Mitsubishi Heavy Industries SRK25QA-S User manual

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Mitsubishi Heavy Industries Air Conditioners
Technical Manual
Manual Number: 2011 No. W1-01
Variable Frequency Wall Mounted Type
Room Air Conditioners
(Split system, heat pump type)
SRK25QA-S/SRC25QA-S
SRK35QA-S/SRC35QA-S
(R410A Refrigerant Used)
MITSUBISHI HEAVY INDUSTRIES, LTD.

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Table of Contents
1. GENERAL INFORMATION……..…………………………….……1
1.1 Features…………………………………………………………..…1
1.2 Model identification………………………………………………1
2 MODEL SELECTION…………………………………………………2
2.1 Model function..…………..…….……..………………………..……2
2.2 Range of usage……………………………………………..………4
2.3 Outline drawing…..………………………………………………..…4
2.4 Cooling cycle system diagram….…………………..…………...…5
2.5 Performance curve……………………………………………………6
3 ELECTRICAL WIRING DIAGRAM………………………………….7
4 NAME OF EACH PARTAND ITS FUNCTION……………….….….9
4.1 NAME OF EACH PART………………..………….………………9
4.2 Emergency “ON/OFF” button (back-up switch) …........………..12
4.3 Automatic restart……………..…………..………………………..12
4.4 Flap control………..…………..……..……………………………..12
4.5 Comfort timer setting……..……..……..…………………………..14
4.6 Outline of heating operation.……..………………………….……..15
4.7 Outline of cooling operation ............................................................ 17
4.8 Outline of drying operation ................................................. 18
4.9 Outline of automatic operation ..........................................................20
4.10 Economical operation.....................................................................20
4.11 Air blowing operation.......................................................................20
4.12 CLEAN operation control...................................................21
4.13 EEV control.....................................................................................21
5 INSTALLATION................................................................................22
5.1 Selection of installation location.................................................24
5.2 Installation of indoor unit..................................................................25
5.3 Installation of outdoor unit...............................................................28

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5.4 Pipe connection.................................................................................28
5.5 Precautions for wireless remote controller operation........................30
5.6 Standard running data........................................................................31
6 MAINTENANCE................................................................................32
6.1 Electrical parts failure diagnosis method............................................32
6.2 Servicing.............................................................................................56
7 SERVICING MANUAL.......................................................................57
8MOUNT ASSEMBLY………………………….................................72
8.1 Indoor unit.........................................................................................72
8.2 Outdoor unit......................................................................................80

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1 GENERALINFORMATION
1.1 Features
(1) Inverter
● Heating/cooling
The rotate speed of the compressor is changed steplessly in relation to varying load, and is
linked with the fans of indoor and outdoor units controlled by the changes of frequency, thus
controls the power.
● Allowing quick heating/cooling operation during start-up period.
The room temperature is kept constant through fine-tuned control after the machine is
stabilized.
(2) Fuzzy control: According to the fuzzy control technology, the room temperature and humidity,
etc. are obtained through dynamic analysis to accurately regulate the rotate
speeds of the compressor and the fan to realize precise temperature control.
(3) Life: Actual service life: over 20,000 hours; Working life: over 100,000 hours; On/off of relay:
over 100,000 times; Continuous on of LED: over 50,000 hours; On/off of emergency
switch: over 10,000 times.
(4) Self diagnosis function: We will continuously provide the best services for our customers
through devices judging abnormal operation, as follows:
The air conditioner indicates the error of the indoor and outdoor sensors (thermistors) only when
it is in the stop mode. Error indication is removed after restart.
1.2 Model identification
R410A Refrigerant used
Master pattern change code
Master pattern
Capacity
Wall mounted type (C is the code for outdoor unit.)
Split type room air conditioner
TIMER lamp
ON
RUN lamp
keeps flashing
RUN lamp
ON
RUN lamp
Flash 2 times
RUN lamp
Flash 1 time
Flash 2 times
Flash 5 times
Flash 6 times
TIMER lamp
Flash 1 time
Flash 2 times
Flash 4 times
Flash 1 time
Flash 2 times
Flash 3 times
Flash 4 times
Flash 5 times
Flash 6 times
Flash 2 times
Failure Causes
Heat exchanger sensor error
Room temperature sensor error
Abnormal voltage input
Indoor fan motor error
Outdoor unit temperature sensor
error
Outdoor unit heat exchanger liquid
pipe sensor error
Vent-pipe sensor error
Current cut
Outdoor unit error
Safe current
Power transistor error
Compressor over heat protection
Signal transmission error
Rotor lock
Heat exchanger sensor wire break, poor connector connection
Room temperature sensor wire break, poor connector connection
Voltage too high or too low
Failure of fan motor, poor connector connection
Outdoor unit sensor wire break, poor connector connection
Heat exchanger liquid pipe sensor wire break, poor connector
connection
Vent-pipe sensor wire break, poor connector connection
Compressor blockage, compressor output open-phase, power short
circuit, control valve closed
Power-cut, compressor wire break
Vent-pipe sensor wire break, poor connector connection
Compressor not rotating (dead lock)
Overload, over current
Failure of power transistor
Insufficient refrigerant, failure of vent-pipe sensor, control valve
closed
Failure of power supply, signal cable break, failure of
indoor/outdoor unit control device
Failure of compressor
Compressor open-phase
Failure of outdoor unit control device

