Mitsubishi SRK25ZD-S User manual

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3
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INVERTER WALL MOUNTED TYPE
ROOM AIR-CONDITIONER
( Split system, air to air heat pump type )
Alternative refrigerant R410A use models
SRK25ZD-S, 35ZD-S, 50ZD-S
TECHNICAL MANUAL
Collection data
Manual No. ’04
.
SRK-T
.
039

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1
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CONTENTS
1. GENERAL INFORMATION........................................................................... 1
1.1 Specific features .................................................................................... 1
1.2 How to read the model name................................................................ 1
2. SELECTION DATA........................................................................................ 2
2.1 Specifications ........................................................................................ 2
2.2 Range of usage & limitations ............................................................... 5
2.3 Exterior dimensions .............................................................................. 5
2.4 Piping system ........................................................................................ 7
2.5 Selection chart ....................................................................................... 8
3. ELECTRICAL DATA ..................................................................................... 9
3.1 Electrical wiring ..................................................................................... 9
4. OUTLINE OF OPERATION CONTROL BY MICROCOMPUTER ................11
4.1 Operation control function by remote control switch ........................11
4.2 Back-up Switch ......................................................................................12
4.3 Power blackout auto restart function...................................................12
4.4 Flap control ............................................................................................13
4.5 Comfortable timer setting .....................................................................13
4.6 Outline of heating operation.................................................................14
4.7 Outline of cooling operation.................................................................16
4.8 Outline of dehumidifying operation .....................................................17
4.9 Outline of automatic operation.............................................................19
4.10 Economical operation ...........................................................................19
4.11 Protective control function ...................................................................19
5. APPLICATION DATA ....................................................................................25
5.1 Selection of location for installation....................................................26
5.2 Installation of indoor unit......................................................................27
5.3 Installation of outdoor unit ...................................................................29
5.4 Refrigerant piping..................................................................................29
5.5 Test run...................................................................................................31
5.6 Precautions for wireless remote controller installation and
operation ................................................................................................32
6. MAINTENANCE DATA..................................................................................33
6.1 Troubleshooting procedures for electrical equipment.......................33
6.2 Servicing.................................................................................................51
7. REFRIGERANT PIPING INSTALLATION/SERVICING MANUAL
FOR AIR CONDITIONERS USING R410A ..................................................52
7.1 Outline ....................................................................................................52
7.2 Refrigerant piping installation..............................................................53
7.3 Installation, removal and servicing ......................................................59
7.4 Refrigerant recovery..............................................................................64

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Over heat of compressor
Error of signal transmission
Outdoor fan motor error
1 GENERAL INFORMATION
1.1 Specific features
The “Mitsubishi Daiya” room air-conditioner: SRK series are of split and wall mounted type and the unit consists of indoor unit and
outdoor unit with refrigerant precharged in factory. The indoor unit is composed of room air cooling or heating equipment with opera-
tion control switch and the outdoor unit is composed of condensing unit with compressor.
(1) Inverter (Frequency converter) for multi-steps power control
¡Heating/Cooling
The rotational speed of a compressor is changed in step in relation to varying load, interlocked with the indoor and outdoor unit
fans controlled to change frequency, thus controlling the capacity.
¡Allowing quick heating/cooling operation during start-up period. Constant room temperature by fine-tuned control after the
unit has stabilized.
(2) Fuzzy control
¡Fuzzy control calculates the amount of variation in the difference between the return air temperature and the setting temperature
in compliance with the fuzzy rules in order to control the air capacity and the inverter frequency.
(3) Remote control flap
The flap can be automatically controlled by operating wireless remote control.
¡Air scroll (AUTO): Flap operation is automatically control.
¡Swing: This will swing the flap up and down.
¡Memory flap: Once the flap position is set, the unit memorizes the position and continues to operate at the same position from
the next time.
(4) Self diagnosis function
¡We are constantly trying to do better service to our customers by installing such judges that show abnormality of operation as
follows.
Outdoor heat exchanger liquid
pipe sensor error
Discharge pipe sensor error
Outdoor temperature sensor error
2 time flash
4 time flash
RUN lamp
keeps flashing
1 time flash
OFF
OFF
OFF
Trouble of outdoor unit
Over current
Current cut
2 time flash
3 time flash
RUN lamp
ON
1 time flash
2 time flash
3 time flash
1 time flash
5 time flash 5 time flash
TIMER lamp Outdoor (LED)
R410A models
Series No.
Inverter type
Product capacity
Wall mounted type
Split type room air-conditioner
1.2 How to read the model name
Example : SR K 35 Z D - S
Room temperature sensor error
Indoor fan motor error
Heat exchanger sensor error
2 time flash
6 time flash
TIMER lamp
ON
1 time flash
RUN lamp
Rotor lock
6 time flash 6 time flash
7 time flash ON
(25, 35 type only)
2 time flash 7 time flash
RUN lamp
2 time flash

