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B-VMH30SD-1

Century A-VMH36SD-1, A-VMH30SD-1, A-VMH18SU-1, B-VMH24SU-1, B-VMH18SU-1 Service Manual

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Page 1
Service Manual
VMH 9/12/18/24 SU Series
VMH 30/36 SD Series
Inverter Single Zone
Ductless Mini-Split
www.marsdelivers.com
Page 2
CONTENTS
1.1 Safety Precaution ......................................................................................... 1
1.2 Warning ......................................................................................................... 1
2.1 Model Names of Indoor/Outdoor Units ......................................................... 3
2.2 Part Names of Indoor/Outdoor Units ............................................................ 4
3.1 Indoor Unit .................................................................................................... 5
3.2 Outdoor Unit ................................................................................................. 7
6.1 Wrench Torque Sheet for Installation ............................................................ 9
6.2 Connnecting the Cables ............................................................................... 9
6.3 Pipe Length and the Elevation ...................................................................... 9
6.4 Initial Installation ......................................................................................... 10
6.5 Adding the Refrigerant After Running the System for Many Years ............. 10
6.6 Re-installation if the Indoor Unit Has Been Repaired ..................................11
6.7 Re-installation After Outdoor Unit Has Been Repaired ................................11
7. Operation Characteristics............................................................................... 13
8. Electronic Function ......................................................................................... 14
8.1 Abbreviation ................................................................................................ 14
8.2 Display Functions ....................................................................................... 14
8.3 Main Protection ........................................................................................... 15
8.4 Operation Modes and Functions ................................................................. 16
9. Troubleshooting .............................................................................................. 21
9.1 Indoor Unit Error Display ............................................................................ 22
9.2 Outdoor Unit Error Display .......................................................................... 23
9.3 Diagnosis and Solution ............................................................................... 26
10. Disassembly Instructions .............................................................................. 55
10.1 Indoor Unit................................................................................................. 55
10.2 Outdoor Unit .............................................................................................. 59
Page 3
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
1. Precaution
1.1 Safety Precaution
To prevent injury and property
damage, these instructions must be followed.
Incorrect operation due to
ignoring instructions will cause harm or damage.
Before servicing the unit, be sure
to read service manual.
1.2 Warning
INSTALLATION
Do not use a defective or
underrated circuit breaker. Use this appliance on a dedicated circuit.
There is risk of fire or electric shock.
For electrical work, contact the
dealer, seller, a qualified electrician, or an authorized service center.
Do not disassemble or repair this product, there is risk of fire or electric shock.
Always ground this product.
There is risk of fire or electric shock.
Install panel and cover of control
box securely.
There is risk of fire or electric shock.
Always install a dedicated circuit
and breaker.
Improper wiring or installation may cause electric shock.
Use the correctly rated breaker or
fuse.
There is risk of fire or electric shock.
Do not modify or extend the power
cable.
There is risk of fire or electric shock.
Do not install, remove, or reinstall
the unit by yourself (customer).
There is risk of fire, electric shock, explosion, or injury.
Use caution when unpacking and
installing the product.
Sharp edges could cause injury, be especially careful of the case edges and the fins on the condenser and evaporator.
For installation, always contact the
dealer or an authorized service center.
Do not install this product on a
defective installation stand.
Be sure the installation area does
not deteriorate with age.
If the base collapses, the air conditioner could fall with it, causing property damage, product failure, and personal injury.
Do not let the air conditioner run
for a long time when the humidity is very high and a door or a window is left open.
Take care to ensure that power
cable cannot be pulled out or damaged during operation. There is
risk of fire or electric shock.
Do not place anything on the
power cable.
There is risk of fire or electric shock.
Do not plug or unplug the power
supply plug during operation.
There is risk of fire or electric shock.
Do not handle or touch the product
with wet hands.
Do not place a heater or other
appliance near the power cable.
There is risk of fire and electric shock.
Do not allow water to run into
electrical parts.
It may cause fire, failure of the product, or electric shock.
Do not store or use flammable gas
or combustibles near this product.
There is risk of fire or failure of product.
Do not use the product in a tightly
closed space for a long time.
Oxygen deficiency could occur.
When flammable gas leaks, turn off
the gas and open a window for ventilation before turning the product on.
If strange sounds or smoke come
from product, turn the breaker off or disconnect the power supply cable.
There is risk of electric shock or fire.
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
Stop operation and close the window
in storm or hurricane. If possible, remove the product from the window before the hurricane arrives.
There is risk of property damage, failure of product, or electric shock.
Do not open the inlet grill of the
product during operation.
There is risk of physical injury, electric shock, or product failure.
When the product is soaked, contact
an authorized service center. There is
risk of fire or electric shock.
Use caution that water does not
enter the product.
There is risk of fire, electric shock, or product damage.
Ventilate the area from time to time
when operating this unit together with a stove etc.
There is risk of fire or electric shock.
Turn the main power off when
cleaning or maintaining the product.
There is risk of electric shock.
When the product is not be used for
a long time, turn off the breaker.
There is risk of product damage or failure, or unintended operation.
Take care to ensure that nobody can
step on or fall onto the outdoor unit.
This could result in personal injury and product damage.
CAUTION
Always check for gas (refrigerant)
leakage after installation or repair of product.
Low refrigerant levels may cause failure of product.
Install the drain hose to ensure that
water is drained away properly.
A bad connection may cause water leakage.
Keep level even when installing this
product.
It can avoid vibration or water leakage.
Do not install the product where
the noise or hot air from the
outdoor unit could affect neighbors.
Use two or more people to lift and
transport the product.
Do not install the product where it
will be exposed to sea wind (salt spray) directly.
It may cause corrosion on the product. Corrosion, particularly on the condenser and evaporator fins, could cause product malfunction or inefficient operation.
OPERATIONAL
Do not expose the skin directly to
cool air for long periods. (Do not sit in the draft).
Do not use the product for
purposes such as preserving foods, works of art, etc. It is a consumer comfort air conditioner, not a precision refrigeration system.
There is risk of damage or loss of property.
Do not block the inlet or outlet of
air flow.
Use a soft cloth to clean. Do not
use harsh detergents, solvents, etc.
There is risk of fire, electric shock, or damage to the plastic parts of the product.
Do not touch the metal parts of the
product when removing the air filter. They are very sharp.
Do not step on or put anything on
the product. (outdoor units)
Always insert the filter securely.
Clean the filter every two weeks or more often if necessary.
A dirty filter reduces the efficiency of the air conditioner and could cause product malfunction or damage.
Do not insert hands or other
objects through air inlet or outlet while the product is operating.
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
Do not drink the water drained from
the product.
Use a firm stool or ladder when
cleaning or maintaining the product.
Be careful and avoid personal injury.
Replace the all batteries in the
remote control with new ones of the same type. Do not mix old and new batteries or different types of batteries.
There is risk of fire or explosion.
Do not recharge or disassemble the
batteries. Do not dispose of batteries in a fire.
They may explode.
If the liquid from the batteries gets
onto your skin or clothes, wash it well with clean water. Do not use the remote if the batteries have leaked.
2. Part Names And Functions
2.1 Model Names of Indoor/Outdoor units
Series Capacity Indoor units
9k B-VMH09SU-1 A-VMH09SU-1
12k
18k
Inverter
24k
30k
36k
B-VMH12SU-1
B-VMH18SU-1 A-VMH18SU-1
B-VMH24SU-1 A-VMH24SU-1
B-VMH30SD-1 A-VMH30SD-1
B-VMH36SD-1 A-VMH36SD-1
Outdoor units
A-VMH12SU-1
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
2.2 Part names of Indoor/Outdoor units
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
3. Dimension
3.1 Indoor Unit
W D
Model W D H
B-VMH09SU-1
(835mm)
32.9in
(198mm)
7.8in
(280mm)
11.0in
B-VMH12SU-1
B-VMH18SU-1
(990mm)
39.0in
(218mm)
8.6in
(315mm)
12.4in
B-VMH24SU-1
(1186mm )
46.7in
(258mm)
10.2in
(343mm)
13.5in
B-VMH30SD-1
B-VHH36SD-1
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For B-VMH09SU-1, B-VMH12SU-1
For B-VMH18SU-1
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
For B-VMH24SU-1
For B-VMH30SD-1, B-VMH36SD-1
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
3.2 Outdoor Unit
More than 30cm(11.8in)
More than 30cm(11.8in)
Fe
n
c
e
o
o
b
s
r
t
a
c
l
e
s
More than 60cm(23.6in)
More than 70cm(27.6in)
More than 60cm(23.6in) (Service space)
Note: The above drawing is only for reference. The appearance of your units may be different.
Model W in(mm) D in(mm) H in(mm) W1 in(mm) A in(mm) B in(mm)
A-VMH09SU-1
A-VMH12SU-1
A-VMH18SU-1
A-VMH24SU-1
A-VMH30SD-1
A-VMH36SD-1
31.5(800)
33.27(845) 14.29(363) 27.64(702)
37.24(946) 16.14(410) 31.89(810)
13.11(333) 21.81(554)
7
34.25(870) 20.24(514) 13.39(340)
35.98(914) 21.26(540) 13.78(350)
40.55(1030) 26.50(673) 15.87(403)
Page 10
4. Refrigerant Cycle Diagram
INDOOR OUTDOOR
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
HEAT EXCHANGE (EVAPORATOR)
T2 Evaporator temp. sensor
T1 Room temp. sensor
LIQUID SIDE
2-WAY VALVE
GAS SIDE
3-WAY VALVE
CAPILIARY TUBE
Accumulator
Electronic expansion valve
Compressor
CAPILIARY TUBE
T4 Ambient temp. sensor
4-WAY VALVE
T5 Discharge temp. sensor
T3 Condenser temp. sensor
HEAT EXCHANGE (CONDENSER)
COOLING
HEATING
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
5. Wiring Diagram
(Please refer the wiring diagram on the unit)
6. Installation Details
6.1 Wrench torque sheet for installation
Additional
Outside Diameter Torque
Ф6.35mm
Ф9.52mm
Ф12.7mm
Ф15.9mm
1/4in
3/8in
1/2in
5/8in
ll lb-ft
l8 lb-ft
25.8 lb-ft 26.5 lb-ft
33.2 lb-ft
Tightening
Torque
12 lb-ft
19 lb-ft
34.7 lb-ft
6.3 Pipe length and the elevation
Models
VMH09SU-1
VMH12SU-1
VMH18SU-1
VMH24SU-1
VMH30SD-1
VMH36SD-1
Models
A-VMH09SU-1
Standard
Length
(Ф 9.52mm)
(Ф 12.7mm)
(Ф 15.9mm)
Max.
