Comfortaire B-SVH24SA-1 User manual

A-SVH09SA-0 B-SVH09SA-0
A-SVH09SA-1 B-SVH09SA-1
A-SVH12SA-0 B-SVH12SA-0
A-SVH12SA-1 B-SVH12SA-1
A-SVH18SA-1 B-SVH18SA-1
A-SVH24SA-1 B-SVH24SA-1
www.marsdelivers.com
Service Manual
SVH Series
Inverter Single Zone Ductless Mini-Split

Service Manual - SVH 09/12/18/24 Series
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CONTENTS
1. Precaution .................................................................................................................................................. 3
1.1 Safety Precaution .......................................................................................................................... 3
1.2 Warning ......................................................................................................................................... 3
2. Part Names ................................................................................................................................................. 6
2.1 Model Names of Indoor/Outdoor Units ......................................................................................... 6
2.2 Indoor/Outdoor units ...................................................................................................................... 7
3. Dimensions ................................................................................................................................................. 8
3.1 Indoor Unit ..................................................................................................................................... 8
3.2 Outdoor Unit ................................................................................................................................ 11
4. Refrigerant Cycle Diagram...................................................................................................................... 12
5. Wiring Diagram ......................................................................................................................................... 13
6. Installation Details .................................................................................................................................... 13
6.1 Wrench torque sheet for installation ............................................................................................ 13
6.2 Connecting the cables ................................................................................................................. 13
6.3 Pipe length and the elevation ...................................................................................................... 13
6.4 Installation for the first time ......................................................................................................... 14
6.5 Adding the refrigerant after the system has been in operation ................................................... 14
6.6 Re-installation after the indoor unit has been repaired ............................................................... 15
6.7 Re-installation after the outdoor unit has been repaired ............................................................. 16
7. Operation Characteristics ....................................................................................................................... 17
8. Electronic Function .................................................................................................................................. 18
8.1 Abbreviation ................................................................................................................................. 18
8.2 Display Function .......................................................................................................................... 18
8.3 Main Protection ............................................................................................................................ 19
8.4 Operation Modes and Functions ................................................................................................. 20
9. Troubleshooting ....................................................................................................................................... 26
9.1 Indoor Unit Error Display .............................................................................................................. 27
9.2 Outdoor Unit Error Display (TBD) ................................................................................................ 29
9.3 Diagnosis and Solution ................................................................................................................ 33
10. Disassembly Instructions ........................................................................................................................ 58
10.1 Indoor Unit .................................................................................................................................. 58
10.2 Outdoor Unit ............................................................................................................................... 67
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.
This service manual is only for service engineer to use.

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1. Precaution
1.1 Safety Precaution
To prevent injury to the user or other
people and property damage, the following
instructions must be followed.
Incorrect operation due to ignoring
instructionswill cause harm or damage.
Before servicing the unit, be sure to
read this 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 the product,
there is risk of fire or electric shock.
Always ground the product.
There is risk of fire or electric shock.
Install the panel and the cover of
control box securely.
There is risk of fire of 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.
Be cautious 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 the 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
could not 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 touch the product with wet
hands when in operation.
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
combustible gas near the 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 the product, turn the breaker off or
disconnect the power supply cable.

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There is risk of electric shock or fire.
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. (Do not touch the
electrostatic filter, if the unit is so equipped.)
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.
Be cautious that water cannot enter
the product.
There is risk of fire, electric shock, or product
damage.
Ventilate the product from time to
time when operating it 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, disconnect the power supply plug
or turn off the breaker.
There is risk of product damage or failure, or
unintended operation.
Take care to ensure that nobody
could 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 the
product.
It can avoid vibration orwater leakage.
Do not install the product where the
noise or hot air from the outdoor unit could
disturb the neighborhood.
It may cause a problem for your 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 special
purposes, such as preserving foods, works
of art etc. It is a consumer air conditioner,
not a precision refrigerant system.
There is risk of damage or loss of property.
Do not block the inlet or outlet 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 operated.
Do not drink the water drained from
the product.

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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 burn orexplode.
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.

