Mitsubishi Heavy Industries SRK20ZGX-S User manual

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INVERTER WALL MOUNTED TYPE
ROOM AIR-CONDITIONER
( Split system, air to air heat pump type )
SRK20ZGX-S, 25ZGX-S, 35ZGX-S, 50ZGX-S
TECHNICAL MANUAL
Collection data
Manual No. ’07
.
SRK-T
.
065

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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 ............................................................... 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 ....................................................... 14
4.5 Flap and louver control ......................................................................... 14
4.6 Timer operation...................................................................................... 14
4.7 Outline of heating operation ................................................................. 15
4.8 Outline of cooling operation ................................................................. 16
4.9 Outline of automatic operation............................................................. 16
4.10 Protective control function ................................................................... 17
5. APPLICATION DATA .................................................................................... 22
5.1 Selection of location for installation .................................................... 23
5.2 Installation of indoor unit ...................................................................... 24
5.3 Installation of outdoor unit ................................................................... 27
5.4 Refrigerant piping .................................................................................. 27
5.5 Test run ................................................................................................... 29
5.6 Precautions for wireless remote control installation and operation...... 29
6. MAINTENANCE DATA.................................................................................. 30
6.1 Troubleshooting procedures for electrical equipment ....................... 30
6.2 Servicing................................................................................................. 50
7. REFRIGERANT PIPING INSTALLATION/SERVICING MANUAL
FOR AIR CONDITIONERS USING R410A .................................................. 51
7.1 Outline .................................................................................................... 51
7.2 Refrigerant piping installation .............................................................. 52
7.3 Installation, removal and servicing ...................................................... 58
7.4 Refrigerant recovery .............................................................................. 63

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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 tempera-
ture 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.
¡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 sensor
error
Discharge pipe sensor error
Outdoor air 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
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
1.2 How to read the model name
Example : SR K 35 Z GX - S
R410A models
Series No.
Inverter type
Product capacity
Wall mounted type
Split type room air-conditioner

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2 SELECTION DATA
2.1 Specifications
Model SRK20ZGX-S (Indoor unit)
SRC20ZGX-S (Outdoor unit)
Item
Model SRK20ZGX-S SRC20ZGX-S
Cooling capacity(1) W 2000 (500~2800)
Heating capacity(1) W 2400 (500~4600)
Power source 1 Phase, 220-240V, 50Hz
Cooling input kW 0.37 (0.1~0.91)
Running current (Cooling) A 2.1/2.0/1.9
Heating input kW 0.44 (0.09~1.27)
Running current (Heating) A 2.5/2.4/2.3
Inrush current A 2.5/2.4/2.3
COP Cooling: 5.41 Heating: 5.45
Cooling Sound level Hi 42, Me 34, Lo 21 44
Noise level Power level dB 57 57
Heating Sound level Hi 42, Me 35, Lo 25 43
Power level 58 57
Exterior dimensions
Height ×Width ×Depth mm 298 ×840 ×259 540 ×780 ×290
Color Fine snow Stucco white
Net weight kg 12 38
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 1.2 (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 27 24
(Cooling) 11.8 30
Air flow (at High) (Heating) CMM 12 25
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), 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: 0.54 m
Gas line : 0.47 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2 m (3 cores with Earth)
Recommended breaker size A 16
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 ×1, Photocatalytic washable deodorizing filter ×1)
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.)
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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Item
Model SRK25ZGX-S SRC25ZGX-S
Cooling capacity(1) W 2500 (500 ~ 3000)
Heating capacity(1) W 3000 (500 ~ 5000)
Power source 1 Phase, 220-240V, 50Hz
Cooling input kW 0.50 (0.10 ~ 0.64)
Running current (Cooling) A 2.5/2.4/2.3
Heating input kW 0.59 (0.09 ~ 1.16)
Running current (Heating) A 2.9/2.8/2.7
Inrush current A 2.9/2.8/2.7
COP Cooling: 5.00 Heating: 5.08
Cooling Sound level Hi 43, Me 34, Lo 21 45
Noise level Power level dB 58 58
Heating Sound level Hi 43, Me 36, Lo 26 47
Power level 59 59
Exterior dimensions
Height ×Width ×Depth mm 298 ×840 ×259 540 ×780 ×290
Color Fine snow Stucco white
Net weight kg 12 38
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 1.2 (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 27 24
(Cooling) 11.8 30
Air flow (at High) (Heating) CMM 12 27
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 light 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: 0.54 m
Gas line : 0.47 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2 m (3 cores with Earth)
Recommended breaker size A 16
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 ×1, Photocatalytic washable deodorizing filter ×1)
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.)
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)
Model SRK25ZGX-S (Indoor unit)
SRC25ZGX-S (Outdoor unit)