Elevation
Pipe Size
Gas Liquid
3/8in
1/2in
5/8in
Max.
Length
A
1/4in
(Ф 6.35mm)
1/4in
(Ф 6.35mm)
3/8in
(Ф 9.52mm)
Additional
Refrigerant
Ф19mm
3/4in
47.9 lb-ft 49.4 lb-ft
6.2 Connecting the cables
The power cord should be selected according to the
following specifications sheet.
Appliance Amps AWG Wire Size
10 18
13 16
18 14
25 12
30 10
The cable size and the current of the fuse or switch
are determined by the maximum current indicated
on the nameplate which is located on the side
panel of the unit. Please refer to the nameplate
before selecting the cable, fuse and switch.
B-VMH09SU-1
A-VMH12SU-1
B-VMH12SU-1
A-VMH18SU-1
B-VMH18SU-1
A-VMH24SU-1
B-VMH24SU-1
A-VMH30SD-1
B-VMH30SD-1
A-VMH36SD-1
B-VMH36SD-1
7.5m
(24.6ft)
7.5m
(24.6ft)
7.5m
(24.6ft)
7.5m
(24.6ft)
10m
(32.8ft)
20m
(65ft)
25m
(82ft)
30m
(82.0ft)
25m
(82.0ft)
30m
(98ft)
50m
(164ft)
65m
(213ft)
15g/m
(0.16oz/ft)
15g/m
(0.16oz/ft)
30g/m
(0.32oz/ft)
30g/m
(0.32oz/ft)
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
6.4 Initial Installation
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 unit 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 and 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 form, the pipes have leakage.
5) Evacuate for 30 minutes and check that
micron gauge reads <500 microns. If not, it
should be pumped 20 minutes more. If the
pressure can’t achieve <500 microns after
pumping 50 minutes, please check for
leakage points. Fully close the handle valve
of the low pressure manifold set and stop the
operation of the vacuum pump. Confirm that
the gauge needle does not move above 500
microns (approximately 5 minutes after
turning off the vacuum pump).
6) 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.
7) Fully open the 2-way valve and 3-way valve
and securely tighten the cap of the 3-way
valve.
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 low pressure charge hose to
the 3-way valve's gas service port.
3) Connect the high pressure hose to the
vacuum pump.
4) Fully open the handle of the low pressure
manifold valve.
6.5 Adding the refrigerant after running the system for many years
Procedure
1) Connect the charge hose to the 3-way
service port, open the 2-way valve and the
3-way valve. Connect the charge hose to
the valve at the bottom of the cylinder. Turn
the cylinder bottom up to ensure liquid
charge.
2) Purge the air from the charge hose. Open
the valve at the bottom of the cylinder and
press the check valve on the charge set to
purge the air (be careful of the liquid
refrigerant).
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
3) Put the charging cylinder onto the electronic
scale and record the weight.
4) Operate the air conditioner in the cooling
mode.
5) Open the valves (Low side) on the charge set
and charge the system with liquid refrigerant.
6) When the electronic scale displays the proper
weight (refer to the gauge and the pressure
of the low side), disconnect the charge hose
from the 3-way valve’s service port
immediately and turn off the air conditioner
before disconnecting the hose.
7) Mount the valve stem caps and the service
port. Use torque wrench to tighten the
service port cap to a torque of 13F.P.
Be sure to check for gas leakage.
6.6 Re-installation if the indoor unit has been repaired
1. Air purging with vacuum pump
5) Operate the vacuum pump to evacuate.
6) Evacuate for 30 minutes and check
whether the compound meter indicates
500 microns. If the meter does not indicate
500 microns after pumping 30 minutes, it
should be pumped 20 minutes more. If the
pressure can’t achieve 500 microns after
pumping 50 minutes, please check for
leakage points. Fully close the low
pressure valve of the manifold 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 7
seconds 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.
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 low pressure charge hose to
the 3-way valve's gas service port.
3) Connect the high pressure charge hose to
the vacuum pump.
4) Fully open the low pressure handle of the
manifold.
6.7 Re-installation after outdoor unit has been repaired
1. Evacuation for the whole system
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
Procedure:
1) Confirm that both the 2-way and
3-way valves are set to the opened
position.
2) Connect the vacuum pump to 3-way
valve’s service port.
3) Evacuate for approximately one hour.
Confirm that the compound meter
indicates <500 microns.
4) Close the valve (Low side) on the
charge set, turn off the vacuum pump,
and confirm that the gauge needle
does not move (approximately 5
minutes after turning off the vacuum
pump).
5) Disconnect the charge hose from the
vacuum pump.
2. Refrigerant charging
Procedure:
1) Connect the charge hose to the charging
cylinder, open the 2-way valve and the 3-
way valve. Connect the charge hose
which you disconnected from the vacuum
pump to the valve at the bottom of the
cylinder. Turn the cylinder bottom up to
ensure liquid charge.
2) Purge the air from the charge hose. Open
the valve at the bottom of the cylinder and
press the check valve on the charge set
to purge the air (be careful of the liquid
refrigerant).
3) Put the charging cylinder onto the
electronic scale and record the weight.
4) Open the valves (Low side) on the charge
set and charge the system with liquid
refrigerant. If the system cannot be
charged with the specified amount of
refrigerant, or can be charged with a little
at a time (approximately 5oz. each time),
while operating the air conditioner in the
cooling cycle, wait approximately one
minute and then repeat the procedure.
5) When the electronic scale displays the
proper weight, disconnect the charge
hose from the 3-way valve’s service port
immediately. If the system has been
charged with liquid refrigerant while
operating the air conditioner, turn off the
air conditioner before disconnecting the
hose.
6) Mount the valve stem caps and the
service port. Use torque wrench to tighten
the service port cap to a torque of 13F.P.
Be sure to check for gas leakage.
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
7. Operation Characteristics
Mode
Room temperature
Outdoor temperature
VMH30SD-1
VMH36SD-1
Outdoor temperature
VMH09SU
VMH12SU
VMH18SU
VMH24SU
Temperature
Cooling operation Heating operation Drying operation
17℃～32℃
(62℉～90℉)
0
～50°C
°C
～122°F)
(32
°F
°C
～50
°C
°C
-15°C～50
(5°F～122°F)
(need low ambient cooling function)
-30
(-22°F～122°F)
0℃～30℃
(32℉～86℉)
°C
-15
～30
(5°F～86°F)
-30
～30
°C
(-22°F～86
°C
°C
°F
(32
)
(32
10℃～32℃
(50℉～90℉)
°C
0
～50°C
～122°F)
°F
0
～50°C
°C
～122°F)
°F

 
+32
CAUTION:
1. If the air conditioner is used beyond the above conditions, certain safety protection features
may come into operation and cause the unit to operate abnormally.
2. The room relative humidity should be less than 80%. If the air conditioner operates beyond
this figure, the surface of the air conditioner may attract condensation. Please set the vertical air
flow louver to its maximum angle (vertically to the floor), and set HIGH fan mode.
3. The optimum performance will be achieved during this operating temperature zone.
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
8. Electronic Function
8.1 Abbreviation
T1: Indoor room temperature
T2: Coil temperature of evaporator
T3: Coil temperature of condenser
T4: Outdoor ambient temperature
TP: Compressor discharge temperature
8.2 Display function
8.2.1 Icon explanation on indoor display board.
ION indication lamp (optional function)：This lamp illuminates when Clean
Air feature is activated.
DEFROST indication lamp: Lights up when the air conditioner starts defrosting
automatically or when the warm air control feature is activated in heating operation.
OPERATION indication lamp：This lamp illuminates when the air conditioner is in
operation.
TIMER indication lamp：Lights up during Timer operation.
Temperature indicator：Displays the temperature settings when the air conditioner
is operational. Displays the malfunction code.
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
8.3 Main Protection
8.3.1 Three minutes delay at restart for
compressor
Less than one minute delay for the first time
start-up and a three minute delay for others.
8.3.2 Temperature protection of compressor
top
The unit will stop working when the compressor
top temp. protector cuts off, and will restart after
the compressor top temp. protector restarts.
8.3.3 Temperature protection of compressor
discharge
Compressor discharge temp. TP >115°F
(239°F) for 5s, compressor stops.
8.3.4 Fan speed is out of control
When Indoor fan speed runs too low
(300RPM) or too high (1500RPM) for a pre-
determined time, the unit will stop and the LED
will display the failure
8.3.7 Compressor preheating functions
Preheating permitting condition: When T4 (outdoor ambient temperature) ＜3°C
(37.4°F), the preheating function will be
activated.
8.3.8 Zero crossing detection error
protection
If AC detects time interval is not correct for
continuous 240s, the unit will stop and the LED
will display the failure. The correct zero
crossing signal time interval should be between
6-13ms.
8.3.9 Sensor protection at open circuit and
breaking disconnection.
When there is only one temperature sensor in
malfunction, the air conditioner will keep
working but show the error code, in case of any
emergency use.
When there is more than one temperature
sensor in malfunction, the air conditioner will
stop working.
8.3.5 Inverter module protection
The Inverter module has a protection function
for current, voltage and temperature. If these
protections happen, the corresponding code
will display on indoor unit and the unit will stop
working.
8.3.6 Indoor fan delayed open function
When the unit starts up, the louver will be active
immediately and the indoor fan will open 10
seconds later.
If the unit runs in heating mode, the indoor fan
will also be controlled by anti-cold wind
function. Fan will turn on, low speed, at 87°F
coil temperature. Fan will switch to high speed
at 114°F coil temperature.
