Summary of the content on the page No. 1
Revision B:
• MXZ-2A20NA- 1 , MXZ-4A36NA, MSZ-FD,
MSZ-D and MSY-D have been added.
Please void OBT16 REVISED EDITION-A.
No. OBT16
REVISED EDITION-B
SERVICE TECHNICAL GUIDE
Wireless type Models
MS-A•WA · MU-A•WA
MSZ-A•NA · MUZ-A•NA
U
· MUZ-A•NA -
MSY-A•NA · MUY-A•NA
MSZ-FD•NA · MUZ-FD•NA
U
· MUZ-FD•NA -
MSZ-D•NA · MUZ-D•NA
U
· MUZ-D•NA -
MSY-D•NA · MUY-D•NA
Inverter-controlled multi system type Models
· MXZ-A•NA
CONTENTS
1. MS MICROPROCESSOR CONTROL ·················
Summary of the content on the page No. 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. 2
Summary of the content on the page No. 3
1. MS MICROPROCESSOR CONTROL ···························································4 Indoor unit models Outdoor unit models MS-A09WA MU-A09WA MS-A12WA MU-A12WA 1-1. COOL OPERATION ···············································································4 1-2. DRY OPERATION ··················································································4 1-3. AUTO VANE OPERATION ·····································································6 2. MSZ, MSY MICROPROCESSOR CON
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1 MS MICROPROCESSOR CONTROL MS-A•WA MU-A•WA 1-1. COOL ( ) OPERATION 1. Thermostat control Thermostat is ON or OFF by difference between room temperature and set temperature Room temperature minus Room temperature minus set temperature (Initial) set temperature (During operation) Thermostat ON -1.8 °F or more OFF less than-1.8 °F -1.8 °F -1.3 °F 2. Indoor fan speed control Indoor fan operates continuously at the set speed by FAN SPEED CONTROL button regardless of the thermostat’s OFF-
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1. Thermostat control Thermostat is ON or OFF by difference between room temperature and set temperature. Room temperature minus Room temperature minus set temperature (Initial) set temperature (During operation) Thermostat ON -1.8 °F or more OFF less than-1.8 °F -1.8 °F -1.3 °F 2. Indoor fan speed control Indoor fan operates at the set speed by FAN SPEED CONTROL button. When thermostat OFF (compressor OFF), fan speed becomes Very Low. In AUTO the fan speed is as follows. Room temperat
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1-3. AUTO VANE OPERATION 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 higher than that in COOL mode. Also the horizontal vane swings in various cycle according to the temperature of indoor heat exchanger (indoor coil thermistor). SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher than that in COOL mode, the air conditio
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2 MSZ,MSY MICROPROCESSOR CONTROL MSZ-A•NA MSY-A•NA MUZ-A•NA MUY-A•NA MSZ-FD•NA MSY-D•NA MUZ-FD•NA MUY-D•NA MSZ-D•NA MUZ-D•NA 2-1. COOL ( ) OPERATION 1. Thermostat control Thermostat is ON or OFF by difference between room temperature and set temperature Room temperature minus Room temperature minus set temperature (Initial) set temperature (During operation) Thermostat ON -1.8 °F or more OFF less than-1.8 °F -1.8 °F -1.3 °F 2. Indoor fan speed control Indoor fan operates continuously
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Set temperature and 2-2. DRY ( ) OPERATION °F initial room temperature in dry mode 95 Set temperature is as shown on the right chart. The system for dry operation uses the same refrigerant circuit as the 86 cooling circuit. The compressor and the indoor fan are controlled by the room tem- 77 perature. By such controls, indoor flow amounts will be reduced in order to 68 lower humidity without much room temperature decrease. 59 50 50 59 68 77 86 95 °F Ini
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(2) Cold air prevention control MSZ-A09/12/15/17 MSZ-FD MSZ-D When the compressor is not operating, ( ) if the temperature of room temperature thermistor is less than 66 °F, the fan stops. ( ) if the temperature of room temperature thermistor is 66 °F or more and ( ) if the temperature of indoor coil themistor is less than 32 °F, the fan stops. ( ) if the temperature of indoor coil themistor is 32 °F or more, the fan operates at Very Low. When the compressor is operating, ( ) if the tem
Summary of the content on the page No. 10
(2) Releasing conditions of defrosting Defrosting is released when any of the following conditions is satisfied: a) The defrost thermistor continues to read 50 °F or more (MUZ-A09/12 MUZ-D) / 41 °F or more (MUZ-A15/17 MUZ-FD) / 59 °F or more (MUZ-A24) for 30 seconds. b) Defrosting time has exceeded 10 minutes. c) Any other mode than HEAT mode is set during defrosting. Time chart of defrosting in HEAT mode (reverse type) horizontal set position set position Horizontal vane horizon
