Mitsubishi Heavy Industries SRK20ZG-S User manual

INVERTER WALL MOUNTED TYPE
ROOM AIR-CONDITIONER
( Split system, air to air heat pump type )
SRK20ZG-S, SRK25ZG-S, SRK35ZG-S, SRK50ZG-S
Manual No. ’06
.
SRK-T
.
060

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 ....................................................... 6
2.3 Exterior dimensions ...................................................................... 6
2.4 Piping system ................................................................................ 8
2.5 Selection chart .............................................................................. 9
3 ELECTRICAL DATA .............................................................................. 10
3.1 Electrical wiring ............................................................................. 10
4 OUTLINE OF OPERATION CONTROL BY MICROCOMPUTER ......... 12
4.1 Operation control function by remote control switch................ 12
4.2 Unit ON/OFF button....................................................................... 13
4.3 Power blackout auto restart function .......................................... 13
4.4 Custom cord switching procedure .............................................. 13
4.5 Flap and louver control................................................................. 14
4.6 3D auto operation .......................................................................... 15
4.7 Timer operation ............................................................................. 16
4.8 Installation location setting .......................................................... 16
4.9 Outline of heating operation ........................................................ 17
4.10 Outline of cooling operation ........................................................ 18
4.11 Outline of automatic operation .................................................... 18
4.12 Protective control function........................................................... 19
5 APPLICATION DATA ............................................................................. 24
5.1 Selection of location for installation ........................................... 25
5.2 Installation of indoor unit ............................................................. 26
5.3 Installation of outdoor unit ........................................................... 29
5.4 Connection of refrigerant pipings ............................................... 29
5.5 Test run .......................................................................................... 31
5.6 Precautions for wireless remote control installation and
operation ........................................................................................ 31

6 MAINTENANCE DATA .......................................................................... 32
6.1 Troubleshooting procedures for electrical equipment .............. 32
6.2 Servicing ........................................................................................ 51
7 INTERFACE KIT (OPTIONAL PARTS).................................................. 52
7.1 Applicable model........................................................................... 52
7.2 List of connectable devices ......................................................... 52
7.3 Exterior dimensions ...................................................................... 52
7.4 Circuit board component layout .................................................. 52
7.5 System configuration.................................................................... 53
7.6 Installation of interface kit ............................................................ 54
7.7 Wired remote control .................................................................... 59
7.8 Insatallation of wired remote control .......................................... 60
7.9 Setting functions using the wired remote control ..................... 61
7.10 Super link adapter ......................................................................... 65
7.11 Operation permission/prohibition control .................................. 67
7.12 External control (remote display) /control of input signal......... 68
8 REFRIGERANT PIPING INSTALLATION / SERVICING MANUAL
FOR AIR CONDITIONERS USING R410A........................................... 69
8.1 Outline ............................................................................................ 69
8.2 Refrigerant piping installation ..................................................... 70
8.3 Installation, removal and servicing.............................................. 76
8.4 Refrigerant recovery ..................................................................... 81

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1
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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 HEAVY INDUSTRIES, LTD” 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 operation 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 & louver
The flap & louver can be automatically controlled by operating wireless remote control.
¡Flap swing : The flaps swing up and down successively.
¡Louver swing : The louvers swing left and right successively.
¡3D auto operation : Fan speed and air flow direction are automatically controlled, allowing the entire room to be efficiently
conditioned.
¡Memory flap : Once the flap & louver 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 light
keeps flashing
1 time flash
Trouble of outdoor unit
Over current
Current cut
2 time flash
3 time flash
RUN light
ON
1 time flash
5 time flash
TIMER light
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 G - S
Room temperature sensor error
Indoor fan motor error
Heat exchanger sensor error
2 time flash
6 time flash
TIMER light
ON
1 time flash
RUN light
Rotor lock
6 time flash
7 time flash
2 time flash
RUN light
2 time flash
4 time flash Power transistor error