8.3.10 Refrigerant leakage detection
This function is only active in cooling mode. It
can better prevent the compressor being
damaged by refrigerant leakage or
compressor overload.
Open condition:
When compressor is active, the value of the
coil temperature of evaporator T2 has no
change, or very little change.
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
8.4 Operation Modes and Functions
8.4.1 Fan mode
1) Outdoor fan and compressor stop.
2) Temperature setting function is disabled, and no setting temperature is displayed.
3) Indoor fan can be set to high/med/low/auto.
4) The louver operates same as in cooling mode.
5) Auto fan:
T1
a
b
c
d
e
8.4.2 Cooling Mode
8.4.2.1 Compressor running rules
When T1-Ts<-2℃(28.4°F), the compressor will stop, when T1—T
compressor will be activated.
When the AC runs in mute mode, the
compressor will run at low frequency. When
the current is more than set value, the current
protection function will be activated, and the
compressor will stop.
>-0.5℃(31.1°F), the
S
medium, low and auto.
When the setting temp. is reached, if the
compressor stops running, indoor fan motor
will run in Minimum speed or set speed. The
indoor fan is controlled as below:
Setting fan
speed
H
M
L
T1-Td ℃(°F)
A H（=H） B C
D M(M=M) E F
G L(L=L) H I
Actual fan speed
H+(H+=H+G)
H-（H-=H-G)
M+(M+=M+Z)
M-(M-=M-Z)
L+(L+=L+D)
L-(L-=L-D)
The auto fan acts as below rules:
T1
a
b
c
d
e
8.4.2.4 Condenser temperature protection
T3
Off
Decrease
8.4.2.2 Outdoor fan running rules
The outdoor unit will be run at different fan
speeds according to T4.
For different outdoor units, the fan speeds are
different.
T 4
A+
A
B
C
D
E
8.4.2.3 Indoor fan running rules
In cooling mode, indoor fan runs all the time
Hold
Resume
When condenser temperature temp. is more than setting value, the compressor will stop.
8.4.2.5 Evaporator temperature protection
When Evaporator temperature is less than setting value, the compressor will stop.
8.4.3 Heating Mode
8.4.3.1 Compressor running rules
When T1-Ts>-ΔT, the compressor will stop, when T1-T
<ΔT-1.5，the compressor will be
S
on. ΔT is the programmed parameter of
16
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
When the AC runs in mute mode, the compressor will run with low frequency. When the current is more than set value, the current protection function will be activated and the compressor will stop.
8.4.3.2 Outdoor fan running rules
The outdoor unit will be run at different fan speeds according to T4. For different outdoor units, the fan speeds are different.
T4
E
D
C
B
A
A+
8.4.3.3 Indoor fan running rules When the compressor is on, the indoor fan can be set to high/med/low/auto/mute. When indoor unit coil temp. is low, the anti-cold air function will start and indoor fan motor will run at low speed, the speed can’t be changed, when the temp. is lower than setting value, the indoor fan motor will stop. When the indoor temp reaches the setting temp., the compressor will stop, the indoor fan motor will run at the minimum speed or setting speed. (The anti-cold air function is valid). The indoor fan is controlled as below:
Setting fan
speed
H
M
L
T1-Td
℃
Actual fan speed
H-（H-=H-G)
）
H（=H
H+(H+=H+G)
M-(M-=M-Z)
M(M=M)
M+(M+=M+Z)
L-(L-=L-D)
L(L=L)
L+(L+=L+D)
Auto fan action in heating mode:
T1-Td+ΔT
8.4.3.4 Defrosting mode
AC will enter the defrosting mode according to
the value of temp. of T3 and the value range of
temp. change of T3 and also the compressor
running time.
During the defrosting mode, the compressor
keeps running, indoor and outdoor motor will
stop, defrost lamp of the indoor unit will be lit.
“ .” Will be displayed.
8.4.3.5 Evaporator coil temperature
protection
Off
Decrease
Hold
Resume
When evaporator temperature temp. is more
than the setting protection value, the compressor
will stop.
8.4.4 Auto-mode
This mode can be chosen with remote controller
and the setting temperature can be changed
between 17°C(62.6°F)~30°C(86°F). In auto
mode, the machine will choose cooling, heating
or fan-only mode according to ΔT.
17
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
(ΔT =T1-Ts).
T1-Ts
Cooling
Fan only
Heating*
Heating*:
Indoor fan will run at auto fan of the relevant mode. The louver operates same as in relevant mode. If the machine switches mode between heating and cooling, the compressor will stop and then choose mode according to T1-Ts. If the setting temperature is modified, the machine will choose running function again.
8.4.5 Drying mode
8.4.5.1 Indoor fan speed is fixed at breeze and can’t be changed. The louver angle is the same as in cooling mode.
8.4.5.2 Low indoor room temperature protection In drying mode, if room temperature is lower than 10°C(50°F), the compressor will stop and not resume until room temperature exceeds 12°C(53.6°F).
8.4.5.3 Evaporator anti-freezing protection, condenser high temperature protection and outdoor unit frequency limit are active and the same as that in cooling mode.
In forced auto, forced cooling or any other operation mode, pressing touch button will turn
off the machine.
8.4.6.2 In forced operation mode, all general protections and remote control are available.
8.4.6.3 Operation rules: Forced cooling mode: The compressor runs at F2 frequency and indoor fan runs as breeze. After running for 30 minutes. the machine will turn to auto mode as 24°C(75.2°F) setting temperature. Forced auto mode: The action of forced auto mode is the same as normal auto mode with 24°C(75.2°F) setting temperature.
8.4.7 Auto-Restart function
The indoor unit is equipped with auto-restart function, which is carried out through an auto­restart module. In case of a sudden power failure, the module memorizes the setting conditions before the power failure. The unit will resume the previous operation setting (not including swing function) automatically after 3 minutes when power returns. If the memorization condition is forced cooling mode, the unit will run in cooling mode for 30 minutes and turn to auto mode as 24°C(75.2° F) setting temp. If AC is off before power off and AC is required to start up now, the compressor will have 1 minute delay when power on. Other conditions, the compressor will have 3 minutes delay when restarting.
8.4.5.4 The outdoor fan operates the same as in cooling mode.
8.4.6 Forced operation function
8.4.6.1 Enter forced operation function: When the machine is off, pressing the touch button will carry the machine to forced auto mode. If pressing the button once again within 5 seconds, the machine will turn into forced cooling mode.
8.4.8 Refrigerant Leakage Detection
With this new technology, the display area will
show “EC” when the outdoor unit detects
refrigerant leakage.
8.4.9 8°C Heating (optional)
When the compressor is running, the indoor
fan motor will run without anti-cold air function.
When the compressor is off, the indoor
fan motor is off.
18
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
8.4.10 Point check function
Press the LED DISPLAY or LED or MUTE button of the remote controller three times, and then
press the AIR DIRECTION or SWING button three times in ten seconds, the buzzer will sound
for two seconds. The air conditioner will enter into the information inquiry status. You can
press the LED button, then DIRECT button to check the next or front item’s information. When
the AC enters the “information inquiry” status, it will display the code name
details are as follows.
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 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
Causes of compressor stop. ST Causes of compressor
Reserve A0
Reserve A1
Reserve 0
Reserve 1
Reserve 2
Reserve 3
Reserve 4
Reserve 5
Reserve 6
Reserve L
Reserve A
Reserve U
Reserve T
running time
stop.
in 2 seconds, the
19
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
When the AC enters into the information inquiry status, it will display the following code values
during the next 25s
Enquiry
Display value Meaning Remark
information
T1,T2,T3,T4,
T2B,TP,TH,
Targeted
Frequency,
Actual
Frequency
-1F,-1E,-1d,-1c,-
1b,-1A
-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 /
0 OFF
1,2,3,4 Low speed, Medium
Outdoor fan
speed
14-FF
.
-25,-24,-23,-22,-21,-2
0
1. Display temperature is actual value.
2. Temperature is °C no matter what kind
of remote controller is used.
3. T1,T2,T3,T4,T2B display range:-25~70,
TP display range:-20~130.
4. Frequency display range: 0~159HZ.
5. If the actual value exceeds the range, it
will display the maximum value or
minimum value.
For some big capacity motors.
speed, High speed,
Turbo
Actual fan speed =
Display value turns
to decimal value and
then multiply 10. The
For some small capacity motors,
display value is from 14-FF(hexadecimal),
the corresponding fan speed range is from
200-2550RPM.
unit is RPM.
EXV opening
0-FF
angle
Compressor
0-FF 0-255 minutes If the actual value exceeds the
continuous
running time
Causes of
0-99 For the detailed
compressor
stop.
Reserve 0-FF
Actual EXV opening
value = Display
value turns to
decimal value and
then multiply 2.
range, it will display the maximum
value or minimum value.
Decimal display
meaning, please
consult with engineer
20
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
9. Troubleshooting
Safety
An electric charge is still kept in capacitors even when the power supply is shut off. Do not forget to discharge the
electricity in capacitor.
Electrolytic Capacitors
(HIGH VOLTAGE! CAUTION!)
For other models, please connect discharge resistance (approx.100Ω 40W) or soldering iron (plug) between +, -
terminals of the electrolytic capacitor on the contrary side of the outdoor PCB.
Note: The picture above is only for reference. Your plug may be different.
