Mitsubishi MCFH-24NV-EB, MUCFH-24NV-EB Service Manual

Note:

●Refer to OB196 REVISED EDITION-A for the details of

MCFH-24NV- EA and MUCFH-24NV- EA .

FLOOR AND CEILING TYPE AIR CONDITIONERS

No. OB266

SERVICE MANUAL

Wireless type Models

MCFH-24NV-

EB (WH) ·MUCFH-24NVEB-

(When installed on the floor)

(When installed on the ceiling)

CONTENTS

1.TECHNICAL CHANGES ··················

2.PART NAMES AND FUNCTIONS··············

3.SPECIFICATION·····················

4.OUTLINES AND DIMENSIONS ···············

5.WIRING DIAGRAM ····················

6.REFRIGERANT SYSTEM DIAGRAM ············

7.PERFORMANCE CURVES ················

8.MICROPROCESSOR CONTROL ··············

9.SERVICE FUNCTIONS ··················

10.TROUBLESHOOTING···················

11.DISASSEMBLY INSTRUCTIONS··············

12.PARTS LIST·······················

13.OPTIONAL PARTS····················

1 TECHNICAL CHANGES

MCFH-24NV - EA →MCFH-24NV - EB

1. Only model name has changed.

MUCFH-24NV - EA →MUCFH-24NV - EB

1.Ball valve has changed to stop valve.

2.Deicer P.C. board has changed.

2 PART NAMES AND FUNCTIONS

MCFH-24NV - EB

INDOOR UNIT

(When installed on the floor)

Operation section

(When the air inlet grille is opened.)

Emergency operation switch

ACCESSORIES

	Item	Q'ty
	Installation plate	2
	Unit fixing screw 5 o 12mm	2
	Wireless remote controller	1
	Remote controller mounting hardware	1
	Fixing screw for 3.5 o 16mm (Black)	2
	Battery (AAA) for remote controller	2
	Drain hose	1
	Drain pipe cover	1
	Knockout cover	1
	Screw for 4 o 10mm	2

2

Vertical vanes

Horizontal vane

Operation indicator lamp

Receiving section

Front panel

Air cleaning filter (whilte bellows type)(option)

Air inlet

Air filter

Deodorizing filter (gray sponge type)(option)

Remote controller

(When installed on the ceiling)

MUCFH-24NV - EB

OUTDOOR UNIT

Air outlet

Air inlet

MCFH-24NV - EB

g

CLOCK

RESET

3

3 SPECIFICATION

Indoor model

Function

	Capacity	Power supply
		Capacity	kW
		Air flow(High)	K /h
		Dehumidification	L/h
		Power outlet	A
	Electrical data	Running current	A
		Power input	W
		Auxiliary heater	A(kW)
		Power factor	%
		Starting current	A
		Fan motor current	A
	Coefficient of performance(C.O.P)
	Fan motor	Model
		Winding
		resistance(at20:)	"
		Dimensions WOHOD	mm
		Weight	kg
	Special remarks	Air direction
		Sound level (High)	dB
		Fan speed (High)	rpm
		Fan speed regulator
		Thermistor RT11(at25:)	k"
		Thermistor RT12(at25:)	k"
		Outdoor model
	Capacity Air flow (High)		K /h
	Electrical data	Fan motor current	A
		Compressor motor current	A
	Compressor	Model
		Output	W
		Winding	"
		resistance(at20:)
	Fan motor	Model
		Winding	"
		resistance(at20:)
		Dimensions WOHOD	mm
		Weight	kg
		Sound level(High)	dB
		Fan speed(High)	rpm
		Fan speed regulator
	Special remarks	Refrigerant filling	kg
		capacity(R22)
		Refrigerating oil (Model)	cc
		Thermistor RT61(at0:)	k"
		Thermistor RT63(at0:)	k"

NOTE:Test conditions are based on ISO 5151 Cooling : Indoor DB27°C WB19°C

Outdoor DB35°C WB(24°C)

	MCFH-24NV- EB
Cooling	Heating
Single phase 220 - 240 V, 50Hz
6.0	6.2
	840
3.1	-
	25
12.5-11.7	11.7-11.3
2,720-2,750	2,540-2,650
-	-
99-98	98-98

