENTS
1. Indoor Unit Combination .......................................................................................................................................... 4
2. Suggested Indoor Unit Model Numbers ................................................................................................................... 6
3. Dimension Of Outdoor Unit...................................................................................................................................... 7
4. Refrigerant Cycle Diagram ........................................................................................................................................ 8
5. Installation Details .................................................................................................................................................... 9
6.1 Wrench torque sheet for installation ................................................................................................................. 9
6.2 Connecting the cables ........................................................................................................................................ 9
6.3 Pipe length and the elevation............................................................................................................................. 9
6.4 Installation for the first time .............................................................................................................................. 9
6.5 Adding the refrigerant after running the system for many years .................................................................... 11
6.6 Re-installation while the indoor unit need to be repaired...............................................................................11
6.7 Re-installation while the outdoor unit need to be repaired ............................................................................12
6. Electronic Function ................................................................................................................................................. 13
7.1 Abbreviation ..................................................................................................................................................... 13
7.2 Electric control working environment.............................................................................................................. 13
7.3 Main Protection................................................................................................................................................ 13
7.4 Control and Functions ......................................................................................................................................15
7. Wiring Diagrams......................................................................................................................................................19
8. Troubleshooting......................................................................................................................................................32
9.1Safety................................................................................................................................................................. 32
8.2 Indoor Unit Error Display............................................................................................................................. 33
9.3 Outdoor Unit Display ........................................................................................................................................36
9.4 Diagnosis and Solution ..................................................................................................................................... 40
9.5 Trouble Criterion Of Main Parts. ......................................................................................................................89
9. Disassembly Instructions ......................................................................................................................................100
Model: M2OC-18HFN1-M, M2OD-18HFN1-M (W210 metal plate)..................................................100

Model: M3OD-27HRDN1-M (W210 metal plate).................................................................................106
Model: M3OC-30HRFN1-M (W310 metal plate)..................................................................................113
Model: M4OC-36HRFN1-M (W520 metal plate)..................................................................................121

1. Indoor Unit Combination
Multi DC
Outdoor Unit
Nominal
capacity
Suggested
Combination
Limit
1drive 2(M2OC)
5.2kW
7
None
9
12
7+9
7+12
9+9
9+12
Multi DC
Outdoor Unit
Nominal
capacity
Suggested
Combination
Limit
1drive 2(M2OD)
5.2kW
7
None
9
12
7+9
7+12
9+9
9+12
12+12
Multi DC
Outdoor Unit
Nominal
capacity
Suggested
Combination
Limit
1 drive 3(27K)
7.5kW
7
The 18k indoor
unit should not
be Floor Ceiling
or Duct unit;
There should be
only one Floor
Ceiling, Oasis or
Duct unit;
9
12
18
7+7
7+9
7+12
7+18
9+9
9+12
9+18
12+12
12+18
7+7+7
7+7+9
7+7+12
7+7+18
7+9+9
7+9+12
7+9+18
7+12+12
9+9+9
9+9+12
9+12+12
Multi DC
Outdoor Unit
Nominal
capacity
Suggested
Combination
Limit
1 drive 3(30K)
8.0kW
7
There should be
only one Floor
Ceiling or Duct
unit;
9
12
18
7+7
7+9
7+12
7+18
9+9
9+12
9+18
12+12
12+18
18+18
7+7+7
7+7+9
7+7+12
7+7+18
7+9+9
7+9+12
7+9+18
7+12+12
7+12+18
9+9+9
9+9+12
9+9+18
9+12+12
9+12+18
12+12+12
Multi DC
Outdoor Unit
Nominal
capacity
Suggested
Combination
Limit
1 drive 4(36K)
10.5kW
7
None
9
12
18

7+7
7+9
7+12
7+18
9+9
9+12
9+18
12+12
12+18
18+18
7+7+7
7+7+9
7+7+12
7+7+18
7+9+9
7+9+12
7+9+18
7+12+12
7+12+18
9+9+9
9+9+12
9+9+18
9+12+12
9+12+18
9+18+18
12+12+12
12+12+18
12+18+18
7+7+7+7
7+7+7+9
7+7+7+12
7+7+7+18
7+7+9+9
7+7+9+12
7+7+9+18
7+9+9+9
7+9+9+12
7+9+9+18
7+9+12+12
7+9+12+18
7+12+12+12
7+12+12+18
9+9+9+9
9+9+9+12
9+9+9+18
9+9+12+12
9+9+12+18
9+12+12+12
9+12+12+18
12+12+12+12