21
Page 24
9.1 Indoor Unit Error Display
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
Operation
lamp
☆ 1 time
☆ 2 times
☆ 3 times
☆ 4 times
☆ 5 times
☆ 6 times
☆ 7 times
☆ 1 times
☆ 2 times
☆ 3 times
☆ 4 times
Timer lamp Display LED STATU S
X E0 Indoor unit EEPROM parameter error
X E1 Indoor / outdoor units communication error
X E2 Zero-crossing signal detection error
X E3 Indoor fan speed has been out of control
X E4
X E5
Indoor room temperature sensor T1 open circuit or short
circuit
Evaporator coil temperature sensor T2 open circuit or
short circuit
X EC Refrigerant leakage detection
O F0 Overload current protection
O F1
O F2
O F3
Outdoor ambient temperature sensor T4 open circuit or
short circuit
Condenser coil temperature sensor T3 open circuit or
short circuit
Compressor discharge temperature sensor TP open
circuit or short circuit
☆ 5 times
☆ 6 times
☆ 1 times ☆
☆ 2 times ☆
☆ 3 times ☆
☆ 4 times ☆
☆ 5 times ☆
☆ 7 times ☆
O F4 Outdoor unit EEPROM parameter error
O F5 Outdoor fan speed has been out of control
P0 IPM malfunction or IGBT over-strong current protection
P1 Over voltage or over low voltage protection
P2 High temperature protection of IPM module
P3* Outdoor ambient temperature too low.
P4 Inverter compressor drive error
P6 Low pressure protection(Only for 36K)
O（light） X（off） ☆（flash）
*P3
1) In heating mode, when the outdoor temperature is lower than -13°F for 1 hour, the indoor
unit display error code P3.
2) If the outdoor temperature is higher than -7.6°F for 10 minutes and compressor stop for 1 hour
or outdoor temperature is higher than 23°F for 10 minutes, then the unit will return to work.
* Fault Symptom:
The display board shows a garbled code or a code that is not an error code found in the service
manual nor a temperature reading.
Troubleshooting:
Use the remote controller. If the unit does not respond to the remote, the indoor PCB needs to be
replaced; if the unit does respond, then the display board needs to be replaced.
22
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
9.2 Outdoor Unit Error Display
For A-VMH09SU-1, A-VMH12SU-1, A-VMH18SU-1
290-330VDC standby
fast recovery diode (FRD )
IPM for compressor
connect to DC motor
0V AC standby
’
10~200V AC
IGBT
running
IGBT1
R18
R18A
E305
IPM1
C243C244
R20
R67
R47
C84 R88
R19 R57
C242
connect to reactance
-
AC AC
+
A
K
K
R316
R316A
NW NV NU
W
V
U
P
210-300VDC running
BR1
CN12
REACTOR
CN25
CN13
D5
C30
BLACK
W
CN29
RED
V
CN28
U
BLUE
CN27
C2
R38
C41
ZR4
C58
bridge
R141
R154
R153
R155
R150
R142
R151
R152
DZ6
+
D8
+
R34
D9
R89
R39
R35
E2
C11
C12
IC4 R36
R37
R51
C38
D12
C54
C10
D15
D10
R135
C44
E301
IC32
C31
C45
R136
R104
R61
R59
R109
R60
C306
C307
C310
C308
C311
R58
C309
C34
R110
R156R158
+
DZ301
Q3
C103
R171
R172
VNC
C85
CIN
R169
C83
FO
C86 R170
W
V
VN1
R315
R159
C312
W­V-
R157
C301
C91
C302
U-
D11
VP1
R75
R84
C76
W+
IC34
V+ U+
E302
C60
DZ302
+
C314
VWB
VVB
E303
C61
DZ303
+
VUB
C316
C318
DZ304
E304
C62
+
U
PTC1
+
E5
P
N
+
E3
C96
R123
C95
R122
C66
R119 C98
CN30
R125
R118
C99
R126
R117
R102
R86
E8
+
D4
R56
C21
R69
R168
R54
R55
R68
R90
1
CN9
connect to PC communication
LED2 （red）&LED3（green）: status light combination LED2 and LED3 show errors
refer to the attechment Word
（
connect to the DR module
CN22
DR
C5
L1
C6
R11
C82
R127
CN21
DR
+
RY1
E4
C40
C403
A
7
R140
0 1 R
IC402
R107
R408
C110
R108
R406
R404
R407
R46
IC403
R45
+
R322
Q2
R321
+
C19
E17
E14
R77 R76
R320
C18
D2
R82R81
C514
E6
R520
C43
R50
C92
C80
R124
C516
C20
R521
R12
LED3
+
R83
R80
+
C15
C79
C25
R14
R79
C515
LED2
C17
R48
C47
17
C94
33
C506
E407
C93
C27
C49
IC9
C33
C97
R70
R15
1
49
C52
R10
R17
C32
R41
R148
C37
R134
R42
R178
R177
C35
C22
PC817
R62
IC31
C90
C65C67 R64 R121
R49
R176
IC7
R63
R65 R66
24LC08
24LC512
IC8
IC21
PC817
17122200000309
）
fuse 250V 30A
C3
C4
E409
Rdi
Low-Fre NO
Have
YES
No
Rdi
Ripm
C105
Ripm
Temp-Pro
Have
YES NO
No
R401
C50
E402
C401
T401
10
1
D401
9
IC11
3
7
4
5
C402
6
R402
R405
D402
R85
R78
C408
E401
+
+
Q8
IC406
E403
D14
+
C406
E406
C407
+
15V17V
IC405
7815
C409
+
E404
IC407
R516
R518
R517
R519
C513
CN24
311 TEST
R508
R507
PC817
E503
IC5
C36
R73
+
R25
C39
R22
OSC1
C51
C53
E504
DZ2
+
E27
R93
PC817
IC3
+
R99
R95 R96 C73 R106
CN19
KFR-72W/BP2-( 311+0515+6061HD+ PSS30S92F6-AG+6822+HEAT).D.13.WP2.1
test port
reserve
internal drive motor
6 5 4 3 1
drive power voltage: +15VDC
rotate speed feedback signal
0-15V square signal
DC negative pole: GND
DC positive pole P: 315VDC
D404
+
C1
IC404
7805
+
+
12V 5V
C404
+
R403
E405
D403 IC14
+
R166
R164
C411
R24
R23
R165
R43
R414
C46
R44
R16
C14
R52
LED1
J4
J5
+
E410
+
R91
IC101
C153
R21
R53
+
E10
R74
C28
R120
R175
+
E408
+
DZ503
C503
+
+
DZ504
C504
LED: status light（yellow slow flicker：standby（0.5Hz quick flicker：error （2Hz continuous li ght: running
connect to earth
[V1.8] 2015-01-16
CN6
CN6-1
CN3
DSA1
CN7
ZR2
65T 250V30A
ZR1
ZR3
RY2
IN
-
+
RY3
RY4
D13
RY5
C405
+
C147
CN39
24LC08
IC12
E28
R415
R161
R167
R412
R162
C87
R413
22
11
R160
1
C23
34
IC17
44
D7
C74
R9
C75
R72
R28
R26
C507
R514
C511
R510
+
C509
DZ501
R512
R501
R505
R503
C501
C502
C505
~ ~
CN38
1
D3
R163
C89
+
J1
J3
J2
X1
R13
C26
C24
C42
C78
C77
R30
C510
C512
R509
R511
R513
C508
R502
R504
R506
+
DZ502
+
E502
）
）
CN2
RC3
4-WAY
RC1
AC
RC2
AC-FAN
RC4
R137
D20
C7
HEAT
D1
R2
R1
C8
R40
IC10
R97
R92
IC1 PC817
J6
IC2
PC851
C48
E1
Q1
C9
R6
C13
R3
R4
R5
R7
R32
R87
E11
R419
R33
R522
R8
R515
R515A
C517
R523
R101 R100
R71
E22
+
E23
+
E24
R29
R27
R31
NTC4
DC-FAN
IPM2
Exhaust
CN10
TPT3T4
CN17
）
pipe temp.sensor& room temp. sensor
exhaust temp. sensor
L-IN
PMV
CN18
CN23
HuiQi
S
+
TestPort
+
+
Suction
CN414
CN1
CN60
CN5
EEPROM Programmer Port
CN16
CN20
TP T4 T3
7 6 5 4 3 2 1
+5V DC
RT
reserve
U
V W
RT
N-IN
FUSE1
CN8
power supply 208-230V AC connect to the terminal
connect to 4-way val ve when 4-way is on, output 208-230V AC
/CN4 connect to
CN5
chassis
when heater is on, output 208-230V A C
AC FAN mototr
connect to compressor heater when heater is on, output 208-230V AC
Connect to PC communication
connect to electric expansion valve
test port
external drive motor connect to DC motor 0V AC standby 10~200V AC
running
’
IPM for DC FAN
+5V DC
+5V DC
RT
heater
1 low speed
2 hign speed
3 ground
6 5 4 3 2 1
+12VDC
+12VDC
+12V DC pul se wav e between( +4)-GND
+12V DC pulse wa ve between( +3)-GND
+12V DC pulse wa ve between( +2)-GND
+12V DC pulse wa ve between( +1)-GND
After power on, LED3(Green color) and LED2(Red color) will be flash if the unit has some
problems.