59

0.36

2.21-2.18 2.44-2.34

RB4V36-AB

WHT-BLK 82.9 BLK-YLW 65.6

YLW-BLU 36.0 BLUBRN 27.0

BRN-RED 13.7

1,100 650 180

26

5

48-48

1,310-1,330

3

10

10

MUCFH-24NV- EB

2,640-2,760

11.56-10.76	10.76-10.36
0.58	0.58
NH-47VMDT
2,200
C-R 0.96	C-S 2.07

RA6V85-AA

WHT-BLK 62.7 BLK-YLW 30.2

YLW-RED 62.9

870 850 295

72

53

720-750

2

2.40

1.2(MS32N1)

33.18

33.18

Heating : Indoor DB20°C WB15°C

Outdoor DB 7°C WB 6°C

4

4	OUTLINES AND DIMENSIONS
MCFH-24NV - EB				Unit: mm
INDOOR UNIT				114
			16
	80.8	906		112.8
	(When installed on the floor)
50cm or more	50cm or more

50cm	(When installed on the ceiling)
	or
	more

moreor100cm

50cm or more

650	616.5		93
			77
	170
	42.5		113	143
		1100		180
		17.5	Gas line
	56		{15.88
			Liquid line
	160		{9.52

5

6

	185				185
	(7-9/32)			500(19-11/16)	(7-9/32)
Outdoor Unit-Necessary surrounding clearance
(Concentrated installation)	The upper side must be open.			Air intake

		Air intake
100	10	200
		Air outlet
	For 10 units or less	1000

17
39.5 27.5 330(13)	362(14-1/4)
15

Outdoor Unit-Necessary surrounding clearance

200

Note:Allow adequate 10 10 upper clearance

Front opening

500	150
10
Service space
500

EB - 24NV-MUCFH

870(34-1/4)

		7 295(11-5/8) 24(1)	302
Handle		Outlet guide
for moving
		installation hole
	Side air intake
	Rear fresh
	air intake	Handle for moving
			524
		441	403
138			179

Terminal block for indoor and outdoor unit connection

Handle for moving

Service panel

	553	850(33-7/16)	Refrigerant-pipe flared
337	352		connection [15.88 5/8F
			Refrigerant-pipe flared
			connection [9.52 3/8F

45

95	23	33	40	524	60			Knock out hole		60	53
	Rear piping hole							for front piping		120	Knock out holes for
								(refrigerant,drainage			power line 2-[27
				2-12o23 Oval holes				and wiring)
					104			Knock out hole
				(standard bolt M10)
					33	42	45
								for right piping
			Drain hole					(refrigerant,drainage		R20
								and wiring)	R20
					Bottom
										80	max.25
					piping hole

Drain hole	2-U-shaped		R6		Standard bolt length
	notched
					65
	holes			17
		12			Front right piping holes-
					detail figures

mm Unit:

5 WIRING DIAGRAM

INDOOR UNIT		MODEL MCFH-24NV- EB
	TB
POWER		GRN/YLW
SUPPLY	N
CORD		BLU
~/N									CN
220-240V	L					HIC1			112
50Hz		WHT
									LDCOM
					3	3 52C	NR11	C11
									LDC12
						4			LDC11
					2
	N BLU				1			SR144 LDFH
TO OUTDOOR				CN201		TRANS		SR143 LDFM
UNIT	2	WHT			BRN	F11		SR142 LDFL
CONNECTING			CN	CN	CN			SR141 LDFVL
	3
		RED	101	113	151 ELECTRONIC CONTROL P.C BOARD
GRN/YLW			5		6
				4	6
			5		MV
		REMOTE	DISP/	SW/THERMO
			RECEIVER	P.C.BOARD
		CONTROLLER
			P.C.BOARD

