Mitsubishi Electric CITY MULTI PKFY-P24NKMU-E Operating manual

TECHNICAL & SERVICE MANUAL
CONTENTS
1. PART NAMES AND FUNCTIONS .......... 2
2. SPECIFICATION ..................................... 4
3. OUTLINES AND DIMENSIONS.............. 6
4. WIRING DIAGRAM................................. 7
5. REFRIGERANT SYSTEM DIAGRAM.......... 8
6. MICROPROCESSOR CONTROL........... 9
7. TROUBLESHOOTING .......................... 14
8. DISASSEMBLY PROCEDURE............. 21
Indoor unit
[Model names] [Service Ref.]
No. OCH462
REVISED EDITION-A
INDOOR UNIT
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
R22R410A
Note:
•This manual describes only
service data of the indoor
units.
•RoHS compliant products
have <G> mark on the spec
name plate.
May 2011
PARTS CATALOG (OCB462)
PKFY-P24NKMU-E PKFY-P24NKMU-E.TH
PKFY-P30NKMU-E PKFY-P30NKMU-E.TH
Revision:
•3. OUTLINES AND
DIMENSIONS has been modi-
fied in REVISED EDITION-A.
•Some descriptions have been
modified.
•Please void OCH462.

2
ON/OFF TEMP
FAN
VANE
TEST RUN
AUTO STOP
AUTO START
h
min
LOUVER
MODE
CHECK
RESETSET CLOCK
MODEL SELECT
NOT AVAILABLE
CHECK TEST RUN
°C
AMPM
AMPM
°F
VANE CONTROL button
Used to change the air flow
CLOCK button
RESET button
SET button
ON/OFF button
The unit is turned ON and OFF alternately
each time the button is pressed.
LOUVER button
Changes left/right airflow direction.
(Not available for this model.)
MODE SELECT button
Used to switch the operation mode between
cooling, drying, fan, heating and auto mode.
CHECK-TEST RUN button
Only press this button to perform an
inspection check or test operation.
Do not use it for normal operation.
FAN SPEED SELECT button
Used to change the fan speed.
TIMER display
Displays when in timer operation or when
setting timer.
button
SET TEMPERATURE button sets any desired
room temperature.
CLOCK display
Displays the current time.
“ ” “ ” display
Displays the order of timer operation.
“ ” “ ” display
Displays whether timer is on or off.
+In case the outdoor unit is cool only type,
the heating and auto mode are not
available.
Buttons used to set the “hour and minute” of
the current time and timer settings.
h and min buttons
display
display
FAN SPEED display indicates which fan
speed has been selected.
display
The vertical direction of air flow is indicated.
display
Blinks when model is selected.
display
display
CHECK and TEST RUN display indicate that
the unit is being checked or test-run.
display
OPERATION MODE display
Operation mode display indicates which
operation mode is in effect.
TIMER CONTROL buttons
AUTO STOP (OFF timer): when this switch is
set, the air conditioner will be automatically
stopped at the preset time.
AUTO START (ON timer): when this switch is
set, the air conditioner will be automatically
started at the preset time.
MODEL SELECT
CHECK TEST RUN
SET TEMP. display indicates the set desired
temperature.
Lights up while the signal is transmitted to
the indoor unit when the button is pressed.
1PART NAMES AND FUNCTIONS
Indoor unit
Wireless remote controller
Emergency operation
switch
Front grille
Air inlet
Filter
Air outlet
Louver
Vane
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.