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Item Model SRK25ZD-S SRC25ZD-S
Cooling capacity(1) W 2500
Heating capacity(1) W 3400
Power source 1 Phase, 220/230/240V, 50Hz
Cooling input kW 0.62
Running current (Cooling) A 3.1/3.0/2.9
Heating input kW 0.94
Running current (Heating) A 4.5/4.3/4.1
Inrush current A 4.5/4.3/4.1
COP Cooling: 4.03 Heating: 3.62
Cooling Sound level Hi 37, Me 30, Lo 22 44
Noise level Power level dB 53 58
Heating Sound level Hi 39, Me 33, Lo 26 47
Power level 55 61
Exterior dimensions
Height ×Width ×Depth mm 250 ×815 ×249 540 ×720 ×290
Color Cool white Stucco white
Net weight kg 9.0 32
Refrigerant equipment
Compressor type & Q’ty –RM-B5077MD1 (Rotary type) ×1
Motor kW –0.75
Starting method – Line starting
Heat exchanger Louver fins & inner grooved tubing
Refrigerant control Capillary tubes + Electronic expansion valve
Refrigerant(3) kg R410A 0.9 (Pre-Charged up to the piping length of 15m)
Refrigerant oil R0.35 (MA68)
Deice control Microcomputer control
Air handling equipment
Fan type & Q’ty Tangential fan ×1 Propeller fan ×1
Motor W 29 24
(Cooling) 8.0 30
Air flow (at High) (Heating) CMM 8.7 25
Air filter, Q’ty Polypropylene net (washable) ×2–
Shock & vibration absorber – Cushion rubber (for compressor)
Electric heater ––
Operation control
Operation switch Wireless-Remote controller –
Room temperature control Microcomputer thermostat –
Pilot lamp RUN (Green), TIMER (Yellow), HI POWER (Green), ECONO (Orange)
Safety equipment
O.D mm (in) Liquid line: φ6.35 (1/4″) Gas line: φ9.52 (3/8″)
Connecting method Flare connecting
Attached length of piping Liquid line: 0.47 m
Gas line : 0.40 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2.5 m (3 cores with Earth)
Size ×Core number 1.5 mm2×4 cores (Including earth cable)
Connection wiring Connecting method Terminal block (Screw fixing type)
Accessories (included) Mounting kit
Optional parts –
Notes (1) The data are measured at the following conditions.
2 SELECTION DATA
2.1 Specifications
Model SRK25ZD-S (Indoor unit)
SRC25ZD-S (Outdoor unit)
Item Indoor air temperature Outdoor air temperature Standards
Operation DB WB DB WB
Cooling 27ºC 19ºC 35ºC 24ºC ISO-T1, JIS C9612
Heating 20ºC – 7ºC 6ºC ISO-T1, JIS C9612
(2) The operation data are applied to the 220/230/240V districts respectively.
(3) The refrigerant quantity to be charged includes the refrigerant in 15 m connecting piping.
(Purging is not required even for the short piping.)
Operation data
(1)
Refrigerant
piping
Compressor overheat protection, Heating overload protection (High pressure control), Overcurrent protection,
Frost protection, Serial signal error protection, Indoor fan motor error protection, Cooling overload protection
The piping length is 7.5m.

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Item Model SRK35ZD-S SRC35ZD-S
Cooling capacity(1) W 3500
Heating capacity(1) W 4500
Power source 1 Phase, 220/230/240V, 50Hz
Cooling input kW 1.09
Running current (Cooling) A 5.4/5.2/5.0
Heating input kW 1.24
Running current (Heating) A 5.9/5.7/5.4
Inrush current A 5.9/5.7/5.4
COP Cooling: 3.21 Heating: 3.63
Cooling Sound level Hi 41, Me 32, Lo 23 48
Noise level Power level dB 58 62
Heating Sound level Hi 45, Me 36, Lo 27 50
Power level 59 64
Exterior dimensions
Height ×Width ×Depth mm 250 ×815 ×249 540 ×720 ×290
Color Cool white Stucco white
Net weight kg 9.0 35
Refrigerant equipment
Compressor type & Q’ty –RM-B5077MD1 [Rotary type] ×1
Motor kW –0.90
Starting method – Line starting
Heat exchanger Louver fins & inner grooved tubing
Refrigerant control Capillary tubes + Electronic expansion valve
Refrigerant(3) kg R410A 1.1 (Pre-Charged up to the piping length of 15m)
Refrigerant oil R0.35 (MA68)
Deice control Microcomputer control
Air handling equipment
Fan type & Q’ty Tangential fan ×1 Propeller fan ×1
Motor W 29 24
(Cooling) 8.9 34
Air flow (at High) (Heating) CMM 10.3 34
Air filter, Q’ty Polypropylene net (washable) × 2 –
Shock & vibration absorber – Cushion rubber (for compressor)
Electric heater ––
Operation control
Operation switch Wireless-Remote controller –
Room temperature control Microcomputer thermostat –
Pilot lamp RUN (Green), TIMER (Yellow), HI POWER (Green), ECONO (Orange)
Safety equipment
O.D mm (in) Liquid line: φ6.35 (1/4″) Gas line: φ9.52 (3/8″)
Connecting method Flare connecting
Attached length of piping Liquid line: 0.47 m
Gas line : 0.40 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2.5 m (3 cores with Earth)
Size ×Core number 1.5 mm2×4 cores (Including earth cable)
Connection wiring Connecting method Terminal block (Screw fixing type)
Accessories (included) Mounting kit
Optional parts –
Notes (1) The data are measured at the following conditions.
Model SRK35ZD-S (Indoor unit)
SRC35ZD-S (Outdoor unit)
Item Indoor air temperature Outdoor air temperature Standards
Operation DB WB DB WB
Cooling 27ºC 19ºC 35ºC 24ºC ISO-T1, JIS C9612
Heating 20ºC – 7ºC 6ºC ISO-T1, JIS C9612
(2) The operation data are applied to the 220/230/240V districts respectively.
(3) The refrigerant quantity to be charged includes the refrigerant in 15 m connecting piping.
(Purging is not required even for the short piping.)
Operation data
(1)
Refrigerant
piping
Compressor overheat protection, Heating overload protection (High pressure control), Overcurrent protection,
Frost protection, Serial signal error protection, Indoor fan motor error protection, Cooling overload protection
The piping length is 7.5m.

