Mitsubishi Electric FDT71VNPWVH User manual

(Split system, air to air heat pump type)
Manual No.'19・PAC-SM-312
STANDARD INVERTER PACKAGED
AIR-CONDITIONERS
SERVICE MANUAL
CEILINING CASSETTE-4 WAY TYPE
FDT71VNPWVH
DUCT CONNECTED-LOW/MIDDLE
STATIC PRESSURE TYPE
FDUM71VNPWVH
WALL MOUNTED TYPE
SRK71VNPWZR
DUCT CONNECTED-HIGH STATIC
PRESSURE TYPE
FDU71VNPWVH
CEILING SUSPENDED TYPE
FDE71VNPWVH

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TABLE OF CONTENTS
1. OUTLINE OF OPERATION CONTROL BY MICROCOMPUTER ....................3
1.1 Remote control (Option parts) ...................................................................3
1.2 Operation control function by the wired remote control .........................7
1.3 Operation control function by the indoo control ......................................10
1.4 Operation control function by the outdoor control ..................................39
(1) Compressor speed .....................................................................................39
(2) Compressor protection start .......................................................................39
(3) Outdoor fan control .....................................................................................39
(4) Defrost operation ........................................................................................41
(5) Cooling overload protective control ............................................................42
(6) Cooling high pressure control .....................................................................42
(7) Cooling low outdoor temperature protective control ...................................43
(8) Heating high pressure control .....................................................................43
(9) Heating overload protective control ............................................................44
(10) Heating low outdoor temperature protective control ...................................44
(11) Compressor overheat protection ................................................................44
(12) Current safe ................................................................................................45
(13) Current cut ..................................................................................................45
(14) Outdoor unit failure .....................................................................................45
(15) Serial signal transmission error protection ..................................................45
(16) Rotor lock ....................................................................................................45
(17) Refrigeration cycle system protection .........................................................45
(18) Silent mode .................................................................................................46
(19) Broken wire detection on temperature sensor ............................................46
2. MAINTENANCE DATA .....................................................................................47
2.1 FDT, FDU, FDUM, FDE series ...................................................................47
2.1.1 Diagnosing of microcomputer circuit .....................................................47
(1) Selfdiagnosis function .................................................................................47
(2) Troubleshooting procedure .........................................................................50
(3) Troubleshooting at the indoor unit ..............................................................50
(4) Troubleshooting at the outdoor unit ............................................................56
(5) Check of anomalous operation data with the remote control .....................60
(6)
Power transistor module (Including the driver PCB) inspection procedure ...62
(7) Inverter checker for diagnosis of inverter output .........................................63
(8) Outdoor unit control failure diagnosis circuit diagram .................................64
2.1.2 Troubleshooting ow ...............................................................................65
(1) List of troubles ............................................................................................65
(2) Troubleshooting ..........................................................................................66

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2.2 SRK series ..................................................................................................110
(1) Cautions ....................................................................................................110
(2) Items to check before troubleshooting ......................................................110
(3) Troubleshooting procedure (If the air-conditioner does not run at all) ......110
(4) Troubleshooting procedure (If the air-conditioner runs) ............................111
(5) Self-diagnosis table ..................................................................................112
(6) Service mode (Trouble mode access function) ........................................113
(7) Inspection procedures corresponding to detail of trouble .........................121
(8) Phenomenon observed after short-circuit, wire breakage on sensor .......123
(9) Checking the indoor electrical equipment .................................................123
(10) How to make sure of wireless remote control ...........................................125
(11) Inspection procedure for blown fuse on the indoor unit PCB ...................125
3. ELECTRICAL WIRING ...................................................................................126
(1) Indoor units ...............................................................................................126
(2) Outdoor units ............................................................................................131
4. PIPING SYSTEM .............................................................................................132