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2 MODEL SELECTION
2.1 Model function
2.1.1 Model: SRK25QA–S (Indoor unit)
SRC25QA–S (Outdoor unit)
Item
Unit
Indoor unit SRK25QA–S
Outdoor unit SRC25QA–S
Net weight
kg
9
31
Machine
dimension
mm
790×222×268
780×290×540
Package
dimension
Length× Width
×Height
830×340×280
920×380×590
Color
White
Ash-colored
Fan
Through-flow type, AS resin + glass
fiber
Axial flow type, AS resin + glass
fiber
Air flow
m3/h
550
1830
Noise in cool
room
dB(A)
Hi/Me/Lo:
37/30/23(completely mute,
SPL)
45(completely mute, SPL)
Noise in warm
room
dB(A)
Hi/Me/Lo:
37/32/28(completely mute,
SPL)
48(completely mute, SPL)
Fan motor
Nominal value
16W, 4-step capacitor type
asynchronous motor, insulation
grade E
25W, AC motor, insulation grade B
Power of motor
W (reference
value)
40
50
Power of electric
control
W (reference
value)
2
7.5
Power supply and
power cord
Single-phase, 220V, 50Hz and 3-core, 1.0mm2, 250V, 10A, 2m, w/o plug
Heat exchanger
Spiral, hydrophilic, 3-folded,
16-section, 2-row, 452-fin, 1-2
circuit
Spiral, hydrophilic, 20-section,
1-row, 621-fin, 2-1 circuit
Compressor
Nominal value
THACOM RM - B5077MDE2, 527W, DC frequency conversion
compressor, insulation grade E
Refrigerating
machine oil
ml
300, DIAMOND FREEZE MA68
Refrigerant
controller
Electronic expansion valve (Φ1.65mm) + hush pipe
Refrigerant
g
R-410A, 850g, addition/reduction not needed within the use range of 15m
Operating
pressure limit
Mpa
Max.: 4.1, Min.: 1.47
Air filter
Mould-proof air filter
Accessories and
quantity
Indoor unit 1, mounting plate 1, tapping screw 5, battery 2, use and
installation manual 1, remote controller 1, outdoor unit 1, Drain elbow 1,
Water shutoff plug 1
Operation control
devices
Wireless remote controller, electronic thermostat controlling room
temperature, microcomputer controlling defrosting
Safety devices
Serial signal protection, fan error protection, compressor over heat
protection, high voltage protection, over current protection, etc.
* The nominal values of “Noise in cool room” and “Noise in warm room” in the above table are tested in a dead
room.
Item
Unit
Rating cooling
Rating heating
Capacity
W
2500
3200
Power
W
700
870
Energy efficiency ratio
3.57
3.68
Energy efficiency grade
Grade A (European norm)
Note (1) The data are measured at the following conditions. The pipe length is 5m.
Item
Operation
Indoor air temperature
Outdoor air temperature
Standards
DB
WB
DB
WB
Cooling
27℃
19℃
35℃
24℃
Heating
20℃
—
7℃
6℃
Low temperature Heating
20℃
—
2℃
1℃
(2) The operation data are applied to the 220Vdistricts respectively.
(3) The refrigerant quantity to be charged includes the refrigerant in 15m connecting piping.
(Purging is not required even for the short piping.)