No. Problems
1
Normal, Standby
LED3
(Green)
O X
LED2
(Red)
2 Normal, Operation X O
3 IPM malfunction or IGBT over-strong current protection
☆
X P0
4 Over voltage or too low voltage protection O O P1
5 EEPROM parameter error O
6 Inverter compressor drive error X
7 Inverter compressor drive error
8 Inverter compressor drive error
☆
☆ ☆
☆
☆
O P4
O（light） X（off） ☆（2.5Hz flash）
IU
display
E5
P4
P4
23
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
For A-VMH24SU-1, A-VMH30SD-1, A-VMH36SD-1
+12V DC
+12V DC
Connect to the Indoor evap.pipe
out temp. sensor
connect to the 4-WAY
when 4-way is ON, output 208-230VAC
connect to compressor heater
when heater is ON, output 208-230V AC
CN43-4/CN37 CONNECT TO
AC FAN MOTOR(LOW SPEED)
CN43-3/CN36 AC fan motor low speed connector
CN43-2/CN35 AV fan motor N phase
CN43-5,CN43-1/CN41,CN42 AC fan motor capacitor connector
CN22 L CN3 N
CN44 L
electric
CN10 N
heater1
CN40 L
electric
CN4 N
heater 2
pipe temp sensor
(3.3V)
(3.3V)
room temp sensor
high pressure sensor
low pressure sensor
T2B-A、T2B-B、T2B-C、T2B-D、T2B-E
connect to exhaust temp. sensor
Fuse 5A/250V
T3
connect to trmp. sensor
T4
connect to high and low pressure sensor
CONNECT TO INVERTER driver
CN42
CN3
CN35
Electric Expansion Value E
C
N
CN4
N
N
CN10
N
HEA T1
CN40
CN44
HEA T2
CN8
T3
T4
CN9
HIGHLOW
CN7
Electric Expansion Value D
CN19
E
[1.4]2014.06.26
FAN -L
CN37
CN36
FAN -H
CN43
FAN
C
CN41
4-W AY
CN22
CN18
D
+12V DC pulse wave between (+2)-GND
+12V DC pulse wave between (+3)-GND
+12V DC pulse wave between (+4)-GND
+12V DC pulse wave between (+1)-GND
6 5 4 3 2 1
Electric Expansion Value C
CN17
C
T2B -E
T2B -C
CN33
TP
T2B -D
CN14
Electric Expansion Value B
CN21
T2B -BT2B -A
CN13
CompTop
CN20
AB
Electric Expansion Value A
CN34
485 communication
testPort connect to detector
CN16
CN12
FAN_OUT
N-IN
CN2
S
external drive DC fan motor connector
external drive DC fan motor ouput terminal
FAN_IN
CN11
N
CN1
L-IN
EAR TH
P-1
external drive DC fan motor input terminal
CN30
S-A
CN29
S-B
L
CN28
S-C
CN27
S-D
CN26
S-E
current loop communication A
current loop communication B
current loop communication C
current loop communication C
current loop communication D
current loop communication E
Fuse T30A/250V
connect to earth
Signal wire connect to the terminal 24VDC Pulse wave
power supply
208-230V AC
connect to the terminal
208-230V AC
connect to the terminal
CN23 reserve
CN5
N-OUT
CN6
L-OUT
CN23
202302141206
SHOW/SW
EU-KFR105W/BP3T5N1-350S.D.13.WP1-1
test report connect to detector
digital display button
digital display
24
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
IPM Board
CN57 Debug
EU-KFR105W/BP2T3N1-350(767).D.13.MP2-1
IC1424C08
IC1
connect to DC fan motor 0VAC (standby) 10-200VAC (running)
202302141237
IPM2
IPM1
CN19
W
V
U
TO MAIN
CN55
+
OU TF AN(DC)
W
CN 55
TO- MAIN
W
connect to the compressor
0VAC (standby)
V
10-200VAC (running)
U
V
U
CAPACITOR Voltage
­290-330VDC (standby)
+
210-300VDC (Running)
CN 54
L-I N2
PFC-L2
N-I N2
CN53
CN54
power supply
208-230V AC
connect to the terminal
PFC-L1
CN51CN52
PFC inductance terminal
[1.6]2014.10.16
CN58
EATTH
EARTH
25
Page 28
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
9.3 Diagnosis and Solution
9.3.1 EEPROM parameter error diagnosis and solution(E0/F4)
Error Code
E0/F4
Malfunction conditions
Indoor or outdoor PCB main chip does not receive feedback
from EEPROM chip.
Possible causes
● Installation error
● PCB faulty
Troubleshooting:
Power off , then restart the
unit 2 minutes later.
Yes
Replace the indoor /outdoor
main PCB.
EEPROM: a read-only memory whose contents can be erased and reprogrammed using a pulsed
voltage. For the location of EEPROM chip, please refer to the below photos.
Indoor PCB
Note: The two photos above are only for reference, they may not be the same as your unit.
Outdoor PCB
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9.3.2 Indoor / outdoor unit’s communication diagnosis and solution(E1)
Error Code
E1
Malfunction condition
Possible causes ● Wiring error
Indoor unit does not receive the feedback from outdoor unit during
110 seconds and this condition happens four times continuously.
● Indoor or outdoor PCB faulty
Trouble shooting:
Check the outdoor wiring connection.
Is the wiring correct?
Check the indoor wiring connection.
Is the wiring correct?
Check reactor OHM
between terminals
to ground
∞
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Remark:
Use a multimeter to test the DC voltage
between 2 port and 3 port of outdoor unit.
The red pin of multimeter connects with 2
port while the black pin is for 3 port.
When AC is running normal, the voltage
will move alternately between -25V to
25V.
If the outdoor unit has m alfunction, the
voltage will move alternately with positive
value.
If the indoor unit has a malfunction, the
voltage will be an unchanging value.
Remark:
Use a multimeter to test the resistance
of the reactor which does not connect
with capacitor.
The normal value should be around
zero ohm. Otherwise, the reactor has
malfunctioned.
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9.3.3 Zero crossing detection error diagnosis and solution (E2)
Error Code
Malfunction conditions
E2
When PCB does not receive zero crossing signal feedback for 4
minutes or the zero crossing signal time interval is abnormal.
Possible causes ● Connection error
● PCB faulty
Troubleshooting:
Check if the connections and
power supply are normal?
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
9.3.4 Fan speed has been out of control diagnosis and solution (E3)
Error Code
Malfunction conditions
Possible causes
Troubleshooting:
Does Not Run
Shut off the power supply,
fan rotates by hand
E3/F5
When indoor fan speed remains too low (300RPM) for certain
time, the unit will stop and the LED will display the failure.
● Wiring error
● Fan assembly faulty
● Fan motor faulty
● PCB faulty
Runs
Is fan motor wiring correct
and solid?
Measure the voltage for
the fan motor from the
main PCB. OK?
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
Index 1:
1. Indoor or Outdoor DC Fan Motor (control chip is in fan motor)
Power on and when the unit is in standby, measure the voltage of pin1-pin3, pin4-pin3 in fan
motor connector. If the value of the voltage is not in the range showing in below table, the
PCB has problems and needs to be replaced.
DC motor voltage input and output(voltage: 220-240V~)
NO. Color Signal Voltage
1 Red Vs/Vm 280V~380V
2 --- --- ---
3 Black GND 0V
4 White Vcc 14-17.5V
5 Yellow Vsp 0~5.6V
6 Blue FG 14-17.5V
DC motor voltage input and output(voltage :115V~)
NO. Color Signal Voltage
1 Red Vs/Vm 140V~190V
2 --- --- ---
3 Black GND 0V
4 White Vcc 14-17.5V
5 Yellow Vsp 0~5.6V
6 Blue FG 14-17.5V
2. Outdoor DC Fan Motor (control chip is in outdoor PCB)
Power on, and check if the fan runs normally. If the fan runs normally, the PCB has problems and
needs to be replaced, If the fan does not run normally, measure the resistance of each two pins.
If the resistances are not equal to each other, the fan motor has problems and needs to be
replaced, otherwise the PCB has problems and needs to be replaced, otherwise the PCB has
problems and needs to be replaced.
3. Indoor AC Fan Motor
Power on and set the unit running in fan mode at high fan speed. After running for 15 seconds,
measure the voltage of pin1 and pin 2. If the value of the voltage is less than 100V, the PCB has
problems and needs to be replaced.
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9.3.5 Open circuit or short circuit of temperature sensor diagnosis and solution (E5)
Error Code
Malfunction conditions
E4/E5/F1/F2/F3
If the sampling voltage is lower than 0.06V or higher than 4.94V,
the LED will display the failure.
Possible causes ● Wiring error
● Sensor faulty
Troubleshooting:
Check the connection
between temperature
sensor and PCB. OK?
Measure the resistance
value of the sensor. OK?
Correct the connection
Replace the sensor
Replace indoor or
outdoor main PCB.
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
9.3.6 Refrigerant Leakage Detection diagnosis and solution (EC)
Error Code
Malfunction conditions
Possible causes
Troubleshooting:
EC
Define the evaporator coil temp.T2 of the compressor just starts
running as Tcool.
In the beginning 5 minutes after the compressor starts up, if T2
Tcool－2
＜
°C(
Tcool－35.6
seconds and this situation happens 3 times, the display area will
show “EC” and AC will turn off.
●
T2 sensor faulty
Indoor PCB faulty
●
System problems, such as leakage or blocking.
●
°F)
does not keep continuous 4
Is there any refrigerant leakage? Especially the joints, such as the
gas valve and the liquid valve.
Is there any blockage? (Such as the
capillary or the welded points of the pipes.)
Clear the blockage.
Check if T2 sensor is well
connected. Correct the
installation or replace T2 sensor.
Does the problem remain again?
Repair the leak and
recharge the refrigerant.
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9.3.7 Overload current protection diagnosis and solution (F0)
Error Code
Malfunction conditions
F0
An abnormal current rise is detected by checking the specified
current detection circuit.
Possible causes ● Power supply problems.
● System blockage
● PCB faulty
● Wiring error
● Compressor malfunction
Troubleshooting:
Check the power supply.
Is it normal?
Is there any blockage?
Check the compressor
resistance values.
Refer to [Compressor Checking].
Is it normal?
Stop the unit.
Check the power supply.
Clear the blockage
Replace the compressor
Check to make sure connections
and wiring are correct.
Check the reactor.
Is it normal?
Replace the outdoor main PCB.
Correct the connections
or replace the wires.
Replace the reactor.
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9.3.8 IPM malfunction or IGBT over-strong current protection diagnosis and solution (P0)
Error Code
Malfunction conditions
Possible causes
Troubleshooting:
For 9K~18K:
Check the wiring between main
PCB and compressor. Are the wires
and connectors broken?
IPM continuity check. Check to
make sure the IPM terminal
resistance values are uniform.
P0
When the voltage signal that IPM send to compressor drive chip
is abnormal, the display LED will show “P0” and AC will turn off.
● Wiring error
● IPM malfunction
● Outdoor fan assembly faulty
● Compressor malfunction
● Outdoor PCB faulty
Correct the connection or replace
the wires and connectors.
Replace the IPM board or replace the
main PCB if the IPM board and main
PCB are integrated together.
Check whether the outdoor fan
runs properly or the outdoor
unit ventilation is good.
Check whether the compressor
resistance values are uniform.
Replace the outdoor main PCB if the
main PCB and IPM are separate.