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1. OUTLINE OF OPERATION CONTROL BY MICROCOMPUTER
1.1 Remote control (Option parts)
(1) Wired remote control
Model RC-EX3A
'16 • PAC-T-251
④Operation lamp
① Run/Stop switch
② F1 switch③F2 switch
Touch panel system, which is operated by tapping the LCD screen with a finger, is employed
for any operations other than the ①Run/Stop, ②F1 and ③F2 switches.
One push on the button starts operation and
another push stops operation.
This switch starts operation that is set in F1/F2
function change.
This lamp lights in green(yellow-green) during
operation. It changes to red(orange) if any
error occurs.
Operation lamp luminance can be changed.
⑤LCD (with backlight)
A tap on the LCD lights the backlight.
The backlight turns off automatically if there
is no operation for certain period of time.
Lighting period of the backlight lighting can be
changed.
If the backlight is ON setting, when the screen is
tapped while the backlight is turned off,the backlight
only is turned on.(Operations with switches ①,②
and ③are excluded.)
⑥USB port
USB connector (mini-B) allows connecting to a
personal computer.
For operating methods, refer to the instruction
manual attached to the software for personal
computer (remote control utility software).
Note(1) When connecting to a personal computer, do not connect
simultaneously with other USB devices.
Please be sure to connect to the computer directly,without
going through a hub, etc.
Model RC-EX3A
1.10 OUTLINE OF OPERATION CONTROL BY MICROCOMPUTER
1.10.1 Remote control
(1) Wired remote control
P044-055.pdf2017/03/1713:53:02
⑤LCD (with backlight)
③F2 switch
④Operation lamp
⑥USB port (mini-B)
①Run/Stop switch
②F1 switch

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(1) Wired remote control
Model RC-E5
The figure below shows the remote control with the cover opened. Note that all the items that may be displayed in
the liquid crystal display area are shown in the figure for the sake of explanation
Characters displayed with dots in the liquid crystal display area are abbreviated.
＊ All displays are described in the liguid crystal display for explanation.
The figure below shows the remote control with the cover opened.
Ventilaion display
Displayed during ventilation operation
Central control display
Displayed when the air conditioning system is
controlled by central control.
Timer operation display
Displays the timer operation setting.
Temperature setting buttons
These buttons are used to set the
temperature of the room.
Timer button
This button is used to set
the timer mode.
Timer setting buttons
These buttons are used to set
the timer mode and the time.
ESP button
This button is used to
select the auto static
pressure adjustment mode.
Cover
AIR CON No. button
Display the indoor unit number connected to this
remote control.
CHECK button
This button is used at servicing.
TEST button
This button is used during test operation.
Weekly timer display
Displays the settings of the
weekly timer.
Operation setting display area
Displays setting temperature, air flow
volume, operation mode and oparation
message.
Operation/check indicator light
During oparation: Lit in green
In case of error: Flashing in red
Operation/stop button
This button is used to operate and stop
the air-conditioning system.
Press the button once to operate the
system and press it once again to stop
the system.
MODE button
This button is used to change the
operation mode.
FAN SPEED button
This button is used to set the air flow
volume.
VENT button
This button is used to operate external
ventilator.
LOUVER button
This button is used to operate/stop the
swing louver.
SET button
●This button is used to fix the setting.
●This button is used to set the silent mode.
RESET button
●Press this button while making settings to go back to the
previous operation.
●This button is also used to reset the "FILTER CLEANING" display.
(Press it after cleaning the air filter)
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(2) Wireless remote control
Indication section
Operation section
D
C
4
5
6
1 8 9
@
B
A
3 7 2
①
OPERATION MODE display Indicates selected operation mode.
②
SET TEMP display Indicates set temperature.
SLEEP TIMER time display Indicates the amount of time remaining on the sleep timer.
Indoor function setting
number display Indicates the setting number of the indoor function setting.
③FAN SPEED display Indicates the selected air ow volume.
④UP/DOWN AIR FLOW
display Indicates the up/down louver position.
⑤LEFT/RIGHT AIR FLOW
display Indicates the left/right louver position.
⑥Clock display Indicates the current time. If the timer is set, the ON
TIMER and OFF TIMER setting times are indicated.
⑦ON/OFF TIMER display Displayed when the timer is set.
⑧ECO mode display Displayed when the energy-saving operation is active.
⑨HI POWER display Displayed when the high power operation is active.
⑩NIGHT SETBACK display Displayed when the home leave mode is active.
⑪SILENT display Displayed when the silent mode control is active.
⑫Motion sensor display Displayed when the infrared sensor control(motion sensor
control) is enabled.
⑬Anti draft setting display Displayed when anti draft setting is enabled.
⑭Child lock display Displayed when child lock is enabled.
Transmitter:Sends signal to the air-
conditioner.
①
⑲
⑤
②
⑫④
③
⑰
⑮
⑨
⑩
⑯
⑪
⑧
⑥
⑭
⑦
⑬
⑱
①ON/OFF button
When this is pressed once, the air-conditioner starts to
operate and when this is pressed once again, it stops
operating.
②MODE button
Every time this button is pressed, displays switch as below
(AUTO) (COOL) (HEAT)
(FAN) (DRY)
③
TEMP button
Change the set temperature by pressing or button.
④FAN SPEED button The fan speed is switched in the following order: 1-speed
➞2-speed ➞3-speed ➞4-speed ➞AUTO ➞1-speed.
⑤U/D button Used to determine the up/down louver position.
⑥ON TIMER button Used to set the ON TIMER.
⑦OFF TIMER button Used to set the OFF TIMER.
⑧SELECT button
Used to switch the time when setting the timer or adjusting the time.
Used to switch the settings of the indoor function.
⑨SET button
Used to determine the setting when setting the timer or
adjusting the time.
Used to determine the settings of the indoor function.
When press and hold SET button ,Child Lock is enabled.
⑩CANCEL button Used to cancel the timer setting.
⑪SLEEP button Used to set the sleep timer.
⑫ECO button Pressing this button starts the energy-saving operation.
Pressing this button again cancels it.
⑬HI POWER button Pressing this button starts the high power operation.
Pressing this button again cancels it.
⑭SILENT button Pressing this button starts the silent mode control.
Pressing this button again cancels it.
⑮NIGHT SETBACK button Pressing this button starts the home leave mode.
Pressing this button again cancels it.
⑯FILTER button Pressing this button resets FILTER SIGN.
⑰
FUNCTION SETTING switch Used to set the indoor function.
⑱TIME SETUP switch Used to set the current time.
⑲ACL switch Used to reset the microcomputer.
(2) Wireless remote control
(a) RCN-E2 (Except SRK series)
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(2) Wireless remote control
Indication section
Operation section

