Mitsubishi Heavy Industries SCM50ZS-W User manual

Manual No.'19・SCM-SM-281
SERVICE MANUAL
INVERTER MULTI-SPLIT SYSTEM
RESIDENTIAL AIR-CONDITIONERS
(Split system, air to air heat pump type)
(OUTDOOR UNIT)
SCM50ZS-W
60ZS-W
(INDOOR UNIT)
Wall mounted type
SRK20ZSX-W,-WB,-WT
Duct connected-Low/Middle static pressure type
FDUM50VH
SKM20ZSP-W
25ZSP-W
35ZSP-W
25ZSX-W,-WB,-WT
35ZSX-W,-WB,-WT
50ZSX-W,-WB,-WT
60ZSX-W,-WB,-WT
SRK20ZS-W,-WB,-WT
25ZS-W,-WB,-WT
35ZS-W,-WB,-WT
50ZS-W,-WB,-WT
4-way ceiling cassette type
FDTC25VH
35VH
50VH
60VH
Ceiling concealed type
SRR25ZM-W
35ZM-W
50ZS-W
60ZS-W
Ceiling suspended type
FDE50VH

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'19 • SCM-SM-281
CONTENTS
1.1 SRK, SKM and SRR series ..........................................................................7
1. OUTLINE OF OPERATION CONTROL BY MICROCOMPUTER ...................7
..............................................8
1.1.1 SRK-ZSX series
(4) Installing two air-conditioners in the same room
..................................................................................8(3) Auto restart function
(2) Unit ON/OFF button ...................................................................................8
.......................................................................................7
(1) Operation control function by wireless remote control ...............................7
(9) Air flow direction adjustment ....................................................................10
(8) Economy operation .................................................................................10
................................................................................9(6) Heating only function
................................................................................9(7) High power operation
(10) 3D auto operation ....................................................................................11
(11) Timer operation .......................................................................................12
(14) Air flow range setting ..............................................................................13
(13) Night setback operation ...........................................................................13
....................................................9(5) Selection of the annual cooling function
................................................................14
(16) AUTO OFF operation .............................................................................14
(15) Display brightness adjustment
(19) Protective control function .......................................................................15
(18) Outline of automatic operation .................................................................15
...............................................14(17) Outline of dehumidifying (DRY) operation
.............................................18
1.1.2 SRK-ZS series
(4) Installing two air-conditioners in the same room
.................................................................................18(3) Auto restart function
(2) Unit ON/OFF button ..................................................................................18
.......................................................................................17
(1) Operation control function by wireless remote control .............................17
...............................................................................19
(7) High power operation
..................................................19(5) Selection of the annual cooling function
(9) Air flow direction adjustment ....................................................................20
...............................................................................19
(6) Heating only function
..................................................................................20(8) Economy operation
(10) 3D auto operation ....................................................................................21
(12) Silent operation .......................................................................................13

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(12) Silent operation ........................................................................................22
(11) Timer operation ........................................................................................22
(13) Night setback operation ...........................................................................22
(14) Air flow range setting ...............................................................................23
................................................................23(15) Display brightness adjustment
(18) Protective control function ........................................................................25
(17) Outline of automatic operation .................................................................24
...............................................24(16) Outline of dehumidifying (DRY) operation
.............................................34
1.1.4 SRR series
(4) Installing two air-conditioners in the same room
...............................................................................33(3) Auto restart function
(2) Unit ON/OFF button ................................................................................33
.............................................................................................32
(1) Operation control function by wireless remote control .............................32
..............................................................................35(6) High power operation
..................................................................................35(7) Economy operation
(8) Timer operation .......................................................................................36
..................................................34(5) Selection of the annual cooling function
......................................27
1.1.3 SKM-ZSP series
(4) Installing two air-conditioners in the same room
...............................................................................27(3) Auto restart function
(2) Unit ON/OFF button ...............................................................................27
....................................................................................26
(1) Operation control function by wireless remote control .............................26
(8) Timer operation .......................................................................................29
(7) Air flow direction adjustment ...................................................................28
.............................................................................28(5) High power operation
.................................................................................28(6) Economy operation
(9) Outline of heating operation ....................................................................29
(10) Outline of cooling operation ....................................................................30
(12) Outline of automatic operation .................................................................30
(13) Protective control function .......................................................................31
(11) Outline of dehumidifying (DRY) operation ..............................................30
(9) Night setback operation ...........................................................................36
.............................................................36
(11) Drain pump abnormalities detection ........................................................36
(10) Determining the operating mode