2	2		RT12
	WHT	1	WHT
	ORN	2	ORN
	RED	3	RED
	YLWBLK	4	YLWBLK MF
	BLU	5	BLU
		6
	BRN 7		BRN
		8	GRN/YLW

RT11

SYMBOL	NAME	SYMBOL	NAME	SYMBOL	NAME
C11	FAN MOTOR CAPACITOR	MV	VANE MOTOR	SR142~SR144	SOLID STATE RELAY
F11	FUSE (3.15A)	NR11	VARISTOR	TB	TERMINAL BLOCK
HIC1	DC/DC CONVERTER	RT11	ROOM TEMP. THERMISTOR	52C	CONTACTOR
MF	FAN MOTOR(INNER PROTECTOR)	RT12	COIL TEMP. THERMISTOR
NOTE:1. About the outdoor side electric wiring, refer to the outdoor unit electric wiring diagram for servicing.					VG79B063H01

2.Use copper conductors only.(For field wiring)

3.Symbols below indicate;

:Terminal block, : Connector

OUTDOOR UNIT

CONNECTING

TO INDOOR UNIT

MODEL MUCFH-24NV- EB

RT61

RT63

MF

WHT

YLW

BLK

ORN

RED

6

5

4

3

2

1 RED

YLW

BLK

WHT

ORN

C2

CN661

CN662

1

2

3 CN711

CN721

SR62

1

X62

2

21S4

SR61

COM

NO 3

X62

X52

TAB52

COM

NO

F61

X52

T61

NR61

1

TB

3

DEICER PC BOARD CN730 5

RED

BLU WHT BLU

3

2

N

GRN/YLW

WHT

DSAR

WHT 1

2

WHT

52C

C1

RED S

BLU

BLK MC C

BLU

A2 52C A1

R

SYMBOL	NAME	SYMBOL	NAME	SYMBOL	NAME
C1	COMPRESSOR CAPACITOR	NR61	VARISTOR	T61	TRANSFORMER
C2	FAN MOTOR CAPACITOR	RT61	DEFROST TEMPERATURE THERMISTOR	X52	CONTACTOR
DSAR	SURGE ABSORBER	RT63	AMBIENT TEMPERATURE THERMISTOR	X62	R.V. COIL RELAY
F61	FUSE(3.15A)	SR61	SOLID STATE RELAY	21S4	R.V. COIL
MC	COMPRESSOR (INNER PROTECTOR)	SR62	SOLID STATE RELAY	52	COMPRESSOR CONTACTOR
MF	FAN MOTOR (INNER PROTECTOR)	TB	TERMINAL BLOCK

NOTES: 1.Use copper conductors only (For field wiring).		SG79J186H01
2.Since the indoor and outdoor unit connecting wires have polarity, connect them according to the numbers (3,2,N).
3.Symbols below indicate.
:Terminal block,	:Connector
	7

6

REFRIGERANT SYSTEM DIAGRAM

MCFH-24NV- EB

MUCFH-24NV- EB

INDOOR UNIT

Refrigerant pipe [15.88

4-way valve

OUTDOOR UNIT

(Option)

(with heat insulator)

Muffler

Indoor

Stop valve

heat

Distributor

(with service port)

Strainer

Outdoor

exchanger

Flared connection

heat

exchanger

Coil temperature

thermistor

RT12

Compressor

Accumulator

Discharge pressure

Capillary tube

Check

regurator open

Room temperature

Flared connection

[3.0o[1.6o350

23.5Of/F

thermistor

valve

RT11

Capillary tube [3.0o[2.0o350

Strainer

Refrigerant pipe

Stop valve

Capillary tube

(Option) [9.52

Check

[4.0o[2.4o200

(with heat insulator)

Refrigerant flow in cooling

valve

Refrigerant flow in heating

MAX. REFRIGERANT PIPING LENGTH & MAX. HEIGHT DIFFERENCE

Models

Refrigerant piping MAX. length : m

Piping size O.D. : mm

A

Gas

Liquid

MCFH-24NV - EB

15

{15.88

{9.52

wIt does not matter which unit is higher.

Height difference *	5m
Max.