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Model SRK50ZD-S (Indoor unit)
SRC50ZD-S (Outdoor unit)
Item Model SRK50ZD-S SRC50ZD-S
Cooling capacity(1) W 5000
Heating capacity(1) W 6300
Power source 1 Phase, 220/230/240V, 50Hz
Cooling input kW 1.66
Running current (Cooling) A 7.6/7.3/7.0
Heating input kW 1.96
Running current (Heating) A 9.0/8.6/8.2
Inrush current A 9.0/8.6/8.2
COP Cooling: 3.01 Heating: 3.21
Cooling Sound level Hi 48, Me 42, Lo 26 48
Noise level Power level dB 61 61
Heating Sound level Hi 46, Me 40, Lo 34 49
Power level 62 64
Exterior dimensions
Height ×Width ×Depth mm 250 ×815 ×249 640 ×850 ×290
Color Cool white Stucco white
Net weight kg 9.0 43
Refrigerant equipment
Compressor type & Q’ty –5CS102XFA [Scroll type] ×1
Motor kW –1.5
Starting method – Line starting
Heat exchanger SLIT fin + Louver fins & inner grooved tubing
Refrigerant control Capillary tubes + Electronic expansion valve
Refrigerant(3) kg R410A 1.35 (Pre-Charged up to the piping length of 15m)
Refrigerant oil R0.36 (RB68A)
Deice control Microcomputer control
Air handling equipment
Fan type & Q’ty Tangential fan ×1 Propeller fan ×1
Motor W 29 45
(Cooling) 11.5 42
Air flow (at High) (Heating) CMM 13.0 42
Air filter, Q’ty Polypropylene net (washable) × 2 –
Shock & vibration absorber – Cushion rubber (for compressor)
Electric heater ––
Operation control
Operation switch Wireless-Remote controller –
Room temperature control Microcomputer thermostat –
Pilot lamp RUN (Green), TIMER (Yellow), HI POWER (Green), ECONO (Orange)
Safety equipment
O.D mm (in) Liquid line: φ6.35 (1/4″) Gas line: φ12.7 (1/2″)
Connecting method Flare connecting
Attached length of piping Liquid line: 0.47 m
Gas line : 0.40 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2.5 m (3 cores with Earth)
Size ×Core number 1.5 mm2×4 cores (Including earth cable)
Connection wiring Connecting method Terminal block (Screw fixing type)
Accessories (included) Mounting kit
Optional parts –
Notes (1) The data are measured at the following conditions.
Item Indoor air temperature Outdoor air temperature Standards
Operation DB WB DB WB
Cooling 27ºC 19ºC 35ºC 24ºC ISO-T1, JIS C9612
Heating 20ºC – 7ºC 6ºC ISO-T1, JIS C9612
(2) The operation data are applied to the 220/230/240V districts respectively.
(3) The refrigerant quantity to be charged includes the refrigerant in 15 m connecting piping.
(Purging is not required even for the short piping.)
If the piping length is longer, when it is 15 to 25m, add 20 g refrigerant per meter.
Operation data
(1)
Refrigerant
piping
Compressor overheat protection, Heating overload protection (High pressure control), Overcurrent protection,
Frost protection, Serial signal error protection, Indoor fan motor error protection, Cooling overload protection
The piping length is 7.5m.

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2.2 Range of usage & limitations
2.3 Exterior dimensions
(1) Indoor unit
Models SRK25ZD-S, 35ZD-S, 50ZD-S
Indoor return air temperature
(Upper, lower limits)
Refrigerant line (one way) length Max. 15m
SRK25ZD-S, 35ZD-S SRK50ZD-S
Refer to the selection chart
Power source voltage Rating ±10%
Voltage at starting Min. 85% of rating
Frequency of ON-OFF cycle Max. 10 times/h
ON and OFF interval Max. 3 minutes
Outdoor air temperature
(Upper, lower limits)
Vertical height difference between
outdoor unit and indoor unit Max. 10m (Outdoor unit is higher) Max. 10m (Outdoor unit is lower)
Max. 25m
Max. 15m (Outdoor unit is higher)
Max. 15m (Outdoor unit is lower)
Item
Models
VIEW A
117.5 580 117.5
148.5
216.5216.5
8.2
44.5
236.1
5.7
450
450
67.5
42.7 47.2
175
44.5
216.5216.5
148.5
53.5 Piping for Gas
Drain hose 540 (ø16)
Piping for Liquid 465.1 (ø6.35)
Piping hole (ø65) Piping hole (ø65)
( )
25.35:ø9.52
50:ø12.7 397.1
45
14.5
60
788
560
45
815
A
250
Unit: mm
Piping hole right(left)
Terminal block
960
45
3
249
150
18
56
Remote controller