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2. Part Names
2.1 Model Names of Indoor/Outdoor Units
Series Capacity Indoor Units Outdoor Units
Inverter
9K
9K
12K
12K
18K
24K
B-SVH09SA-1 A-SVH09SA-1
B-SVH12SA-0 A-SVH12SA-0
B-SVH12SA-1 A-SVH12SA-1
B-SVH18SA-1 A-SVH18SA-1
B-SVH24SA-1 A-SVH24SA-1
B-SVH09SA-0 A-SVH09SA-0

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2.2 Indoor/Outdoor units

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3. Dimensions
3.1 Indoor Unit
Model WxDxH (mm) WxDxH (inch) Mounted plate
B-SVH09SA-0
B-SVH09SA-1 715x194x285 28.15x7.64x11.22 A
B-SVH12SA-0
B-SVH12SA-1 805x194x285 31.69x7.64x11.22 B
B-SVH18SA-1 957x213x302 37.68x8.39x11.89 C
B-SVH24SA-1 1040x220x327 40.94x8.67x12.87 D

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For Mounting Plate A
For Mounting Plate B
For Mounting Plate C

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For Mounting Plate D

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3.2 Outdoor Unit
More than 60cm(23.6in)
More than 70cm(27.6in)
More than 30cm(11.8in)
More than 60cm(23.6in)
(Service space)
Fence or
obstacles
More than 30cm(11.8in)
Note: The above drawing is only for reference. The appearance of your units may be different.
Model W D H W1 A B
A-SVH09SA-0
A-SVH09SA-1
A-SVH12SA-0
A-SVH12SA-1
770(mm) 300(mm) 555(mm) 840(mm) 487(mm) 298(mm)
30.31(inch) 11.81(inch) 21.85(inch) 33.07 (inch) 19.17(inch) 11.73 (inch)
A-SVH18SA-1
800(mm) 333(mm) 554(mm) 870(mm) 514(mm) 340(mm)
31.50(inch) 13.11(inch) 21.81(inch) 34.25 (inch) 20.24 (inch) 13.39(inch)
A-SVH24SA-1 845(mm) 363(mm) 702(mm) 914(mm) 540(mm) 350(mm)
33.27(inch) 14.29(inch) 27.64(inch) 35.98 (inch) 21.26 (inch) 13.78 (inch)

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4. Refrigerant Cycle Diagram
LIQUID SIDE
GAS SIDE
HEAT
EXCHANGE
(EVAPORATOR)
HEAT
EXCHANGE
(CONDENSER)
COMPRESSOR
2-WAY VALVE
3-WAY VALVE
4-WAY VALVE
COOLING
HEATING
T2 Evaporator
temp. sensor
T1 Room temp.
sensor
ACCUMULATOR
INDOOR OUTDOOR
CHECK VALVE
(Heating Model only)
CAPILIARY TUBE