A:Refrigerant piping Max.length

15m

ADDITIONAL REFRIGERANT CHARGE (R22 : g)

If pipe length exceeds 7m, additional refrigerant (R22) charge is required

	Models	Outdoor unit:precharged		Refrigerant piping length (one way)
		(up to 7m)	7m	8m	9m	10m	11m	12m	13m	14m	15m
	MCFH-24NV - EB	2,400	0	65	130	195	260	325	390	455	520

Calculation : og=65g/mo(Refrigerant piping length minus 7m)

8

7 PERFORMANCE CURVES

The standard data contained in these specifications apply only to the operation of the air conditioner under normal condition. Operating conditions vary according to the areas where these units are installed. The following information has been provided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.

(1)GUARANTEED VOLTAGE

198~264V, 50Hz

(2)AIR FLOW

Air flow should be set at MAX..

(3) MAIN READINGS

COOLING		HEATING
(1)	Indoor intake air wet-bulb temperature : ˚CWB	(1)	Indoor intake air dry-bulb temperature : ˚CDB
(2)	Indoor outlet air wet-bulb temperature : ˚CWB	(2)	Indoor outlet air dry-bulb temperature : ˚CDB
(3)	Outdoor intake air dry-bulb temperature : ˚CDB	(3)	Outdoor intake air wet-bulb temperature : ˚CWB
(4) Total input : W		(4) Total input : W

Indoor air wet/dry-bulb temperature difference on the left side of the chart on page 16 shows the difference between the indoor intake air wet/dry-bulb temperature and the indoor outlet air wet/dry-bulb temperature for your reference at service.

How to measure the indoor air wet-bulb/dry-bulb temperature difference

1.Attach at least 2 sets of wet-and-dry-bulb thermometers to the indoor air inlet as shown in the figure, and at least 2 sets of wet- and-dry-bulb thermometers to the indoor air outlet. The thermometers must be attached to the position where air speed is high.

2.Attach at least 2 sets of wet-and-dry-bulb thermometers to the outdoor air inlet.

Cover the thermometers to prevent direct rays of the sun.

3.Check that the air filter is cleaned.

4.Open windows and doors of the room.

5.Press the EMERGENCY OPERATION switch once(twice) to start the EMERGENCY COOL(HEAT) MODE.

6.When system stabilizes after more than 15 minutes, measure temperature and take an average temperature.

7.10 minutes later, measure temperature again and check that the temperature does not change.

INDOOR UNIT	Wet-and dry-bulb	OUTDOOR UNIT
Air out	thermometers

Air in

Wet-and dry-bulb thermometers BACK VIEW

FRONT VIEW

14.7

13.4

12.1

10.9

9.7

8.5

MCFH-24NV- EB

29.0

26.7

24.5

22.3

20.0

17.8

15.6

13.4

MCFH-24NV- EB

9

OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT

COOL operation

1 Both indoor and outdoor units are under the same temperature/humidity condition.

Dry Bulb temperature (˚C)	Relative humidity (%)
20	50
25	60
30	70

2 Air flow should be set at MAX..

3 The unit of pressure has been changed to MPa on the international system of units(SI unit system). The converted score against the traditional unit system can be gotten according to the formula below.

1(MPa • G) =10.2(kgf/f • G)

MUCFH-24NV- EB

(kgf/F• G) (MPa•G)
	7				0.7
pressure	6					0.6
	5							0.5
low											220-240V
	4						0.4
Outdoor
	3	0.3
	2			0.2
		15 18 20									25		30 32 35(:)
		50									60		70		(%)

Outdoor unit current (A)

13

220V

12

240V

11

10

9

8

7

15 18 20	25	30	32 35(:)
50	60	70	(%)

Ambient temperature (:)	Ambient temperature (:)
Ambient humidity (%)	Ambient humidity (%)

HEAT operation

Condition Indoor : Dry bulb temerature 20.0:	Outdoor : Dry bulb temerature 7, 15, 21:
Wet bulb temerature 14.5:	Wet bulb temerature 6, 13, 15.3:

Outdoor unit current (A)

	13
		220V
		240V

11

9

7

0 2 5

10

15

20

25(:)

Ambient temperature (:)

10

Example

Previous operation

COOL mode of

“I FEEL CONTROL” or COOL mode

8 MICROPROCESSOR CONTROL

MCFH-24NV - EB MUCFH-24NV - EB

WIRELESS REMOTE CONTROLLER

g

CLOCK

RESET

INDOOR UNIT DISPLAY SECTION

OPERATION INDICATOR lamp

The operation indicator at the right side of the indoor unit indicates the operation state.