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(2) Outdoor unit
Models SRC25ZD-S, 35ZD-S
Drain hole
286.4
12
50
290
49.6 43.5
850
203.1 510 136.9
476
Elogated hole
(2-12x16)
314 12
328
Terminal block
Service valve (Liquid)
ø6.35 (1/4'')
Service valve (Gas)
ø12.7 (1/2'')
Ground
terminal
124 34.6
20˚
20˚
42.7
100.3
15
640
14
Model SRC50ZD-S
Unit: mm
290
540
14.4 47.4 42.6
264.5
71
404.5
510
720
17.8
Drain holes
50 12
39.7
99.9
340
312.5 13.5
14
139 2-16x12
61.9
139.3 33.3 Flare connection ø6.35 (1/4")
Service valve (Liquid)
40
°
40
°
Flare connecting ø9.52 (3/8")
Service valve (Gas)
Terminal block

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2.4 Piping system
Models SRK25ZD-S, 35ZD-S
Outdoor unitIndoor unit
Room temp.
thermistor
Heat
exchanger
Flare connecting
Heat
exchanger
thermistor
Piping
(Liquid)
ø6.35
Check joint
4 way valve
Service valve (Liquid)
Flare connecting
Discharge temp.
thermistor
Cooling cycle
Heating cycle Outdoor air
temp. thermistor
Heat
exchanger
Heat exchanger
thermistor
Compressor
Capillary tube
Strainer
Accumulator
Service valve
(Gas)
Electronic
expansion valve
Piping
(Gas)
ø9.52
Model SRK50ZD-S
Outdoor unitIndoor unit
Room temp.
thermistor
Heat
exchanger
Flare connecting
Heat
exchanger
thermistor
Piping
(Liquid)
ø6.35
Check joint
4 way valve
Service valve (Liquid)
Flare connecting
Discharge temp.
thermistor
Cooling cycle
Heating cycle Outdoor air
temp. thermistor
Heat
exchanger
Heat exchanger
thermistor
Compressor
Capillary tube
Strainer
Strainer
Service valve
(Gas)
Capillary tube
Electronic
expansion valve
Piping
(Gas)
ø12.7
Muffler
Capillary tube

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2.5 Selection chart
Correct the cooling and heating capacity in accordance with the conditions as follows. The net cooling and heating capacity can be
obtained in the following way.
Net capacity = Capacity shown on specification ✕ Correction factors as follows.
(1) Coefficient of cooling and heating capacity in relation to temperatures
(2) Correction of cooling and heating capacity in relation to one way length of refrigerant piping
It is necessary to correct the cooling and heating capacity in relation to the one way piping length between the indoor and outdoor
units.
(3) Correction relative to frosting on outdoor heat exchanger during heating
In additions to the foregoing corrections (1), (2) the heating capacity needs to be adjusted also with respect to the frosting on the
outdoor heat exchanger.
How to obtain the cooling and heating capacity
Example : The net cooling capacity of the model SRK35ZD-S with the piping length of 15m, indoor wet-bulb temperature at 19.0˚C
and outdoor dry-bulb temperature 35˚C is Net cooling capacity = 3500 ✕0.975 ✕1.0 =3413 W
SRK35ZD-S Length 15m Factor by air
temperatures
15
ISO-T1 Standard ConditionOutdoor air W.B. temperature °C W.B.
010-10 -5 5
14 16 18 20 22
15
10
27
25
20
15
20
25
30
35
40
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
43
24
20
ISO-T1 Standard ConditionIndoor air W.B. temperature °C W.B.
Heating
Cooling
Applicable range
Coefficient of cooling & Heating capacity in relation to temperature
Cooling operation
Outdoor air D.B.
temperature
°C D.B.
Heating operation
Indoor air D.B.
temperature
°C D.B.
Piping length [m]
Cooling
Heating
7
1.0
1.0
10
0.99
1.0
15
0.975
1.0
20
0.965
1.0
25
0.95
1.0
Air inlet temperature of
outdoor unit in ˚CWB
Adjustment coefficient
-10
0.95
-9
0.94
-7
0.93
-5
0.91
-3
0.88
-1
0.86
1
0.87
3
0.92
5
1.00

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3 ELECTRICAL DATA 3.1 Electrical wiring
Models SRK25ZD-S, 35ZD-S
Power source
1 Phase
220/230/240V 50Hz
Outdoor unit
Indoor unit
HEAT
EXCHANGER
Printed circuit
board
Printed circuit board
BR
BL
Y/GN
BK
WH
RD
RD
1
3
4
5
6
CNU
BK
WH
Y
BL
TB TB
F2 (250V 20A)
F1
250V
3.15A
BK
WH
RD U
V
W
BK
C2 S.IN R.IN
Re
G
WH
RD
Y/GN
N
ZNR
CNM CNE CNG
52C3
52C
52C4 J
Th4
Th1 Th2 Th5
Th6
CNB
CNE
CNA
CND
1
2
3
NP
Power
transistor
20S
52C
EEV
FMo
DS
CM
1
2
3
( )
FM
I
SM
Display
Wireless
R-Amp
Black
Brown
Red
Blue
White
Yellow/Green
BK
BR
RD
BL
WH
Y/GN
Color symbol
Meaning of marks
Symbol Parts name
CM Compressor motor
FFuse
FM
I
F
Fan motor (Indoor)
FMo Fan motor (Outdoor)
SM
RE Flap motor
Reactor
Symbol Parts name
Th
1
Room temp. thermistor
Th
2
Heat exchanger thermistor (Indoor unit)
Th
4
Heat exchanger thermistor (Outdoor unit)
Th
5
Outdoor air temp. thermistor
Th
ZNR
6
Dischar
Varistorge temp. thermistor
Symbol Parts name
20S 4 way valve (coil)
52C Magnetic contactor
DS Diode stack
EEV Electronic expansion valve

