Mitsubishi Electronics MUY-A15/17/24NA manuale d’uso

SER VICE TECHNICAL GUIDE CONTENTS 1. MS MICROPROCESSOR CONTROL ·················· 4 2. MSZ, MSY MICROPROCESSOR CONTROL ······ 7 3. MXZ MICROPROCESSOR CONTROL ·············· 21 4. MFZ MICROPROCESSOR CONTROL ·············· 35 SPLIT -TYPE AIR CONDITIONERS No. OBT16 REVISED EDITION-G Please void OBT16[...]

2 Revision A: • MXZ-3A30NA- 1 has been added. Revision B: • MXZ-2A20NA- 1 , MXZ-4A36NA, MSZ-FD, MSZ-D and MSY -D have been added. Revision C: • MXZ-2A20NA- 2 has been added. Revision D: • MSZ-GA•NA and MSY -GA•NA have been added. Revision E: • MSZ-FE•NA, MSZ-GE•NA, MSY -GE•NA and MXZ-B•NA have been added. Revision F: • MXZ-2[...]

3 1. MS MICROPROCESSOR CONTROL ·································································································· ················· 4 Indoor unit models Outdoor unit models MS-A09/12W A MU-A09/12W A 1-1. COOL OPERA TION[...]

4 1-1. COOL ( ) OPERA TION 2. Indoor fan speed control Indoor fan operates continuously at the set speed by F AN SPEED CONTROL button regardless of the thermostat's OFF- ON. In AUTO the fan speed is as follows. 1. Thermostat control Thermostat turns ON or OFF by the difference between room temperature and set temperature. 1-2. DR Y ( ) OPERA T[...]

5 1. Thermostat control Thermostat turns ON or OFF by the difference between room temperature and set temperature. 2. Indoor fan speed control Indoor fan operates at the set speed by F AN SPEED CONTROL button. When thermostat OFF (compressor OFF), fan speed becomes V ery Low . In AUTO the fan speed is as follows. 4. Coil frost prevention Coil frost[...]

6 1-3. AUTO V ANE OPERA TION 1. Horizontal vane ECONO COOL ( ) operation (ECONOmical operation) When ECONO COOL button is pressed in COOL mode, set temperature is automatically set 3.6°F (2°C) higher than that in COOL mode. Also the horizontal vane swings in various cycle according to the temperature of indoor heat exchanger (indoor coil thermist[...]

7 2-1. COOL ( ) OPERA TION 2. Indoor fan speed control Indoor fan operates continuously at the set speed by F AN SPEED CONTROL button regardless of the thermostat's OFF- ON. In AUTO the fan speed is as follows. 1. Thermostat control Thermostat turns ON or OFF by the difference between room temperature and set temperature. ON -1.8°F(-1°C) or [...]

8 2-2. DR Y ( ) OPERA TION Set temperature is as shown on the right chart. The system for dry operation uses the same refrigerant circuit as the cooling circuit. The compressor and the indoor fan are controlled by the room tem- perature. By such controls, indoor flow amounts will be reduced in order to lower humidity without much room temperature d[...]

9 (2) Cold air prevention control MSZ-A09/12/15/17 MSZ-FD MSZ-FE MSZ-D MSZ-GE When the compressor is not operating, ( ) if the temperature of room temperature thermistor is less than 66°F (19°C), the fan stops. ( ) if the temperature of room temperature thermistor is 66°F (19°C) or more and ( ) if the temperature of indoor coil thermistor is le[...]

10 set position set speed set position set speed Indoor fan Compressor normal Outdoor fan R.V . coil (21S4) OFF (COOL) OFF Maximum frequency horizontal Horizontal vane V ery Low (temperature of indoor coil thermistor > 64 °F) 30 seconds 30 seconds 30 seconds 40 seconds 5 seconds 5 seconds 40 seconds OFF (39°C) (18°C) OFF OFF ON (HEA T) ON ON [...]

11 (2) Mode change In case of the following conditions, the operation mode is changed. COOL mode changes to HEA T mode when 15 minutes have passed with the room temperature 2 - 4°F (1 - 2°C) below the set temperature. HEA T mode changes to COOL mode when 15 minutes have passed with the room temperature 2 - 4°F (1 - 2°C) above the set temperatur[...]

12 <SWING operation> In swing operation of ECONO COOL operation mode, the initial air flow direction is adjusted to “Horizontal”. According to the temperature of indoor coil thermistor RT12 at starting of this operation, next downward blow time is decided. Then when the downward blow has been finished, next horizontal blow time is decided[...]

13 MUZ-A24 MUY -A24 MUZ-D MUY -D MUZ-FE18 MUZ-GA MUY -GA MUZ-GE24 MUY -GE24 POWER SUPPL Y NOISE FIL TER CIRCUIT RESISTOR RELA Y SMOOTHING CAP ACITOR CURRENT TRANSFORMER COMPRESSOR REACTOR P W V U N IPM PFC U W MS 3~ V + Function of main parts NAME FUNCTION INTELLIGENT POWER MODULE (IPM) It supplies 3-phase AC power to compressor . SMOOTHING CAP ACI[...]

