background image

Difference between room
temperature and set temperature
during operation.

1deg. 1.7deg.

2deg.

4deg.

13

— HEAT mode of “I FEEL CONTROL” —

1. Indoor fan speed control

(1) In AUTO the fan speed is as follows.

Set temperature minus room temperature: 2 degrees or more················································· Hi
Set temperature minus room temperature: Between 1 and 2 degrees ····································· Me
Set temperature minus room temperature: less than 1 degree················································· Lo

(2) Cold air prevention control

The fan runs at set speed when the indoor coil thermistor RT12 temperature exceeds 22°C. The fan operates at VLo
when the temperature of indoor coil thermistor RT12 is below 18°C. But the fan stops when the indoor fan operates at
VLo and the room temperature is 15°C or less.
NOTE : At initial in hysteresis this control works.

(3) Warm air control.

When compressor starts in heating operation or after defrosting, the fan changes the speed due to 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 ························Lo
2 minutes to 4 minutes···················Me
4 minutes or more ··························Hi
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 VLo.
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 at set speed until the indoor coil thermistor RT12 reads 22°C or more.

Initial temperature difference

Fan speed

Released

Cold Air Prevention

18

:

22

:

Fan speed 
Set speed
VLo or stop

High pressure protection

Released

56

:

60

:

ON

Outdoor fan 

OFF

2. High pressure protection

During heating operation, the outdoor fan motor is controlled by the temperature of indoor coil thermistor RT12 for excess
rise protection of compressor discharge pressure.
Outdoor fan OFF : 60°C 
Outdoor fan ON : 56°C 

High pressure protection chart
Example
Indoor coil thermistor

RT12 temperature

60˚C

56˚C

Outdoor fan motor

Outdoor fan motor
turn OFF

Outdoor fan motor
turn ON

ON

ON

OFF

OFF

NOTE 1 During high pressure protection and for 4 minutes and 15 seconds after high pressure protection, defrosting of 

outdoor heat exchanger is not detected by the defrost thermistor RT61.

NOTE 2 When connected to MXZ-32NV- 

or MXZ-32NV- 

or MXZ-32RV- 

outdoor unit, the indoor unit send the data

for the temperature to the outdoor unit according to the indoor coil temperature.
For the further information, refer to the service manual No.OB185 REVISED EDITION C(Outdoor unit: MXZ-32NV- 

or MXZ-32NV- 

) or the service manual No.OB227 REVISED EDITION-B(Outdoor unit: MXZ-32RV- 

).

E1

E2

E1

E1

E2

E1

Summary of Contents for MSH-18NV

Page 1: ...EMBLY INSTRUCTIONS 30 12 PARTS LIST 34 13 OPTIONAL PARTS 37 Wireless type Model MSH 18NV WH MUH 18NV E4 E4 No OB229 REVISED EDITION A MSH 18NV E4 Refer to the Service Manual OB185 REVISED EDITION C when MSH 18NV is connected with MXZ 32NV or MXZ 32NV as multi system units Refer to the Service Manual OB227 REVISED EDITION B when MSH 18NV is connected with MXZ 32RV as multi system units E1 E4 E2 E1 ...

Page 2: ...2 PART NAMES AND FUNCTIONS 2 INDOOR UNIT When the grille is open Front panel MSH 18NV E4 TECHNICAL CHANGES MSH 18NV became possible the connection to MXZ 32RV as multi system units E1 E4 1 ...

Page 3: ...ttons VANE CONTROL button SWING button OFF TIMER button RESET button Signal transmitting section Operation display section OPERATE STOP ON OFF button OPERATION SELECT button FAN SPEED CONTROL button SLEEP button ON TIMER button CLOCK SET button HR button MIN button TIMER SET button MSH 18NV E4 REMOTE CONTROLLER ...

Page 4: ...dB rpm rpm kg cc k k k MSH 18NV E4 Single phase 220 240V 50Hz INDOOR 756 OUTDOOR 2142 2244 15 52 58 INDOOR 0 25 OUTDOOR 0 39 PH 36VPET 1600 C R1 03 C S2 04 RA4V27 EA or EF WHT BLK183 8 BLK RED250 5 RA6V50 OF or OG WHT BLK116 4 BLK RED111 0 1 015 320 190 850 605 290 14 54 5 42 52 1 180 810 845 4 1 1 65 900 MS32N1 10 10 33 18 Cooling 5 1 2 5 9 4 9 2 2 030 2 120 98 96 8 76 8 56 2 51 2 41 Heating 5 4 ...