3. Suggested Indoor Unit Model
Numbers
SUGGESTED INDOOR
M2OC-18HFN1-M
7K
MS9AI-07HRDN1-M
9K
MS9AI-09HRDN1-M(A)
MSV1I-09HRDN1-M
12K
MSV1I-12HRDN1-M
MS9AI-12HRDN1-M
MTBI-12HWDN1-M
MTBU-12HRDN1-M
MFAI-12HRDN1-M
MFAU-12HRFN1-M
MCA2I-12HRDN1-M
MCA2U-12HRFN1-M
MUBI-12HRDN1-M
MUBU-12HRFN1-M
SUGGESTED INDOOR
M2OD-18HFN1-M
7K
MS9AI-07HRDN1-M
9K
MS9AI-09HRDN1-M(A)
MSV1I-09HRDN1-M
MS11M-09HRFN1-MX4W
MS11M-09HRFN1-MX4W
12K
MSV1I-12HRDN1-M
MS9AI-12HRDN1-M
MS11M-12HRFN1-MV0W
MTBI-12HWDN1-M
MTBU-12HRDN1-M
MFAI-12HRDN1-M
MFAU-12HRFN1-M
MCA2I-12HRDN1-M
MCA2U-12HRFN1-M
MUBI-12HRDN1-M
MUBU-12HRFN1-M
MS11M-12HRFN1-MW0W
MS11M-12HRFN1-MV0W
SUGGESTED INDOOR
M3OD-27HRDN1-M
7K
MS9AI-07HRDN1-M
9K
MS9AI-09HRDN1-M(A)
MSV1I-09HRDN1-M
12K
MSV1I-12HRDN1-M
MS9AI-12HRDN1-M
MTBI-12HWDN1-M
MTBU-12HRDN1-M
MFAI-12HRDN1-M
MFAU-12HRFN1-M
MCA2I-12HRDN1-M
MCA2U-12HRFN1-M
MUBI-12HRDN1-M
MUBU-12HRFN1-M
18K
MSV1I-18HRDN1-M
MS9AI-18HRDN1-M
MCA2I-18HRDN1-M
MCA2U-18HRFN1-M
SUGGESTED INDOOR
M3OC-30HRFN1-M
7K
MS9AI-07HRDN1-M
9K
MS9AI-09HRDN1-M(A)
MSV1I-09HRDN1-M
MS11M-09HRFN1-MX4W
MS11M-09HRFN1-MW0W
12K
MSV1I-12HRDN1-M
MS9AI-12HRDN1-M
MS11M-12HRFN1-MV0W
MS11M-12HRFN1-MW0W
MTBI-12HWDN1-M
MTBU-12HRDN1-M
MFAI-12HRDN1-M
MFAU-12HRFN1-M
MCA2I-12HRDN1-M
MCA2U-12HRFN1-M
MUBI-12HRDN1-M
MUBU-12HRFN1-M
18K
MSV1I-18HRDN1-M
MS9AI-18HRDN1-M
MS11M-18HRFN1-MU0W
MTBI-18HWDN1-M
MTBU-18HRDN1-M
MCA2I-18HRDN1-M
MCA2U-18HRFN1-M
MUBI-18HRDN1-M
MUBU-18HRFN1-M
SUGGESTED INDOOR
M4OC-36HRFN1-M
7K
MS9AI-07HRDN1-M
9K
MS9AI-09HRDN1-M(A)
MSV1I-09HRDN1-M
MS11M-09HRFN1-MX4W
MS11M-09HRFN1-MW0W
12K
MSV1I-12HRDN1-M
MS9AI-12HRDN1-M
MS11M-12HRFN1-MV0W
MS11M-12HRFN1-MW0W
MTBI-12HWDN1-M
MTBU-12HRDN1-M
MFAI-12HRDN1-M
MFAU-12HRFN1-M
MCA2I-12HRDN1-M
MCA2U-12HRFN1-M
MUBI-12HRDN1-M
MUBU-12HRFN1-M
18K
MSV1I-18HRDN1-M
MS9AI-18HRDN1-M
MS11M-18HRFN1-MU0W
MTBI-18HWDN1-M
MTBU-18HRDN1-M
MCA2I-18HRDN1-M
MCA2U-18HRFN1-M
MUBI-18HRDN1-M
MUBU-18HRFN1-M