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Power source
1 Phase
220/230/240V 50Hz
Outdoor unit
Indoor unit
HEAT
EXCHANGER
Printed circuit board
BR
BL
Y/GN
BK
WH
Y
OR
RD
RD
BK
WH
Y
BL
TB TB
F2 (250V 15A)
F1
250V
3.15A
BK
G3 N-1 L-1
CNO.1
WH
RD
Y/GN
N
ZNR
CNM CNE CNG CNF
52C3
52C
52C4 J
1
2
3
52C
FMo
EEV
CM
CFo
SWITCHING
POWER
CIRCUIT
CNS PWB1
PWB3
PWB2
1 CNG 2N_1 N_3
P_1
P_1
RD
RD RD
OR
OR
BK
BK
GR
N-OUT2
GR
AC.N AC.L
AF_L1
AF_L2
BL
BL
L-OUT2
U
V
WWH
BK
DC-N DC-P
CNJ
CNB
CND CNN CNG
CNH
CNH
RL
1
2
3
( )
FM I
SM
Display
Wireless
R-Amp
Th1 Th2
Th3
Th4
Th5
Th6
20S
Power
transistor
NP
L
N1
N2 P2
IC12
DS
L
1
3
4
5
6
CNU
Black
Brown
Red
Blue
White
Yellow/Green
BK
BR
RD
BL Orange
OR
Green
GR
WH
Y/GN
Color symbol
Meaning of marks
Symbol Parts name
CFo Capacitor for FMo
CM Compressor motor
FFuse
FM
I
F
Fan motor (Indoor)
FMo Fan motor (Outdoor)
SM
RL
L
Flap motor
Inspection lamp
Inductor
Symbol Parts name
Th 1
Room temp. thermistor
Th
2
Heat exchanger thermistor (Indoor unit)
Th 3
Humidity sensor
Th
4
Heat exchanger thermistor (Outdoor unit)
Th 5
Outdoor air temp. thermistor
Th
6
Discharge temp. thermistor
Symbol Parts name
ZNR Varistor
20S 4 way valve (coil)
52C Magnetic contactor
DS Diode stack
EEV Electronic expansion valve
Model SRK50ZD-S

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11
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LO
MED
HI
AUTO
HI POWER ECONO
ON OFF
AM PM
HI POWER TEMP ECONO
AIR FLOW
CANCEL
ON OFF
RESERVE
TIMER
TIME ACL
FAN SPEED
ON
MODE
LO
MED
HI
AUTO
TIME
OFF
HI POWER ECONO
ON OFF
AM PM
FAN SPEED button
Each time the button is pushed, the
indicator is switched over in turn.
•The above illustration shows all controls, but in practice
only the relevant parts are shown.
OPERATION MODE select button
Each time the button is pushed, the
indicator is switched over in turn.
AIR FLOW button
This button changes the flap mode. When
pressed, this button changes the mode in the
following order:
ON/OFF button
Press for starting operation, press again for
stopping.
HI POWER button
This button changes the HI POWER mode.
ECONOMY button
This button changes the ECONOMY mode.
RESET switch
Switch for resetting microcomputer.
ON TIMER button
This button selects ON TIMER operation.
Clock switch
This switch for setting the clock.
OFF TIMER button
This button selects OFF TIMER operation.
TEMPERATURE button
This button sets the room temperature.
(This button changes the present time and
TIMER time.)
CANCEL button
This button cancels the ON timer and OFF
timer.
RESERVE button
This button sets the present time and
TIMER time.
SIndication section
OPERATION MODE Indicator
Indicates selected operation with lamp.
[ (Auto) • (Cool) • (Heat) • (Dry)]
TEMPERATURE Indicator
Indicates set temperature.
(Does not indicate temperature when operation
mode is on AUTO)
FAN SPEED Indicator
Indicates set air flow rate with lamp.
AIR FLOW Indicator
Shows selected flap mode.
HI POWER MODE indicator
Indicates during Hi power mode operation.
ECONOMY MODE indicator
Indicates during economy mode operation.
ON TIMER Indicator
Indicates during ON TIMER operation.
Clock Indicator
Indicates present time or timer setting time.
OFF TIMER Indicator
Indicates OFF TIMER operation.
Models All models
Remote controller
SOperation section
4 OUTLINE OF OPERATION CONTROL BY MICROCOMPUTER
4.1 Operation control function by remote control switch
(Air scroll) (SWING)