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2.1.2 Model: SRK35QA–S (Indoor unit)
SRC35QA–S (Outdoor unit)
Item
Unit
Indoor unit SRK35QA–S
Outdoor unit SRC35QA–S
Net weight
kg
9.5
35
Machine
dimension
mm
790×222×268
780×290×540
Package
dimension
Length× Width
×Height
830×340×280
920×380×590
Color
White
Ash-colored
Fan
Through-flow type, AS resin + glass
fiber
Axial flow type, AS resin + glass
fiber (embedded damping spindle
sleeve)
Air flow
m3/h
520
1940
Noise in cool
room
dB(A)
Hi/Me/Lo: 40/33/25
47
Noise in warm
room
dB(A)
Hi/Me/Lo: 39/35/27
48
Fan motor
Nominal value
16W, 4-step capacitor type
asynchronous motor, insulation
grade E
24W, DC motor, insulation grade E
Power of motor
W (reference
value)
40
20
Power of electric
control
W (reference
value)
2
7.5
Power supply and
power cord
Single-phase, 220V, 50Hz and 3-core, 1.0mm2, 250V, 10A, 2m, w/o plug
Heat exchanger
Spiral, hydrophilic, 3-folded,
16-section, 2-row, 452-fin, 1-4
circuit
Child heat exchanger: Spiral,
hydrophilic, 1-row, 4-section,
408-fin
Spiral, hydrophilic, 20-section,
2-row, 1221-fin, 2-1 circuit
Pf1.4
Compressor
Nominal value
THACOM RM - B5077MDE2, 527W, DC frequency conversion
compressor, insulation grade E
Refrigerating
machine oil
ml
300, DIAMOND FREEZE MA68
Refrigerant
controller
Electronic expansion valve (Φ1.5mm) + hush pipe
Refrigerant
g
R-410A, 900g, addition/reduction not needed within the use range of 15m
Operating
pressure limit
MPa
Max.: 4.15, Min.: 1.47
Air filter
Mould-proof air filter
Accessories and
quantity
Indoor unit 1, mounting plate 1, tapping screw 5, battery 2, use and
installation manual 1, remote controller 1, outdoor unit 1, Drain elbow 1,
Water shutoff plug 1
Operation control
devices
Wireless remote controller, electronic thermostat controlling room
temperature, microcomputer controlling defrosting
Safety devices
Serial signal protection, fan error protection, compressor over heat
protection, high voltage protection, over current protection, etc.
* The nominal values of “Noise in cool room” and “Noise in warm room” in the above table are tested in a dead
room.
Item
Unit
Rating cooling
Rating heating
Capacity
W
3500
4000
Power
W
1020
1100
Energy efficiency ratio
3.43
3.64
Energy efficiency grade
Grade A (European norm)
Note (1) The data are measured at the following conditions. The pipe length is 5m.
Item
Operation
Indoor air temperature
Outdoor air temperature
Standards
DB
WB
DB
WB
Cooling
27℃
19℃
35℃
24℃
Heating
20℃
—
7℃
6℃
Low temperature Heating
20℃
—
2℃
1℃
(2) The operation data are applied to the 220Vdistricts respectively.
(3) The refrigerant quantity to be charged includes the refrigerant in 15m connecting piping.