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2
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Item
Model SRK20ZG-S SRC20ZG-S
Cooling capacity(1) W 2000 (500~2800)
Heating capacity(1) W 2700 (500~4600)
Power source 1 Phase, 220-240V, 50Hz
Cooling input kW 0.44 (0.1~0.91)
Running current (Cooling) A 2.4/2.3/2.2
Heating input kW 0.62 (0.09~1.27)
Running current (Heating) A 3.0/2.9/2.8
Inrush current A 3.0/2.9/2.8
COP Cooling: 4.55 Heating: 4.35
Cooling Sound level Hi 35, Me 29, Lo 21 44
Noise level Power level dB 51 58
Heating Sound level Hi 35, Me 32, Lo 25 45
Power level 53 59
Exterior dimensions
Height ×Width ×Depth mm 268 ×790 ×199 540 ×780 ×290
Color Fine snow Stucco white
Net weight kg 8.5 35
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 Straight 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 38 24
(Cooling) 7.4 30
Air flow (at High) (Heating) CMM 8.5 23
Air filter, Q’ty Polypropylene net (washable) ×2–
Shock & vibration absorber – Cushion rubber (for compressor)
Electric heater ––
Operation control
Operation switch Wireless-Remote control –
Room temperature control Microcomputer thermostat –
Pilot lamp RUN (Green), TIMER (Yellow), HI POWER (Green), 3D AUTO (Green)
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: 0.4 m
Gas line : 0.33 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2 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, Clean filter (Allergen clear filter x1, Photocatalytic washable deodorizing filter x1)
Optional parts Interface kit
Notes (1) The data are measured at the following conditions.
2 SELECTION DATA
2.1 Specifications
Model SRK20ZG-S (Indoor unit)
SRC20ZG-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.)
(4) If the interface kit (SC-BIK-E) (sold separately) is connected to the terminals on the indoor unit’s circuit board, a wired remote control (sold separately)
can be connected, a Super Link can be connected, and the unit can be turned on and off from a CNT terminal.
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.
(220/230/240V)

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3
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Item
Model SRK25ZG-S SRC25ZG-S
Cooling capacity(1) W 2500 (500~3000)
Heating capacity(1) W 3400 (500~4800)
Power source 1 Phase, 220-240V, 50Hz
Cooling input kW 0.62 (0.1~0.97)
Running current (Cooling) A 3.1/3.0/2.9
Heating input kW 0.93 (0.09~1.30)
Running current (Heating) A 4.5/4.3/4.1
Inrush current A 4.5/4.3/4.1
COP Cooling: 4.03 Heating: 3.66
Cooling Sound level Hi 36, Me 30, Lo 22 44
Noise level Power level dB 52 58
Heating Sound level Hi 36, Me 33, Lo 26 47
Power level 54 62
Exterior dimensions
Height ×Width ×Depth mm 268 ×790 ×199 540 ×780 ×290
Color Fine snow Stucco white
Net weight kg 8.5 35
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 Straight 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 38 24
(Cooling) 7.6 30
Air flow (at High) (Heating) CMM 8.7 23
Air filter, Q’ty Polypropylene net (washable) ×2–
Shock & vibration absorber – Cushion rubber (for compressor)
Electric heater ––
Operation control
Operation switch Wireless-Remote control –
Room temperature control Microcomputer thermostat –
Pilot lamp RUN (Green), TIMER (Yellow), HI POWER (Green), 3D AUTO (Green)
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: 0.4 m
Gas line : 0.33 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2 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, Clean filter (Allergen clear filter x1, Photocatalytic washable deodorizing filter x1)
Optional parts Interface kit
Notes (1) The data are measured at the following conditions.
Model SRK25ZG-S (Indoor unit)
SRC25ZG-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.)
(4) If the interface kit (SC-BIK-E) (sold separately) is connected to the terminals on the indoor unit’s circuit board, a wired remote control (sold separately)
can be connected, a Super Link can be connected, and the unit can be turned on and off from a CNT terminal.
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.
(220/230/240V)