Page 5: ...e 12 0 43m Insulation 50 O D 28 I D Insulation 28 Drain hose 16 Air out Air in If the right left sides or back side is vacant the front has only to be 50cm unobstructed If the front or right left sides are vacant the top has only to be 10cm unobstructed Drainage 3holes 33 Air out Air in Air in Service panel Liquid refrigerant pipe joint Refregerant pipe flared 6 35 Gas refregerant pipe joint Refre...

Page 6: ... RED WHT BLU BLU RED BLK CN730 C65 DEICER P C BOARD RT61 F61 IC881 X62 CN711 BLK TRANS TAB20 BLK R C C1 FROM INDOOR UNIT CONNECTING GRN YLW 12VDC TB 220 240V N 2 3 4 1 4 3 2 1 BLK BLK CN661 NO NR61 S 3 2 NAME NAME NAME SYMBOL C1 C65 DSAR F61 IC881 SYMBOL TB X62 21S4 52C SYMBOL MC MF NR61 RT61 SR61 COMPRESSOR CAPACITOR OUTDOOR FAN CAPACITOR SURGE ABSORBER FUSE 2A DC DC CONVERTER COMPRESSOR INNER TH...

Page 7: ...ant flow in cooling Refrigerant flow in heating with heat insulator Strainer Distributor Reversing valve 4 way valve Model Piping size O D mm Length of connecting pipe m Refrigerant piping Max length m A 15 Indoor unit Gas 0 43 Liquid 0 5 Gas 15 88 Liquid 6 35 Outdoor unit Gas 0 Liquid 0 MSH 18NV E4 Indoor unit wMax Height difference 5m A Refrigerant Piping Max Length w Height difference should be...

Page 8: ...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 intake as shown in the figure and at least 2 sets of wet and dry bulb thermometers to the indoor air outle...

Page 9: ...onal system of units SI unit system The conversion factor is 1 MPa G 10 2 kgf f f G 15 20 50 25 60 30 70 35 0 3 0 4 0 5 0 6 0 7 18 32 220V 240V 7 6 5 4 3 15 20 50 25 60 30 70 35 6 7 8 9 10 11 18 32 220V 240V MUH 18NV E4 MUH 18NV E4 Outdoor low pressure Ambient temperature C Ambient humidity Ambient temperature C Ambient humidity Outdoor unit current A kgf F G MPa G HEAT operation Condition indoor ...

Page 10: ...ate Indication Operation Indicator Operation Indicator lamp The operation indicator at the right side of the indoor unit indicates the operation state INDOOR UNIT DISPLAY SECTION WIRELESS REMOTE CONTROLLER Example Previous operation COOL mode of I FEEL CONTROL or COOL mode Once the mode is fixed the mode does not change by room temperature afterwards Under the ON TIMER operation mode is determined...

Page 11: ... s preference to heat or cool So this is called Fuzzy control and works only in I FEEL CONTROL mode 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 4 The initial set temperature is decided by the initial room temperature 1 Indoor fan speed control Indoor fan operates at the set ...

Page 12: ...e operation of the compressor and indoor outdoor fan Compressor operates by room temperature control and time control Set temperature is controlled to fall 2 C from initial room temperature Indoor fan and outdoor fan operate in the same cycle as the compressor When the room temperature is 23 C or over When the thermostat is ON the compressor repeats 8 minutes ON and 3 minutes OFF When the thermost...

Page 13: ... 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 VLo 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 at set speed until the indoor coil thermistor RT12 reads 22 C or more Initial tem...

Page 14: ...door vane ON OFF ON OFF ON OFF ON OFF ON OFF Horizontal Set position Max 10 min 30 sec 15 sec 30 sec 5 15 sec NOTE1 3 Defrosting Defrosting of outdoor heat exchanger is controlled by DEICER P C board with detection by the defrost thermistor RT61 1 Starting conditions of defrost When all conditions of a c are satisfied the defrosting operation starts a Under the heat operation the compressor cumula...

Page 15: ...ill not function when the room temperature is 13 C or below 5 When DRY operation functions the fan speed is lower than cool operation 8 4 HEAT OPERATION 1 Press OPERATE STOP ON OFF button Operation Indicator lamp of the indoor unit turns on with a beep tone 2 Select HEAT mode with the OPERATION SELECT button 3 Press TEMPERATURES button TOO WARM or TOO COOL button to select the desired temperature ...

Page 16: ...or lock up protection When the rotational frequency feedback signal has not output for 12 seconds or when the microprocessor cannot detect the signal for 12 seconds the fan motor is regarded locked up Then the electric current to the fan motor is shut off 3 minutes later the electric current is applied to the fan motor again During the fan motor lock up the Operation Indicator lamp flashes on and ...