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(Purging is not required even for the short piping.)
2.2 Range of usage
Please use the air conditioners within the following range of usage, otherwise the protector will be
triggered.
Cooling Operation
Heating Operation
Outdoor temperature
About 18℃~43℃
About -15~24℃
Room temperature
About18℃~32℃
About below 30℃
Indoor humidity
About below 80%
25~35 Models
Max. piping one-way length
Within 15 m
Vertical height difference
Within 5 m
Additional R410A Refrigerant
Not required
Voltage
Rating ±10%
Starting voltage
At least 85% of rating
Switching frequency
Max. 10 times per hour
Time interval between stop and start
Min. 3 min
2.3 Outline drawing
(1) Indoor unit: SRK25QA–S/ SRK35QA–S Unit: mm
Piping hole right (left)
Terminal block
Remote controller
Flare connecting (Gas)
Flare connecting (Liquid)
Drainage pipe
Piping hole
Piping hole
VIEWA

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(2) Outdoor unit: SRC25QA-S/ SRC35QA-S Unit: mm
2.4 Cooling cycle system diagram
Models: QA-S Series
Note (1)……line is piping for site construction.
Drain holes
Terminal block
Flare connecting
Flare connecting
Operation valve (Gas)
Operation
valve
(Liquid)
Indoor unit
Outdoor unit
Circulation of cooling
Circulation of heating
Flare connecting
Operation valve (Gas)
Outdoor air
temp. sensor
Air heat
exchanger
Heat exchanger
sensor
Gas liquid
separator
Compressor
Discharge pipe sensor
4-way valve
Check joint
Gas pipeNote (1)
model
Air heat
exchanger
Inlet air temp.
sensor
Air heat
exchanger sensor
Liquid pipe
Flare connecting
Filter
Electronic expansion valve
Hush pipe
Hush pipe
Operation valve (Liquid)
Refrigerant inlet pipe
Refrigerant outlet
pipe

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2.5 Performance curve
The cooling and heating capacities are measured in the following conditions. The actual capacity
can be obtained with the following formula.
Actual capacity = Rating capacity x Correction factor
(1) Capacity correction according to indoor and outdoor temperatures:
Outdoor air W.B. temperature (°C W.B.) ISO-T1 Standard
⑵Capacity correction according to one way length of refrigerant piping:
It is necessary to correct the cooling and heating capacity according to the one way length of
refrigerant piping.
Piping length (m)
7
10
15
Cooling
1.0
0.99
0.975
Heating
1.0
1.0
1.0
⑶Capacity correction according to frosting on outdoor heat exchanger during heating:
In additions to the foregoing corrections (1) and (2), the heating capacity also needs to be
corrected according to the frosting on the outdoor heat exchanger.
Air inlet temperature of
outdoor unit
-10
-9
-7
-5
-3
-1
1
3
5
Frosting correction factor
0.95
0.94
0.93
0.91
0.88
0.86
0.87
0.92
1.00
⑷Example of cooling and heating capacity calculation:
The actual cooling capacity of model SRK25QA-S with the one way piping length of 25m at the
indoor wet-bulb temperature of 19℃and outdoor dry-bulb temperature of 35℃in summer or
indoor dry-bulb temperature of 20℃, outdoor dry-bulb temperature of 1℃and indoor wet-bulb
temperature of -1℃in winter is
Actual cooling capacity = 2500 x 1.0 x 0.95 ≈ 2375W
Nominal cooling Temp. correction Piping length
capacity factor correction factor
Actual heating capacity = 3200 x 0.81 x 0.95 x 0.86 ≈2118W
Nominal heating Temp. correction Piping length Frosting
capacity factor correction factor correction factor
Cooling
Heating
Accommodation
Cooling operation
Heating operation
Indoor air D.B.
temperature
Outdoor air D.B.
temperature
Indoor air W.B. temperature (°C W.B.) ISO-T1 Standard
Correction factor of cooling & heating
capacity in relation to temperature

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3 ELECTRICALWIRING DIAGRAM
3.1 Circuit diagram: 25QA-S