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4
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Item
Model SRK35ZG-S SRC35ZG-S
Cooling capacity(1) W 3500 (500~3900)
Heating capacity(1) W 4200 (500~5100)
Power source 1 Phase, 220-240V, 50Hz
Cooling input kW 1.05 (0.1~1.22)
Running current (Cooling) A 4.9/4.7/4.5
Heating input kW 1.14 (0.09~1.32)
Running current (Heating) A 5.3/5.1/4.9
Inrush current A 5.3/5.1/4.9
COP Cooling: 3.33 Heating: 3.68
Cooling Sound level Hi 40, Me 32, Lo 23 48
Noise level Power level dB 56 62
Heating Sound level Hi 41, Me 36, Lo 27 50
Power level 59 64
Exterior dimensions
Height ×Width ×Depth mm 268 ×790 ×199 540 ×780 ×290
Color Fine snow Stucco white
Net weight kg 8.5 38
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 Straight 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 38 24
(Cooling) 8.5 30
Air flow (at High) (Heating) CMM 10.8 33
Air filter, Q’ty Polypropylene net (washable) × 2 –
Shock & vibration absorber – Cushion rubber (for compressor)
Electric heater ––
Operation control
Operation switch Wireless-Remote control –
Room temperature control Microcomputer thermostat –
Pilot lamp RUN (Green), TIMER (Yellow), HI POWER (Green), 3D AUTO (Green)
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: 0.4 m
Gas line : 0.33 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2 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, Clean filter (Allergen clear filter x1, Photocatalytic washable deodorizing filter x1)
Optional parts Interface kit
Notes (1) The data are measured at the following conditions.
Model SRK35ZG-S (Indoor unit)
SRC35ZG-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.)
(4) If the interface kit (SC-BIK-E) (sold separately) is connected to the terminals on the indoor unit’s circuit board, a wired remote control (sold
separately) can be connected, a Super Link can be connected, and the unit can be turned on and off from a CNT terminal.
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.
(220/230/240V)

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5
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Model SRK50ZG-S (Indoor unit)
SRC50ZG-S (Outdoor unit)
Item
Model SRK50ZG-S SRC50ZG-S
Cooling capacity(1) W 5000 (600~5300)
Heating capacity(1) W 5800 (600~7900)
Power source 1 Phase, 220-240V, 50Hz
Cooling input kW 1.66 (0.12~2.1)
Running current (Cooling) A 7.6/7.3/7.0
Heating input kW 1.70 (0.11~2.71)
Running current (Heating) A 7.9/7.5/7.2
Inrush current A 7.9/7.5/7.2
COP Cooling: 3.01 Heating: 3.41
Cooling Sound level Hi 47, Me 42, Lo 26 48
Noise level Power level dB 61 61
Heating Sound level Hi 48, Me 40, Lo 34 50
Power level 62 64
Exterior dimensions
Height ×Width ×Depth mm 268 ×790 ×199 640 ×850 ×290
Color Fine snow Stucco white
Net weight kg 8.5 43
Refrigerant equipment
Compressor type & Q’ty –5CS102XFA [Scroll type] ×1
Motor kW –1.5
Starting method – Line starting
Heat exchanger Slit fins + Louver fins & inner grooved tubing Straight 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 38 34
(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 control –
Room temperature control Microcomputer thermostat –
Pilot lamp RUN (Green), TIMER (Yellow), HI POWER (Green), 3D AUTO (Green)
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: 0.4 m
Gas line : 0.33 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2 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, Clean filter (Allergen clear filter x1, Photocatalytic washable deodorizing filter x1)
Optional parts Interface kit
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.
(4) If the interface kit (SC-BIK-E) (sold separately) is connected to the terminals on the indoor unit’s circuit board, a wired remote control (sold
separately) can be connected, a Super Link can be connected, and the unit can be turned on and off from a CNT terminal.
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.
(220/230/240V)