33
Wired remote controller
°F°C
°F°C
ERROR CODE
AFTER
TIMER
TIME SUN MON TUE WED THU FRI SAT
ON
OFF
Hr
AFTER
FILTER
FUNCTION
ONLY1Hr.
WEEKLY
SIMPLE
AUTO OFF
PAR-21MAA
ON/OFF
FILTER
CHECK
OPERATION
CLEAR
TEST
TEMP.
MENU
BACK DAY
MONITOR/SET
CLOCK
ON/OFF
●
●
Display Section
For purposes of this explanation,
all parts of the display are shown.
During actual operation, only
the relevant items will be lit.
Identifies the current operation
Shows the operating mode, etc.
*Multilanguage display is available.
“Centrally Controlled” indicator
Indicates that operation from the
remote controller has been prohib-
ited by a master controller.
“Timer is Off” indicator
Indicates that the timer is off.
Temperature Setting
Shows the target temperature.
Day-of-Week
Shows the current day of the week.
Time/Timer Display
Shows the current time, unless the simple or Auto Off
timer is set.
If the simple or Auto Off timer is set, the time to be
switched off is shown.
“Sensor” indication
Displays when the remote controller
sensor is used.
“Locked” indicator
Indicates that remote controller but-
tons have been locked.
“Clean The Filter” indicator
To be displayed on when it is time to
clean the filter.
Timer indicators
The indicator comes on if the corre-
sponding timer is set.
Up/Down Air Direction indica-
tor
The indicator shows the direc-
tion of the outcoming airflow.
“One Hour Only” indicator
Room Temperature display
Shows the room temperature. The room
temperature display range is 46–102°F.
The display blinks if the temperature
is less than 46°F or 102°F or more.
Louver display
Indicates the action of the swing louver.
Does not appear if the louver is not
running.
(Power On indicator)
Indicates that the power is on.
Fan Speed indicator
Shows the selected fan speed.
Ventilation indicator
Appears when the unit is running in
Ventilation mode.
Operation Section
Temperature setting buttons
Down
Up
Timer Menu button
(Monitor/Set button)
Mode button (Return button)
Set Time buttons
Back
Ahead
Timer On/Off button
(Set Day button)
Opening the
cover
ON/OFF button
Fan Speed button
Filter button
(<Enter> button)
Test Run button
Check button (Clear button)
Airflow Up/Down button
Louver button
( Operation button)
To return operation
number
Ventilation button
( Operation button)
To go to next operation
number
Note:
“PLEASE WAIT” message
This message is displayed for approximately 3 minutes when power is supplied to the indoor unit or when the unit is recovering from a power failure.
“NOT AVAILABLE” message
This message is displayed if an invalid button is pressed (to operate a function that the indoor unit does not have).
If a single remote controller is used to operate multiple indoor units simultaneously that are different types, this message will not be displayed as
far as any of the indoor units is equipped with the function.
Built-in temperature sensor
Displays if the airflow is set to
Low or downward during COOL
or DRY mode. (Operation varies
according to model.)
The indicator goes off in one hour,
at which time the airflow direction
also changes.