Operation Indicator	lighted
	not lighted

		Difference
		between set
Indication	Operation state	temperatuer
		and room
		temperature
	This shows that the air
	conditioner is operating
	to reach the target temp-	Approx. 2 :
	erature.	or more
	Please wait until the
	target temperature is
	obtained.
	This shows that the
	room temperature is	Approx. 2 :
	approaching the target	or less
	temperature.

Once the operation mode are set, the same operation mode can be repeated by simply turning the OPERATE/STOP button ON.

Indoor unit receives the signal with a beep tone.

When the system turns off, 3-minute time delay will operate to protect system from overload and compressor will not restart for 3 minutes.

8-1. “I FEEL CONTROL”( ) OPERATION

(1)Press OPERATE/STOP button on the remote controller. OPERATION INDICATOR lamp of the indoor unit will turn on with a beep tone.

(2)Press OPERATION SELECT button to set “I FEEL CONTROL”( ). Then a beep tone is heard.

(3)The operation mode is determined by the initial room temperature at start-up of the operation.

	Initial room temperature	mode
	more than 25°C	COOL mode of
		“I FEEL CONTROL”
	23.0°C to 25°C	DRY mode of
		“I FEEL CONTROL”
	less than 23°C	HEAT mode of
		“I FEEL CONTROL”

●Once the mode is fixed, the mode will not change by room temperature afterwards.

●Under the ON-TIMER() timer operation, mode is

determined according to the room temperature as the operation starts.

●When the system is stopped with the OPERATE/ STOP button on the remote controller, and restarted within 2 hours in “I FEEL CONTROL”( ) mode, the system operates in previous mode automatically regardless of the room temperature.

Example
Previous operation			Restart
COOL mode of			COOL mode of
“I FEEL CONTROL”			“I FEEL CONTROL”
or COOL mode

● When the system is restarted after 2 hours, the operation

mode is determined by the initial room temperature at start-up of the operation. Restart

COOL or DRY or HEAT mode of “I FEEL CONTROL” that is determined by

initial room temperature at start-up of the operation.

11

(4) The initial set temperature is decided by the initial room temperature.

	Model	Initial room temperature	Initial set temperature
		26°C or more	24°C
	COOL mode of			w1
	“I FEEL CONTROL”
		26°C or less	Initial room temperature
			minus 2°C
	DRY mode of	23°C to 25°C	Initial room temperature
	“I FEEL CONTROL”		minus 2°C
	HEAT mode of	23°C or less	26°C
	“I FEEL CONTROL”

w1 After the system restarts by the remote controller, the system operates with the previous set temperature regardless of the initial set temperature.

The set temperature is calculated by the previous set temperature.

(5)TEMPERATURE buttons

In “I FEEL CONTROL” mode, set temperature is decided by the microprocessor based on the room temperature.

In addition, set temperature can be controlled by or TOO WARM or TOO COOL buttons when you feel too warm or too cool. Each pressing the TOO WARM or TOO COOL button ,indoor unit receives the signal a beep tone.

●Fuzzy control

When the TOO COOL or TOO WARM button is pressed, the microprocessor changes the set temperature, considering the room temperature, the frequency of pressing TOO COOL or TOO WARM button and the user’s preference to heat or cold. So this is called “Fuzzy control”, and works only in “I FEEL CONTROL” operation.

In DRY mode of “I FEEL CONTROL”, the set temperature doesn’t change.

▲TOO

COOL … To raise the set temperature 1~2 degrees(°C)

▼ TOO

WARM … To lower the set temperature 1~2 degrees(°C)

12

— COOL mode of “I FEEL CONTROL” —

NOTE : Coil frost prevention during COOL mode of “I FEEL CONTROL”

There are two types of controls in coil frost prevention as follows.

1Temperature control

When the indoor coil thermistor RT12 reads -1°C or below, the coil frost prevention mode starts immediately. However the coil frost prevention will not work for 5 minutes after the compressor starts.

During the coil frost prevention compressor stops and the indoor fan operates at the set speed for 5 minutes. After that, if RT12 still reads below -1°C, this mode is prolonged until the RT12 reads over -1°C.

