Mitsubishi Electric Mr. Slim PLA-A12EA7 User manual

SERVICE MANUAL
CONTENTS
1. REFERENCE MANUAL........................ 2
2. SAFETY PRECAUTION........................ 3
3. PARTS NAMES AND FUNCTIONS...... 5
4. SPECIFICATIONS............................... 13
5. NOISE CRITERION CURVES............. 15
6. OUTLINES AND DIMENSIONS............17
7. WIRING DIAGRAM ............................. 18
8. REFRIGERANT SYSTEM DIAGRAM
...... 19
9. TROUBLESHOOTING ........................ 20
10. FUNCTION SETTING ......................... 34
11. SPECIAL FUNCTION.......................... 35
12. DISASSEMBLY PROCEDURE........... 39
PARTS CATALOG (OCB640)
WIRED REMOTE
CONTROLLER
(Option)
IR WIRELESS REMOTE
CONTROLLER
(Option)
ON/OFF TEMP
INDOOR UNIT
Model name
indication for
MAIN UNIT
Model name
indication for GRILLE
PLA-A12EA7
PLA-A18EA7
PLA-A24EA7
PLA-A30EA7
PLA-A36EA7
PLA-A42EA7
PLA-A12EA7
PLA-A18EA7
PLA-A24EA7
PLA-A30EA7
PLA-A36EA7
PLA-A42EA7
Indoor unit
[Model Name] [Service Ref.]
SPLIT-SYSTEM HEAT PUMP
No. OCH640
REVISED EDITION-D
December 2019
Revision:
• Some descriptions have
been modified
in REVISED EDITION-D.
OCH640 REVISED EDITION-C
is void.
MENU ON
OFF
RETURN SELECT
HOLD
Grille model
[Model Name]
PLP-40EAEU
PLP-41EAEU

2 3
OCH640D
1REFERENCE MANUAL
OUTDOOR UNIT SERVICE MANUAL
Model Name Service Ref. Service Manual No.
MXZ-2B20NA
MXZ-3C24/30NA2, MXZ-4C36NA2
MXZ-2B20NA-2
MXZ-3C24/30NA2-U1, MXZ-4C36NA2-U1
OBH560
OBB560
MXZ-2C20NAHZ2, MXZ-2C24NAHZ2
MXZ-2C30NAHZ2, MXZ-5C42NA2
MXZ-2C20NAHZ2-U1, MXZ-2C24NAHZ2-U1
MXZ-2C30NAHZ2-U1, MXZ-5C42NA2-U1
OBH702
OBB702
MXZ-4C36NAHZ, MXZ-5C42NAHZ
MXZ-8C48NAHZ, MXZ-8C48NA
MXZ-8C60NA
MXZ-4C36NAHZ, MXZ-5C42NAHZ
MXZ-8C48NAHZ, MXZ-8C48NA
MXZ-8C60NA
OCH573
OCB573
PUZ-A12/18/36/42NKA7(-BS)
PUZ-A24/30NHA7(-BS)
PUY-A12/18/36/42NKA7(-BS)
PUY-A24/30NHA7(-BS)
PUZ-A12/18/36/42NKA7(-BS)
PUZ-A24/30NHA7(-BS)
PUY-A12/18/36/42NKA7(-BS)
PUY-A24/30NHA7(-BS)
OCH636
OCB636
Remote controller (Optional parts)
Wired remote controller IR wireless remote controller
COOL
DRY
AUTO
FAN
HEAT
MENU ON
OFF
RETURN SELECT
HOLD

3
OCH640D
SAFETY PRECAUTION
2
Cautions for units utilising refrigerant R410A
2-2. CAUTIONS RELATED TO NEW REFRIGERANT
Use new refrigerant pipes.
Charge refrigerant from liquid phase of gas
cylinder.
If the refrigerant is charged from gas phase, composition
change may occur in refrigerant and the efficiency will be
lowered.
Use a vacuum pump with a reverse flow check
valve.
Vacuum pump oil may flow back into refrigerant cycle and
that can cause deterioration of refrigerant oil, etc.
Use the following tools specifically designed for
use with R410A refrigerant.
The following tools are necessary to use R410A refrigerant.
Handle tools with care.
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
Do not use a charging cylinder.
If a charging cylinder is used, the composition of refrigera-
nt will change and the efficiency will be lowered.
Flare tool
Electronic refrigerant
charging scale
Vacuum pump adaptor
Size adjustment gauge
Gauge manifold
Torque wrench
Gas leak detector
Charge hose
Tools for R410A
Contamination inside refrigerant piping can cause deterio-
ration of refrigerant oil, etc.
If large amount of mineral oil enters, that can cause deterio-
ration of refrigerant oil, etc.
The refrigerant oil applied to flare and flange
connections must be ester oil, ether oil or
alkylbenzene oil in a small amount.
Make sure that the inside and outside of refrige-
rant piping is clean and it has no contaminants
such as sulfur, oxides, dirt, shaving particles, etc,
which are hazards to refrigerant cycle.
In addition, use pipes with specified thickness.
Store the piping indoors, and keep both ends of
the piping sealed until just before brazing.
(Leave elbow joints, etc. in their packaging.)
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of compressor.
Do not use refrigerant other than R410A.
If other refrigerant (R22, etc.) is used, chlorine in refrige-
rant can cause deterioration of refrigerant oil, etc.
Ventilate the room if refrigerant leaks during
operation. If refrigerant comes into contact with
a flame, poisonous gases will be released.
Use the specified refrigerant only.
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the
unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the
spec labels provided with our products.
We will not be held responsible for mechanical failure,
system malfunction, unit breakdown or accidents caused
by failure to follow the instructions.
2-1. ALWAYS OBSERVE FOR SAFETY
Before obtaining access to terminal, all supply
circuits must be disconnected.