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(14) Operation permission/prohibition control ...............................................38
(13) Outline of automatic operation ...............................................................37
.......................38
(16) Hot keep operation ................................................................................39
(15) External control (remote display)/control of input signal
(17) Frost prevention control .........................................................................39
(18) Indoor fan motor protection ...................................................................39
1.2 FDTC, FDUM and FDE series ..................................................................40
.............................451.2.3 Operation control function by the indoor control
1.2.2 Operation control function by the wired remote control ...................42
(1) Auto operation ...........................................................................................45
(2) Operations of functional items during cooling/heating ..............................46
(4) Timer operation .........................................................................................47
(5) Hot start (Cold draft prevention at heating) ..............................................48
(6) Hot keep ....................................................................................................48
(3) Dehumidifying (DRY) operation ................................................................46
(8) Thermostat operation ................................................................................50
(7) Auto swing control (FDTC and FDE only) ................................................49
...............................................................52
...................................................................................52
......................................................................53
.............................52
.....................................................53
...................................................................................54
...............................................................................53
...............54
.......55
(12) Drain pump motor (DM) control
(11) Drain pump control
(15) Heating overload protection
(13) Operation check/drain pump test run operation mode
(14) Cooling, dehumidifying frost protection
(18) High ceiling control
(16) Anomalous fan motor
(17)
Plural unit control - Control of 16 units group by one remote control
(19)
Abnormal temperature sensor (return air/indoor heat exchanger) broken wire/short-circuit detection
............................................55(20) External input/output control (CnT or CnTA)
....................................................51(10) Compressor inching prevention control
(9) Filter sign ..................................................................................................51
..............................................37(12) Outline of dehumidifying (DRY) operation
...................................................401.2.1 Wired remote control (Option parts)
..................................59(23) Selection of cooling/heating external input function
(22) Temporary stop input ................................................................................59
(21) Operation permission/prohibition ...............................................................57

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(1) Summary ..................................................................................................64
(1) Summary ..................................................................................................66
(3) Defrost operation .....................................................................................65
(2) Operation of major functional components in heating mode ....................64
(2) Operation of major functional components in cooling mode .....................66
1.3.1 Outline of heating operation ................................................................64
1.3 Outdoor units ...........................................................................................64
1.3.2 Outline of cooling operation ................................................................66
......................................................60(26) Return air temperature compensation
(25)
Room temperature detection temperature compensation during heating ............60
.....................................................60
..........................................................60
.................................................60
............................................................60
...............................................60
(27) High power operation (RC-EX3A only)
(30) Home leave mode (RC-EX3A only)
(28) Energy-saving operation (RC-EX3A only)
(29) Warm-up control (RC-EX3A only)
(31) Auto temperature setting (RC-EX3A only)
...................................................61(34) Auto fan speed control (RC-EX3A only)
...............................62
(35) Indoor unit overload alarm (RC-EX3A only) .............................................61
...............................................61(32) Fan circulator operation (RC-EX3A only)
(33)
The operation judgment is executed every 5 minutes (RC-EX3A only) ......61
(1) Cooling overload protective control ..........................................................67
(6) Heating low outdoor temperature protective control
................................................70(8) Service valve (gas side) closing operation
(7) Refrigeration cycle system protective control ..........................................70
.................................69
...................................................................67
(4) Heating high pressure control ...................................................................68
(5) Heating overload protective control ..........................................................69
(3) Cooling low outdoor temperature protective control
(2) Cooling high pressure control
.................................68
1.3.3 Protective control function .................................................................67
................................................................61(36) Peak-cut timer (RC-EX3A only)
(24) Fan control at heating startup ...................................................................60
(37) Motion sensor control (RC-EX3A and RCN-E2 only)
(10) Current safe ..............................................................................................71
(11) Current cut ...............................................................................................72
(9) Compressor overheat protection ..............................................................71

