Midea MSH-21HRN1-QB8 User manual

Cover
Service manual
Service manualService manual
Service manual
Room airconditioner
Room airconditionerRoom airconditioner
Room airconditioner
Split Wall mounted Type
Split Wall mounted TypeSplit Wall mounted Type
Split Wall mounted Type
Applied to:
MSH-21HRN1-QB8
MSH-24HRN1-QB8

Content
2
Content
1.
Precaution...........................................................................................................................................2
1.1 Safety Precaution.................................................................................................................................2
1.2 Warning................................................................................................................................................2
2. Function..............................................................................................................................................3
3. Dimension...........................................................................................................................................5
3.1 Indoor unit............................................................................................................................................5
3.2 Outdoor unit .........................................................................................................................................5
4. Refrigerant cycle diagram.................................................................................................................8
5. Operation limits..................................................................................................................................9
5.1 Cooling operation.................................................................................................................................9
5.2 Heating operation.................................................................................................................................9
6. Wiring diagram...................................................................................................................................9
7. Installation details............................................................................................................................10
7.1 Wrench torque sheet for installation ..................................................................................................10
7.2 Connecting the cables .......................................................................................................................10
7.3 Pipe length and the elevation.............................................................................................................10
7.4 Air purging of the piping and indoor unit............................................................................................11
7.5 Pumping down (Re-installation).........................................................................................................12
7.6 Re-air purging (Re-installation)..........................................................................................................13
7.7 Balance refrigerant of the 2-way, 3-way valves.................................................................................14
7.8 Evacuation .........................................................................................................................................17
7.9 Gas charging......................................................................................................................................18
8. Electronic function ..........................................................................................................................19
8.1 Proper symbols and their meaning....................................................................................................19
8.2 Function .............................................................................................................................................19
8.3 Protection...........................................................................................................................................19
8.4 Fan-only mode...............................................................................Błąd! Nie zdefiniowano zakładki.
8.5 Cooling mode.................................................................................Błąd! Nie zdefiniowano zakładki.
8.6 Dehumidifying mode ......................................................................Błąd! Nie zdefiniowano zakładki.
8.7 Heating mode.................................................................................Błąd! Nie zdefiniowano zakładki.
8.8 Defrosting mode(available for heating mode)................................Błąd! Nie zdefiniowano zakładki.
8.9 Auto mode......................................................................................Błąd! Nie zdefiniowano zakładki.
8.10 Force cooling function........................................................................................................................24
8.11 Sleep mode........................................................................................................................................24
8.12 Auto restart function...........................................................................................................................25
8.13 Turbo mode........................................................................................................................................25
9. Model and Parameters.....................................................................................................................26

Content
3
10. Troubleshooting...............................................................................................................................27
10.1 Display board.....................................................................................................................................27
10.2 Troubleshooting .................................................................................................................................27
10.3 Diagnostic chart. ................................................................................................................................28
10.4 Resetting phenomenon often occurs during operation......................................................................29
10.5 Operation lamp flashes and Timer lamp off.......................................................................................29
10.6 Operation lamp flashes and Timer lamp on.......................................................................................29
10.7 Operation lamp off and Timer lamp flashes.......................................................................................30
10.8 Operation lamp on and Timer lamp flashes...................................Błąd! Nie zdefiniowano zakładki.
10.9 Operation lamp flashes, Timer lamp flashes..................................Błąd! Nie zdefiniowano zakładki.
11. Characteristic of temperature sensor..................................................Błąd! Nie zdefiniowano zakładki.

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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 instruction will cause harm or damage.
 Before service unit, be sure to read this service manual at first.
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 fore or electric
shock.
 Use the correctly rated breaker of 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 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.
There is risk of fire, electric shock, explosion, or injury.
 Do not install the product on a defective
installation stand.
It may cause injury, accident, or damage to the product.
 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
windows is left open.
Moisture may condense and wet or damage furniture.
 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 (operation) the product with wet
hands.
There is risk of fire or electric shock.
 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 electric parts.
It may cause fire, failure of the product, or electric shock.
 Do not store or use flammable gas or
combustible 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 turn the
product on.
Do not use the telephone or turn switches on or off.
There is risk of explosion or fire.
 If strange sounds, or small or smoke comes
from product. Turn the breaker off or disconnect
the power supply cable.
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

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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 (flooded or
submerged), contact an Authorized service center.
There is risk of fire or electric shock.
 Be caution that water could not 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.
To avoid vibration of water leakage.
 Do not install the product where the noise or
hot air from the outdoor unit could damage the
neighborhoods.
It may cause a problem for your neighbors.
 Use two or more people to lift and transport
the product.
Avoid personal injury.
 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 of time. (Do not sit in the draft).
This could harm to your health.
 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 of air flow.
It may cause product failure.
 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.
There is risk of personal injury.
 Do not step on pr put anything on the product.
(outdoor units)
There is risk of personal injury and failure of product.
 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 object through
air inlet or outlet while the product is operated.
There are sharp and moving parts that could cause
personal injury.
 Do not drink the water drained from the
product.
It is not sanitary could cause serious health issues.
 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 mew 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 of explode.
 If the liquid from the batteries gets onto your
skin or clothes, wash it well with clean water. Do
not use the remote of the batteries have leaked.
The chemical in batteries could cause burns or other
health hazards.