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2.2 Range of usage & limitations
2.3 Exterior dimensions
(1) Indoor unit
Models SRK20ZG-S, 25ZG-S, 35ZG-S, 50ZG-S
Indoor return air temperature
(Upper, lower limits)
Refrigerant line (one way) length Max. 15m
SRK20ZG-S, 25ZG-S, 35ZG-S SRK50ZG-S
Cooling operation : Approximately 18 to 32˚C
Heating operation : Approximately 15 to 30˚C
Cooling operation : Approximately -15 to 46˚C
Heating operation : Approximately -15 to 21˚C
Power source voltage Rating ±10%
Voltage at starting Min. 85% of rating
Frequency of ON-OFF cycle Max. 7 times/h
(Inching prevention 5 minutes)
Max. 4 times/h
(Inching prevention 10 minutes)
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
Unit: mm
Piping hole (ø65)
( )
Piping hole (ø65)
53.5
380.6
Pipng for Liquid 448.6 (ø6.35)
20, 25, 35 : ø9.52
50 : ø12.7
Pipng for Gas
Drain hose 520 (ø16)
53.5
44.5
252.2 7.5
8.3
102.5
585
102.5
133.5450206.5
202450138
44.5 43.2
39.3
200
45
45
60
17.5 60 27
788
60
9
45
199 3
Terminal block
Piping hole right(left)
268
790
A
VIEW A
→

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7
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Drain holes
286.4
12
50
290
49.6 43.5
850
203.1 510 136.9
476
2-16×12
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 SRC50ZG-S
Unit: mm
(2) Outdoor unit
Models SRC20ZG-S, 25ZG-S, 35ZG-S
2-16×12
Drain holes (ø20)
138.4
40˚
61.9
18.9165.1510104.9
439.1
111.4
99.4
349.5
313.1
43.1
290
12
50
350
23.5312.5
14
33.5
40˚
42.595.9
14
540
780
Service valve (Liquid)
Flare connection ø6.35 (1/4'')
Service valve (Gas)
Flare connection ø9.52 (3/8'')
Terminal block

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8
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2.4 Piping system
Models SRK20ZG-S, 25ZG-S, 35ZG-S
Outdoor unitIndoor unit
Room temp.
sensor
Heat
exchanger
Flare connection
Heat
exchanger
sensor
Piping
(Liquid)
ø6.35
Check joint
4 way valve
Service valve (Liquid)
Flare connetion
Discharge pipe
temp. sensor
Cooling cycle
Heating cycle Outdoor air
temp. sensor
Heat
exchanger
Heat exchanger
sensor
Compressor
Capillary tube
Strainer
Accumulator
Service valve
(Gas)
Electronic
expansion valve
Piping
(Gas)
ø9.52
Model SRK50ZG-S
Outdoor unitIndoor unit
Room temp.
sensor
Heat
exchanger
Flare connection
Heat
exchanger
sensor
Piping
(Liquid)
ø6.35
Check joint
4 way valve
Service valve (Liquid)
Flare connection
Discharge pipe
temp. sensor
Cooling cycle
Heating cycle Outdoor air
temp. sensor
Heat
exchanger
Heat exchanger
sensor
Compressor
Capillary tube
Strainer
Strainer
Service valve
(Gas)
Capillary tube
Electronic
expansion valve
Piping
(Gas)
ø12.7
Muffler
Capillary tube
Muffler
Humidity
sensor
(35 type only)
Humidity
sensor