Page 17: ...Set position Indoor coil thermistor RT12 temperature NOTE At initial in hysteresis this control works 8 8 TIMER OPERATION 1 How to set the timer 1 Press OPERATE STOP ON OFF button to start the air conditioner 2 Check that the current time is set correctly NOTE Timer operation will not work without setting the current time Initially AM0 00 blinks at the current time display of TIME MONITOR so set t...

Page 18: ...minutes of operation is the test run operation This operation is for servicing The indoor fan runs at high notch and the system is in continuous operation The thermostat is ON After 30 minutes of test run operation the system shifts to EMERGENCY COOL HEAT MODE with a set temperature of 24 C The fan shifts to Me notch This operation continues until the EMERGENCY OPERATION switch is pressed again or...

Page 19: ...et time can be shortened by short circuit of JPG and JPS the electronic control P C board The time will be shortened as follows 3 minutes delay 3 minutes 3 seconds AUTO START 1 hour 1 minute AUTO STOP 1 hour 1 minute Short the connector during the timer mode The P C board has the print J1 and J2 Jumper wires are mounted to each J1 and J2 Cut J1 and J2 according to the number of indoor unit as show...

Page 20: ...After the power is restored the unit restarts automatically according to the memory However it takes at least 3 minutes for the compressor to start running NOTE The operation settings are memorized when 10 seconds have passed after the remote controller was operated If main power is turned off or a power failure occurs while AUTO START STOP timer is active the timer setting is cancelled If the uni...

Page 21: ...the remote controller can not be repaired only by the battery replacement To operate the remote controller normally discharge the remote controller in the following order This remote controller has the RESET button After refilling new batteries press the RESET button with tip end of ball point pen or the like and then use the remote controller Lead wiring Housing point RESET button MSH 18NV E4 NOT...

Page 22: ...nic control P C board on page 26 Cause indoor outdoor unit connecting Trouble of mis wiring Trouble of the serial signal Cause Indoor unit 2 time Room temperature Indoo r coil thermistor trouble 3 time Indoor fan motor trouble Refer to How to check mis wiring and signal error when outdoor unit doesn t work on page 27 1 6 time flash 2 5 second OFF Cause outdoor unit 6 time check the defrost thermis...

Page 23: ...k indoor electronic control P C board Disconnect connector CN211 and then check connector CN121 to make sure rotational frequency feedback signal of 1 5V or over exists Check indoor electronic control P C board Check indoor fan motor Reconnect connector Check outdoor DEICER P C board Check resistance of thermistor Reconnect connector 2 3 5 Outdoor power system 5 time flash 2 5 second OFF Outdoor u...

Page 24: ... the resistance between the terminals with a tester Part temperature10 C 30 C Figure P BLK R MAIN AUX RED S C WHT Normal 8k 20k Abnormal Opened or short circuited Normal 0 90 1 11 1 79 2 20 C R C S Normal Abnormal Opened or short circuited 176 192 240 261 WHT BLK BLK RED BRN YLW YLW GRY Normal 4 5 5 5V Abnormal Remain 0V or 5V When fan revolved one time 0V 5V 0V Approx Normal Abnormal Opened or sh...

Page 25: ...ltage between receiver P C board connector No 2 and No 1 when the remote controller button is pressed Is the voltage approx 4V DC Replace the indoor electronic control P C board Replace the receiver P C board Replace the remote controller Re install the unit away from lights Attach a filter on receiving part Yes 0 or No others Yes No Yes No Switch on the remote controller Is LCD display on the the...

Page 26: ...se and varistor in any case Replace the fan motor Replace the indoor electronic control P C board Is winding resistance of fan motor 0 Is winding resistance of vane motor 0 No Yes Replace the vane motor No Yes Yes Is varistor NR11 burnt Replace the varistor Yes Turn OFF the power supply Remove indoor fan motor connector CN211 and vane motor connector CN151 from the indoor electronic control P C bo...

Page 27: ...2 N 2 Is there 5V DC between J8 J9 on the outdoor DEICER P C board 2 Is there 10V DC between both ends of R601 2 By tester the stylus is between 5 10V Replace the outdoor DEICER P C board Rectify in out connecting wire Check and rectify the fuse and the varistor on the outdoor DEICER P C board Rectify in out connecting wire Replace the indoor electronic control P C board 1 Short circuit of JPG and...

Page 28: ... Fan motor power supply Fuse 250V AC 3 15A Power supply input 220 240V AC 5V DC Indoor coil thermistor RT12 JPS Time short mode point JPG Emergency operation switch 12V DC P C board 0 20V DC R132 Room temperature thermistor RT11 C144 C144 JPG JP41 ...