4
Note : Unit converter
kcal/h = kW × 860
Btu/h = kW × 3,412
cfm = m3/min × 35.31
lb = kg/0.4536
*Above specification data is
subject to rounding variation.
Model
Power source
Cooling capacity
(Nominal)
Heating capacity
(Nominal )
External finish
External dimension H × W × D
Net weight
Heat exchanger
Fan
Noise level (Low-High)
(measured in anechoic room)
Insulation material
Air filter
Protection device
Refrigerant control device
Connectable outdoor unit
Diameter of
refrigerant pipe
Field drain pipe size
Standard
attachment
Optional parts
Remarks
Power input
Current input
Power input
Current input
Type × Quantity
External
static press.
Motor type
Motor output
Driving mechanism
Airflow rate
(Low-High)
Liquid
Gas
Document
Accessory
External heater adapter
Installation
kW
Btu/h
kW
A
kW
Btu/h
kW
A
mm
in.
kg (lb)
Pa
mmH2O
kW
m3/min
L/s
cfm
dB <A>
mm (in.)
mm (in.)
mm (in.)
*1
*1
*2
*2
(R410A)
(R22)
(R410A)
(R22)
Installation Manual, Instruction Book
PAC-YU25HT
1-phase 208-230V 60Hz
Cross fin (Aluminum fin and copper tube)
DC motor
Direct-drive
Polyethylene sheet
PP honeycomb
Fuse
LEV
R410A, R22 CITY MULTI
PKFY-P24NKMU-E
Plastic, MUNSELL (1.0Y 9.2/0.2)
7.0
24,000
0.04
0.29
7.9
27,000
0.04
0.29
365 × 1170 × 295
14-3/8" × 46-1/16" × 11-5/8"
21 (46)
Line flow fan × 1
0
0
0.056
20 - 24
333 - 400
710 - 850
43 - 49
I.D. 16mm (5/8")
ø9.52 (ø3/8")
ø9.52 (ø3/8")
ø15.88 (ø5/8")
ø15.88 (ø5/8")
Flare
Flare
Flare
Flare
PKFY-P30NKMU-E
8.8
30,000
0.06
0.43
10.0
34,000
0.06
0.43
16 - 20
267 - 333
570 - 710
39 - 45
Flare
Flare
Flare
Flare
*1 Nominal cooling conditions
Indoor :
Outdoor :
Pipe length :
Level difference :
80°FDB/67°FWB (26.7°CDB/19.4°CWB)
95°FDB (35°CDB)
25 ft. (7.6 m)
0 ft (0 m)
*2 Nominal heating conditions
70°FDB(21°CDB)
47°FDB/43°FWB (8.3°CDB/6.1°CWB)
25 ft. (7.6 m)
0 ft (0 m)
* Due to continuing improvement, above specification may be subject to change without notice.
ø9.52 (ø3/8")
ø9.52 (ø3/8")
ø15.88 (ø5/8")
ø15.88 (ø5/8")
Details on foundation work, insulation work, electrical wiring, power source switch, and other items shall be referred to
the Installation Manual.
2SPECIFICATION
2-1. Specifications

55
Parts name
Service Ref.
Symbol
TH21
TH22
TH23
TH24
FUSE
MF
MV
LEV
TB2
TB5
TB15
Resistance 30°F/15.8k, 50°F/9.6k, 70°F/6.0k, 80°F/4.8k, 90°F/3.9k, 100°F/3.2k
Resistance 30°F/15.8k, 50°F/9.6k, 70°F/6.0k, 80°F/4.8k, 90°F/3.9k, 100°F/3.2k
Resistance 30°F/15.8k, 50°F/9.6k, 70°F/6.0k, 80°F/4.8k, 90°F/3.9k, 100°F/3.2k
250V 3.15A
8-Pole Output 56W / RCOJ56-AC
MSBPC20 DC12V
(L1, L2, GR) 250V 20A
(M1, M2, S) 250V 20A
(1, 2) 250V 10A
Liquid pipe thermistor
Gas pipe thermistor
Linear expansion valve
PKFY-P24NKMU-E.TH
Room temperature
thermistor
Fuse
(Indoor controller board)
Fan motor
Vane motor
(with limit switch)
Power supply terminal
block
Transmission terminal
block
PKFY-P30NKMU-E.TH
MA remote controller
terminal block
EFM-40YGME
DC 12 V
EFM-80YGME
DC 12 V
PKFY-P24NKMU-E
External static pressure : 0Pa
Power source : 208,230V, 60Hz
* Measured in anechoic room.
OCTAVE BAND PRESSURE LEVEL (dB) 0dB = 20MPa
3.3 ft. (1m)
Measurement location
PKFY-P24NKMU-E.TH
PKFY-P30NKMU-E.TH
39 - 45
43 - 49
Sound level dB (A)
Sound level at anechoic room : Low-High
Service Ref.
Approximate minimum
audible limit on
continuous noise
High speed
Low speed
3.3 ft.
(1m)
OCTAVE BAND CENTER FREQUENCIES(Hz)
PKFY-P30NKMU-E
External static pressure : 0Pa
Power source : 208,230V, 60Hz
OCTAVE BAND PRESSURE LEVEL (dB) 0dB = 20MPa
OCTAVE BAND CENTER FREQUENCIES(Hz)
Approximate minimum
audible limit on
continuous noise
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
70.0
63 125 250 500 1k 2k 4k 8k
NC60
NC50
NC40
NC30
NC20
High speed
Low speed
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
70.0
63 125 250 500 1k 2k 4k 8k
NC60
NC50
NC40
NC30
NC20
2-2. Electrical parts specifications
2-3. Sound levels
2-4. NC curves