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9
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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 SRK20ZG-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 = 2000 ✕0.975 ✕1.0 =1950 W
Length 15m Factor by air
temperatures
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
SRK20ZG-S
Cooling
Heating
2220181614
0.6
0.7
0.8
0.9
1.0
1.2
1.1
1.3
0
-5
-10
-15
Applicable range
Depends on installed situation
24
26
20
25
30
35
40
46
10
15
20
25
27
Outdoor air W.B. temperature ˚C W.B.
-15 -10 -5 0 5 10 15
Indoor air W.B. temperature ˚C W.B. ISO-T1 Standard Condition
Cooling operation
Outdoor air D.B.
temperature
˚CD. B.
Coefficient of cooling &
Heating capacity in relation to temperature
Heating operation
Indoor air D.B.
temperature
˚CD. B.
ISO-T1 Standard Condition
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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10
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3 ELECTRICAL DATA 3.1 Electrical wiring
Models SRK20ZG-S, 25ZG-S, 35ZG-S
+
~~
-+
+
+
Indoor unit Outdoor unit
BL
Y
WH
BK
RD
FM I
6
CNU
1
3
4
5
CNM
5
SM
52C
CNX
5
LM
1
LM 2
CNY
5
R-AMP
WIRELESS
DISPLAY
Th
1
Th 2
Th 3
CNE
BACK UP SW
8
BOARD
PRINTED CIRCUIT
PRINTED CIRCUIT BOARD
CNG
22
(35 TYPE ONLY)
2
CNF
250V 3.15A
F
52C
ZNR
52C-4 52C-3NGJ
1
3
2/N
1
3
2/N
Y/GN
RD
WH
BK
RD
WH
BK
BR
WH
BK
Y/GN
RD
EXCHANGER
HEAT
BR
LB
Y/GN
220/230/240V 50Hz
1 Phase
POWER SOURCE
BOX
CONTROL
U
TB TB
250V 15A
F
R.IN C-2S.IN
NP
POWER
TRANSISTOR
U
V
W
RD
WH
BK
CM
CND
Th
4
Th 5
Th 6
CNA
FM
O
CNB
20S
EEV
DS
L
G
G
CNE
BK
BL
BR
Y
WH
LB
Y/G
RD
Color symbol
Black
Blue
Brown
Yellow
White
Light blue
Yellow/Green
Red
Meaning of marks
Symbol Parts name Symbol Parts name Symbol Parts name
CM
F
FM
I
FM O
SM
LM
1
Th 1
Th 2
Compressor motor
Fuse
Fan motor(Indoor)
Fan motor(Outdoor)
Flap motor
Louver motor(L)
LM
2
Louver motor(R)
Room temp.sensor
Heat exch.sensor(Indoor unit)
Th
3
Th 4
Th 5
Th 6
ZNR
20S
EEV
DSHumidity sensor
Heat exch.sensor(Outdoor unit)
TB Terminal blockOutdoor air temp.sensor
Discharge pipe temp.sensor
Varistor
4 way valve(coil)
Electronic expansion valve
Diode stack
L Inductor

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Model SRK50ZG-S
Indoor unit Outdoor unit
BL
Y
WH
BK
RD
FM I
6
CNU
1
3
4
5
CNM
5
SM
CNX
5
LM
1
LM 2
CNY
5
R-AMP
WIRELESS
DISPLAY
Th
1
Th 4
Th 5
Th 6
Th 2
Th 3
CNE
BACK UP SW
8
BOARD
PRINTED CIRCUIT
CNG
22 2
CNF
250V 3.15A
250V 15A
F
52C
ZNR
52C-4 52C-3NGJ
1
3
2/N
1
3
2/N
Y/GN
RD
WH
BK
RD
WH
BK
BR
WH
BK
Y/GN
RD
EXCHANGER
HEAT
BR
LB
Y/GN
220/230/240V 50Hz
1 Phase
POWER SOURCE
BOX
CONTROL
U
TB TB
F
BK
BL
BR
Y
WH
LB
Y/G
RD
Color symbol
Black
Blue
Brown
GR Gray
Yellow
White
Light blue
OR Orange
Yellow/Green
Red
Meaning of marks
Symbol Parts name Symbol Parts name Symbol Parts name
CM
F
FM
I
FM O
SM
LM
1
Th 1
Th 2
Compressor motor
Fuse
Fan motor(Indoor)
Fan motor(Outdoor)
Flap motor
Louver motor(L)
LM
2
Louver motor(R)
Room temp.sensor
Heat exch.sensor(Indoor unit)
Th 3
Th 4
Th 5
Th 6
ZNR
20S
EEV
DSHumidity sensor
Heat exch.sensor(Outdoor unit)
TB
Terminal block
Outdoor air temp.sensor
Discharge pipe temp.sensor
Varistor
4 way valve(coil)
Electronic expansion valve
Diode stack
L Inductor
FM O
20S
CNT
CNB
CND
EEV CNJ
CNI
CNH CNH
CNGCNG
PWB1(MAIN)
PWB2(POWER)
AF_L2
AF_L1
V
WU
BK
WH
RD
OR
OROR
OR
BK
RD
WH
L
CM
N_1
P_1
AC.N AC.L
AC.N AC.L
BL
GR
BL
GR
BK
RD
N_1
P_1
DC-N
DC-P
CNG
PWB3(CAPACITOR)
BK
RD
L-1G3 N-1 CNO.1
Y/G
52C