Please refer to the solution of [Fan Speed Has
Been Out Of Control] malfunction.
Replace the compressor.
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
For example:
Note: The photos below are only for reference, it may be not be the same as your equipment.
P-U
P-V
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
P-W
N-U
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
N-V
N-W
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
For 24K~36K:
At first test the resistance between all points; U, V, W of IPM and P, N. If any result is 0 or close to 0, the
IPM is defective. If OK, please follow the procedure below:
Check whether the power
voltage is normal
Measure whether outdoor
terminal voltage is normal?
Measure whether the voltage
between L and N is normal?
Measure whether input voltage of
bridge rectifier is normal?
Measure whether the voltage
between P and N is normal
(refer to Appendix 4)?
Measure whether the
connecting wire between main
board and the IPM board is
connected tightly
Check whether the connecting
wire of the compressor is
connected correctly or tightly
Reconnect
Reconnect
Restart the unit when the power
supply is normal
Power connections
Check the wiring
of L and N
Check the wiring
of bridge rectifier
Reconnect
Reconnect
Reconnect
Check whether bridge
rectifier is normal
Replace the PFC module (if applicable)
Check the wiring of
reactor or inductor
Replace the bridge rectifier
Reconnect the wiring
Check if the outdoor unit
ventilation is good
Check if the outdoor fan
runs properly
Replace IPM board
Replace the outdoor main PCB
Check that the
compressor is normal
Check whether the refrigerant system is OK.
Provide ventilation
Please refer to the solution of [fan
speed has been out of control
malfunction] to correct problem.
Replace the compressor
Check whether
reactor or inductor
is normal
Replace reactor
or inductor
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
9.3.9 Over voltage or too low voltage protection diagnosis and solution (P1)
Error Code
Malfunction conditions
Possible causes
Troubleshooting:
Check the power supply.
Is it OK?
Check the connections
and wires. Are they OK?
Check the voltage between
P and N. Is it OK?
P1
An abnormal voltage rise or drop is detected by checking the
specified voltage detection circuit.
● Power supply problems
● System leakage or blockage
● PCB faulty
Stop the unit
Correct the connections or
replace the wires
Replace the IPM board
Check the reactor. Is it OK?
Replace the reactor
P
Replace outdoor main PCB
Remark:
Measure the DC voltage between P and N port. The normal value should be around 310V.
N
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
9.3.10 High temperature protection of IPM module diagnosis and solution (P2)
Error Code
Malfunction conditions
Possible causes
Troubleshooting:
Check if the fastening screws
on the PCB and IPM radiator
are attached properly.
Tighten the screws and
apply silicon grease.
P2
If the voltage is not 5V, the LED will display the failure.
●
PCB faulty
Replace the outdoor control PCB.
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9.3.11 Inverter compressor drive error diagnosis and solution (P4)
Error Code
Malfunction conditions
Possible causes
Troubleshooting:
For 9K~18K:
Check that the wiring between
main PCB and compressor
are connected well.
P4
An abnormal inverter compressor drive is detected by a special
detection circuit, including communication signal detection,
voltage detection, compressor rotation speed signal detection
and so on.
● Wiring error
● IPM malfunction
● Outdoor fan assembly faulty
● Compressor malfunction
● Outdoor PCB faulty
Correct the connection
or replace the wires
and connectors.
Check the reactor or
inductor. Is it normal?
Check the IPM.
Is it installed correctly?
IPM continuity check.
Make sure the IPM terminal
resistance values are uniform.
Check the outdoor fan to make
sure it runs properly and the
outdoor unit ventilation is good.
Check that the compressor
resistance values are uniform.
Replace the reactor
or inductor.
Correct the installation,
tighten the screws and
apply silicon grease.
Replace the IPM board or replace the
main PCB if the IPM board and main
PCB are integrated together.
Please refer to the solution of [Fan Speed Has Been Out Of
Control] malfunction
Replace the compressor.
Replace the outdoor main PCB if the
main PCB and IPM are separate.
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IPM continuity check
Turn off the power, let the large capacity electrolytic capacitors discharge completely, and dismount the IPM. Use a
digital tester to measure the resistance between P and UVWN; UVW and N.
Digital tester Normal resistance value Digital tester Normal resistance value
(+)Red (-)Black
N U
P
U V
V W
W (+)Red
∞
(Several MΩ)
(+)Red (-)Black
N
∞
(Several MΩ)
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For 24K~36K:
T
est the resistance between all ports of U, V, W of IPM and P, N. If any result is 0 or close to 0, the
IPM is defective. Otherwise, please follow the procedure below:
Check whether the power
voltage is normal.
Measure whether outdoor
terminal voltage is normal?
Measure whether the voltage
between L and N is normal?
Measure whether input voltage
of bridge rectifier is normal?
Measure whether the voltage
between P and N is normal.
Refer to Appendix 4.
Check whether the
connecting wire between
main board and the IPM
board is connected tightly.
Check whether the
connecting wire of the
compressor is connected
correctly and tightly.
Check that the wiring
of power wires is
correct and tight
Check that the
wiring of L and N is
correct and tight
Check that the wiring
of bridge rectifier is
correct and tight
Reconnect
Reconnect
Restart the unit when the
power supply is normal
Reconnect
Reconnect
Reconnect
Check whether
bridge rectifier is
normal.
Replace the PFM module (if applicable)
Check the wiring
of reactor or
inductor
Replace bridge rectifier
Reconnect the
wiring
Check if the outdoor unit
ventilation is good.
Check if the outdoor fan
runs properly.
Replace IPM board
Replace the outdoor
main PCB
Is the compressor
functioning normal?
Check whether the refrigerant
system is OK.
Correct ventilation issue
Please refer to the solution of
[Fan Speed Has Been Out of Control] malfunction. Find out the cause and have it solved.
Replace the
compressor
Check whether
reactor or inductor
is normal
Replace reactor
or inductor
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9.3.12 Low pressure protection diagnosis and solution (P6)
Error Code
P6
Malfunction conditions When the pressure of system reaches a preset value, the low
pressure protector will switch off. After the pressure returns to
normal, the protection code will disappear.
Possible causes ● Wiring error
● Pressure protector faulty
● Fan motor faulty
● PCB faulty
● System problems
Troubleshooting:
Is the wiring between the
low pressure protector
and main control board
connected tightly and
correctly?
Is the low
pressure protector
broken?
Correct wiring
Disconnect the plug.
Measure the resistance of
the low pressure protector.
If the protector is normal
the value is 0.
Is the outdoor ambient
temperature too low?
Is the valve core of high
pressure valve open?
Does the indoor
fan run properly in
cooling mode?
Replace outdoor
main board
Is refrigerant level OK?
Replace low pressure protector
Stop the unit
Back seat valve core
of high pressure valve
Please refer to the solution of [Fan Speed Has Been Out Of
Control] malfunction. Find out the
cause and have it solved.
Check whether the
refrigerant system is OK
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Main parts check
1. Temperature sensor checking
Disconnect the temperature sensor from PCB, measure the resistance value with a tester.
Temperature sensors:
Room temp.(T1) sensor,
Indoor coil temp.(T2) sensor,
Outdoor coil temp.(T3) sensor,
Outdoor ambient temp.(T4) sensor,
Compressor discharge temp.(TP) sensor.
Measure the resistance value of each winding by using a multi-meter.