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Item
Model SRK35ZGX-S SRC35ZGX-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 0.87 (0.10 ~ 0.98)
Running current (Cooling) A 4.2/4.0/3.8
Heating input kW 1.00 (0.09 ~ 1.19)
Running current (Heating) A 4.9/4.7/4.5
Inrush current A 4.9/4.7/4.5
COP Cooling: 4.02 Heating: 4.20
Cooling Sound level Hi 44, Me 35, Lo 22 47
Noise level Power level dB 59 60
Heating Sound level Hi 44, Me 37 , Lo 27 50
Power level 60 63
Exterior dimensions
Height ×Width ×Depth mm 298 ×840 ×259 540 ×780 ×290
Color Fine snow Stucco white
Net weight kg 12 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 1.2 (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 27 24
(Cooling) 12 30
Air flow (at High) (Heating) CMM 12.2 27
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 light 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: 0.54 m
Gas line : 0.47 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2 m (3 cores with Earth)
Recommended breaker size A 16
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 ×1, Photocatalytic washable deodorizing filter ×1)
Optional parts –
Notes (1) The data are measured at the following conditions.
Model SRK35ZGX-S (Indoor unit)
SRC35ZGX-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.
(220/230/240V)

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Model SRK50ZGX-S (Indoor unit)
SRC50ZGX-S (Outdoor unit)
Item
Model SRK50ZGX-S SRC50GX-S
Cooling capacity(1) W 5000 (600~5300)
Heating capacity(1) W 6000 (600~7900)
Power source 1 Phase, 220-240V, 50Hz
Cooling input kW 1.56 (0.12~2.1)
Running current (Cooling) A 7.5/7.2/6.9
Heating input kW 1.66 (0.11~2.71)
Running current (Heating) A 7.9/7.6/7.3
Inrush current A 7.9/7.6/7.3
COP Cooling: 3.21 Heating: 3.61
Cooling Sound level Hi 45, Me 38, Lo 26 48
Noise level Power level dB 60 61
Heating Sound level Hi 47, Me 39, Lo 34 50
Power level 62 65
Exterior dimensions
Height ×Width ×Depth mm 298 ×840 ×259 640 ×850 ×290
Color Fine snow Stucco white
Net weight kg 12 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 27 34
(Cooling) 12.5 42
Air flow (at High) (Heating) CMM 13.5 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), 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: 054 m
Gas line : 0.47 m –
Insulation Necessary (Both sides)
Drain hose Connectable
Power source cord 2 m (3 cores with Earth)
Recommended breaker size A 20
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 ×1, Photocatalytic washable deodorizing filter ×1)
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.
(220/230/240V)

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2.2 Range of usage & limitations
Indoor return air temperature
(Upper, lower limits)
Refrigerant line (one way) length Max. 15m
SRK20ZGX-S, 25ZGX-S, 35ZGX-S SRK50ZGX-S
     
     
     
     
Power source voltage   
Voltage at starting   ! 
Frequency of ON-OFF cycle
ON and OFF interval   "#
  #$%
&'(% )  *  + #$% &'(% )  *
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
2.3 Exterior dimensions
(1) Indoor unit
Models All models


A
  



    


 






VIEW A
 




     
 
   ! 
"    
    