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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]
(b) SRK series only

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1.2 Operation control function by the wired remote control
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'16 • PAC-T-251
Service & Maintenance
Special settings
Indoor unit capacity display
Back
Select the item.
前ページ
Previous Back
Erase IU address
CPU reset
Restore of default setting
Touch panel calibration
Special settings
Select the item.
R/C function settings
Ventilation setting
Auto-restart
Auto temp setting
Back
Select the item.
Previous
Auto fan speed
②Auto-restart
Auto-restart
Back
Select the item.
Enable
Disable
1.10.2 Operation control function by the wired remote control
●Model RC-EX3A
(1) Switching sequence of the operation mode switches of remote control
(a) Tap the change operation mode button on the TOP screen.
(b) When the change operation mode screen is displayed, tap the button of desired mode.
(c) When the operation mode is selected, the display returns to the TOP screen.
Icons displayed have the following meanings.
Cooling Fan
Dry Heating
Auto
Notes(1) Operation modes whichcannot be selected depending on combinations of indoor
unit and outdoor unit are not displayed.
(2) When the Auto is selected,the cooling and heating switching operation is performed
automatically according to indoor and outdoor temperatures.
(2) CPU reset
Reset CPU from the remote control as follows.
TOP screen Menu Service setting Service & Maintenance Service password
The selected screen is
displayed.
The selected screen is
displayed.
① Service & Maintenance #2 ②Special settings
⇒ ⇒ ⇒
CPU reset
Microcomputers of indoor unit and outdoor unit connected are reset
(State of restoration after power failure).
(3) Power failure compensation function (Electric power source failure)
Enable the Auto-restart function from the remote control as follows.
TOP screen Menu ⇒ Service setting ⇒ R/C function settings Service password
⇒
① R/C function settings menu #3
If the unit stops during operation,
It returns to the state before the power failure as soon asthe power
source is restored (After the end of the primary control at the power
on).
It stops after the restoration of power source.
Enable
Disable
●Since the status of remote control is retained in memory always, it restarts operations according to the contents of memory
as soon as the power source is restored. Although the timer mode is cancelled, the weeklytimer, peakcut timerand silent
mode timer operate according to the following contents:
・When the clock setting is valid : These timer settings are also valid.
・When the clock setting is invalid : These timer settings become “Invalid” since the clock setting is invalid.
These timer settings have to be changed to “Valid” after the timer setting.