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Models All models
Remote control
SOperation section
4 OUTLINE OF OPERATION CONTROL BY MICROCOMPUTER
4.1 Operation control function by remote control switch
RUN TIMER
ON / OFF
HI POWER 3D AUTO
ON
OFF
1.5 sec.
0.5 sec.
3D AUTO light (green)
Illuminates during 3D AUTO operation.
HI POWER light (green)
Illuminates during HIGH POWER operation.
RUN (HOT KEEP) light (green)
•Illuminates during operation and CLEAN
operation.
•
Blinks at air flow stop due to the ‘HOT KEEP’.
TIMER light (yellow)
Illuminates during TIMER operation.
In emergencies, this button can be used for turning on/off the unit
when remote control is not available.
Remote control signal receiver
Unit ON/OFF button
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 pushed, the
indicator is switched over in turn.
ON/OFF (luminous) button
Press for starting operation, press again
for stopping.
HI POWER/ECONO button
This button changes the HIGH POWER/
ECONOMY mode.
AIR FLOW (UP/DOWN) button
This button changes the air flow (up/down) mode.
This button changes the air flow (left/right) mode.
SLEEP button
This button selects to SLEEP operation.
CLEAN switch
This switch changes the CLEAN mode.
ON TIMER button
This button selects ON TIMER operation.
AIR FLOW (LEFT/RIGHT) button
3D AUTO button
This button sets 3D AUTO operation.
This button selects ALLERGEN CLEAR
operation.
ALLERGEN CLEAR button
RESET switch
Switch for resetting microcomputer and
setting time.
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.)
This button cancels the ON timer, OFF
timer, and SLEEP operation.
CANCEL button
Unit indication section
Models All models

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Unit ON/OFF button
4.2 Unit ON/OFF button
When the remote control batteries become weak, or if the remote control is lost or malfunctioning, this button may be used to turn the
unit on and off.
(1) Operation
Push the button once to place the unit in the automatic mode. Push it once more to turn the unit off.
(2) 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 24ºC
Thermal dry About 24ºC Auto Auto Continuous
Heating About 26ºC
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 (J12) “AUTO RESTART” is cut, auto restart is disabled. (See the diagram at right)
4.4 Custom cord switching procedure
If two wireless remote controls are installed in one room, in order to prevent wrong operation
due to mixed signals, please modify the printed circuit board in the indoor unit’s control box
and the remote control using the following procedure. Be sure to modify both boards. If only
one board is modified, receiving (and operation) cannot be done.
(1) Modifying the indoor unit’s printed circuit board
Take out the printed circuit board from the control box and cut off jumper wire (J13)
using wire cutters.
After cutting of the jumper wire, take measures to prevent contact with the other the lead
wires, etc.
(2) Modifying the wireless remote control
(a) Remove the battery.
(b) Cut the jumper wire shown in the figure at right.
Jumper wire (J12)
Jumper wire (J13)
Cut

