MDV MFS2i-24ARN1 User manual

SERVICE MANUAL
MIDEA AIRCONDITIONER
FLOOR STANDING TYPE
Model:
MFS2i-24ARN1
MFS2i-48ARN1

CONTENTS
1. Safety Precautions.............................................................................................................. 1
1.1 Precaution.............................................................................................................................. 1
1.2 Installation.............................................................................................................................. 1
1.3 Caution .................................................................................................................................. 1
1.4 Operational............................................................................................................................ 2
2. Dimension ............................................................................................................................ 3
2.1 Indoor Unit.................................................................................................................................. 3
2.2 Outdoor Unit............................................................................................................................... 4
3．Refrigerant cycle diagram.................................................................................................. 5
3.1Heat pump mode......................................................................................................................... 5
4 . Wiring diagram ........................................................................................................................ 6
4.1 MFS2i-24ARN1.......................................................................................................................... 6
4.2 MFS2i-48ARN1........................................................................................................................ 7
5．Installation details................................................................................................................... 8
5.1 Installation place......................................................................................................................... 8
5.2 Installing ..................................................................................................................................... 9
5.3 Refrigerant pipe connection..................................................................................................... 12
5.4 Drain Pipe of The Indoor Unit................................................................................................... 23
5.5 Wiring ....................................................................................................................................... 24
5.6 TEST RUN................................................................................................................................ 24
6．External view and display.................................................................................................... 25
6.1 External view............................................................................................................................ 25
6.2 CONTROL PANEL ................................................................................................................... 26
7.Operation characteristics....................................................................................................... 26
8.Electronic function.................................................................................................................. 27
8.1 Main data Introduction......................................................................................................... 27
8.2 Operation Modes and Functions......................................................................................... 27

8.3 Other Functions................................................................................................................... 30
9.Characteristic of temperature sensor................................................................................... 31
10.Trouble shooting ................................................................................................................... 31
10.1 Protective Function.............................................................................................................. 31
10.2 Self-diagnosis...................................................................................................................... 33
10.3 LEDs for the indication of outdoor trouble........................................................................... 33
10.4 Troubles and Solutions........................................................................................................ 34

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1. Safety Precautions
1.1 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 Installation
For electrical work, contact the dealer, seller, a qualified electrician, or an Authorized service
center.
Do not disassemble or repair the product by yourself.
Sharp edges could cause injury, be especially careful of the case edges and the fins on the
condenser and evaporator.
Be sure the installation area does not deteriorate with age.
Take care to ensure that power cable could not be pulled out or damaged during operation.
Do not place anything on the power cable.
Do not plug or unplug the power supply plug during operation.
Do not store or use flammable gas or combustible near the product.
When flammable gas leaks, turn off the gas and open a window for ventilation before turn the
product on.
If strange sounds, or small or smoke comes from product. Turn the breaker off or disconnect the
power supply cable as soon as possible.
When the product is soaked (flooded or submerged), contact anAuthorized service center.
Be caution that water could not enter the product.
Turn the main power off when cleaning or maintaining the product.
When the product is not be used for a long time, disconnect the power supply plug or turn off the
breaker.
1.3 Caution
Always check for gas (refrigerant) leakage after installation or repair of product.
Install the drain hose to ensure that water is drained away properly.
Keep level even when installing the product.
Do not install the product where the noise or hot air from the outdoor unit could damage the
neighborhoods.
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.

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1.4 Operational
Do not expose the skin directly to cool air for long periods of time. (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.
Do not block the inlet or outlet of air flow.
Use a soft cloth to clean. Do not use harsh detergents, solvents, etc.
Do not touch the metal parts of the product when removing the air filter. They are very sharp.
Do not step on pr put anything on the product. (outdoor units)
Always insert the filter securely. Clean the filter every two weeks or more often if necessary.
Do not insert hands or other object through air inlet or outlet while the product is operated.
Do not drink the water drained from the product.
Use a firm stool or ladder when cleaning or maintaining the product.
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.
Do not recharge or disassemble the batteries. Do not dispose of batteries in a fire.
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.