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Appendix 1: Temperature Sensor Resistance Value Table for T1,T2,T3,T4 (°C--K)
°C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm
-20 -4 115.266 20 68 12.6431 60 140 2.35774 100 212 0.62973
-19 -2 108.146 21 70 12.0561 61 142 2.27249 101 214 0.61148
-18 0 101.517 22 72 11.5 62 144 2.19073 102 216 0.59386
-17 1 96.3423 23 73 10.9731 63 145 2.11241 103 217 0.57683
-16 3 89.5865 24 75 10.4736 64 147 2.03732 104 219 0.56038
-15 5 84.219 25 77 10 65 149 1.96532 105 221 0.54448
-14 7 79.311 26 79 9.55074 66 151 1.89627 106 223 0.52912
-13 9 74.536 27 81 9.12445 67 153 1.83003 107 225 0.51426
-12 10 70.1698 28 82 8.71983 68 154 1.76647 108 226 0.49989
-11 12 66.0898 29 84 8.33566 69 156 1.70547 109 228 0.486
-10 14 62.2756 30 86 7.97078 70 158 1.64691 110 230 0.47256
-9 16 58.7079 31 88 7.62411 71 160 1.59068 111 232 0.45957
-8 18 56.3694 32 90 7.29464 72 162 1.53668 112 234 0.44699
-7 19 52.2438 33 91 6.98142 73 163 1.48481 113 235 0.43482
-6 21 49.3161 34 93 6.68355 74 165 1.43498 114 237 0.42304
-5 23 46.5725 35 95 6.40021 75 167 1.38703 115 239 0.41164
-4 25 44 36 97 6.13059 76 169 1.34105 116 241 0.4006
-3 27 41.5878 37 99 5.87359 77 171 1.29078 117 243 0.38991
-2 28 39.8239 38 100 5.62961 78 172 1.25423 118 244 0.37956
-1 30 37.1988 39 102 5.39689 79 174 1.2133 119 246 0.36954
0 32 35.2024 40 104 5.17519 80 176 1.17393 120 248 0.35982
1 34 33.3269 41 106 4.96392 81 178 1.13604 121 250 0.35042
2 36 31.5635 42 108 4.76253 82 180 1.09958 122 252 0.3413
3 37 29.9058 43 109 4.5705 83 181 1.06448 123 253 0.33246
4 39 28.3459 44 111 4.38736 84 183 1.03069 124 255 0.3239
5 41 26.8778 45 113 4.21263 85 185 0.99815 125 257 0.31559
6 43 25.4954 46 115 4.04589 86 187 0.96681 126 259 0.30754
7 45 24.1932 47 117 3.88673 87 189 0.93662 127 261 0.29974
8 46 22.5662 48 118 3.73476 88 190 0.90753 128 262 0.29216
9 48 21.8094 49 120 3.58962 89 192 0.8795 129 264 0.28482
10 50 20.7184 50 122 3.45097 90 194 0.85248 130 266 0.2777
11 52 19.6891 51 124 3.31847 91 196 0.82643 131 268 0.27078
12 54 18.7177 52 126 3.19183 92 198 0.80132 132 270 0.26408
13 55 17.8005 53 127 3.07075 93 199 0.77709 133 271 0.25757
14 57 16.9341 54 129 2.95896 94 201 0.75373 134 273 0.25125
15 59 16.1156 55 131 2.84421 95 203 0.73119 135 275 0.24512
16 61 15.3418 56 133 2.73823 96 205 0.70944 136 277 0.23916
17 63 14.6181 57 135 2.63682 97 207 0.68844 137 279 0.23338
18 64 13.918 58 136 2.53973 98 208 0.66818 138 280 0.22776
19 66 13.2631 59 138 2.44677 99 210 0.64862 139 282 0.22231
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A
ppendix
2: Temperature Sensor Resistance Value Table for TP (°C --K)
°C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm
-20 -4 542.7 20 68 68.66 60 140 13.59 100 212 3.702
-19 -2 511.9 21 70 65.62 61 142 13.11 101 214 3.595
-18 0 483 22 72 62.73 62 144 12.65 102 216 3.492
-17 1 455.9 23 73 59.98 63 145 12.21 103 217 3.392
-16 3 430.5 24 75 57.37 64 147 11.79 104 219 3.296
-15 5 406.7 25 77 54.89 65 149 11.38 105 221 3.203
-14 7 384.3 26 79 52.53 66 151 10.99 106 223 3.113
-13 9 363.3 27 81 50.28 67 153 10.61 107 225 3.025
-12 10 343.6 28 82 48.14 68 154 10.25 108 226 2.941
-11 12 325.1 29 84 46.11 69 156 9.902 109 228 2.86
-10 14 307.7 30 86 44.17 70 158 9.569 110 230 2.781
-9 16 291.3 31 88 42.33 71 160 9.248 111 232 2.704
-8 18 275.9 32 90 40.57 72 162 8.94 112 234 2.63
-7 19 261.4 33 91 38.89 73 163 8.643 113 235 2.559
-6 21 247.8 34 93 37.3 74 165 8.358 114 237 2.489
-5 23 234.9 35 95 35.78 75 167 8.084 115 239 2.422
-4 25 222.8 36 97 34.32 76 169 7.82 116 241 2.357
-3 27 211.4 37 99 32.94 77 171 7.566 117 243 2.294
-2 28 200.7 38 100 31.62 78 172 7.321 118 244 2.233
-1 30 190.5 39 102 30.36 79 174 7.086 119 246 2.174
0 32 180.9 40 104 29.15 80 176 6.859 120 248 2.117
1 34 171.9 41 106 28 81 178 6.641 121 250 2.061
2 36 163.3 42 108 26.9 82 180 6.43 122 252 2.007
3 37 155.2 43 109 25.86 83 181 6.228 123 253 1.955
4 39 147.6 44 111 24.85 84 183 6.033 124 255 1.905
5 41 140.4 45 113 23.89 85 185 5.844 125 257 1.856
6 43 133.5 46 115 22.89 86 187 5.663 126 259 1.808
7 45 127.1 47 117 22.1 87 189 5.488 127 261 1.762
8 46 121 48 118 21.26 88 190 5.32 128 262 1.717
9 48 115.2 49 120 20.46 89 192 5.157 129 264 1.674
10 50 109.8 50 122 19.69 90 194 5 130 266 1.632
11 52 104.6 51 124 18.96 91 196 4.849
12 54 99.69 52 126 18.26 92 198 4.703
13 55 95.05 53 127 17.58 93 199 4.562
14 57 90.66 54 129 16.94 94 201 4.426
15 59 86.49 55 131 16.32 95 203 4.294
16 61 82.54 56 133 15.73 96 205 4.167
17 63 78.79 57 135 15.16 97 207 4.045
18 64 75.24 58 136 14.62 98 208 3.927
19 66 71.86 59 138 14.09 99 210 3.812
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Appendix
°C °F °C °F °C °F °C °F °C °F
3:
-5 23 21 69.8 51 123.8 82 179.6 113 235.4
-4 24.8 22 71.6 52 125.6 83 181.4 114 237.2
-3 26.6 23 73.4 53 127.4 84 183.2 115 239
-2 28.4 24 75.2 54 129.2 85 185 116 240.8
-1 30.2 25 77 55 131 86 186.8 117 242.6
0 32 25.5 77.9 56 132.8 87 188.6 118 244.4
0.5 32.9 26 78.8 57 134.6 88 190.4 119 246.2
1 33.8 27 80.6 58 136.4 89 192.2 120 248
1.5 34.7 28 82.4 59 138.2 90 194 121 249.8
2 35.6 29 84.2 60 140 91 195.8 122 251.6
2.5 36.5 30 86 61 141.8 92 197.6 123 253.4
3 37.4 31 87.8 62 143.6 93 199.4 124 255.2
3.5 38.3 32 89.6 63 145.4 94 201.2 125 257
4 39.2 33 91.4 64 147.2 95 203 126 258.8
4.5 40.1 34 93.2 65 149 96 204.8 127 260.6
5 41 35 95 66 150.8 97 206.6 128 262.4
6 42.8 36 96.8 67 152.6 98 208.4 129 264.2
7 44.6 37 98.6 68 154.4 99 210.2 130 266
8 46.4 38 100.4 69 156.2 100 212 131 267.8
9 48.2 39 102.2 70 158 101 213.8 132 269.6
10 50 40 104 71 159.8 102 215.6 133 271.4
11 51.8 41 105.8 72 161.6 103 217.4 134 273.2
12 53.6 42 107.6 73 163.4 104 219.2 135 275
13 55.4 43 109.4 74 165.2 105 221 136 276.8
14 57.2 44 111.2 75 167 106 222.8 137 278.6
15 59 45 113 76 168.8 107 224.6 138 280.4
16 60.8 46 114.8 77 170.6 108 226.4 139 282.2
17 62.6 47 116.6 78 172.4 109 228.2 140 284
18 64.4 48 118.4 79 174.2 110 230 141 285.8
19 66.2 49 120.2 80 176 111 231.8 142 287.6
20 68 50 122 81 177.8 112 233.6 143 289.4
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Appendix
4:
Normal voltage of P and N
208-240V (1-phase, 3-phase) 380-420V (3-phase)
In standby
around 310VDC around 530VDC
In operation
With passive
PFC module
>200VDC >310VDC >370VDC >450VDC
With partial active PFC
module
With fully
active PFC
module
/
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2. Compressor checking
Measure the resistance value of each winding by using the tester.
Position Resistance Value
Blue -
Red
Blue -
Black
Red -
Blue
DA110S1
C-30FZ
0.8Ω
(20°C
/68°F)
DA130M1C-
31FZ
1.77Ω
(20°C
/68°F)
DA250S2C-3
0MT
0.55Ω
(20°C
/68°F)
ATM115D43
UFZ2
1.87Ω
(20°C
/68°F)
ATM150D23
UFZ
1.72Ω
(20°C
/68°F)
TNB306FPG
MC-L
0.53Ω
(20°C
/68°F)
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3. IPM continuity check
Turn off the power, let the large capacity electrolytic capacitors discharge completely, and dismount the
IPM. Use a digital tester to measure the resistance between P and UVWN; UVW and N.
Digital tester Normal resistance value Digital tester Normal resistance value
(+)Red (-)Black
N U
U V
P
V W
W (+)Red
∞
(Several MΩ)
(+)Red (-)Black
N
∞
(Several MΩ)
4. Indoor AC Fan Motor
Measure the resistance value of each winding by using the tester.
Position
Black - Red 100.5Ω±8%
(20°C /68°F)
(Brand: Weiling)
White - Black 64.5Ω±8%
(20°C /68°F)
(Brand: Weiling)
Resistance Value
RPG13B RPG50B(YKFG-50-4-1)
100Ω±8%
(20°C /68°F)
(Brand: Dayang)
68.5Ω±8%
(20°C /68°F)
(Brand: Dayang)
82.2Ω±8%
(20°C /68°F)
(Brand: Weiling)
72.3Ω±8%
(20°C /68°F)
(Brand: Weiling)
85Ω±8%
(20°C /68°F)
(Brand: Dayang)
57.8Ω±8%
(20°C /68°F)
(Brand: Dayang)
52
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
5. Pressure On Service Port
Cooling chart:
°F(°
C
)
IDT
ODT
75
(23.89)
85
(29.44)
95
(35)
105
(40.56)
115
(46.11)
BAR 70/59 8.2 7.8 8.1 8.6 10.1
BAR 75/63 8.6 8.3 8.7 9.1 10.7
BAR 80/67 9.3 8.9 9.1 9.6 11.2
°F(°
)
C
IDT
ODT
75
(23.89)
85
(29.44)
95
(35)
105
(40.56)
115
(46.11)
PSI 70/59 119 113 117 125 147
PSI 75/63 124 120 126 132 155
PSI 80/67 135 129 132 140 162
°F(°
C
)
IDT
ODT
75
(23.89)
85
(29.44)
95
(35)
105
(40.56)
115
(46.11)
MPA 70/59 0.82 0.78 0.81 0.86 1.01
MPA 75/63 0.86 0.83 0.87 0.91 1.07
MPA 80/67 0.93 0.89 0.91 0.96 1.12
53
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
Heating Chart:
°F
(°C)
IDT
ODT
57/53
(13.89/11.67)
47/43
(8.33/6.11)
37/33
(2.78/0.56)
27/23
(-2.78/-5)
17/13
(-8.33/-10.56)
BAR 55 30.3 28.5 25.3 22.8 20.8
BAR 65 32.5 30.0 26.6 25.4 23.3
BAR 75 33.8 31.5 27.8 26.3 24.9
°F
(°C)
IDT
ODT
57/53
(13.89/11.67)
47/43
(8.33/6.11)
37/33
(2.78/0.56)
27/23
(-2.78/-5)
17/13
(-8.33/-10.56)
PSI 55 439 413 367 330 302
PSI 65 471 435 386 368 339
PSI 75 489 457 403 381 362
°F
(°C)
IDT
ODT
57/53
(13.89/11.67)
47/43
(8.33/6.11)
37/33
(2.78/0.56)
27/23
(-2.78/-5)
17/13
(-8.33/-10.56)
MPA 55 3.03 2.85 2.53 2.28 2.08
MPA 65 3.25 3.00 2.66 2.54 2.33
MPA 75 3.38 3.15 2.78 2.63 2.49
54
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
Panel
10 Disassembly Instructions
Note: This part is for reference, the photos may have slight difference with your machine.