6
OUTLINES AND DIMENSIONS
3
PKFY-P24NKMU-E.TH
PKFY-P30NKMU-E.TH
Unit : inch (mm)
Front side
46-1/16(1170)
9-1/2(241)
33-21/32(855)2-29/32(74)
14-3/8(365)
Emergency operation switch
(cooling/heating)
Terminal block for power supply
Terminal block for
MA-remote controller
Front side(Grille open)
Terminal block for transmission
Filter hook
6-1/16(154)
4-27/32(123)
18-31/32(482)Liquid pipe
17-15/32(444)Gas pipe
23-1/32(585)Drain hose 5-9/32(134)
Min.9/32(7)
Center measurement hole
:3/32(:2.5)
Knockout hole for
rear piping
2-15/16×18-29/32(75×480)
75- : 3/16( : 5.1)
Tapping
screw hole
Mount board
Wall hole for
right rear piping
Indoor unit outline
4- : 11/32( : 9) Bolt hole
Wall hole for
left rear piping
1/8(3)
R1-15/32(R37.5)
2-1/8(54)
0
5/8(15.5) 0
17-9/32(439) 0
17-9/32(439)
15-1/8(384)
13/32(10) 20-3/8(517.4) 17-7/8(454) 16-3/32(408.5) 15-1/8(384) 14-11/32(364) 12-3/8(314) 4-11/32(110) 2-3/8(60) 13/32(10) 18-5/16(465.5) 17-7/8(454)
16-3/32(408.5)
15-1/8(384.5) 14-11/32(364) 12-3/8(314) 4-11/32(110) 2-3/8(60)
1-1/4(32)
12-5/32(308.5)
31/32(25)
11-1/2(292)
11(279.5)
9-17/32(242)
7-9/16(192)
5-19/32(142)
4-29/32(125)
4-19/32(117)
3-15/16(100)
2-15/16(75)
1-31/32(50)
15-1/8(384)
0
13-3/4(349.2)
16-15/16(430.5)
1/2(12.5)
11-1/2(292)
10-13/32(264)
9-1/32(229.5)
8-17/32(217)
6-9/16(167)
5-3/32(129.5)
4-1/8(104.5)
3-7/16(87.5)
2-15/32(62.5)
1-15/32(37.5)
1/2(12.5)
2-1/8(54)
31/32(25)
0
12-1/4(311)
8-17/32(216.5)
13-11/32(339)
20-7/8(530.5)
7-7/16(189)
13-11/32(339)
17-11/16(449.2)
23-1/32(585)
23-1/32(585)
A
5/16(7.8)
3-1/32(77)
2-5/8(67)
2-9/16(65)
B
Knockout hole for piping
13/32(10.7)
2-9/16(65)
3-1/32(77)
3-7/16(87)
C
5/16(7.8)
2-9/16(65)
3-1/32(77)
2-5/8(67)
Louver (manual)
Vane(auto)
Knockout hole
for lower piping
Under side
BB
Receiver
DEFROST/STAND BY lamp
Operation lamp
2-19/32(66)
23/32(18)
1-1/4(32)
2-3/32(53)
1-3/16(30)
1-3/8(35)
Mount board
C
Knockout hole
for right piping
Right side
11-5/8(295) 3/16(5)
Left side
A
Knockout hole
for left piping
Top side
2-9/16(65.2)
5-17/132(140.3)
7/16(11)
17(431.7)
16-11/16(423.7)
Air outlet
Air inlet
Min.1-7/8(48)
Min.9-27/32(250)
Required space(Indoor unit)
Min.3-31/32(100.5)
Min.8-21/32(220)
Min.2-1/16(52.3)