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4.5 Flap and louver control
Control the flap and louver by AIRFLOW 
(UP/DOWN) and(LEFT/RIGHT) button on the wireless remote control.
(1) Flap
Each time when you press the AIRFLOW 
(UP/DOWN) button the mode changes as follows.
(2) Louver
Each time when you press the AIRFLOW(LEFT/RIGHT) button the mode changes as follows.
(3) Swing
(a) Swing flap
Flap moves in upward and downward
directions continuously.
(b) Swing louver
Louver moves in left and right directions continuously.
(4) Memory flap (Flap or Louver stopped)
When you press the AIRFLOW (UP/DOWN or LEFT/RIGHT) button once while the flap or louver is operating, it stops swinging
at an angle. Since this angle is memorized in the microcomputer, the flap or louver will automatically be set at this angle when the
next operation is started.
(5) When not operating
The flap returns to the position of air flow directly below, when operation has stopped.
COOL , DRY
Remote control
display
HEAT
• Angle of Flap from Horizontal
Approx. 10˚
Approx. 20˚
Approx. 20˚
Approx. 35˚
Approx. 30˚
Approx. 50˚
Approx. 45˚
Approx. 60˚
Approx. 60˚
Approx. 70˚
(Swing)
(Flap stopped)
Center installation
Remote control
display
Right end installation
Left end installation
• Angle of Louver
Left Approx. 45˚
Left Approx. 45˚
Left Approx. 20˚
Left Approx. 30˚
Center
Left Approx. 20˚
Right Approx. 20˚
Center
Right Approx. 45˚
Right Approx. 20˚
Left Approx. 20˚ Center Right Approx. 20˚ Right Approx. 30˚ Right Approx. 45˚
(Louver stopped)
(Swing) (Spot) (Wide)
S In HEAT operation S In COOL, DRY operation S In HEAT operation S In COOL, DRY operation
Approx. 30˚
Approx. 70˚
Approx.
10˚
Approx. 30˚

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4.6 3D auto operation
Control the flap and louver by 3D AUTO button on the wireless remote control.
Air flow selection and air flow direction are automatically controlled, allowing the entire room to efficiently conditioned.
(1) During Cooling and Heating (Including auto cooling and heating)
(a) Air flow selection is determined according to room temperature and setting temperature.
(b) Air flow direction is controlled according to the room temperature and setting temperature.
1) When 3D auto operation starts
2) When Room temp. – Setting temp. is ≤_ 5ºC during cooling and when Setting temp. – Room temp. is ≤_ 5ºC during
heating, the system switches to the following air flow direction control. After the louver swings left and right symmetrically
for 3 cycles, control is switched to the control in 3).
3) After the flap swings for 5 cycles, control is switched to the control in 4).
4) For 5 minutes, the following air flow direction control is carried out.
5) After 5 minutes have passed, the air flow direction is determined according to the room temperature and setting
temperature.
(2) During DRY Operation (including auto DRY operation)
At cooling
Air flow selection
Operation mode AUTO HI MED LO
At heating
Room temp. – Setting temp. >5˚C Room temp. – Setting temp. ≤_ 5˚C
Setting temp. – Room temp. >5˚C Setting temp. – Room temp. ≤_ 5˚C
HIGH POWER AUTO HI MED LO
HIGH POWER AUTO
Flap
Louver
Cooling
Up/down Swing
Heating
Wide (fixed) Center (fixed)
Flap
Louver
Cooling Heating
Left/right Swing
Horizontal blowing (Fixed) Slant forwardl blowing (Fixed)
Flap
Louver
Cooling
Up/down Swing
Heating
Center (Fixed)
Wide (Fixed)
Flap
Louver
Cooling Heating
Horizontal blowing (Fixed) Slant forwardl blowing (Fixed)
Operation mode
Room temp. – Setting temp. ≤_ 2˚C
Setting temp. – Room temp. ≤_ 2˚C
At heating
At cooling
Air flow direction contorol
2˚C < Setting temp. – Room temp. ≤_ 5˚C
2˚C < Room temp.
– Setting temp. ≤_ 5˚C Room temp. – Setting temp. > 5˚C
Setting temp. – Room temp. > 5˚C
The control in 4) continues. Control returns to the control in 2). Control returns to the control in 1).
The control in 4) continues. Control returns to the control in 2). Control returns to the control in 1).
Wide (Fixed)
Flap
Air flow selection
Louver
According to DRY operation.
Horizontal blowing (Fixed)