## 
 
  $  

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 








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7
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(2) Outdoor unit
Models SRC20ZGX-S, 25ZGX-S, 35ZGX-S
 




 

  

 ´ 
 

 
   !"#
$ %&&#
  '#
$ %&&#
'!"
(
 
)
)





Model SRC50ZGX-S
 ´ 
  



 








 




 

   !
" #  $%%
  &
" #  $%%
'( )*

-
8
-
2.4 Piping system
Models SRK20ZGX-S, 25ZGX-S, 35ZGX-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 SRK50ZGX-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

-
9
-
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 SRK35ZGX-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
SRK35ZGX-S Length 15m Factor by air
temperatures
  

















Coefficient of cooling & Heating capacity in relation to temperature
Heating operation
Indoor air D.B.
temperature
˚CD. B.
Cooling operation
Outdoor air D.B.
temperature
˚CD. B.
Outdoor air W.B. temperature ˚C W.B.
ISO-T1 Standard Condition
05-5-10-15 10 15
24
26
0.6
0.7
0.8
0.9
1.0
1.2
1.1
1.3
0
-5
-10
-15
20
25
30
35
40
46
10
15
20
25
27
Cooling
Applicable range
Heating
2220181614
Depends on installed situation
Indoor air W.B. temperature ˚C W.B. ISO-T1 Standard Condition
Air inlet temperature of
outdoor unit in ûCWB
Adjustment coefficient
-10
0.95
-9
0.94
-7
0.93
-5
0.91
-3
0.88
-1
0.8
1
0.87
3
0.92
5
1.00

-
10
-
3 ELECTRICAL DATA 3.1 Electrical wiring
Models SRK20ZGX-S, 25ZGX-S, 35ZGX-S
+
~~
- +
+
+
Indoor unit Outdoor unit
CNX
LM
BL
Y
WH
BK
RD
FM I
6
CNU
1
3
4
5
CNM
SM
52C
R-AMP
WIRELESS
DISPLAY
Th
1
Th
2
CNE
BACK UP SW
PRINTED CIRCUIT
BOARD
PRINTED CIRCUIT BOARD
CNG
250 3.15A
F
52C
ZNR
52C-4 52C-3N GJ
1
3
2/N
1
3
2/N
Y/G
RD
BK
WH
RD
WH
BK
BR
WH
BK
Y/G
RD
EXCHANGER
HEAT
BR
LB
Y/G
220/230/240V 50Hz
1 Phase
POWER SOURCE
BOX
CONTROL
TB TB
250 15A
F
R.IN C-2S.IN
NP
POWER
TRANSISTOR
U
W
RD
WH
BK
CM
CND
Th
4
Th
5
Th
6
CNA
FMO
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
Th
1
Th 2
Compressor motor
Fuse
Fan motor(Indoor)
Fan motor(Outdoor)
Flap motor
LM
Louver motor
Room temp. sensor
Heat exch. sensor(Indoor unit)
Th 4
Th 5
Th 6
ZNR
20S
EEV
DS
Heat exch. sensor(Outdoor unit)
TB
Terminal block
Outdoor air temp. sensor
Discharge pipe temp. sensor
aristor
4 way valve(coil)
Electronic expansion valve
Diode stack
L
Reactor

-
11
-
Model SRK50ZGX-S
Indoor unit Outdoor unit




LM





FM
I







SM

PRINTED CIRCUIT
BOARD

 



  


 



 





 
220/230/240V 50Hz
1 Phase
POWER SOURCE
!!
!