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5. Wiring Diagram
(Please refer to the wiring diagram on the unit)
6.Installation Details
6.1 Wrench torque sheet for installation
Outside diameter Torque
Additional tightening
torque
Ф6.35mm 1/4in 1500N.cm(153kgf.cm) 1600N.cm(163kgf.cm)
Ф9.52mm 3/8in 2500N.cm(255kgf.cm) 2600N.cm(265kgf.cm)
Ф12.7mm 1/2in 3500N.cm(357kgf.cm) 3600N.cm(367kgf.cm)
Ф15.9mm 5/8in 4500N.cm(459kgf.cm) 4700N.cm(479kgf.cm)
Ф19mm 3/4in 6500N.cm(663kgf.cm) 6700N.cm(683kgf.cm)
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
located on the side panel of the unit. Please
refer to the nameplate before selecting the
cable, fuse and switch.
6.3 Pipe length and the elevation
Models
Pipe size
Gas Liquid
A-SVH09SA-0
B-SVH09SA-0
3/8in
(Ф9.52mm)
1/4in
(Ф6.35mm)
A-SVH09SA-1
B-SVH09SA-1
3/8in
(Ф9.52mm)
1/4in
(Ф6.35mm)
A-SVH12SA-0
B-SVH12SA-0
1/2in
(Ф12.7mm)
1/4in
(Ф6.35mm)
A-SVH12SA-1
B-SVH12SA-1
1/2in
(Ф12.7mm)
1/4in
(Ф6.35mm)
A-SVH18SA-1
B-SVH18SA-1
1/2in
(Ф12.7mm)
1/4in
(Ф6.35mm)
A-SVH24SA-1
B-SVH24SA-1
5/8in
(Ф15.9mm)
3/8in
(Ф9.52mm)
Models
Standard
length
Max.
Elevation
Max.
Length
A
Additional
refrigerant
7.5m
(24.6ft)
10m
(32.8ft)
25m
(82.0ft)
15g/m
(0.16oz/ft)
7.5m
(24.6ft)
10m
(32.8ft)
25m
(82.0ft)
15g/m
(0.16oz/ft)
7.5m
(24.6ft)
10m
(32.8ft)
25m
(82.0ft)
15g/m
(0.16oz/ft)
7.5m
(24.6ft)
10m
(32.8ft)
25m
(82.0ft)
15g/m
(0.16oz/ft)
7.5m
(24.6ft)
20m
(65.6ft)
30m
(98.4ft)
15g/m
(0.16oz/ft)
7.5m
(24.6ft)
25m
(82.0ft)
50m
(164ft)
30g/m
(0.32oz/ft)
A-SVH09SA-0
B-SVH09SA-0
A-SVH09SA-1
B-SVH09SA-1
A-SVH12SA-0
B-SVH12SA-0
A-SVH12SA-1
B-SVH12SA-1
A-SVH18SA-1
B-SVH18SA-1
A-SVH24SA-1
B-SVH24SA-1

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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 and
outdoor unit connections by a soft brush to
check for leakage of the connecting points of
the piping. If bubbles appear, 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.
6.5 Adding the refrigerant after the system
has been in operation
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. If the refrigerant is
R410A, make 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

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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) Operate the air conditioner at the cooling
mode.
5) Open the valves (Low side) on the charge set
and charge the system withliquid 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 18N.m.
Be sure to check for gas leakage.
6.6 Re-installation after the indoor unit has
been repaired
1. Collecting the refrigerant into the outdoor
unit
Procedure
1) Confirm that both the 2-way and 3-way
valves are set to the opened position
Remove the valvestem caps and confirm that
the valve stems are in the opened position.
Be sure to use a hexagonal wrench to operate
the valve stems.
2) Connect the charge hose with the push pin
of handle lo to the 3-way valves gas service
port.
3) Air purging of the charge hose.
Open the handle Lo valve of the manifold valve
slightly to purge air from the charge hose for 5
seconds and then close it quickly.
4) Set the 2-way valve to the close position.
5) Operate the air conditioner at the cooling cycle
and stop it when the gauge indicates 0.1 Mpa
(14.5Psi).
6) Set the 3-way valve to the closed position
immediately
Do this quickly so that the gauge ends up
indicating 0.3Mpa (43.5Psi) to 0.5 Mpa (72.5Psi).
Disconnect the charge set, and tighten the
2-way and 3-way valve’s stem nuts.
Use a torque wrench to tighten the 3-way valves
service port cap to a torque of 18N.m.
Be sure to check for gas leakage.
2. 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

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pumping 50 minutes, please check if there are
someleakage points. Fully close the handle Lo
valveof 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 comingout, then tighten the flare nut again.
Make sure the pressure display in the pressure
indicator is a little higher than the atmosphere
pressure. Then removethe charge hose from
the 3 way valve.
8) Fully open the 2 way valveand 3 way valve
and securely tighten the cap of the 3way valve.
6.7 Re-installation after the outdoor unit has
been repaired
1. Evacuation for the whole system
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) Evacuation for approximately one hour.
Confirm that the compound meter indicates
-0.1Mpa (14.5 Psi).
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 vacuumpump to the
valve at the bottom of the cylinder. If the
refrigerant is R410A,make 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 chargedwith the specified
amount of refrigerant, or can be charged with a
little at a time (approximately 5 oz. each time) ,
operating the air conditioner in the cooling
cycle; however, one time is not sufficient, wait
approximately 1 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 18N.m. Be sure to check
for gas leakage.