5
OCH640D 4
Electronic weighing scale
Unit
[3] Service tools
Use the below service tools as exclusive tools for R410A refrigerant.
[2] Additional refrigerant charge
When charging directly from cylinder
(1) Check that cylinder for R410A on the market is a syphon type.
(2) Charging should be performed with the cylinder of syphon stood vertically. (Refrigerant is charged from liquid phase.)
[1] Cautions for service
(1) Perform service after recovering the refrigerant left in the unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the cycle with specified amount of refrigerant.
(4) When performing service, install a filter drier simultaneously.
Be sure to use a filter drier for new refrigerant.
No. Tool name Specifications
1Gauge manifold · Only for R410A
· Use the existing fitting specifications. (UNF1/2)
· Use high-tension side pressure of 768.7 PSIG [5.3MPa·G] or over.
2Charge hose · Only for R410A
· Use pressure performance of 738.2 PSIG [5.09MPa·G] or over.
3Electronic weighing scale —
4Gas leak detector · Use the detector for R134a, R407C or R410A.
5Adaptor for reverse flow check · Attach on vacuum pump.
6Refrigerant charge base —
7Refrigerant cylinder · Only for R410A · Top of cylinder (Pink)
· Cylinder with syphon
8Refrigerant recovery equipment —

5
OCH640D
3PARTS NAMES AND FUNCTIONS
Drain pipe
Air outlet
Liquid pipe
Gas pipe
i-See sensor
(option)
Vane
Air intake
(Intake grille)
Filter
3-1. INDOOR UNIT

6 7
OCH640D
3-2. Wired Remote Controller <PAR-40MAA>
Function buttons
MENU
ON
OFF
RETURN SELECT
HOLD
When the backlight is off, pressing any button turns the backlight on
and does not perform its function. (except for the [ON/OFF] button)
The functions of the function buttons change depending on the
screen.
Refer to the button function guide that appears at the bottom of
the LCD for the functions they serve on a given screen.
When the system is centrally controlled, the button function
guide that corresponds to the locked button will not appear.
Press to turn ON/OFF the indoor unit.
This lamp lights up in green while the unit is in operation. It blinks
while the remote controller is starting up or when there is an error.
1[ON/OFF] button 6ON/OFF lamp
Press to save the setting.
When the Main menu is displayed, pressing this button will
enable/disable the HOLD function.
Main display: Press to change the operation mode.
Menu screen: The button function varies with the screen.
2 [SELECT/HOLD] button
7 Function button [F1]
Press to return to the previous screen. Main display: Press to decrease temperature.
Main menu: Press to move the cursor left.
Menu screen: The button function varies with the screen.
3[RETURN] button 8Function button [F2]
4[MENU] button
9Function button [F3]
Press to bring up the Main menu.
Main display: Press to increase temperature.
Main menu: Press to move the cursor right.
Menu screen: The button function varies with the screen.
Operation settings will appear.
When the backlight is off, pressing any button turns the
backlight on and it will stay lit for a certain period of time
depending on the screen.
Main display: Press to change the fan speed.
Menu screen: The button function varies with the screen.
5Backlit LCD
0Function button [F4]
83
83
Fri
Room
Set temp.
Mode Temp. Fan
Cool Auto
Main Main menu
Energy saving
Main menu: RETURN
Cursor
Operation
Vane·Louver·Vent. (Lossnay)
High power
Comfort
Main menuMain display
Menu screen
7 8 9 0
7 8 9 0
7 8 9 0
Function guide
Controller interface