4. Dimension Of Outdoor Unit
Model
Dimension (mm(in.))
W
D
H
W1
A
B
M2OC-18HFN1-M
845(33.3)
320(12.6)
700(27.6)
908(35.7)
560(22)
335(13.2)
M2OD-18HFN1-M
M3OD-27HRDN1-M
M3OC-30HRFN1-M
900(35.4)
315(12.4)
860(33.9)
980(38.6)
590(23.2)
333(13.1)
M4OC-36HRFN1-M
990(39)
345(13.6)
965(38)
1075(42.3)
624(24.6)
366(14.4)

5. Refrigerant Cycle Diagram
5.1Refrigeration circuit drawing of inverter dual zone
LIQUID VALVE A
GAS VALVE A
HEAT
EXCHANGE
(EVAPORATOR) HEAT
EXCHANGE
(CONDENSER)
Compressor
4-WAY VALVE
COOLING
HEATING
T2 Evaporator
temp. sensor
middle
T1 Room
temp. sensor
T3
Condenser
temp. sensor
T5 Discharge
temp. sensor
T4 Ambient
temp. sensor
INDOOR OUTDOOR
EXV A CAPILIARY A
CHECK VALVE
CAPILIARY TUBE
EXV B CAPILIARY B
LIQUID VALVE B
GAS VALVE B
Accumulator
T2B-A Evaporator
temp. sensor outlet
T2B-B
5.2 Refrigeration circuit drawing of inverter tri-zone
LIQUID VALVE A
GAS VALVE A
HEAT
EXCHANGE
(EVAPORATOR) HEAT
EXCHANGE
(CONDENSER)
Compressor
4-WAY VALVE
COOLING
HEATING
T2 Evaporator
temp. sensor
middle
T1 Room
temp. sensor
T3
Condenser
temp. sensor
T5 Discharge
temp. sensor
T4 Ambient
temp. sensor
INDOOR OUTDOOR
EXV A CAPILIARY A
CHECK VALVE
CAPILIARY TUBE
EXV B CAPILIARY B
LIQUID VALVE B
GAS VALVE B
EXV C CAPILIARY C
LIQUID VALVE C
GAS VALVE C Accumulator
T2B-A Evaporator
temp. sensor outlet
T2B-B
T2B-C
5.3 Refrigeration circuit drawing of inverter qua-zone
LIQUID VALVE A
GAS VALVE A
HEAT
EXCHANGE
(EVAPORATOR) HEAT
EXCHANGE
(CONDENSER)
Compressor
4-WAY VALVE
COOLING
HEATING
T2 Evaporator
temp. sensor
middle
T1 Room
temp. sensor
T3
Condenser
temp. sensor
T5 Discharge
temp. sensor
T4 Ambient
temp. sensor
INDOOR OUTDOOR
EXV A CAPILIARY A
CHECK VALVE
CAPILIARY TUBE
EXV B CAPILIARY B
LIQUID VALVE B
GAS VALVE B
EXV C CAPILIARY C
LIQUID VALVE C
GAS VALVE C
EXV D CAPILIARY D
LIQUID VALVE D
GAS VALVE D
Accumulator High pressure
switch
Low pressure
switch
T2B-A Evaporator
temp. sensor outlet
T2B-B
T2B-C
T2B-D