Refrigerant pipe: 3/8 O.D(:9.52)
Refrigerant pipe: 5/8 O.D(:15.88)
5/8(:16) O.D
Drain hose
Piping connection
Liquid pipe
Gas pipe
Through hole
:2-15/16
(:75) :2-15/16~:3-5/32
(:75~:80)
Sleeve
(purchased locally)
Flared connection: 5/8F
Flared connection: 3/8F

7
WIRING DIAGRAM4
PKFY-P24NKMU-E.TH PKFY-P30NKMU-E.TH
For the detail, refer to Fig. 1.
<Fig. 1>
See Fig. 1.
SYMBOL
I.B
CN24
CN32
CN51
CN52
BZ
DSA
FUSE
LED1
LED2
SW2
SW3
SW4
SWE
X1
MOV 01,02
LEV
MF
MV
TB2
TB5
TB15
INDOOR CONTROLLER BOARD
CONNECTOR
BUZZER
SURGE ABSORBER
FUSE (T3.15AL 250V)
POWER SUPPLY (I.B)
POWER SUPPLY (I.B)
SWITCH
AUX.RELAY DRAIN PUMP
VARISTOR
LINER EXPANSION VALVE
FAN MOTOR
VANE MOTOR
TERMINAL
BLOCK
EXTERNAL HEATER
REMOTE SWITCH
CENTRALLY CONTROL
REMOTE INDICATION
CAPACITY CODE
MODE SELECTION
MODE SELECTOR
DRAIN PUMP (TEST MODE)
POWER SUPPLY
TRANSMISSION
MA-REMOTE CONTROLLER
TH21 THERMISTOR
TH22
TH23
TH24
A.B ADDRESS BOARD
SWA SWITCH
SW1
SW11
SW12
SW14
S.B SWITCH BOARD
SWE1 EMERGENCY OPERATION (HEAT)
SWE2 EMERGENCY OPERATION (COOL)
W.B
PCB FOR WIRELESS REMOTE CONTROLLER
LED1 LED (OPERATION INDICATION: GREEN)
LED2 LED (OPERATION INDICATION: ORANGE)
RU RECEIVING UNIT
NAME NAME
ROOM TEMP. DETECTION
(32°F/15kΩ, 77°F/5.4kΩ)
PIPE TEMP. DETECTION/LIQUID
(32°F/15kΩ, 77°F/5.4kΩ)
PIPE TEMP. DETECTION/GAS1
(32°F/15kΩ, 77°F/5.4kΩ)
PIPE TEMP. DETECTION/GAS2
(32°F/15kΩ, 77°F/5.4kΩ)
FAN SPEED SELECTOR
MODE SELECTION
ADDRESS SETTING 1s DIGIT
ADDRESS SETTING 10ths DIGIT
BRANCH No.
SYMBOL
The black square (■) indicates
a switch position.

8
5REFRIGERANT SYSTEM DIAGRAM
Strainer (#50mesh)
Strainer (#100mesh)
Strainer1 (#50mesh)
Strainer2 (#100mesh)
Heat exchanger
Room temparature thermistor TH21
Gas pipe thermistor (1) TH23
Liquid pipe thermistor TH22
Linear expansion valve
Gas pipe
Liquid pipe
Flare connection
Gas pipe
Liquid pipe
PKFY-P24NKMU-E PKFY-P30NKMU-E
:15.88 (5/8)
:9.52 (3/8)
Item
Model
Unit : mm (inch)
Gas pipe thermistor (2) TH24
:15.88 (5/8)
:9.52 (3/8)
PKFY-P24NKMU-E.TH PKFY-P30NKMU-E.TH