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7. Operation Characteristics
Temperature
Mode Cooling operation Heating operation Drying operation
Room temperature 17℃～32℃
(62℉～90℉)
0℃～30℃
(32℉～86℉)
10℃～32℃
(50℉～90℉)
Outdoor temperature
0°C～50°C
(32°F～122°F)
-15°C～30°C
(5°F～86°F)
0°C～50°C
(32°F～122°F)
-15°C～50°C
(5°F～122°F)
(need low ambient cooling function)
󰇛󰇜  󰇛󰇜
+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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8. Electronic Function
8.1 Abbreviation
T1: Indoor room temperature
T2: Coil temperature of evaporator
T3: Coil temperature of condenser
T4: Outdoor ambient temperature
T5: Compressor discharge temperature
8.2 Display Function
8.2.1 Icon explanation on indoor display board.
“fresh” when fresh feature is activated (if
applicable).
“defrost” when defrosting is activated.
“run” when the unit is on.
“timer” when TIMER is set.
Digital display (for some units):
Displays the temperature settings when the air
conditioner is operational.
Displays the room temperature in Fan and
Drying mode.
Displays the self-diagnostic codes.
Displays ‘ ’ for three seconds when
Timer ON, Fresh, Swing, Turbo or Silence
feature is activated.
Displays ‘ ’ for three seconds when
Timer OFF, Fresh, Swing, Turbo or Silence
feature is canceled.
Displays ‘ ’ under defrosting operation.
Displays ‘ ’ when anti-cold air feature is
activated under heating mode.
Displays ‘ ’ during self clean operation (if
applicable).
Displays ‘ ’ when freeze protection is
turned on (if applicable).
NOTE:
A guide on using the infrared remote is not
included in this literature package.

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8.3 Main Protection
8.3.1 Three minute delay at restart for
compressor
Less than 1 minute delay for the first time
start-up and 3 minute delay for others.
8.3.2 Temperature protection of compressor
top
The unit will stop working when the compressor
top temp. protector cut off, and will restart after
the compressor top temp. protector restarts.
8.3.3 Temperature protection of compressor
discharge
Compressor discharge temp. T5>115℃for
five seconds, compressor stops.
8.3.4 Fan speed is out of control
When indoor fan speed keeps too low
(300RPM) for certain time, the unit will stop
and the LED will display the failure.
8.3.5 Inverter module protection
The Inverter module has a protection function
about 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
seven seconds later.
If the unit runs in heating mode, the indoor fan
will be also controlled by anti-cold wind
function.
8.3.7 Compressor preheating functions
Preheating permitting condition:
When T4 (outdoor ambient temperature) ＜3°
C, the preheating function will be activated.
8.3.8 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.
8.3.9 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
little or no change.
8.3.10 Zero crossing detection error
protection
If A/C 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.

Service Manual - SVH 09/12/18/24 Series
20
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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:
a
b
c
d
T1
e
8.4.2Cooling Mode
8.4.2.1 Compressor running rules
WhenT1-Ts<ΔT -2℃, the compressor will stop,
when T1—Ts >ΔT -0.5℃，the compressor will
be activated.
ΔT is the programmed parameter of
temperature compensation.
When the AC run in mute mode, the
compressor will run at low frequency.
When the current is more than setting value,
the current protection function will be activated,
and the compressor will stop.
8.4.2.2 Outdoorfan running rules
The outdoor unit will be run at different fan
speed according to T4.
For different outdoor units, the fan speeds are
different.
High
Low
8.4.2.3 Indoor fan running rules
In cooling mode, indoor fan runs all the time
and the speed can be selected as high,
medium, low and auto.
The indoor fan is controlled as below:
Setting fan
speed
Actual fan speed
H+(H+=H+G)
AH（=H）
B
C
M+(M+=M+Z)
DM(M=M)
E
F
L+(L+=L+D)
GL(L=L)
H
I
T1-Td ℃(°F)
L
L-(L-=L-D)
H
H-（H-=H-G)
M
M-(M-=M-Z)
The auto fan acts as below rules:
a
b
c
d
T1
e
8.4.2.4 Condenser temperature protection
TP3+5
T3
Resume
Off
Decrease
TP3
TP3-3
Hold