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.......................................73
(15) Serial signal transmission error protection ...............................................73
(14) Regulation of outdoor air flow ...................................................................73
(13) Discharge pipe temperature sensor disconnection protection control
.. ......72
(16) Rotor lock .................................................................................................73
(17) Outdoor fan motor protection ....................................................................73
(20) Limit of the number of compressor starts .................................................75
(18) Outdoor fan control at low outdoor temperature
2.1 SRK, SKM and SRR series ......................................................................76
2. MAINTENANCE DATA ...................................................................................76
(1) Cautions ...................................................................................................76
(2) Items to check before troubleshooting ......................................................76
............76
(4) Troubleshooting procedure (If the air-conditioner runs)
(3) Troubleshooting procedure (If the air-conditioner does not run at all)
...........................77
(5) Self-diagnosis table ..................................................................................78
(6) Service mode (Trouble mode access function) ........................................79
.........................87(7) Inspection procedures corresponding to detail of trouble
(9) Checking the indoor electrical equipment ................................................93
(8)
Phenomenon observed after short-circuit, wire breakage on sensor ................92
(11) Inspection procedure for blown fuse on the indoor and outdoor unit PCB ......94
..........................................94(10) How to make sure of wireless remote control
(6) Inverter checker for diagnosis of inverter output ...................................107
(4) Troubleshooting at the outdoor unit ........................................................104
(12) Outdoor unit inspection points ..................................................................95
2.2.1 Diagnosing of microcomputer circuit .................................................97
2.2 FDTC, FDUM and FDE series ...................................................................97
(1) Selfdiagnosis function .............................................................................97
(2) Troubleshooting procedure ......................................................................100
...........................................................100
(5) Check of anomalous operation data with the remote control .................105
(3) Troubleshooting at the indoor unit
(19) Outdoor fan control at overload .............. ..................................................74
(12) Outdoor unit failure ..................................................................................72
2.2.2 Troubleshooting flow .........................................................................108
(1) List of troubles ........................................................................................108
(7) Outdoor unit inspection points ................................................................107

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3. ELECTRICAL WIRING ..................................................................................153
4. PIPING SYSTEM ..........................................................................................161
......................................................................................109(2) Troubleshooting

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'19 • SCM-SM-281
RUN light (green)
󱓻RUN lights blink quickly during invalid operation mode.
Unit display section
TIMER light (yellow)
Illuminates during TIMER operation.
1. OUTLINE OF OPERATION CONTROL BY MICROCOMPUTER
1.1 SRK, SKM and SRR series
1.1.1 SRK-ZSX series
(1) Operation control function by wireless remote control
OPERATION MODE select button
Each time the button is pressed, the
mode changes.
The above illustration shows all controls, but in
practice only the relevant parts are shown.
ALLERGEN CLEAR button
This button selects ALLERGEN CLEAR
operation.
ON/OFF (luminous) button
Press to start operation, press again
to stop.
TEMPERATURE button
This button sets the room temperature.
AIRFLOW (UP/DOWN) button
This button changes the air flow (up/
down) direction.
TIME SET UP switch
This switch is used for setting the
time.
SLEEP button
This button selects SLEEP operation.
MENU switch
This switch selects the brightness
adjustment, AUTO OFF operation, SELF
CLEAN operation and PRESET operation.
ON TIMER button
This button selects ON TIMER
operation.
TIMER button
This button is used for setting the
current time and timer function.
ACL switch
This switch resets the program to
default state.
PROGRAM button
This button sets WEEKLY TIMER.
HI/ECO button
This button changes the HIGH
POWER/ECO operation.
AIRFLOW (LEFT/RIGHT) button
This button changes the air flow (left/
right) direction.
SILENT button
This button sets the SILENT operation.
OFF TIMER button
This button selects OFF TIMER
operation.
WEEKLY button
This button switches the WEEKLY
TIMER to ON/OFF.
FAN SPEED button
Each time the button is pressed, the
fan speed changes.
3D AUTO button
This button sets 3D AUTO operation.
NIGHT SETBACK button
This button sets NIGHT SETBACK
operation.
SET/Child lock button
Use this button to set the timer and
Child lock.
CANCEL button
This button cancels the ON timer, OFF
timer, and SLEEP operation.
Transmission section
[View with the cover opened]
Illuminates during operation.