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Unit indication section
Models All models
4.2 Back-up switch
When the remote controller batteries become weak, or if the remote controller is lost or malfunctioning, this switch may be used to turn
the unit on and off.
(a) Operation
Push the switch once to place the unit in the automatic mode. Push it once more to turn the unit off.
(b) Details of operation
The unit will go into the automatic mode in which it automatically determines, from room temperature (as detected by sensor),
whether to go into the cooling, thermal dry or heating modes.
Function Room temperature
Operation mode
setting Fan speed Flap Timer switch
Cooling About 25ºC
Thermal dry About 25ºC Auto Auto Continuous
Heating About 26ºC
ON/OFF button
ECONOMY light (orange)
Illuminates during ECONOMY operation.
TIMER light (yellow)
Illuminates during TIMER operation.
HI POWER light (green)
Illuminates during HI POWER operation.
RUN (HOT KEEP) light (green)
•Illuminates during operation.
•Flashes at air flow stop due to the ‘HOT KEEP’.
4.3 Power blackout auto restart function
(1) Power blackout auto restart function is a function that records the operational status of the air-conditioner immediately prior to it
being switched off by a power cut, and then automatically resumes operations at that point after the power has been restored.
(2) The following settings will be cancelled:
(a) Timer settings
(b) High-power operations
Notes (1) The power blackout auto restart function is set at on when the air-conditioner is shipped from the
factory. Consult with your dealer if this function needs to be switched off.
(2) When power failure ocurrs, the timer setting is cancelled. Once power is resumed, reset the timer.
(3)
If the jumper wire (J7) “REMOTE/AUTORESTART” is cut, auto restart is disabled. (See the diagram at
right)

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4.4 Flap control
Control the flap by AIRFLOW button on the wireless remote control.
(1) Air scroll (AUTO)
The flap will be automatically set to the angle of air flow best to operation.
(a) Starting time of operation
(3) Swing flap
Flap moves in upward and downward directions continuously.
(b) When not operating
The flap returns to the position of air flow directly below, when operation has stopped.
(2) Memory flap
While the flap is operating if the AIRFLOW button is pushed once, it stops swinging at an angle.
As this angle is memorized in the microcomputer, the flap will be automatically set to the angle when next operation is started.
¡Recommendable stopping angle of the flap
Corrects the starting time of next operation by
calculating the temperature difference.
(Example) Heating
Setting temperature
Room temperature
Operation starting time
Time Setting time 15 min. 10 min. 5 min.
earlier earlier earlier
¡If the difference (= Setting temperature –Room tempera-
ture) is 4ºC, the correction value is found to be +5 min-
utes from the table shown above so that the starting time
of next operation is determined as follows:
15 min. earlier + 5 min. = 20 min. earlier
↑↑
Current operation Correction value
start time
sDuring cooling andt
dry operation
Thick line : Rapid movement
Thin line : Slow movement
Stops for approximately
5 seconds in the
horizontal position.
sDuring heating t
operation
Stops for approximately
5 seconds in this
position. Thick line : Rapid movement
Thin line : Slow movement
Horizontal
blowing
COOL•DRY Slant forward
blowing
HEAT
4.5 Comfortable timer setting
If the timer is set at ON when the operation select switch is set at the cooling or heating, or the cooling or heating in auto mode operation
is selected, the comfortable timer starts and determines the starting time of next operation based on the initial value of 15 minutes and the
relationship between the room temperature at the setting time (temperature of room temperature thermistor) and the setting temperature.
(Max. 60 minutes)
Operation mode Operation start time correction value (Min.)
3 < Room temp. –Setting temp. 1 < Room temp. –Setting temp. ≤3 Room temp. –Setting temp. ≤1
At cooling +5 No change –5
3 < Setting temp. –Room temp. 2 < Setting temp. –Room temp. ≤3 Setting temp. –Room temp. ≤2
At heating +5 No change –5
Notes (1) At 5 minutes before the timer ON time, operation starts regardless of the temperature of the room temperature thermistor (Th1).
(2) This function does not operate when in the Dry or Auto Dry mode.
However, the operation in item (1) does operate in the Auto Dry mode.
(3) During the comfortable timer operation, both the operation lamp and timer lamp illuminate and the timer lamp goes off after expiration of the timer, ON setting
time.
=
=
=
=