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2. Dimension
2.1 Indoor Unit
Dimension
Mode
W(mm)
D(mm)
H(mm)
MFS2i-24ARN1
500
273
1665
MFS2i-48ARN1
540
379
1775

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2.2 Outdoor Unit
Dimension
Mode
W(mm)
D(mm)
H(mm)
W1(mm)
A(mm)
B(mm)
MFS2i-24ARN1
845
335
695
918
560
335
Dimension
Mode
W(mm)
D(mm)
H(mm)
W1(mm)
A(mm)
B(mm)
MFS2i-48ARN1
990
355
965
1075
623
366

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3．Refrigerant cycle diagram
3.1Heat pump mode

6
4 . Wiring diagram
4.1 MFS2i-24ARN1
Indoor Unit
Outdoor Unit

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4.2 MFS2i-48ARN1
Indoor Unit
Outdoor Unit

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5．Installation details
5.1 Installation place
5.1.1 Indoor Unit
a. A place which provides the spaces around the indoor unit as required above in the
diagram.
b. A place where is no obstacle near the inlet and outlet area.
c. A place which can bear the weight of the indoor unit.
d. A place which allows the air filter to be removed downward.
e. A place where the reception range is not exposed to direct sunlight.
f. In the center of the room where possible.
5.1.1.1 Please stand the unit in hard and flat ground;
Please reserve space for installation and maintenance.
5.1.1.2 Please check the elevation difference between the indoor unit and the outdoor
unit, the length of the refrigerant pipe, and the curved places (bend) of the pipe are no
more than the following numbers:
Elevation difference: no more than 10M(24K) or 15M(42K) (if the elevation
difference between indoor and outdoor unit is more than 10
or 15 meters, it is recommended that the indoor unit be
located higher than the outdoor unit.)
Pipe length: no more than 20M(24K) or 30M(42K)
Bends: no more than 3 places.
5.1.2 Outdoor Unit
5.1.2.1 Before installing the outdoor unit, you should:
a). Select a place where no direct sunlight or other heat-radioactivity may reach. A
sunshade is needed if it is unavoidable.
b). Select a place that is easy to connect indoor unit's pipe and electric wires.
c).Avoid a place where combustible gas may leak or stay.
d). Keep it in mind that water may drain out of the outdoor unit while in "Heat" mode.

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Caution:
Installation in the following places may cause trouble. If it is unavoidable to use in such
places, please consult with the dealer.
a.A place full of machine oil.
b.A saline place such as coast.
c. Hot-spring resort.
d.A place full of sulfide gas.
e.A place where there are high frequency machines such as wireless installation, welding
machine, medical facility.
f.A place of special environmental conditions.
5.1.2.2 If the outdoor unit is to be installed on a roof or where no constructions are
around, you should avoid hard wind blows directly to the air outlet, because
it may cause trouble for air-flow shortage.
5.1.2.3 Reserve enough space for installation, maintenance and unit-functioning.
Remove as many obstacles as possible nearby.
5.2 Installing
5.2.1 Indoor Unit:
1.Anti-falling;
To prevent the indoor unit from falling, you must:
a. Pay full attention to the unit because its long outer shape makes it easy to fall;
b. Firmly fix the unit to the wallor in the ground to avoid accidental falling.

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2. Dismounting the air-inlet grid
Please take off the air-inlet grid before connecting the pipes/wires.
Pull down the two knobs on the grid, take off the two screws, then the air-inlet
grid goes free.
3. Take the Pipe Clip off before connecting the pipes and wiring; fit it when these finished.
Use accessories to connect the pipes/wires on both sides and back side.

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5.2.2 Outdoor Unit:
1. Ship the a/c to the installation place originally packed;
2. Be careful while hanging the unit because the center of gravity of the unit is not
centralized;
3. Do not make the angle of inclination more than 45 degrees while shipping;(Avoid
horizontal storage)
4. Be sure the electric insulation work is well done if installed on metal ceiling / wall.
5. Fix the unit feet with bolts (M10/M8). Be sure the unit is fixed strongly enough to
against blast or earthquake.
6. Make a concrete basement to the unit by the following references.
Dimension
Mode
A(mm)
B(mm)
MFS2i-24ARN1
560
335
MFS2i-48ARN1
623
366

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5.3 Refrigerant pipe connection
5.3.1 Pipe length and the elevation
The correct refrigerant quantity filled in the 5-meter-long pipe of the outdoor unit is marked
on the Product Data Plate. If you have to use longer pipe for every meter plus pipe, the
refrigerant should be added according to the following calculation.
Capacity
Btu/h
Pipe size
Standard
length
(m)
Max.
Elevation
B (m)
Max.
Length
A (m)
Additional
refrigerant
(g/m)
Gas
Liquid
MFS2i-24
ARN1
5/8’’
(Ф16.0)
3/8’’
(Ф9.52)
5
10
20
40
MFS2i-48
ARN1
3/4’’
(Ф19)
1/2’’
(Ф12.7)
5
15
30
60
Caution:
Capacity is base on standard length and maximum allowance length is base of reliability.
Oil trap should be installed per 5-7 meters.
5.3.2 Piping connection
5.3.2.1 Connecting Of Refrigerant Pipe