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3
2. Function
The function will be
operate in any operation
mode.
Indoor unit
Operation ON/OFF by remote controller
Room temperature sensor.
Pipe temperature sensor.
Sensing by room temperature
Indoor fan is delayed for 5 sec at the starting.
Starting temperature control
Restarting is for approx. 3
minutes..
Time Delay Safety control
high, med, low, breeze.
Indoor fan speed control
Light up in the VLED for each operation mode.
The unit will decide the louver direction according to operation mode.
Two-direction air vane
The fan is turn to low speed (cooling/heating).
The unit will be turn off at the seventh hour.
Sleep mode auto control
The function is usually used in rainy days in
springtime or damp areas.
Independent dehumidification
Operation indication Lamps (VLED)
The louver can be set at the desired position or swing up and
down automatically
Air flow Direction control
The unit can be change by the room temperature.
Auto mode
Easy clean panel
Flexible wiring connection
Defrost mode
Prevent the cold wind at
the beginning of unit start.
Anti-cold function
Auto-restart function
Self-diag. function
Turbo mode

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The unit has 3 mins delay between continuously ON/OFF operations.
Outdoor unit
Power relay control
Bird tail propeller fan makes the outdoor unit run more quietly.
Low noise air flow system
The hydrophilic fin can improve the heating efficiency at operation mode.
Hydrophilic aluminum fin
It is only operated in the heating operation mode except defrosting operation.
Discharge pipe temperature protect
Anti-rust cabinet
Valve protection cover
4 way valve control

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3. Dimension
3.1 Indoor unit
Dimension
Mode W H D
21K 1030 313 221
24K 1030 313 221
3.2 Outdoor unit
Dimension
Mode W H D L1 L2 L3
21K 845 695 335 560 360 560
24K 845 695 335 560 360 560

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Specification：
MSH-21HRN1-QB8 MSH-24HRN1-QB8
Ph-V-Hz
1, 220-240V~, 50Hz 1, 220-230V~, 50Hz
Capacity Btu/h 21000 24000
Input W 2150 2450
Rated current A 9,3 10,7
EER Btu/w.h 9.8,2.86 9.8,2.87
Capacity Btu/h 24000 27000
Input W 2190 2470
Rated current A 9,5 10,7
COP W/W 3,21 3,21
A 15 18
Model PA270X3CS-4MU1 PA290X3CS-4MU1
Type Rotary Rotary
Brand TOSHIBA TOSHIBA
Capacity Btu/h 6670/6720 7180/7210
Input W 2280/2350 2430/2540
Rated current(RLA) A 10.70/10.70 11.40/11.90
Locked rotor Amp(LRA)
A 45 61
Thermal protector Internal Internal
Capacitor uF 50 50
Refrigerant oil ml 950 950
Model YDK36-4C YDK36-4C
Brand Welling Welling
Input W 65/64/62 65/64/62
Capacitor uF 2µF/450V 3µF/450V
Speed(hi/mi/lo) r/min 1120/1080/1000 1235/1145/1045
m3/h 1000/960/880 1080/1020/960
dB(A) 47/45/43 48/46/43
Model YDK53-6E YDK100-6C
Brand Welling Welling
Input W 181 173
Capacitor uF 3 5
Speed r/min 840 900
m
3
/h 2500 2500
dB(A) 60 62
g R410A/1950 R410A /2000
MPa 4,2 4,2
Liquid side/ Gas side mm Ф9.53/Ф16.0 Φ9.52/Φ16
Max. refrigerant pipe length
m 25 25
Max. differencein level
m 10 10
℃17-30 17-30
℃-7-43 -7-43
m
2
34~49 45~60
Ambient temp
Applicationarea
Outdoornoiselevel
Refrigerant type R410A
Design pressure
Refrigerant
piping
Indoor noise level (Hi/Mi/Lo)
Outdoor
fanmotor
Outdoorair flow
Operationtemp
Max. current
Compressor
Indoor
fanmotor
Indoor air flow(Hi/Mi/Lo)
Model
Power supply
Cooling
Heating
Note:
 The noise date is base on hemi-anechoic chamber during actual operation, these values are normally
somewhat different as a result of ambient condition.
 The above design and specifications are subject to change without prior notice for product improvement.