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(2) Sleep timer operation
Pressing the SLEEP button causes the temperature to be controlled as shown in the following chart with respect to the set tempera-
ture.
4.7 Timer operation
(1) Comfortable timer setting (ON timer)
(3) OFF timer operation
The Off timer can be set at a specific time (in 10-minute units) within a 24-hour period.
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 sensor) and the
setting temperature.
4.8 Installation location setting
When the indoor unit is installed at the end of a room, control the air flow direction so that it is not toward the side walls. If you set the
remote control’s installation position, keep it so that the air flow is within the range shown in the following figure.
(1) Setting
1If the air conditioning unit is running, press the ON/OFF button to stop.
The installation location setting cannot be made while the unit is running.
2Press the AIR FLOW
(UP/DOWN) button and the
AIRFLOW(LEFT/RIGHT) button together for 5 seconds
or more.
The installation location display illuminates.
3Setting the air-conditioning installation location.
Press the AIR FLOW(LEFT/RIGHT) button and adjust to the desired
location.
Each time the AIR FLOW(LEFT/RIGHT) button is pressed, the
indicator is switched in the order of:
4Press the ON/OFF button.
The air-conditioner's installation location is set.
Press within 60 seconds of setting the installation location (while the
installation location setting display illuminates).
Airflow range Airflow range Airflow range
(Left End Installation) (Center Installation) (Right End Installation)
1, 4
2
3
(Center Installation) (Right End Installation) (Left End Installation)

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4.9 Outline of heating operation
(1) Operation of major functional components in heating mode
(2) 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.
When the defrosting, protection device, etc. is actuated, operation is performed in the corresponding mode.
(b) 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 sensor) to prevent blowing of cool wind.
ON OFF OFF
ON ON OFF
ON OFF
(few minutes ON) OFF
ON ON(HOT KEEP) OFF
OFF
OFF
(3 minutes ON)
OFF
OFF
Thermostat ON Thermostat OFF Defrost Failure
Heating
Compressor
Indoor fan motor
Outdoor fan motor
4-way valve
30~100rps 30~102rps 15~122rps
30~100rps 30~102rps 15~122rps
30~70rps 30~72rps 30~84rps 15~84rps
30~44rps 30~54rps 30~62rps 15~66rps
SRK20ZG-S
Model
Fan speed SRK25ZG-S SRK35ZG-S SRK50ZG-S
Auto
MED
HI
LO
(3) Defrosting operation
(a) Starting conditions (Defrosting operation can be started only when all of the following conditions are met.)
1After start of heating operation
When it elapsed 45 minutes (35, 50 type : 35 minutes). (Accumulated compressor operation time)
2After end of defrosting operation
When it elapsed 45 minutes(35, 50 type : 35 minutes). (Accumulated compressor operation time)
3Outdoor unit heat exchanger sensor (Th4) temperature
When the temperature has been below –5ºC for 3 minutes continuously.
4The difference between the outdoor air sensor temperature and the outdoor unit heat exchanger sensor temperature
¡The outdoor air temperature ≥_ -17°C : 7°C (35type : 5°C, 50type : 4°C) on higher
¡The outdoor air temperature < -17°C : -5°C or higher
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, 2, 3and 5above and the outdoor air temperature is 3°C or less 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.
(b) Ending conditions (Operation returns to the heating cycle when either one of the following is met.)
1Outdoor heat exchanger sensor (Th4) temperature: 13ºC or higher
2Continued operation time of defrosting →For more than 10 min.