"
#$$
#$"




 " $






 


 











 

Color symbol
%&'(
%)*
+,-.
 +&/
*%%,-
01*
021 3%)*
! !+&.2*
*%%,- +**.
*4
Meaning of marks
Symbol Parts name Symbol Parts name Symbol Parts name
CM
F
FM
I
FM O
SM
LM
Th
1
Th 2
,56+*77,+ 5,1,+
)7*
&. 5,1,+8#.4,,+9
&. 5,1,+8!)14,,+9
%&6 5,1,+
,):*+ 5,1,+
,,5 1*56 7*.7,+
*&1 *;' 7*.7,+ 8#.4,,+ ).019
Th 3
Th 4
Th 5
Th 6
ZNR
20S
EEV
DS
)50401/ 7*.7,+
*&1 *;' 7*.7,+ 8!)14,,+ ).019
TB
*+50.&% 3%,'(
!)14,,+ &0+ 1*567*.7,+
07'&+2* 606* 1*567*.7,+
&+071,+
 -&/ :&%:*8',0%9
%*'1+,.0' *;6&.70,. :&%:*
0,4* 71&'(
L
*&'1,+
FM O
20S



EEV

#
 

" 8#9
" 8"!9
<
<





!
!
!
!



L
CM
<
"<
 
 






<
"<

"

" 8"#!9


  !
 
52C
 




-
12
-
SIndication section
Models All models
SOperation section
4 OUTLINE OF OPERATION CONTROL BY MICROCOMPUTER
4.1 Operation control function by remote control switch
Wireless remote control
FAN SPEED button
Each time the button is pushed, the indi-
cator 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 indi-
cator 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.
TIME SET UP switch
This switch for setting the time.
SLEEP button
This button selects SLEEP operation.
CLEAN switch
This switch changes the CLEAN mode.
ON TIMER button
This button selects ON TIMER operation.
TEMPERATURE button
This button sets the room temperature.
(This button changes the present time and
TIMER time.)
OFF TIMER button
This button selects OFF TIMER operation.
RESET switch
Switch for resetting microcomputer.
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.
CLEAN indicator
Indicates during CLEAN operation.
SLEEP indicator
Indicates during SLEEP operation.
ON/OFF TIMER indicator
Indicates during ON/OFF TIMER operation.
TIME indicator
Indicates present time or timer setting time.
AIR FLOW indicator
Shows selected flap and louver mode.
AIR FLOW (LEFT/RIGHT) button
This button changes the air flow (left/right)
mode.
CANCEL button
This button cancels the ON timer, OFF
timer, and SLEEP operation.
HI POWER/ ECONO MODE indicator
Indicates during HIGH POWER/ECONOMY
mode operation.

-
13
-
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.
(a) Operation
Push the button 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
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)
Unit ON/OFF button
  
Unit indication section
Models All models
ECONO light (orange)
Illuminates during ECONOMY operation.
TIMER light (yellow)
Illuminates during TIMER operation.
HI POWER light (green)
Illuminates during HIGH POWER operation.
RUN (HOT KEEP) light (green)
•Illuminates during operation.
•Brinks at air flow stop due to the ‘HOT KEEP’
and ‘CLEAN’ operation.
ON
OFF
ON
1.5 sec.
0.5 sec.
1 sec.
3 sec.
OFF
HOT KEEP
CLEAN
operation

-
14
-
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 (J6) 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
1) Remove the battery.
2) Cut the jumper wire shown in the figure at right.
  
Slant forward
blowing
HEAT
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) Swing flap
Flap moves in upward and downward directions continuously.
(2) Swing louver
Louver moves in left and right directions continuously.
(3) When not operating
The flap returns to the position of air flow directly below, when operation has stopped.
(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.
¡Recommendable stopping angle of the flap
Horizontal
blowing
COOL•DRY
Cut
(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 temperature.
4.6 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.

-
15
-
4.7 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.
  
  
 
   
   


  


Thermostat ON Thermostat OFF Defrost Failure
Heating
Compressor
Indoor fan motor
Outdoor fan motor
4-way valve
30~94rps 30~102rps 20~120rps
30~94ps 30~102rps 20~120rps
30~66rps 30~72rps 30~76rps 20~80rps
30~38rps 30~42rps 30~46rps 20~38rps
SRK20ZGX-S
Model
Fan speed SRK25ZGX-S SRK35ZGX-S SRK50ZGX-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 35 minutes. (Accumulated compressor operation time)
2After end of defrosting operation
When it elapsed 35 minutes. (Accumulated compressor operation time)
3Outdoor unit heat exchanger sensor (Th4) temperature
When the temperature has been below –5ºC for 3 minutes continuously.
4When the temperature difference between the outdoor air sensor temperature and the outdoor unit heat exchanger sensor
temperature exceeded 20. 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, 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.