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(c) Hot keep operation
If the hot keep operation is selected during the heating operation, the indoor blower is controlled based on the temperature of
the indoor unit heat exchanger (detected with Th2, indoor unit heat exchanger thermistor) to prevent blowing of cool wind.
Note (1) Refer to the table shown above right for the values A and B.
¡Normal mode (Normal heating operation, operation after HI POWER completion)
Indoor heat exchanger temp. (˚C)
¡Values of A, B
AB
At 0 rps command 22 25
Other than 0 rps 17 19
command
AB 25·35ZD: 23°C
50ZD: 20°C
28 29.5 31.5 34 36 37.5 39 40
1st speed
3rd speed
4th speed
5th speed
6th speed
7th speed
OFF
Indoor fan
(3) Details of control at each operation mode (pattern)
(a) Fuzzy operation
Deviation between the room temperature setting correction temperature and the suction air temperature is calculated in
accordance with the fuzzy rule, and used for control of the air capacity and the inverter speed.
(b) Heating thermostat operation
¡Operating conditions
If the speed obtained with the fuzzy calculation drops below -24 rps during the heating fuzzy operation, the operation
changes to the heating thermostat operation.
¡Detail of operation
4.6 Outline of heating operation
(1) Operation of major functional components in heating mode
(2) Air flow selection
(a) Speed of inverter changes within the range of selected air flow.
(b) When the defrosting, protection device, etc. is actuated, operation is performed in the corresponding mode.
(c) Outdoor unit blower operates in accordance with the inverter command speed.
Model SRK25ZD-S, 35ZD-S SRK50ZD -S
Item
Inverter speed 0rps [Comp. stopped] 10 rps [10sec.] →0rps [Comp. stopped]
Indoor fan Hot keep normal mode →1st speed
Outdoor fan Stop 2nd speed [1min.] →stop
Flap Horizontal
Model SRK25ZD-S SRK35ZD-S SRK50ZD-S
Air flow selection
Inverter command speed 30~102rps 15~120rps
Air flow Depends on inverter command speed.
Inverter command speed 30~102rps 15~120rps
Air flow 8th speed fixed 6th/7th speed
Inverter command speed 30~72rps 30~76rps 15~62rps
Air flow 6th speed fixed 4th/5th speed
Inverter command speed 30~42rps 30~46rps 15~38rps
Air flow 4th speed fixed 3rd speed fixed
Auto
HI
MED
LO
Item
Indoor fan motor ON ON OFF
Flaps ON or OFF ON or OFF Stop position control
Display Lights up Lights up Lights up or flashes
52C ON ON OFF after stop mode
Outdoor fan motor OFF (25, 35 type) ON OFF (25, 35 type)
Depending on the stop mode (50 type) Depending on the stop mode (50 type)
4-way valve Depending on the stop mode ON Depending on the stop mode
Electronic expansion valve Depending on the EEV control
When the inverter
speed is 0rps When the inverter speed is other than 0rps When the inverter speed is 0rps due to an anomalous stop
Functional
components
(25, 35ZD only)
8th speed
(25, 35ZD only)
9th speed

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Notes (1) Refer to the table shown above right for the values A and B.
Note (2) Values in ( ) are for type 25, 35.
¡Hot keep M mode [During HI POWER operation (for 15 min.)]
Indoor heat exchanger temp. (˚C)
A B 29 31 32 34 36 43
(40) (43) (47)
1st speed
3rd speed
4th speed
5th speed
6th speed
7th speed
OFF
Indoor fan
(d) Defrosting operation
(i) Starting conditions (Defrosting operation can be started only when all of the following conditions are met.)
1After start of heating operation →When it elapsed 35 minutes. (Accumulated operation time)
2After end of defrosting operation →When it elapsed 35 minutes. (Accumulated compressor operation time)
3Outdoor unit heat exchanger thermistor (Th4) temperature →When the temperature has been below –5ºC for 3
minutes continuously.
4When the temperature difference between the outdoor air thermistor temperature and the outdoor unit heat exchanger
thermistor temperature exceeded 25 type: 7.0°C, 35 type: 5.0°C, 50 type: 4.0°C
5During continuous compressor operation
In addition, when the speed command from the indoor controller of the indoor unit during heating operation has
counted 0 rps 10 times or more and all conditions of 1, 2and 3above are satisfied (note that when the temperature
for Th4 is -5°C or less: 62 rps or more, -4°C or less: less than 62 rps), defrost operation is started.
(ii) Operation of functional components during defrosting operation
¡25, 35 type
Indoor fan
Operation lamp
Corresponding
to speed
OFF
ON
Flashing
(Hot keep)
Outdoor fan
Inverter
command
Fuzzy calculated
value 70 rps
0
Corresponding
to speed
OFF
OFF
ON
(1)
4-way valve
Final defrost operation
Defrost control
Hot keep
Indoor unit
Outdoor unit
60 sec.
Hot keep
50 sec. Normal heating operation restored
Defrost end
(Th4 ≥13˚C, 10 minutes)
Defrost operation
Defrost operation
preparation
6th speed 6th speed
¡Values of A, B
AB
At 0 rps command 22 25
Other than 0 rps 17 19
command
8th speed
9th speed
(25, 35ZD only)
(25, 35ZD only)
Note (1) When outdoor unit heat exchanger thermistor (Th4) temperature becomes 2°C or higher, inverter command changes 70 rps to
50 rps.

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(iii) Ending conditions (Operation returns to the heating cycle when either one of the following is met.)
1Outdoor heat exchanger thermistor (Th4) temperature: 13ºC or higher (50 type: 20°C or higher)
2Continued operation time of defrosting →For more than 10 min.
Indoor fan
Operation lamp
Corresponding
to speed
OFF
ON
Flashing
(Hot keep)
Outdoor fan
Inverter
command
Fuzzy calculated
value 70 rps
(1)
0
Corresponding
to speed
OFF
OFF
ON
4-way valve
Final defrost operation
Defrost control
Hot keep
Indoor unit
Outdoor unit
75 sec.
Hot keep
60 sec. Normal heating operation restored
Defrost end
(Th4≥20°C, 10 minutes)
Defrost operation
Defrost operation
preparation
2nd speed 2nd speed
(e) Heating “HI POWER”operation (HI POWER button on remote controller: ON)
Operation is maintained for 15 minutes with a higher blow out air temperature.
¡Detail of operation
Model SRK25, 35ZD-S SRK50ZD-S
Item
Inverter speed 102 rps 120 rps
Indoor fan Hot keep M mode (max 8th speed) Hot keep M mode (max 7th speed)
Outdoor fan 4th speed 2nd speed
Notes (1) Room temperature is not adjusted during the HI POWER operation.
(2) Protective functions will actuate with priority even during the HI POWER operation.
4.7 Outline of cooling operation
(1) Operation of major functional components in Cooling mode
¡50 type
Item
Indoor fan motor ON ON OFF
Flaps ON or OFF ON or OFF Stop position control
Display Lights up Lights up Lights up or flashes
52C ON ON OFF after stop mode
Outdoor fan motor OFF (25, 35 type) ON OFF (25, 35 type)
Depending on the stop mode (50 type) Depending on the stop mode (50 type)
4-way valve Depending on the stop mode ON Depending on the stop mode
Electronic expansion valve Depending on the EEV control
When the inverter
speed is 0rps When the inverter speed is other than 0rps When the inverter speed is 0rps due to an anomalous stop
Functional
components
Note (1) When outdoor unit heat exchanger thermistor (Th4) temperature becomes 7°C or higher, inverter instruction changes 70 rps
to 50 rps.

