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OBT16--1.qxp 06.3.29 11:20 AM Page 1
SPLIT-TYPE, AIR CONDITIONERS
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
No. OBT16
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
Inverter-controlled multi system type Models
· MXZ-A•NA
CONTENTS
1. MS MICROPROCESSOR CONTROL ··················3
2. MSZ,MSY MICROPROCESSOR CONTROL ·······6
3. MXZ MICROPROCESSOR CONTROL··············20
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OBT16--1.qxp 06.3.29 11:20 AM Page 2 1. MS MICROPROCESSOR CONTROL ···························································3 Indoor unit models Outdoor unit models MS-A09WA MU-A09WA MS-A12WA MU-A12WA 1-1. COOL OPERATION················································································3 1-2. DRY OPERATION ··················································································3 1-3. AUTO VANE OPERATION ···································································
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OBT16--1.qxp 06.3.29 11:20 AM Page 3 1 MS MICROPROCESSOR CONTROL MS-A09WA MU-A09WA MS-A12WA MU-A12WA 1-1. COOL ( ) OPERATION Difference between room temperature and set temper- 1. Thermostat control ature during operation. Thermostat is ON or OFF by difference between room temperature and set temperature Set temperature Initial temperature difference Thermostat Room temperature minus set temperature : -1.8 degrees or more·····································ON Room temperature
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OBT16--1.qxp 06.3.29 11:20 AM Page 4 Difference between room temperature and set temper- 1. Thermostat control ature during operation Thermostat is ON or OFF by difference between room temperature and set temperature. Initial temperature difference Thermostat Set temperature Room temperature minus set temperature : -1.8 degrees or more·····································ON Room temperature minus set temperature : less than -1.8 degrees···································OFF -1
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OBT16--1.qxp 06.3.29 11:20 AM Page 5 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 degrees higher than that in COOL mode. Also the horizontal vane swings in various cycle according to the temperature of indoor heat exchanger (RT12). SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher than that in COOL mode,
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OBT16--1.qxp 06.3.29 11:20 AM Page 6 2 MSZ,MSY MICROPROCESSOR CONTROL MSZ-A09NA MSY-A15NA MUZ-A09NA MUY-A15NA MSZ-A12NA MSY-A17NA MUZ-A12NA MUY-A17NA MSZ-A15NA MSY-A24NA MUZ-A15NA MUY-A24NA MSZ-A17NA MUZ-A17NA MSZ-A24NA MUZ-A24NA 2-1. COOL ( ) OPERATION Difference between room temperature and set temper- 1. Thermostat control ature during operation. Thermostat is ON or OFF by difference between room temperature and set temperature Initial temperature difference Thermostat Set
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OBT16--1.qxp 06.3.29 11:20 AM Page 7 Set temperature and 2-2. DRY ( ) OPERATION ºF 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 lower humidity without much room temperature decrease. 68 59 50 50 59 68
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OBT16--1.qxp 06.3.29 11:20 AM Page 8 (2) Cold air prevention control MSZ-A09/12/15/17 1 When the compressor is not operating, (1) if the temperature of room temperature thermistor RT11 is less than 66°F, the fan stops. (2) if the temperature of room temperature thermistor RT11 is 66°F or more and (1) if the temperature of RT12 is less than 32°F, the fan stops. (2) if the temperature of RT12 is 32°F or more, the fan operates at Very Low. 2 When the compressor is operating, (1) if the temperatur
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OBT16--1.qxp 06.3.29 11:20 AM Page 9 Time chart of defrosting in HEAT mode (reverse type) horizontal set position set position Horizontal vane Indoor fan Very Low (temperature of indoor coil thermistor > 64°F) set speed set speed OFF 30 seconds Maximum frequency Compressor normal OFF OFF 40 30 40 30 seconds seconds seconds seconds 5 seconds 5 seconds ON ON Outdoor fan OFF ON (HEAT) ON (HEAT) R.V. coil OFF (COOL) (21S4) 2-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION
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OBT16--1.qxp 06.3.29 11:20 AM Page 10 (3) Indoor fan control/ Vane control As the indoor fan speed and the horizontal vane position depend on the selected operation mode, when the operation mode changes over, they change to the exclusive ones. 2-5. OUTDOOR FAN MOTOR CONTROL Fan speed is switched according to the compressor frequency. Fan speed Down Up High Low Min. Compressor frequency Max. Compressor frequency (Hz) Fan speed Mode MUZ-A09
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OBT16--1.qxp 06.3.29 11:20 AM Page 11 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 th
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OBT16--1.qxp 06.3.29 11:20 AM Page 12 2-7. INVERTER SYSTEM CONTROL 2-7-1. MUZ-A09/12/15/17 MUY-A15/A17 2-7-1-1. Inverter main power supply circuit POWER P.C. BOARD INVERTER P.C. BOARD L61 L62 L63 DB61 U Power U R64A R64B C63A P W + CT761 supply C63B V X64 C63C N MC W CT CT781 V IPM TR821 DB65 Booster chopper circucuit Function of main parts SYMBOL NAME FUNCTION It supplies three-phase AC power to compressor. IPM INTELLIGE
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OBT16--1.qxp 06.3.29 11:20 AM Page 13 3. Purpose of PAM adoption PAM : Pulse Amplitude Modulation PAM has been adopted for the efficiency improvement and the adaptation to IEC harmonic current emission standard. Outline of simple partial switching method In conventional inverter models, diode module rectifies AC voltage to DC voltage, smoothing capacitor makes its DC waveform smooth, and IPM converts its DC voltage to imitated AC voltage again in order to drive the compressor motor. Howe
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OBT16--1.qxp 06.3.29 11:20 AM Page 14 Function of main parts SYMBOL NAME FUNCTION IPM INTELLIGENT POWER MODULE It supplies three-phase AC power to compressor. CB1~3 SMOOTHING CAPACITOR It stabilizes the DC voltage. CT1~2 CURRENT TRANSFORMER It measures the current of the compressor motor. CT61 CURRENT TRANSFORMER It measures the current of the main power supply circuit. L It rectifies AC, controls its voltage and improv
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OBT16--1.qxp 06.3.29 11:20 AM Page 15 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 motor efficiently. 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 cert
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OBT16--1.qxp 06.3.29 11:20 AM Page 16 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/mi
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OBT16--1.qxp 06.3.29 11:20 AM Page 17 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 degrees set for each opera- tional frequency of the compressor. However, when any change in indoor/outdoor temperatures or other factors cause air conditioning load fluctuation, the LEV control also works to correct LEV opening degree based on discharge temper- ature (Shell temperature) of the compr
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OBT16--1.qxp 06.3.29 11:20 AM Page 18 (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 (a) Reference value of target discharge temperature (COOL/HEAT (MUZ)ºF) Applied model A B C D E F MUZ-A09/12 50/45 53/52 60/59 66/68 70/76 70/76 MUZ-A15/17 54/49 58/58 64/66 7
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OBT16--1.qxp 06.3.29 11:20 AM Page 19 In COOL operation, the two indoor coil thermistors (one main and one sub) sense temperature ununiformity (super heat) at the heat exchanger, and when temperature difference have developed, the indoor coil thermistors adjust LEV opening degree to get approximate 10 degrees lower temperature than the target temperature in the table above, thus diminishing super heat. (b) Reference value of LEV standard opening degree (COOL/ HEAT (MUZ) pulse) Applied model A
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OBT16--1.qxp 06.3.29 11:20 AM Page 20 3 MXZ MICROPROCESSOR CONTROL MXZ-2A20NA MXZ-3A30NA 3-1. INVERTER SYSTEM CONTROL 3-1-1. Inverter main power supply circuit POWER BOARD NOISE FILTER P. C. BOARD V R64A/R64B L CT1 MC U W POWER U X64 +CB1 CT61 N/F SUPPLY CB2 CB3 PFC IPM V CT2 W Function of main parts SYMBOL NAME FUNCTION IPM INTELLIGENT POWER MODULE It supplies three-phase AC power to compressor. CB1~3 SMOOTHING CAPACITOR