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(2) Mode change In case of the following conditions, the operation mode is changed. COOL mode changes to HEAT mode when 15 minutes have passed with the room temperature 4 °F below the set temperature. HEAT mode changes to COOL mode when 15 minutes have passed with the room temperature 4 °F above the set temperature. In the other cases than the above conditions, the present operation mode is continued. NOTE1: Mode selection is performed when multi standby (refer to NOTE2) is released and the
Summary of the content on the page No. 12
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. For initial 10 minutes the swing operation is performed in table G~H for quick cooling. Also, after 10 minutes when the difference of set temperature and room
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MUZ-A24 MUY-A24 MUZ-D MUY-D CURRENT TRANSFORMER REACTOR U U P NOISE RESISTOR + POWER SMOOTHING MS FILTER PFC V SUPPLY CAPACITOR 3~ V CIRCUIT N W W RELAY IPM COMPRESSOR Function of main parts NAME FUNCTION INTELLIGENT POWER MODULE (IPM) It supplies three-phase AC power to compressor. SMOOTHING CAPACITOR It stabilizes the DC voltage and supplies it to IPM. It measures the current of the compressor motor. CURRENT TRANSFORMER It measures the current of the main power supply circuit. REACTOR It rect
Summary of the content on the page No. 14
2-7-2. Outline of main power supply circuit MUZ-A09/12/15/17 MUY-A15/17 MUZ-FD 1. At the start of operation Main power supply circuit is formed when RELAY is turned ON at COMPRESSOR startup. To prevent rush current from running into the circuit when power supply is turned ON, RESISTOR is placed in sub circuit. 2. At normal operation When AC runs into POWER P.C. board, its external noise is eliminated in NOISE FILTER CIRCUIT. After noise is eliminated from AC, it is rectifi ed to DC by DIO
Summary of the content on the page No. 15
4. Intelligent power module IPM consists of the following components · IGBT (x6) : Converts DC waveform to three-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 simplify and miniaturize. 5. Elimination of electrical noise NOISE FILTER CIRCUIT, which is form
Summary of the content on the page No. 16
2-7-3. Sine wave control In these air conditioners, compressor equips brushless DC motor which doesn't have Hall element. In short, the motor is sensorless. However, it's necessary to locate the polar direction of rotor in order to drive brushless DC mo- tor effi ciently. The general detection method of the polar direction for such a DC motor is to locate it from the voltage induced by unenergized stator. Therefore, it is necessary to have a certain period of time in which the stator is being un
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2-8. OPERATIONAL 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 tem- perature. Second, the target operational frequency is regulated by discharge temperature protection, high pressure protection, electric current protection and overload protection and also by the maximum/minimum frequency. 2. Maximum/minimum frequency in each operation mode. Un
Summary of the content on the page No. 18
2-9. EXPANSION VALVE CONTROL (LEV CONTROL) (1) Outline of LEV control The LEV basic control is comprised of setting LEV opening degree to the standard opening °F set for each operational frequency of the compressor. However, when any change in indoor/outdoor temperatures or other factors cause air con- ditioning load fluctuation, the LEV control also works to correct LEV opening degree based on discharge temperature (Shell temperature) of the compressor, developing the unit’s performance. Min
Summary of the content on the page No. 19
(2) Time chart Air conditioner OFF (thermostat off) Air conditioner ON Positioning Opening degree is corrected according to discharge Standard Commanded temperature. opening to open degree about 5 minutes Time about 15 minutes ON OFF Time (3) Control data 06 F 05 E D 04 03 C 02 B 01 A(target discharge temperature) (Hz) 30 50 70 90 110 130 Operational frequency of the compressor (a) Reference value of target discharge temperature (COOL / HEAT (MUZ) F) Applied mod
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(b) Reference value of LEV standard opening degree (pulse) Applied model A B C D E F COOL 130 190 240 260 260 260 MUZ-A09/12 HEAT 100 130 170 210 230 230 MUZ-A15/17 COOL 290 300 350 350 370 370 MUY-A15/17 HEAT 130 150 220 250 280 300 COOL 150 166 186 206 230 260 MUZ-A24 MUY-A24 HEAT 130 150 170 196 210 226 COOL 180 240 300 320 320 320 MUZ-FD HEAT 130 180 240 270 300 300 MUZ-D COOL 150 170 210 250 280 300 MUY-D HEAT 100 120 140 190 240 280 20