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(3) Detail of control in each mode (Pattern)
(a) Fuzzy operation
During the fuzzy operation, the air flow and the inverter speed are controlled by calculating the difference between the room
temperature setting correction temperature and the suction air temperature.
(b) Cooling thermostat operation
(i) Operating conditions
During the cooling fuzzy operation or when the speed obtained by the fuzzy calculation is less than -24 rps.
(ii) Detail of operation
(2) Air flow selection
(a) Speed of inverter changes within the range of selected air flow.
(b) When any protective function actuates, the operation is performed in the mode corresponding to the function.
(c) Outdoor blower is operated in accordance with the inverter command speed.
(c) Cooling“HI POWER”operation (HI POWER button on remote controller: ON)
The unit is operated continuously for 15 minutes regardless of the setting temperature.
(i) Detail of operation
Model SRK25, 35ZD-S SRK50ZD-S
Item
Inverter speed 0 rps [Comp. stopped] 10rps [10sec.] →0rps [Comp. stopped]
Indoor fan Corresponds to fan speed switch.
Outdoor fan Stop 2nd speed [1min.] →stop
Notes (1) Protective functions will actuate with priority even during the “HI POWER”operation.
(2) Room temperature is not adjusted during the “HI POWER”operation
4.8 Outline of dehumidifying operation
(1) After operating the indoor blower for 20 seconds from immediately after the start of operation, the indoor temperature is checked
and, based on the result of check, the cooling oriented dehumidifying or heating oriented dehumidifying is selected.
Heating oriented dehumidifying Cooling oriented dehumidifying
Low –3 High
Room temperature - Setting temperature (deg)
Cooling or heating oriented dehumidifying is selected again one hour after the first selection of the cooling or heating oriented
dehumidifying.
Model SRK25ZD-S SRK35ZD-S SRK50ZD-S
Item
Inverter speed 62 70 84
Indoor fan 7th speed 7th speed
Outdoor fan 4th speed 2nd speed
Model SRK25ZD-S SRK35ZD-S SRK50ZD-S
Air flow selection
Inverter command speed 20~62rps 20~70rps 15~84rps
Air flow Depends on inverter command speed.
Inverter command speed 20~62rps 20~70rps 15~84rps
Air flow 7th speed fixed 5th~7th speed
Inverter command speed 20~52rps 20~58rps 15~60rps
Air flow 5th speed fixed 3rd~5th speed
Inverter command speed 20~34rps 20~38rps 15~30rps
Air flow 2nd speed fixed
Auto
HI
MED
LO

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D range C range Brange A range
(b) Heating oriented dehumidifying
After interrupting the compressor operation for 3 minutes (by the 3-minute timer) following the determination of heating
oriented dehumidifying, the unit begins in the heating operation. If the room temperature exceeds the setting temperature by
2ºC or more, the unit checks the room temperature at 5-minute intervals and, depending on the result, determines the range of
heating oriented dehumidifying operation.
Operation range D C B A
Low –1 0 +2 High
Room temperature –Setting temperature (deg)
(D) (C) (C) (B)
OFF
3rd speed
25 sec.
OFF
0
25, 35 type : 38
50 type : 24
25, 35 type : 50
50 type : 40
50 type :
4th speed
25, 35 type : 30
50 type : 15
5th speed
2nd speed
1st speed
50 type :
1st speed
50 type :
1st speed
50 type :
1st speed
Inverter speed
Indoor fan
Outdoor fan
Determination of cooling
oriented dehumidifying
operation range
Temperature check
5 min. 5 min. 5 min. 5 min.
Operation pattern
O L M
Low –1 0 High
Room temperature –Setting temperature (deg)
Operation range
Heating operation Orange Lrange Mrange
OFF
4th speed
2nd speed
1st speed
OFF
3rd speed
50 type :
1st speed 50 type :
1st speed 50 type : 1st speed
25, 35 type : 38
50 type : 28
25, 35 type : 30
50 type : 15
25, 35 type : 48
50 type : 44
0
25 sec.
Inverter speed
Indoor fan
Outdoor fan
Determination of heating
oriented dehumidifying
operation range
Temperature check
5 min. 5 min. 5 min.
Depends on
the operation
condition
Operation pattern
Note (1) Figures in the parentheses
( ) show the values at
economical operation.
Note (1) Figures in the parentheses
( ) show the values at
economical operation.
(2) Outline of control
(a) Cooling oriented dehumidifying
Room temperature is checked at 5-minute intervals after selecting the cooling or heating oriented dehumidifying in order to
determine the operation range.
(O) (L) (L)