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4. Refrigerant cycle diagram
 Cooling only
 Heat pump mode

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5. Operation limits
5.1Cooling operation
Outdoor unit air temp.℃DB
Indoor air temp. ℃DB
Note: The chart is the result from the continuous operation under constant air temperature conditions.
However, excludes the initial pull-down stage.
5.2Heating operation
Indoor air temp. ℃DB
Outdoor unit air temp.℃DB
Note: The chart is the result from the continuous operation under constant air temperature conditions.
However, excludes the initial pull-down stage.

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6. Wiring diagram
Indoor：
Outdoor：

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7. Installation details
7.1 Wrench torque sheet for installation
Outside diameter Torque
mm inch Kg.m
φ9.52 3/8 4.2
φ12.7 1/2 5.5
φ15.88 5/8 6.6
7.2 Connecting the cables
The power cord of connect should be selected according to the following specifications sheet.
Grade
Unit 21K 24K
mm
2
2.5 2.5
7.3 Pipe length and the elevation
Pipe size
Capacity
Btu/h GAS LIQUID
Standard
length
(m)
Max.
Elevation
B (m)
Max. Pipe
length
A (m)
Additional
refrigerant
(g/m)
21k~24K 5/8’’ (φ15.88) 3/8’’ (φ9.52) 5 10 20 65
Caution:
Capacity is base on standard length and maximum allowance length is base of reliability.
Oil trap should be install per 5-7 meters.
In case that
more than 5m.

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7.4 Air purging of the piping and indoor unit
Required tools:
Hexagonal wrench; adjustable wrench; torque wrenches, wrench to hold the joints and gas leak detector.
Note:
The air in the indoor unit and in the piping must be purged. If air remains in the refrigeration piping, it will
affect the compressor, reduce the cooling capacity, and could lead to a malfunction of unit.
Be sure, using a torque wrench to tighten the service port cap (after using the service port), so that it
prevents the gas leakage from the refrigeration cycle.
Procedure
Recheck the piping connections.
Open the valve stem of the 2-way valve
counterclockwise approximately 90’, wait 10
seconds, and then set it to closed position.
Be sure to use a hexagonal wrench to operate the
valve stem
Check for gas leakage.
Check the flare connection for gas leakage
Purge the air from the system.
Set the 2-way valve to the open position and
remove the cap from the 3-way valve’s service
port.
Using the hexagonal wrench to press the valve
core pin, discharge for three seconds and then
wait for one minute.
Use torque wrench to tighten the service port cap
to a torque of 1.8 kg.m. (18n.m)
Set the 3-way valve to the opened position.
Mounted the valve stem nuts to the 2-way and
3-way valves.
Check for gas leakage.
At this time, especially check for gas leakage from
the 2-way and 3-way stem nuts, and from the
service port.
Caution:
If gas leakage is discovered in step (3) above,
take the following measures.
If the leaks stop when the piping connections are
tightened further, continue working from step (4).
If the gas leaks do not stop when the connections
are retightened, repair the location of the leak,
discharge all of the gas through the service port,
and then recharge with the specified amount of
gas from a gas cylinder.

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7.5 Pumping down (Re-installation)
Procedure
Confirm that both the 2-way and 3-way valves are set to the opened position.
Remove the valve stem caps and confirm that the valve stems are in the opened position.
Be sure to use a hexagonal wrench to operate the valve stems.
Operate the unit for 10 to 15 minutes.
Stop operation and wait for 3 minutes, then connect the charge set to the service port of the 3-way valve.
Connect the charge hose with the push pin to the gas service port.
Air purging of the charge hose.
Open the low-pressure valve on the charge set slightly to purge air from the charge hose.
Set the 2-way valve to the close position.
Operate the air conditioner at the cooling cycle and stop it when the gauge indicates 0.1MPa.
Immediately set the 3-way valve to the closed position.
Do this quickly so that the gauge ends up indicating 0.3 to 0.5Mpa.
Disconnect the charge set, and amount the 2-way and 3-way valve’s stem nuts and service port caps.
Use a torque wrench to tighten the service port cap to a torque of 1.8 kg.m.
Be sure to check for gas leakage.