Blinks slowly when SELF CLEAN operation (3 seconds ON, 1 second OFF).

Blinks when air flow is stopped to prevent blowing out of cold
air in heating operation. (1.5 seconds ON, 0.5 seconds OFF)
Blinks slowly when AUTO OFF operation during
stand by (3.5 seconds ON, 0.5 second OFF).
This button can be used for turning on/off
the unit when a remote control is not available.
Wireless remote control signal receiver
Unit ON/OFF button
Operation section

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'19 • SCM-SM-281
'09•SRK-DB-087D
Jumper wire (JA2)
(2)ࠉUnit ON/OFF button
(a) Operation
(b) Details of operation
(3)ࠉAuto restart function
(a)
(b)
(i)
(ii)
(4)Custom cord switching procedure
(a) Modifying the indoor printed circuit board
(b) Modifying the wireless remote control
(i)
(ii)
Cut
Function
Operation mode
Room temperature
setting
Fan speed Flap/Louver Timer switch
COOL
HEAT
Unit ON/OFF button
whether to go into the COOL or HEAT modes.
room
Jumper wire (J1)
㻾㻌㻸㻌㻲㻌㻡㻌㻜㻌㻡㻌㻭㻌㻝㻌㻜㻌㻞
00
'09•SRK-DB-087D
(2)ࠉUnit ON/OFF button
(a) Operation
(b) Details of operation
(3)ࠉAuto restart function
(a)
(b)
(i)
(ii)
(J170)
(4)ࠉCustom cord switching procedure
(a) Modifying the indoor printed circuit board
(b) Modifying the wireless remote control
1)
2)
Function
Operation mode
Indoor temperature
setting
Fan speed Flap/Louver Timer Switch
COOL
DRY
HEAT
(J171)
Unit ON/OFF button
Jumper wire (J170)
When two air-conditioners are installed in the room, use this setting when the two air-conditioners are not operated with
one wireless remote control. Set the wireless remote control and indoor unit.
(a)ࠉSetting the wireless remote control
(i) Pull out the cover and take out batteries.
(ii) Disconnect the switching line next to the battery with wire cutters.
(iii) Insert batteries. Close the cover.
(b)ࠉSetting indoor unit
(i) Turn off the power source, and turn it on after 1 minute.
(ii) Point the wireless remote control (that was set according to the procedure
described on the left side) at the indoor unit and send a signal by pressing
the ACL switch on the wireless remote control.
Since the signal is sent in about 6 seconds after the ACL switch is pressed,
point the wireless remote control at the indoor unit for some time.
(iii) Check that the reception buzzer sound "Peep" is emitted from the indoor unit.
At completion of the setting, the indoor unit emits a buzzer sound "Peep".
(If no reception sound is emitted, start the setting from the beginning again.)
Disconnect
(4)ࠉInstalling two air-conditioners in the same room
wireless wireless
Reception
Pii
Jumpre wire (J3)
Jumpre wire (J1)
Jumpre wire (J4)
Reception
Peep
Unit ON/OFF button