10.1 Indoor unit
No. Parts name Procedures Remarks
1 Front panel How to remove the front
panel.
Overview:
1) Pull below side of the
panel and release the
clips. Then remove
the front panel.
2) Remove the filter and
horizontal louver.
3) Remove the four
fixing screws.
4) Remove the cover
(one screw).
5) Lift the panel frame
and release the
connector of display
assembly connectors.
Then remove the
panel frame
assembly.
One screw
fixing the cover
Clip
Clip
Filter
Four screws
Connector for
display assembly
55
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
2 Electrical
parts
How to remove the
electrical parts.
1) After removing the
front panel from
procedure 1, pull out
the room temp.
sensor and
evaporator coil
sensor. Remove the
grounding screws.
2) Pull out the clip
toward the left side
and open the cover.
3) Remove the
mounting screw and
open the electrical
box cover.
Swing motor
Grounding screws
Clip for electronic control box cover
Room temp. sensor
Evaporator coil
temp. sensor
4) Pull out the
connectors of the
swing motor and fan
motor.
5) Remove the
mounting screw and
then remove the
electronic control box
and air outlet
assembly.
Fan motor
connector and
swing motor
Fixing screw
56
Page 59
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
3 Evaporator
How to remove the evaporator.
1) After removing the
front panel assembly
and electrical parts
following procedure 1
and procedure 2,
remove the pipe
holder at the rear
side of the unit.
2) Remove the two
screws on the
evaporator at the
base bearing side.
3) Remove two screws
on the evaporator at
the fixed plates and
then lift the
evaporator assembly.
Two screws at the base bearing side
Two
screws at
the fixed
plates
57
Page 60
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
4 Fan and
motor
How to remove the fan
and motor.
1) After removing the
evaporator assembly
following procedure
1, procedure 2 and
procedure 3, remove
the three screws
attaching the cover.
Three screws
2) Remove the screw
attaching the motor
and then pull out the
motor.
One screw
58
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
10.2 Outdoor unit
A-VMH09SU-1, A-VMH12SU-1
Part name Procedures Remarks
No.
Panel plate
How to remove the panel plate.
1) Stop operation of the air conditioner and turn “OFF” power at the breaker.
Screws of top panel (3 screws, 1 screw is under the big handle)
3 screws of
the big handle
6 screws of
front panel
2) Remove the big
handle first, and then remove the top panel (3 screws).
3) Remove the screws of front panel (6 screws).
4) Remove the screws of the right side panel
(8 screws).
○
2
○
4
○
3
59
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
2 Fan assembly
How to remove the fan assembly.
1) After removing the panel plate following Procedure 1, remove the hex nut fixing the fan and then remove the fan.
2) Disconnect the hooks and open the electronic control box cover.
○
1
○
2
Compressor
Motor
T3,T4,T5 Sensor
4-way valve
Electronic expansion valve
60
Page 63
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
○4
3) Disconnect the connector for fan
motor from the
electronic control board.
4) Remove the four mounting screws of the fan motor. Then remove the fan motor.
○
3
3 Electrical
parts
How to remove the electrical parts.
1) After finishing item 1 and item 2, remove the
connectors for the
compressor.
2) Pull out the two blue wires connected with the four way valve.
○
1
2
○
61
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
3) Pull out connectors of the condenser coil temp. sensor (T3), outdoor ambient temp.
sensor (T4) and
discharge temp. sensor (TP).
4) Disconnect the electronic expansion valve wire.
○
3
○
4
5) Remove the grounding
screw.
6) Remove the wires (1,2,3). Then remove the electronic control box.
62
○
5
○
6
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
4 Four-way
valve
How to remove the four-way valve.
1) Perform work of item1, 3.
2) Recover refrigerant from the refrigerant circuit.
3) Remove the screw of the coil and then remove the coil.
4) Detach the welded parts of four-way valve and pipe.
5) Then the four-way valve assembly can be removed
The picture of four-way valve may be different from your valve.
○
3
○
4
5 Compressor
How to remove the compressor.
1) After performing work of item 1,3; recover refrigerant from the refrigerant circuit.
2) Remove the discharge pipe and suction pipe with a burner.
3) Remove the hex nuts and washers fixing the compressor on bottom plate.
4) Lift the compressor from the base pan assembly.
○
2
○
3
63
Page 66
A-VMH18SU-1
No.
Part name Procedures Remarks
Panel plate
How to remove the panel plate.
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
1) Stop operation of the air conditioner and
turn "OFF" power at the breaker.
3 screws of top panel
3 screws of big handle
9 screws of front panel
2) Remove the top panel (3 screws).
3) Remove the screws of front panel (9 screws).
4) Remove the screws of the right side panel (8 screws).
64
Page 67
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
2
Fan assembly
How to remove the fan assembly.
1) After removing the panel plate following Procedure 1, remove the hex nut attaching the fan and then remove the fan.
2) After removing the top cover, disconnect the hooks and open the electronic control box cover.
○
1
○
2
T3,T4,T5 Sensor Wire
Motor Wire
4-Way Valve Wire Electric Pipe Heater and
Electronic Expansion Valve
Crankcase Electric Heater
Compressor Wire
65
Page 68
3) Disconnect the
○4
connector for fan motor from the electronic control board.
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
3
○
3 Electrical
parts
4) Remove the four mounting screws of the fan motor. Remove the fan motor.
How to remove the electrical parts.
1) After finishing work of item 1 and item 2, remove the connectors for the compressor and reactor.
○
1
66
Page 69
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
2) Pull out the two blue wires connected with the four way valve.
3) Pull out connectors of the condenser coil temp. sensor (T3), outdoor ambient temp.
sensor (T4) and
discharge temp. sensor (TP).
○
○
2
○
2
3
○
3
4) Disconnect the electronic expansion valve wire.
67
○
4
Page 70
5) Remove the electric heaters.
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
5
○
6) Remove the grounding screw.
7) Remove the Wires (1,2,3 or L1,L2,S). Then remove the electronic control box.
⑥
○
7
68
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
4 Four-way
valve
How to remove the four-way valve.
1) Perform work of item 1, 3.
2) Recover refrigerant from the refrigerant circuit.
3) Remove the screw of the coil and then remove the coil.
4) Detach the welded parts of four-way valve and pipe.
5) Then the four-way valve assembly can be removed.
The picture of four-way valve may be different from your equipment.
○
3
④
5
Compressor
How to remove the compressor.
1) After performing work of item 1,3. Recover refrigerant from the refrigerant circuit.
2) Remove the discharge pipe and suction pipe with a torch.
3) Remove the hex nuts and washers attaching the compressor to bottom plate.
4) Lift the compressor from the base pan assembly.
○
2
69
○
3
Page 72
A-VMH30SD-1, A-VMH36SD-1
Part name Procedures Remarks
No.
1 Panel plate
How to remove the panel plate.
1) Stop operation of the air conditioner and turn “OFF” the power breaker.
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
4 screws of big handle
Screws of top panel (3 screws, 1
screw is under the big handle)
Screws of front panel (11 screws)
2) Remove the big handle first,then remove the top cover (7 screws)
3) Remove the screws from front panel (11 screws).
4) Remove the screws of the right side panel (13 screws).
70
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
2 Fan ass’y
How to remove the fan assembly.
1) After removing the panel plate following procedure 1.
2) Remove the nut attaching the fan,
and remove the fan.
Fan
Electronic Control Box
Compressor
2
○
3) Disconnect the hooks and remove the screws, then open the electronic control box cover.
71
○
3
Page 74
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
4) Disconnect the connector for fan
motor from the
electronic control board.
T3,T4,T5
Sensor
Electronic
Expansion
○
4
Pressure
Switch
5
○
4-way
Valve
Compressor
Wire
Motor
Wire
5) Remove the four mounting screws of the fan motor, then remove the motor.
72
○
5
Page 75
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
3 Electrical
parts
How to remove the electrical parts.
1) After finishing item 1 and item 2, remove the connector for the compressor.
2) Pull out the two blue wires connected with the four way valve.
○
1
2
○
3) Pull out connectors of the, condenser coil temp. sensor (T3), outdoor ambient temp. sensor (T4) and discharge temp. sensor (TP).
○
3
73
Page 76
4) Disconnect the
○
○
4
pressure switch connector.
5) Disconnect the electronic expansion valve wire from the control board.
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
5
6) Remove the ground wires.
7) Remove the wires (1,2,3 or L1,L2,S). Then remove the electronic control box.
74
○
6
○
7
Page 77
Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
○4
4 Four-way
valve
5 Compressor
How to remove the four­way valve.
1) Perform work of item 1, 3.
2) Recover refrigerant from the refrigerant circuit.
3) Remove the screw of the coil and then remove the coil.
4) Detach the welded parts of four-way valve and pipe.
5) Then the four-way valve assembly can be removed
How to remove the compressor.
The picture of four-way valve may be
different from the one on your side.
3
○
2
○
1) After performing item 1, 3, recover refrigerant from the refrigerant circuit.
2) Remove the discharge pipe and suction pipe with a torch.
3) Remove the hex nuts and washers attaching the compressor to bottom plate.
4) Lift the compressor from the base pan assembly.
③
75
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Service Manual - VMH 9/12/18/24 SU & VMH30/36S D Series
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1900 Wellworth Ave., Jackson, MI 49203 • Ph. 517-787-2100 • www.marsdelivers.com
12/2016
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