-
16
-
27.5
25.5
19.5
18 30
4.8 Outline of cooling operation
(1) Operation of major functional components in Cooling mode
(2) 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.
  
  
 
      
  
Thermostat ON Thermostat OFF Failure
Cooling
Compressor
Indoor fan motor
Outdoor fan motor
4-way valve
20~65rps 20~74rps 20~92rps
20~65rps 20~74rps
20~86rps
20~86rps 20~92rps
20~44rps 20~56rps 20~58rps 20~62rps
20~30rps 20~34rps 20~38rps 20~30rps
SRK20ZGX-S
Model
Fan speed SRK25ZGX-S SRK35ZGX-S SRK50ZGX-S
Auto
MED
HI
LO
4.9 Outline of automatic operation
(1) Determination of operation mode
The unit checks the room temperature and the outdoor air temperature, determines the operation mode, and then begins in the
automatic operation.
Heating
Dehumidifying
Cooling
Room temperature (˚C)
Outdoor temperature (˚C)
(2) The unit checks the temperature every hour after the start of operation and, if the result of check is not same as the previous
operation mode, changes the operation mode.
(3) When the unit is started again within one hour after the stop of automatic operation or when the automatic operation is selected
during heating, cooling or dehumidifying operation, the unit is operated in the previous operation mode.
(4) Setting temperature can be adjusted within the following range. There is the relationship as shown below between the signals of
the wireless remote control and the setting temperature.
Signals of wireless remote control (Display)
–6 –5 –4 –3 –2 –1 ±0+1+2+3+4+5+6
Setting Cooling 19 20 21 22 23 24 25 26 27 28 29 30 31
temperature Dehumidifying 19 20 21 22 23 24 25 26 27 28 29 30 31
Heating 20 21 22 23 24 25 26 27 28 29 30 31 32

-
17
-
4.10 Protective control function
(1) Frost prevention for indoor heat exchanger (During cooling or dehumidifying)
(a) Operating conditions
(i) Indoor heat exchanger temperature (detected with Th2) is lower than 5ºC.
(ii) 10 minutes after reaching the inverter command speed except 0 rps.
(b) Detail of anti-frost operation
5°C or lower 2.5°C or lower
Item
20: Max 38 rps
Indoor command speed
25: Max 42 rps
0rps
35: Max 56 rps
50: Max 65 rps
Indoor fan Depends on operation mode Max 2nd
Outdoor fan Depends on operation mode OFF
4-way valve OFF Depends on stop mode
(c) Reset conditions: After 5 minutes of operation, the indoor heat exchangertemperature (Th2) is 8ºC or higher.
Indoor heat exchanger
temperature (˚C)
2.5 5 8
0 rps
Upper limit
speed
Inverter
command
speed
Indoor heat exchanger
temperature
(2) Cooling overload protective control
(a) Operating conditions: When the outdoor unit is operating with the outdoor unit speed of other than 0 rps, and when the
outdoor air temperature sensor (Th5) becomes 41ºC or over for 30 seconds continuously.
(b) Detail of operation
1) Outdoor fan is stepped up by 3 speed step. (Upper limit speed is 7th speed.)
2) The lower limit of control speed is set to 30 rps and even if the calculated result becomes lower than that after fuzzy
calculation, the speed is kept to 30 rps. However, when the thermo becomes OFF, the speed is reduced to 0 rps.
3) The upper limit of control speed is 72 rps.
(c) Reset conditions: When either of the following condition is satisfied.
1When the outdoor air temperature becomes 40ºC or less.
2When the inverter command speed is 0rps.
(3) Cooling low outdoor temperature protective control
◆< I>
(a) Operating conditions: When the outdoor air temperature sensor (Th5) is 22ºC or lower continues for 30 seconds while
outdoor speed is other than 0rps.
(b) Detail of operation: After the outdoor fan operates at A speed for 60 seconds; the corresponding outdoor heat
exchanger temperature shall implement the following controls.
1Outdoor heat exchanger temperature =
<
21ºC
After the outdoor fan speed drops (down) to one speed for 60 seconds; if the outdoor heat exchanger temperature is
lower than 21°C, gradually reduce the outdoor fan speed by 1 speed. (Lower limit speed is 1st speed)
221ºC < Outdoor heat exchanger temperature =
<
38ºC
After the outdoor fan speed maintains at A speed for 20 seconds; if the outdoor heat exchanger temperature is 21°C~
38°C, maintain outdoor fan speed.
3Outdoor heat exchanger tempeature > 38ºC
After the outdoor fan speed rises (up) to 1 speed for 60 seconds; if the outdoor heat exchanger temperature is
higher than 38°C, gradually increase outdoor fan speed by 1 speed. (Upper limit speed is 3rd speed)
(c) Reset conditions: When the either of the following conditions is satisfied
1When the outdoor air temperature sensor (Th5) becomes 25ºC or higher.
2When the inverter command speed is 0rps.
Outdoor temperature > 10˚C
Outdoor temperature ≤_ 10˚C
2nd speed
Outdoor fan
1st speed
¡Value of A