7
OCH640D
The main display can be displayed in two different modes: “Full” and “Basic”. The initial setting is “Full”. To switch to the “Basic”
mode, change the setting on the Main display setting. (Refer to operation manual included with remote controller.)
<Full mode> <Basic mode>
All icons are displayed for explanation.
Most settings (except ON/OFF, mode, fan speed, temperature) can be made from the Main menu.
1Operation mode
2Preset temperature
3Clock
4Fan speed
Functions of the corresponding buttons appear here.
5Button function guide
Appears when the ON/OFF operation is centrally controlled.
Appears when the operation mode is centrally controlled.
Appears when the preset temperature is centrally controlled.
Appears when the lter reset function is centrally controlled.
Indicates when lter needs maintenance.
1Room temperature
Appears when the buttons are locked.
Appears when the Weekly timer is enabled.
Appears while the units are operated in the energy saving
mode. (Will not appear on some models of indoor units)
Appears when the built-in thermistor on the remote
controller is activated to monitor the room temperature (1).
appears when the thermistor on the indoor unit is
activated to monitor the room temperature.
Appears when an energy saving operation is performed us-
ing a “3D i-See sensor” function.
Indicates the louver setting.
Indicates the ventilation setting.
Appears when the preset temperature range is restricted.
Indicates the vane setting.
6
7
8
9
0
2
4
5
7
8
9
)
!
Fri
Mode Temp. Fan
Room
Cool Set temp. Auto
83
83
1
2
3
4
5
6
78
90
1
2 34 5 6 7 8
9
)
@
!
#
$
Display
Appears when the On/O󰀨 timer or Auto-o󰀨 timer function is enabled.
3
appears when the timer is disabled by the centralized control system.
appears when the HOLD function is enable.
6
Appears while the outdoor units are operated in the silent mode.
@
Appears for a certain period of time when a centrally-
controlled item is operated.
#Centrally controlled
An check code appears during the preliminary error.
$Preliminary error display
Fri
Cool
Mode Temp. Fan
Set temp. Auto
$
83
5
4
3
2
1
#

8 9
OCH640D
Not all functions are available on all models of indoor units.
Energy saving
Main menu Press the MENU button.
Move the cursor to the desired item with the F1 and F2 buttons, and press the SELECT button.
Operation
Initial setting menu
Manual vane angle
ON/OFF timer
Auto return
Clock
Main/Sub
Temp. range
Auto-OFF timer
Schedule
Daylight saving time
Clock
Administrator password
Operation locked
3D i-See sensor
High power
Vane · Louver · Vent. (Lossnay)
Comfort
Timer
Energy saving
Basic setting
Display setting
Operation setting
Restriction
Weekly timer
OU silent mode
Timer menu
Main display
Display details
Contrast • Brightness
Language selection
Auto mode
Setback mode
Continue to the next page.

9
OCH640D
Maintenance menu
Service menu
Drain pump test run
Serial No. input
Diagnosis
Initialize remote controller
Remote controller information
Initialize maintenance info.
Test run
Model name input
Function setting
Error history
Maintenance password
Dealer information input
Error information
Test run menu
Maintenance information
Filter information
Cleaning
Settings menu
Check menu
Other menu
Auto descending panel
Descending operation
Self check
Descending adjustment
Remote controller check
Continue from the previous page.
Not all functions are available on all models of indoor units.

10
OCH640D
*1Clock setting is required.
*22°F (1°C) increments.
*3This function can only be set when certain outdoor units are connected.
Main menu list
Main
menu Setting and display items Setting details
Operation Vane · Louver · Vent.
(Lossnay)
Use to set the vane angle.
• Select a desired vane setting from 5 di󰀨erent settings.
Use to turn ON/OFF the louver.
• Select a desired setting from "ON" and "OFF."
Use to set the amount of ventilation.
• Select a desired setting from "O󰀨," "Low," and "High."
High power *3Use to reach the comfortable room temperature quickly.
• Units can be operated in the High-power mode for up to 30 minutes.
Comfort Manual
vane angle
Use to x each vane angle.
3D i-See sensor Use to set the following functions for 3D i-See sensor.
• Air distribution • Energy saving option • Seasonal airow
Timer Timer ON/OFF timer *1Use to set the operation ON/OFF times.
• Time can be set in 5-minute increments.
Auto-O󰀨
timer
Use to set the Auto-O󰀨 time.
• Time can be set to a value from 30 to 240 in 10-minute increments.
Weekly timer *1, *2Use to set the weekly operation ON/OFF times.
• Up to 8 operation patterns can be set for each day.
(Not valid when the ON/OFF timer is enabled.)
OU silent mode *1, *3Use to set the time periods in which priority is given to quiet operation of
outdoor units over temperature control. Set the Start/Stop times for each day
of the week.
•Select the desired silent level from "Normal," "Middle," and "Quiet."
Energy
saving
Restriction Temp. range *2Use to restrict the preset temperature range.
• Di󰀨erent temperature ranges can be set for di󰀨erent operation modes.
Operation
locked
Use to lock selected functions.
• The locked functions cannot be operated.
Energy
saving
Auto return *2Use to get the units to operate at the preset temperature after performing
energy saving operation for a specied time period.
• Time can be set to a value from 30 and 120 in 10-minute increments.
(This function will not be valid when the preset temperature ranges are restricted.)
Schedule *1Set the start/stop times to operate the units in the energy saving mode for
each day of the week, and set the energy saving rate.
• Up to 4 energy saving operation patterns can be set for each day.
• Time can be set in 5-minute increments.
• Energy saving rate can be set to a value from 0% or 50 to 90% in 10% increments.