9
6MICROPROCESSOR CONTROL
PAR-21MAA
ON/OFF
FILTER
CHECK
OPERATION
CLEAR
TEST
TEMP.
MENU
BACK DAY
MONITOR/SET
CLOCK
ON/OFF
ûF ûC
ûF ûC
ERROR CODE
AFTER
TIMER
TIME SUN MON TUE WED THU FRI SAT
ON
OFF
Hr
AFTER
FILTER
FUNCTION
ONLY1Hr.
WEEKLY
SIMPLE
AUTO OFF
INDOOR UNIT CONTROL
6-1. COOL OPERATION
<How to operate>
Press POWER ON/OFF button.
Press the operation MODE button to display COOL.
Press the TEMP. button to set the desired temperature.
NOTE: The set temperature changes 2°F when the or button is
pressed one time. Cooling 67 to 87°F
Control modes Control details
1-1. Thermoregulating function (Function to prevent restarting for 3 minutes)
• Room temperature desired temperature + 2°F
···Thermo ON
• Room temperature desired temperature ···Thermo OFF
1-2. Anti-freezing control
Detected condition : When the liquid pipe temp. (TH22) is 32°F or less in 16
minutes from compressors start up, anti-freezing control
starts and the thermo OFF.
Released condition : The timer which prevents reactivating is set for 3 minutes,
and anti-freezing control is cancelled when any one of the
following conditions is satisfied.
Liquid pipe temp. (TH22) turns 50°F or above.
The condition of the thermo OFF has become complete
by thermoregulating, etc.
The operation modes became mode other than COOL.
The operation stopped.
By the remote controller setting (switch of 2 speeds)
2. Fan
1. Thermoregulating
function
Remarks
Type Fan speed notch
[Low], [High]
2 speeds
→
(1)Initial setting: Start at COOL mode and horizontal vane.
(2)Vane position:
Horizontal →Downward A →Downward B →Downward C→Downward D→Swing→Auto
(3)Restriction of the downward vane setting
When setting the downward vane A, B, C or D in [Low] of the fan speed notch,
the vane changes to horizontal position after 1 hour have passed.
3. Vane
(up/down vane change)
· "ONLY 1 Hr"
appears on the
wired remote
controller.

10
Control modes Control details
1-1. Thermoregulating function (Function to prevent restarting for 3 minutes)
Setting the Dry thermo by the thermoregulating signal and the room
temperature (TH21).
Dry thermo ON Room temperature desired temperature + 2°F
Dry thermo OFF Room temperature desired temperature
1-2. Freeze prevention control
No control function
Indoor fan operation controlled depending on the compressor conditions.
1. Thermoregulating
function
Remarks
Room
temperature
3 min. passed since starting operation
Thermoregulating signal
Room temperature (T1)
Dry thermo
ON
time (min)
Dry thermo
OFF
time (min)
Less than 64°F
Over 64°F
ON
OFF
T1 83°F
83°F > T1 79°F
79°F > T1 75°F
75°F > T1
Unconditional
93
73
53
33
10
3
Dry thermo OFF
2. Fan
Note: Remote controller setting is not acceptable.
Dry thermo Fan speed notch
Excluding the following
Room temp. < 64°F
ON
OFF
[Low]
[Low]
Stop
3. Vane
(up/down vane change)
Same control as COOL operation
PAR-21MAA
ON/OFF
FILTER
CHECK
OPERATION
CLEAR
TEST
TEMP.
MENU
BACK DAY
MONITOR/SET
CLOCK
ON/OFF
ûF ûC
ûF ûC
ERROR CODE
AFTER
TIMER
TIME SUN MON TUE WED THU FRI SAT
ON
OFF
Hr
AFTER
FILTER
FUNCTION
ONLY1Hr.
WEEKLY
SIMPLE
AUTO OFF
6-2. DRY OPERATION
<How to operate>
Press POWER ON/OFF button.
Press the operation MODE button to display DRY.
Press the TEMP. button to set the desired temperature.
NOTE: The set temperature changes 2°F when the or button is
pressed one time. Dry 67 to 87°F