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a) Only the correctly installing of indoor and outdoor unit done, can the refrigerant
pipe be connected.
b) The cut-off valves are completely close before ex-work. Before connecting the
refrigerant pipe, be careful to check whether the valves are completely close.
c) The connecting procedure of refrigerant pipe: first, unscrew the two valves on
the outdoor unit and the pipe-jointing nut on the indoor unit(please keep them
care fully). Please connect the refrigerant pipe according to the manual, the
pipe-jointing nut should be screw tightly and no leakage. Note: you need two
wrenches to make balance.
d) When the connecting of refrigerant pipe is finished, before power on the system,
you should vacuum the indoor unit through the maintenance port on the cut-off
valves, or open the high-pressure valve, and exhaust the air through the
maintenance port on the low-pressure valve(closed). It will take about ten
seconds. Then screw tightly the maintenance port. (When supplement the
refrigerant, fill through the maintenance port of the low-pressure valves on the
outdoor unit ).
e) Open all the valves completely before power on the system, or it will be sick for
low efficiency.
f) Gas leak check. Make sure no gas from connections with leak detector or soap
water.
Caution:
A: Lo packed valve B: Hi packed valve
C and D are ends of indoor unit connection.
Caution in Handling the Packed Valve
a.Open the valve stem until it hits against the stopper. Do not try to open it further.
b. Securely tighten the valve stem cap with a spanner or the link.

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Notes for the bendable pipe
a. The bendable pipe should be used on the indoor side;
b. Bend angel may not exceed 90 degrees;
c. The bend location should be made on the center of the pipe if possible, as for bend
radius, the bigger the better;
d. The bendable pipe may not be bent for more than 3 times.
Bend the thin pipe
a. While bending, expose the pipe by cutting the concave gap on the bending
heat-insulation pipe(roll it with soft band after bent).
b. To avoid pipe deformation, the radius is the bigger the better.
c. Use a pipe-bending device to make the compact bending pipe.
5.3.2.2 Using bronze pipe selling in market
Completely shut the cut-off valves of the outdoor unit (as ex-work status). After the
refrigerant pipe has been connected with both the indoor and outdoor unit, let the air
exhaust out from the maintenance gap on he low-pressure cut-off valves of the
outdoor unit. Screw the nuts tightly on the maintenance gap after the air has been
drained.
5.3.2.3 To make the refrigerant pipe unblocked completely
You should keep the cut-off valves of the outdoor unit completely open after you have
finished the above steps (5.3.2.1 or 5.3.2.2)
Note:
1.Before screwing the reamer nut, smear the pipe and the connecting surface with

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refrigerant oil;
2.Check and make sure there is no leakage by soap-water or leakage-checker after
connecting;
3.Be sure the connecting joint on the indoor side is insulated.
4.Use two wrenches to connecting the pipes.
Outside diameter
Torque
Additional
tightening
torque
mm
inch
N.cm
N.cm
Ф9.52
3/8
3270
3990
Ф12.7
1/2
4950
6030
Ф16
5/8
6180
7750
Ф19
3/4
9720
11860

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5.3.3 Air purging with vacuum pump
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.
Air purging with vacuum pump
1. Completely tighten the flare nuts of the indoor and outdoor units, connect the manifold
valve charge.
2. Connect the charge hose connection to the vacuum pump.
3. Fully open the handle Lo of the manifold valve.
4. Operate the vacuum pump to evacuate.After starting evacuation, slightly loose the flare

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nut of the Lo valve on the gas pipe side and check the air is entering. (Operation noise of
the vacuum pump changes and a compound meter indicates 0 stead of minutes)
5. After the evacuation is complete, fully close the handle Lo valve of the manifold valve
and stop the operation of the vacuum pump. Make evacuation for 15 minutes or more and
check the compound meter indicates -76cmHg.
6. Turn the stem of the Hi valve 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.
7. Remove the charge hose from the Lo pressure charge hose.
8. Fully open the Hi and Lo packed valve.
9. Securely tighten the cap of the packed valve.
Gas leak check
Soap water method
Apply soap water or a liquid neutral detergent on the indoor unit connections or outdoor
unit connections by a soft brush to check for leakage of the connecting points of the piping.
If bubbles come out, the pipes have leakage.
5.3.4 Pumping down (Re-installation)