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Clock setting check screen
Misconnection screen
●Content memorized with the power failure compensation are as follows.
Note(1) Items (f) and (g) are memorized regardless whether the power failure compensation is effective or not while the setting of silent mode is cancelled
regardless whether the power failure compensation is effective or not.
(a) At power failure – Operating/stopped
If it had been operating under the off timer mode, sleep timer mode, the state of stop is memorized.
(b) Operation mode
(c) Air flow volume mode
(d) Room temperature setting
(e) Louver auto swing/stop
However, the stop position (4-position) is cancelled so that it returns to Position (1).
(f) “Remote control function items” which have been set with the administrator or installation function settings
(“Indoor function items” are saved in the memory of indoor unit.)
(g) Weekly timer, peak-cut timer or silent mode timer settings
(h) Remote control function setting
Please check the I/U
Set clock first on the initializing
screen & set the timer.
Other than A/C is connected
(4) Alert displays
If the following (a) to (c) appear, check and repair as follows.
Communication check screen ●This appears if communications cannot be established between the remote
control and the indoor unit.
Check whether the system is correctly connected (indoor unit, outdoor unit,
remote control) and whether the power source for the outdoor unit is connected.
●This appears when the timer settings are done without clock setting.
Set the clock setting before the timer settings.
●This appears when something other than the air-conditioner has been connected to the remote
control.
Check the location to which the remote control is connected.
(a) Communication check between indoor unit and remote control
(b) Clock setting check
(c ) Misconnection

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Model RC-E5
(1) Switching sequence of the operation mode switches of remote control
DRY COOL FA N HEAT AUTO
(2) CPU reset
This functions when “CHECK” and “ESP” buttons on the remote control are pressed simultaneously. Operation is
same as that of the power source reset.
(3) Power failure compensation function (Electric power source failure)
• This becomes effective if “Power failure compensation effective” is selected with the setting of remote control
function.
• Sinceitmemorizesalwaystheconditionofremotecontrol,itstartsoperationaccordingtothecontentsofmemory
nosoonerthannormalstateisrecoveredafterthepowerfailure.Althoughtheautoswingstoppositionandthetimer
modearecancelled,theweeklytimersettingisrestoredwiththeholidaysettingforallweekdays.
 Afterrecoveringfromthepowerfailure,itreadjuststheclockandresetstheholidaysettingforeachweekdaysothat
thesettingofweeklytimerbecomeseective.
• Contentmemorizedwiththepowerfailurecompensationareasfollows.
Note(1)Items(f),(g)and(h)arememorizedregardlesswhetherthepowerfailurecompensationiseectiveornotwhilethesettingofsilentmodeis
cancelledregardlesswhetherthepowerfailurecompensationiseectiveornot.
(a) Atpowerfailure–Operating/stopped
 Ifithadbeenoperatingundertheotimermode,sleeptimermode,thestateofstopismemorized.(Although
thetimermodeiscancelledattherecoveryfrompowerfailure,thesettingofweeklytimerischangedtothe
holidaysettingforallweekdays.)
(b) Operation mode
(c) Airowvolumemode
(d) Roomtemperaturesetting
(e) Louverautoswing/stop
 However,thestopposition(4-position)iscancelledsothatitreturnstoPosition(1).
(f) “Remote control function items” which have been set with the remote control function setting (“Indoor
functionitems”aresavedinthememoryofindoorunit.)
(g) Upperlimitvalueandlowerlimitvaluewhichhavebeensetwiththetemperaturesettingcontrol
(h) Sleeptimerandweeklytimersettings(Othertimersettingsarenotmemorized.)
[Parts layout on remote control PCB]
Master/ slave setting when more than one remote controls are used
A maximum of two remote controls can be connected to one indoor unit (or one group of indoor units.)
Remote control cord (no polarity)
Remote control
SW1 "Master"
Switch Setting Content
M Master remote control
SW1 S Slave remote control
Remote control
SW1 "Slave"
Indoor units
Note (1) Don’t change SW2 because it is not used normally.
Caution
When using multiple remote controls, the following dispiays or settings
cannot be done with the slave remote control. It is available only with
the master remote control.
Louver position setting (set upper or lower limit of swinging range)
Setting indoor unit functions
Setting temperature range
Operation data display
Error data display
Silent mode setting
Test operation of drain pump
Remote control sensor setting
XY
SW2
SW1
A
B
M
S
親
子
SW1
SW2