-
18
-
Notes (1) RPSmin: The lower one between the outdoor unit speed and the command speed
Note (2) Values in ( ) are for Type 50.
¡Temperature list
ABC
RPSmin < 40(88) 48 (48.5) 53 (56) 58 (61)
40(88) <
=RPSmin < 50(108)
48 (44) 53 (51.5) 58 (56.5)
50(108) <
=RPSmin 48.5 (39) 56 (46.5) 61 (51.5)
Notes (1) When the indoor unit heat exchanger temperature is in the range of B~C ºC, the speed is reduced by 8 rps at each 20 seconds. When the temperature is C
ºC or over for 1 minute continuously, the inverter is stopped.
(2) When the indoor unit heat exchanger temperature is in the range of A~B ºC, if the inverter command speed is been maintained and the operation has
continued for more than 20 seconds at the same speed, it returns to the normal heating operation.
(3) Indoor blower retains the fan tap when it enters in the high pressure control. Outdoor blower is operated in accordance with the speed.
(4) High pressure control
(a) Purpose: Prevents anomalous high pressure operation during heating.
(b) Detector: Indoor unit heat exchanger sensor (Th2)
(c) Detail of operation:
(Example) Fuzzy
Indoor unit heat exchanger temperature (˚C)
Lower limit
speed 20(35)rps
After lapse of 20 Sec. or over (2)
After lapse of 20 Sec. or over (2)
After lapse of 20 Sec. or over (2)
BC
8 rps(1)
8 rps
0 rps
A
Unit : ºC
◆< II >
(a) Operating conditions: When the outdoor air temperature sensor (Th5) is 22ºC or lower continues for 30 seconds while
outdoor speed is other than 0rps.
(b) Detail of operation:
1The lower limit of inverter command speed is set to C(D)rps and even if the speed becomes lower than C(D)rps, the
speed is kept to C(D)rps. However, when the thermo becomes OFF, the speed is reduced to 0rps.
2The upper limit of control speed is set to A(B)rps and even if the calculated result becomes higher than that after fuzzy
calculation, the speed is kept to A(B)rps.
22 25
OFF
03
Upper limit Arps
Lower limit Crps
ON
ON
Upper limit Brps
Lower limit Drps
Outdoor air temp.( ° C)
20, 25, 35 type
50 type
40
A
Upper limit Lower limit
BCD
60 30 30
50 60 44 30
¡Values of A, B, C, D
(c) Reset conditions: When the either of the following condition is satisfied
1When the outdoor air temperature sensor (Th5) becomes 25ºC or higher.
2When the inverter command speed is 0rps.