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7.6 Re-air purging (Re-installation)
Procedure:
Confirm that both the 2-way and 3-way valves are set to the closed position.
Connect the charge set and a charging cylinder to the service port of the 3-way valve.
Leave the valve on the charging cylinder closed.
Air purging.
Open the valves on the charging cylinder and the charge set. Purge the air by loosening the flare nut on the
2-way valve approximately 45’ for 3 seconds then closing it for 1 minutes; repeat 3 times.
After purging the air, use a torque wrench to tighten the flare nut to on the 2-way valve.
Check the gas leakage.
Check the flare connections for gas leakage.
Discharge the refrigerant.
Close the valve on the charging cylinder and discharge the refrigerant until the gauge indicate 0.3 to 0.5 Mpa.
Disconnect the charge set and the charging cylinder, and set the 2-way and 3-way valves to the open position.
Be sure to use a hexagonal wrench to operate the valve stems.
Mount the valve stems nuts and the service port cap.
Be sure to use a torque wrench to tighten the service port cap to a torque 18N.m.
Be sure to check the gas leakage.

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14
7.7 Balance refrigerant of the 2-way, 3-way valves
Procedure:
Confirm that both the 2-way and 3-way valves are set to the open position.
Connect the charge set to the 3-way valve’s service port.
Leave the valve on the charge set closed.
Connect the charge hose with the push pin to the service port.
Open the valves (Low side) on the charge set and discharge the refrigerant until the gauge indicates 0.05 to 0.1
Mpa.
If there is no air in the refrigeration cycle [the pressure when the air conditioner is not running is higher than
0.1Mpa, discharge the refrigerant until the gauge indicates 0.05 to 0.1 Mpa. If this is the case, it will not be
necessary to apply a evacuation.
Discharge the refrigeration gradually; if it is discharged too suddenly, the refrigeration oil sill be discharged.

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7.8 Evacuation
Procedure:
Connect the vacuum pump to the charge set’s centre hose.
Evacuation for approximately one hour.
Confirm that the gauge needle has moved toward -0.1 Mpa (-76 cmHg) [vacuum of 4 mmHg or less].
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).
Disconnect the charge hose from the vacuum pump.
Vacuum pump oil, if the vacuum pump oil becomes dirty or depleted, replenish as needle.

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7.9 Gas charging
Procedure:
1. Connect the charge hose to the charging cylinder.
 Connect the charge hose which you disconnected from the vacuum pump to the valve at the bottom of
the cylinder.
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. Open the valves (Low side) on the charge set and charge the system with liquid refrigerant.
 If the system cannot be charge with the specified amount of refrigerant, if can be charged with a little at a
time (approximately 150g each time0 while operating the air conditioner in the cooling cycle; however, one time
is not sufficient, wait approximately 1 minute and then repeat the procedure.(pumping down-pin).
4. Immediately disconnect the charge hose from the 3-way valve’s service port.
 Stopping partway will allow the refrigerant to be discharged.
 If the system has been charged with liquid refrigerant while operating the air conditioner, turn off the air
conditioner before disconnecting the hose.
5. Mounted 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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8. Electronic function
8.1 Electronic control working environment
Input voltage: 175~253V or 100~130V
Input power frequency: 60Hz
Ambient temperature: -7°C+43°C
Indoor fan normal working amp is less than 1A
Outdoor fan normal working amp is less than 1.5A
Four-way valve normal working amp is less than 1A
Swing motor: DC12V
Compressor: single-phase power supply. Its normal working amp is less than 15A
8.2 Proper symbols and their meaning
T1: Indoor ambient temperature
T2: Indoor evaporator temperature
T3: Outdoor condenser temperature.
TS: Setting temperature through the remote controller
TE1: Anti-cold wind, from Fan Off to Breeze temperature
TE2: Anti-cold wind, from Breeze to Setting Fan Speed temperature
TE3: Anti-cold wind, from Setting Fan Speed to Breeze temperature
TE4: Anti-cold wind, from Breeze to Fan Off temperature
TE5: Evaporator low temperature protection entering temperature
TE6: Evaporator low temperature protection restoring temperature
TE7: Evaporator high temperature protection, compressor off temperature
TE8: Evaporator high temperature protection, fan off temperature
TE9: Evaporator high temperature protection, restoring temperature
TE10: Condenser high temperature protection, compressor off temperature.
TE11: Condenser high temperature protection, restoring temperature.
TE14: The indoor restoring temperature when the compressor is off on the heating mode.
TE16: The indoor evaporator temperature after the defrost action, fan on temperature.
TC1: Outdoor condenser sensor temperature for the defrost condition 1.
TC2: Condenser sensor temperature after defrost.
TC3: Outdoor condenser sensor temperature for the defrost condition 2.
8.3 Function
Remote receiving
Testing and forced running
Position set for indoor unit wind vane
LED displaying and alarm
On or off Timer
Protection for the compressor
Current protection
High temperature protection of indoor heat exchanger at heating mode
Auto defrosting and heating recovery at heating mode
Anti cold air at heating mode