Page 29: ... fan motor 220 240V AC Reversing valve coil 220 240V AC R601 5 10V DC INPUT 220 240V AC Defrost thermistor RT61 Fuse 2A 250V Defrost interval time short pin J9 J8 5V DC Jumper wire for change in defrost setting JPC JPE See page 19 52C 12V DC 12V DC ...

Page 30: ...el down to your side slightly and unhook the catches at the top 2 Removing the electronic control P C board 1 Remove the front panel Refer to 1 2 Remove the electrical cover 3 Remove the screw remove the terminal cover 4 Remove the screw of terminal block 5 Unhook the catch of the lamp holder 6 Remove the receiver holder 7 Disconnect the connectors and the lead wire from 52C contactor on the elect...

Page 31: ...w fan 1 Remove the front panel 2 Remove the electrical box 3 Unhook the catch on the both sides of the nozzle assembly 4 Remove the nozzle assembly 5 Remove the screws of the bearing support 6 Remove the screw of the heat exchanger unhook the catch 7 Lifting the heat exchanger remove the bearing support 8 Remove the motor support 9 Loose the screw fixing the line flow fan remove the line flow fan ...

Page 32: ...emoving the deicer P C board 1 Remove the service panel and the cabinet 2 Disconnect all the connectors and the terminals on the deicer P C board 3 Remove the deicer P C board 11 2 MUH 18NV OUTDOOR UNIT E4 Photo 1 Photo 3 Photo 2 Black lead wire White lead wire Screws Screws Service panel Terminal block Screws Compressor capacitor Red lead wire Deicer P C board ...

Page 33: ...the soundproof felt 3 Remove the terminal cover on the compressor 4 Remove the electrical assembly Refer to 2 5 Release gas from the refrigerant circuit 6 Disconnect the welded part of the discharge pipe 7 Disconnect the welded part of the suction pipe 8 Remove nuts fixing the compressor 9 Remove the compressor Photo 5 Terminal cover Compressor Discharge pipe Suction pipe Compressor nuts Photo 4 p...

Page 34: ...00 E02 138 010 E02 143 234 E02 141 100 E02 141 970 E02 143 067 E02 168 007 Part number that is circled is not shown in the illustration 5 3 1 2 6 4 MSH 18NV WH 12 1 INDOOR UNIT STRUCTURAL PARTS E4 E02 141 620 E02 138 667 E02 138 666 8 9 10 INDOOR HEAT EXCHANGER UNION LIQUID UNION GAS 6 35 15 88 1 1 1 9 10 8 12 2 INDOOR UNIT HEAT EXCHANGER 12 1 INDOOR UNIT STRUCTURAL PARTS 12 2 INDOOR UNIT HEAT EXC...

Page 35: ...OOR COIL THERMISTOR ROOM TEMPERATURE THERMISTOR FUSE THERMAL FUSE SURGE ABSORBER Part No Symbol in Wiring Diagram Part Name MF MV TB NR11 RT12 RT11 F11 F12 DSAR Q ty unit MSH 18NV 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 WH E4 RA4V27 2PCS SET AUTO RESTART 3 15A 93 Remarks Part number that are circled are not shown in the illustration 8 10 15 11 3 1 2 9 4 6 5 7 14 12 MSH 18NV WH 12 3 INDOOR UNIT FUN...

Page 36: ...TDOOR HEAT EXCHANGER MOTOR SUPPORT COMPRESSOR BASE OUTDOOR FAN MOTOR PROPELLER FAN COMPRESSOR CAPACITOR CONTACTOR TERMINAL BLOCK CAPILLARY TUBE CAPILLARY TUBE COMPRESSOR RUBBER SET STOP VALVE LIQUID STOP VALVE GAS BACK PANEL FUSE DEICER P C BOARD DEFROST THERMISTOR REVERSING VALVE COIL REVERSING VALVE SURGE ABSORBER CHECK VALVE 1 1 1 1 1 1 1 1 1 1 1 1 2 1 4 1 1 1 1 1 1 1 1 1 1 MC MF C1 52C TB F61 ...

Page 37: ... and hydrogen sulphide emitted from tobacco and odor of pets Clean DEODORIZING FILTER every two weeks If the filter is particularly dirty clean the filter more often For cleaning soak the filter in warm water for a while and then wash and rinse it Dry the filter in the shade thoroughly When the filter color is still dark even after cleaning replace the filter with a new one Replace the filter at l...

Page 38: ...nge without notice C C Copyright 1999 MITSUBISHI ELECTRIC ENGINEERING CO LTD Issued in Apr 1999 No OB229 REVISED EDITION A 294 Issued in Jan 1999 No OB229 305 Printed in Japan HEAD OFFICE MITSUBISHI DENKI BLDG MARUNOUCHI TOKYO100 8310 TELEX J24532 CABLE MELCO TOKYO ...

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