6. Installation Details
6.1 Wrench torque sheet for installation
Outside diameter
Torque
Additional tightening torque
mm
inch
N.cm
N.cm
Ф6.35
1/4
1500(153kgf.cm)
1600(163kgf.cm)
Ф9.52
3/8
2500(255kgf.cm)
2600(265kgf.cm)
Ф12.7
1/2
3500(357kgf.cm)
3600(367kgf.cm)
6.2 Connecting the cables
The power cord connection should be
selected according to the following
specifications sheet.
Unit
AWG
Dual-zone(18K outdoor unit)
14
Tri-zone (27K/30K outdoor unit).
14
Quad-zone(36K outdoor unit)
12
For indoor unit and outdoor unit connection
line, 16AWG is ok for all.
6.3 Pipe length and the elevation
Maximum piping length and height difference
1 drive 2
1 drive 3
1 drive 4
Max. length for all rooms
(m)
30(98ft)
45(150ft)
60(200ft)
Max. length for one IU (m)
20(65.6ft)
25(82ft)
30(98ft)
Max. height
difference
between IU
and OU (m)
OU
higher
than IU
10(33ft)
10(33ft)
10(33ft)
OU lower
than IU
15(49.2ft)
15(49.2ft)
15(49.2ft)
Max. height difference
between IUs (m)
10(33ft)
10(33ft)
10(33ft)
Additional refrigerant charge
1 drive 2
1 drive 3
1 drive 4
Chargeless pipe
length (m)
15(49.2ft)
22.5(73.8ft)
30(98.4ft)
Additional
refrigerant
charge
g
15 x (length
for all rooms -
15)
15 x (length
for all rooms –
22.5)
15 x (length
for all rooms -
30)
oz
(.0.161
x(length for all
rooms –
49.2))
(.0.161
x(length for all
rooms –
73.8))
(.0.161x(lengt
h for all rooms
–98.4))
Caution:
●Refrigerant pipe diameter is different
according to indoor unit to be connected.
When using the extension pipe, refer to the
tables below.
●When refrigerant pipe diameter is different
from that of outdoor unit union (for 18K indoor
unit), additional transfer connector needs to
be used on outdoor unit union.
Indoor unit
Extension pipe diameter
(mm/inch)
Model
Pipe diameter
(mm/inch)
9K
Liquid
6.35(1/4)
Liquid
6.35(1/4)
Gas
9.52(3/8)
Gas
9.52(3/8)
12K 18K
Liquid
6.35(1/4)
Liquid
6.35(1/4)
Gas
12.7(1/2)
Gas
12.7(1/2)
Outdoor unit union diameter (mm/inch)
Indoor unit A/B/C/D
Liquid
6.35(1/4)
Gas
9.52(3/8)
6.4 Installation for the first time
Air and moisture in the refrigerant system have
undesirable effects as below:
●Pressure in the system rises.
●Operating current rises.
●Cooling or heating efficiency drops.
●Moisture in the refrigerant circuit may freeze
and block capillary tubing.
●Water may lead to corrosion of parts in the
refrigerant system.
Therefore, the indoor units and the pipes
between indoor and outdoor units must be leak
tested and evacuated to remove gas and
moisture from the system.
Gas leak check (Soap water method):
Apply soap water or a liquid neutral
detergent on the indoor unit connections or
outdoor unit connections by a soft brush to check
for leakage of the connecting points of the piping.
If bubbles come out, the pipes have leakage.
1. Air purging with vacuum pump

1. Completely tighten the flare nuts of the indoor
and outdoor units, confirm that both the 2-way
and 3-way valves are set to the closed
position.
2. Connect the charge hose with the push pin of
handle lo to the 3-way valves gas service
port..
3. Connect the charge hose of handle hi
connection to the vacuum pump.
4. Fully open the handle Lo of the manifold valve.
5. Operate the vacuum pump to evacuate.
6. Make evacuation for 30 minutes and check
whether the compound meter indicates -
0.1Mpa(14.5Psi). If the meter does not indicate -
0.1Mpa(14.5Psi) after pumping 30 minutes, it
should be pumped 20 minutes more. If the
pressure can’t achieve -0.1Mpa(14.5Psi) after
pumping 50 minutes, please check if there are
some leakage points. Fully close the handle Lo
valve of the manifold valve and stop the
operation of the vacuum pump. Confirm that the
gauge needle does not move (approximately 5
minutes after turning off the vacuum pump).
7. Turn the flare nut of the 3-way valves about
45°counterclockwise for 6 or 7seconds after
the gas coming out, then tighten the flare nut
again. Make sure the pressure display in the
pressure indicator is a little higher than the
atmosphere pressure. Then remove the
charge hose from the 3 way valve.
8. Fully open the 2 way valve and 3 way valve
and securely tighten the cap of the 3 way
valve.
2. Air purging by refrigerant
Procedure:
1). Confirm that both the 2-way and 3-way valves
are set to the closed position.
2). Connect the charge set and a charging cylinder
to the service port of the 3-way valve.
3). Air purging.
Open the valves on the charging cylinder and the
charge set. Purge the air by loosening the flare
nut on the 2-way valve approximately 45’ for 3
seconds then closing it for 1 minute; repeat 3
times.
After purging the air, use a torque wrench to tighten
the flare nut on the 2-way valve.
4). Check the gas leakage.
Check the flare connections for gas leakage.
5). Discharge the refrigerant.
Close the valve on the charging cylinder and
discharge the refrigerant by loosening the flare
nut on the 2-way valve approximately 45’ until the
gauge indicates 0.3Mpa(43.5Psi) to 0.5
Mpa(72.5Psi)..
6). Disconnect the charge set and the charging
cylinder, and set the 2-way and 3-way valves to
the open position.
Be sure to use a hexagonal wrench to operate the
valve stems.
7). Mount the valve stems nuts and the service port
cap.
Be sure to use a torque wrench to tighten the
service port cap to a torque 18N·m.
Be sure to check the gas leakage.
3. Adding refrigerant if the pipe length
exceeds chargeless pipe length