14 3. Purpose of P AM adoption P AM (Pulse Amplitude Modulation) has been adopted for the ef fi ciency improvement and the adaptation to IEC harmonic cur- rent emission standard Outline of simple partial switching method In conventional inverter models, DIODE MODULE recti fi es AC voltage to DC voltage, SMOOTHING CAP ACITOR makes its DC waveform [...]

15 4. Intelligent power module IPM consists of the following components · IGBT (x6): Converts DC waveform to 3-phase AC waveform and outputs it. · Drive Circuit: Drives transistors. · Protection circuit: Protects transistors from overcurrent. Since the above components are all integrated in IPM, IPM has a merit to make the control circuit simpli[...]

16 2-7-4. Characteristics of sine wave control in case of brushless DC motor ● Although ordinary 3-phase induction motor requires energy to excite the magnetic fi eld of rotor , brushless DC motor does not need it. So, higher ef fi ciency and torque are provided. ● This control provides the most ef fi cient waveform corresponding to the rota[...]

17 2-8. OPERA TIONAL FREQUENCY CONTROL OF OUTDOOR UNIT 1. Outline The operational frequency is as following: First, the target operational frequency is set based on the difference between the room temperature and the set tempera- ture. Second, the target operational frequency is regulated by discharge temperature protection, high pressure protectio[...]

18 (2) T ime chart OFF T ime Ti m e ON Operational frequency of the compressor Commanded to open Standard opening degree Opening degree is corrected according to discharge temperature. (Refer to (3)) Positioning Air conditioner ON Air conditioner OFF (thermostat off) LEV opening degree About 15 minutes 2-9. EXP ANSION V AL VE CONTROL (LEV CONTROL) [...]

19 (3) Control data F E D C B A T arget discharge temperature Operational frequency of the compressor 30 50 70 90 1 10 130 23 38 53 69 84 99 (Hz) (Hz) ( Other models ) ( MUZ-FE18 MUZ-GE24 MUY -GE24 ) (a) Reference value of target discharge temperature COOL / HEA T ( MUZ ) °F/°C Applied model A B C D E F MUZ-A09/12 COOL 122/50 127/53 140/60 151/66[...]

20 2. Pre-heat control ON condition (1) Pre-heat control is turned ON for 15 or 30 minutes after the breaker is turned ON. (2) 30 min. after the unit is stopped, pre-heat control is turned ON for 15 or 30 minutes and turned OFF for 30 minutes. This is repeated as shown in the graph until the breaker is turned OFF . When the defrost thermistor reads[...]

21 3-1. INVERTER SYSTEM CONTROL POWER SUPPL Y NOISE FIL TER CIRCUIT RESISTOR RELA Y SMOOTHING CAP ACITOR CURRENT TRANSFORMER COMPRESSOR REACTOR P W V U N IPM PFC U W MS 3~ V + 3-1-1. Inverter main power supply circuit Function of main parts NAME FUNCTION INTELLIGENT POWER MODULE (IPM) It supplies 3-phase AC power to compressor . SMOOTHING CAP ACIT [...]

22 3. Power factor improvement Booster coil reactor and PFC rectify AC to DC and control its voltage. In the motor drive system of sine wave control, power factor can be improved by reducing harmonics. PFC and reactor stabi- lize the voltage of DC supplied to inverter circuit and make its waveform smooth. 4. Intelligent power module IPM consists of[...]

23 3-2. EXP ANSION V AL VE CONTROL (LEV CONTROL) Linear expansion valve (LEV) is controlled by “Thermostat ON” commands given from each unit. Indoor unit status LEV opening Stop of all indoor unit Opening before stop → 500 pulses in 15 minutes When outdoor unit is operating, some indoor units stop and some operate. COOL: 5 pulses (full closed[...]

24 In COOL mode, the two indoor coil thermistors (one main and one sub) sense temperature ununiformity (super heat) at the heat exchanger , and when temperature difference develops, the indoor coil thermistors adjust LEV opening to diminish the super heat. This action is called Evaporation T emperature Protection. Indoor heat exchanger (MXZ-3A30NA)[...]

25 23 54 69 84 100 1 15 131 146 38 14 32 41 50 59 68 77 86 MXZ-2A/2B MXZ-3A/4A 23 Compressor operating frequency (Hz) 4Hz 01 02 03 04 05 06 07 08 09 10 LEV Opening (code) Determination of LEV standard opening in each indoor unit • The standard opening is on the straight line, which connects an each standard point in the section where divided into[...]

26 MXZ-3A30NA- 1 MXZ-4A36NA MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA Exclusive LEV Standard opening (pulse) LEV Opening (code) 123456789 1 0 COOL 126 130 134 138 150 160 170 180 190 200 HEA T 248 248 258 266 274 280 286 292 300 306 Difference in capacity Difference in operation number Code3,4 Code5,6 Code7,8 Code9,10 Code1 1,12 Code13,14 Code15or above 23 [...]