2Time control

When the three conditions below have been satisfied for 1 hour and 45 minutes, compressor stops for 3 minutes.

a.Compressor has been continuously operating.

b.Indoor fan speed is Low or Med..

c.Room temperature is below 26°C.

When compressor stops ,the accumulated time is cancelled and when compressor restarts, time counting starts from the beginning.

Time counting also stops temporarily when the indoor fan speed becomes High or the room temperature exceeds 26°C. However, when two of the above conditions (b.And c.) are satisfied again time accumulation is resumed.

●Indoor fan operates at the set speed by FAN SPEED CONTROL button. Followings are the fan speed in AUTO.

	Initial temperature difference	Fan speed
	Room temperature minus set temperature : 2 degrees or more·········································High
	Room temperature minus set temperature : 1 degree or more and less than 2 degrees···Med.
	Room temperature minus set temperature : less than 1 degree·········································Low
			1deg.

2deg. 4deg.

1.7deg.

—DRY mode of “I FEEL CONTROL”—

The system for dry operation uses the same refrigerant circuit as the cooling circuit.

The compressor and the indoor fan are controlled by the temperature and the microprocessor.

By such controls, indoor air flow amounts will be reduced in order to lower humidity without much room temperature decrease.

The operation of the compressor and indoor fan is as follows.

1.When the room temperature is 23°C or over:

Compressor operates by temperature control and time control.

1 Set temperature is controlled to fall 2°C above from initial set temperature.

2When the thermostat is ON, the compressor repeats 8 minutes ON and 3 minutes OFF. When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON. Indoor fan and outdoor fan operate in the same cycle as the compressor.

2.When the room temperature is under 23°C.

When the thermostat is ON, the compressor repeats 2 minutes ON and 3 minutes OFF. When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.

13

18°C 22°C

Operation time chart

Example

1st ON

ON

Thermostat

OFF

OFF

ON

ON

ON

Indoor fan

OFF

OFF

OFF

ON

ON

ON

Outdoor fan

OFF

OFF

OFF

compressor

8 min.

3 min.

4 min. 1 min.

NOTE ● Coil frost prevention during DRY mode of “I FEEL CONTROL”

The operation is same as that of coil frost prevention during COOL mode of “I FEEL CONTROL”. However the indoor fan speed becomes the set speed or Low.

— HEAT mode of “I FEEL CONTROL” —

1. Indoor fan speed control
(1)	Followings are the fan speed in AUTO.
	Initial temperature difference	Fan speed
	Room temperature minus set temperature: 2 degrees or more·········································High
	Room temperature minus set temperature: 1 degree or more and less than 2 degrees···Med.
	Room temperature minus set temperature: less than 1 degree·········································Low						2 deg. 4 deg.
(2)	Cold air prevention control		1 deg. 1.7 deg.

The fan runs at set speed when the indoor coil thermistor RT12 temperature exceeds 22°C. The fan operates at Very Low when the temperature is below 18°C. But the fan stops when the indoor fan operates at Very Low and the room temperature is 15°C or less. Released

Cold Air Prevention NOTE : At initial in hysteresis this control works.

(3)New warm air control.

When compressor starts in heating operation or after defrosting, the fan changes the speed with dependence on the indoor coil thermistor RT12 temperature to blow out warm air.

After releasing of cold air prevention, when the indoor coil temperature is 37°C or above, the fan speed shifts to the set speed, and when the fan speed is changed by the remote controller, the fan speed is the set speed.

When the indoor coil temperature is less than 37°C, the fan speed is controlled by time as below. <Time condition> <Indoor fan speed>

less than 2 minutes························Low 2 minutes to 4 minutes···················Med. 4 minutes or more··························High

The upper limit of the fan speed is the set speed.

If the thermostat turns off, this operation changes to flow soft control.

(4)Flow soft control

After the thermostat turns off, the indoor fan operates at Very Low.

NOTE : When the thermostat turns on, the fan operates at the set speed. Due to the cold air prevention control, the fan does not start until the indoor coil thermistor RT12 reads 22°C or more.

14