27 (1) LEV opening correction by discharge temperature The target discharge temperature is determined according to frequency zone and number of operation unit of the com- pressor . <Correction> COOL DRY HEA T Discharge temperature ● 2 ● 2 ● Each correction • (Each gas pipe temperature thermistor - Minimum gas pipe temperature thermist[...]

28 Correct the LEV opening according to the difference between target discharge temperature and discharge temperature. (2) Separate correction (COOL,DRY) (Correction by the separate super heat) a) Correct the LEV separately by temperature difference between each gas pipe temperature and the minimum gas pipe temperature of all. Calculate each super [...]

29 3-3. OPERA TIONAL FREQUENCY RANGE b) Correct the LEV separately by temperature difference “ ∆ R T” between main/sub indoor coil thermistor . ∆ RT LEV opening correction (pulse) 10.8 ∆ RT 2 7.2 ∆ RT < 10.8 1 ∆ RT < 7.2 1 In addition, decrease the target discharge temperature corresponding ∆ RT . ∆ RT T emperature to be dec[...]

30 MXZ-3A30NA- 1 MXZ-4A36NA Number of operating unit Capacity code COOL (Hz) DRY (Hz) HEA T (Hz) Min. Max. Min. Max. Defrost 1 4 2 55 82 52 07 05 8 7 2 55 82 52 07 05 8 9,10 25 71 25 20 80 58 12 25 80 35 20 80 58 2 8 ~ 10 25 80 31 20 80 58 1 1 ~ 13 25 80 31 20 80 58 14 ~ 16 25 80 42 20 80 58 17 ~ 25 80 42 20 80 58 3 ( MXZ-3A ) 12 ~ 25 80 52 20 80 5[...]

31 3-4. HEA T DEFROSTING CONTROL (1) Starting conditions of defrosting When the following conditions a) ~ c) are satisfied, the defrosting starts. a) The defrost thermistor reads 26.6°F or less. b) The cumulative operation time of the compressor has reached any of the set values (defrost interval: 40-150 min- utes). c) More than 5 minutes have pas[...]

32 COOL Fan speed changes so that the condensing temperature stays within the target range. Fan speed Revolution per minutes (rpm) MXZ-2B20NA- 1 MXZ-3B MXZ-4B 1 100 100 2 150 150 3 200 200 4 250 250 5 300 300 6 350 350 7 400 400 8 450 450 9 500 500 10 550 550 1 1 600 600 12 650 650 13 700 700 14 750 750 HEA T Fan speed is switched according to the [...]

33 1. Pre-heat control is turned ON for 15 or 30 minutes, after the breaker is turned ON. 2. 30 minutes after the unit is stopped, pre-heat control is turned ON for 15 or 30 minutes and turned OFF for 30 minutes. This is repeated as shown in the graph until the breaker is turned OFF . When the defrost thermistor reads less than 69.8°F , pre-heat c[...]

34 1. Thermostat control Thermostat turns ON or OFF by the difference between room temperature and set temperature. 3-9. DR Y OPERA TION 3-10. HEA T OPERA TION 2. High pressure protection In HEA T operation the indoor coil thermistor detects the temperature of the indoor heat exchanger . The compressor opera- tional frequency is controlled to preve[...]

35 4 MFZ MICROPROCESSOR CONTROL 3. Coil frost prevention Refer to MXZ MICROPROCESSOR CONTROL, COOL OPERA TION (3-8.2.). 2. Indoor fan speed control Indoor fan operates continuously at the set speed by F AN SPEED CONTROL button regardless of the thermostat's OFF- ON. In AUTO the fan speed is as follows. 1. Thermostat control Refer to MXZ MICROP[...]

36 1. Thermostat control Refer to MXZ MICROPROCESSOR CONTROL, HEA T OPERA TION (3-10.1.). 4-3. HEA T ( ) OPERA TION 2. Indoor fan speed control (1) Indoor fan operates at the set speed by F AN SPEED CONTROL button. In Auto the fan speed is as follows. 3. High pressure protection In HEA T operation, the indoor coil thermistor detects the temperature[...]

37 4-5. INDOOR F AN MOTOR CONTROL (1) Rotational frequency feedback control The indoor fan motor is equipped with a rotational frequency sensor , and outputs signal to the microprocessor to feed- back the rotational frequency . Comparing the current rotational frequency with the target rotational frequency (Super High, High, Med., Low), the micropr[...]

38 4-6. AUTO V ANE OPERA TION Horizontal vane (1) Cold air prevention in HEA T operation When any of the following conditions occurs in HEA T operation, the vane angle changes to V ertical position automati- cally to prevent cold air blowing on users. Compressor is not operating. Defrosting is performed. Indoor coil thermistor reads 75.2°F or belo[...]

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New publication, effective Sep. 2010. Specifications subject to change without notice. HEAD OFFICE: TOKYO BLDG.,2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAP AN © Copyright 2006 MITSUBISHI ELECTRIC CO.,L TD Distributed in Sep. 2010. No. OBT16 REVISED EDITION-G 6 Distributed in Mar . 2010. No. OBT16 REVISED EDITION-F 6 Distributed in Sep. 2009[...]