INVERTER-Y TRAINING 2009

TOPICS Introduction to Y-Inverter Control Algorithm Troubleshooting 2

INTRODUCTION

INTRODUCTION What is inverter ? What are the advantages ? Differences between Conventional & Inverter A/C Basics of Inverter Technology

INTRODUCTION What is Inverter? Electrical supply has fix frequency Inverter type air conditioner have frequency changer which can change the electrical frequency to control the speed of the compressor This in turn, can control the capacity accordingly

INTRODUCTION Advantages Enhanced room temperature comfort Conventional - More precise room temperature control - Temperature fluctuation is kept within ± 0.5C from set temperature Conventional Inverter

INTRODUCTION Advantages Less on / off cycle Compressor capacity Time Compressor capacity Full capacity Conventional compressor Room temperature control: switching compressor ON & OFF Compressor capacity Inverter Room temperature control: Control compressor rotational speed smoothly Smooth ramp up from zero to high rotational speed Slow down as temperature drops Maintain room temperature at low speed Time

INTRODUCTION Advantages Starting frequency 1.0 hp – 68 rps Compressor frequency (rps) 1.0 hp – 68 rps 1.5 hp – 74 rps Max. 55 35 Target frequency 20 Time (min) 1 2 6

Conventional non-inverter A/C INTRODUCTION Advantages Fast cooling Conventional non-inverter A/C Inverter A/C Room temperature Set temperature Time Quick cooling

INTRODUCTION Advantages Low starting current Running current Conventional A/C: High starting current Frequent on/off cycle Inverter A/C: Low starting current Smooth operation Hours of operation

INTRODUCTION Advantages Higher reliability Less compressor start – stop cycle Low starting current Longer compressor motor lifespan

INTRODUCTION Advantages Low energy consumption with superior efficiency Frequency of supply current is varied according to load requirements – excellent efficiency Range is between 0 – 68 rps (204 Hz) for 1.0 hp 0 – 74 rps (222 Hz) for 1.5 hp Resulting in significantly LESS compressor start/stop – low energy consumption Lowest operating frequency = 60 Hz

INTRODUCTION Advantages Protection Additional software protection against Over current Over heating

INTRODUCTION Description Inverter A/C Conventional A/C Outlook feature Differences Overview Description Inverter A/C Conventional A/C Outlook feature Almost same Controller Variable frequency control Relay sequence control Compressor Inverter 3-Phase 1 or 3-Phase Frequency 0 ~ 204/222 Hz 50 or 60Hz

Inverter-driven Compressor Electronic Expansion Valve (EXV) INTRODUCTION Basics of Inverter Technology Inverter-driven Compressor Energy Savings Creation of Comfort IPM (Inverter Power Module) Electronic Expansion Valve (EXV)

INTRODUCTION Adjust capacity according to actual load by Basics of Inverter Technology Power supply Rectifier circuit Compressor Motor IPM Adjust capacity according to actual load by Controlling the EXV opening Controlling the refrigerant flow

INTRODUCTION Basics of Inverter Technology Inverter system block diagram Energy Source Rectifying Circuit Inverter Compressor Control & Protection Circuitry Feedback

INTRODUCTION Basics of Inverter Technology Inverter drive power circuit IN U M V OUT W Rectifier Inverter

INTRODUCTION Basics of Inverter Technology What are Rectifier / Inverter? Rectifier: Rectifying with smoothing Changing AC  DC Inverter: Inverse transformation with P.W.M. Changing DC  AC

INTRODUCTION Basics of Inverter Technology Inverter drive power circuit - components M IN OUT U W V IPM(Inverter Module) Diode Reactor Electrolytic capacitor

INTRODUCTION Basics of Inverter Technology The system Inverter Output Frequency 222 Hz 60 Hz Power supply Input frequency 50Hz Inverter t1 AC/DC Rectifier DC/AC Inverter u t t 50 Hz 222 Hz 60 Hz compressor motor input IPM

INTRODUCTION Basics of Inverter Technology Indoor PCB

INTRODUCTION Basics of Inverter Technology Outdoor PCB

CONTROL ALGORITHM

CONTROL ALGORITHM Frequency Principle The compressor is frequency-controlled during normal operation. The target frequency is set based on following parameters: i) Outdoor ambient temperature ii) Set temperature iii) Room temperature When the frequency increases, the rotation speed of compressor increases resulting in an increased refrigerant circulation, this lead to higher amount of heat transfer and vice versa when frequency decreases. 25

CONTROL ALGORITHM Operating Modes The system has 2 operating modes. The mode selection is done in Inverter (indoor) controls. The operating modes are: Cool Fan 26

CONTROL ALGORITHM Function – Cool Mode When Tr >= Ts – 1.5°C - Comp, ID Fan and OD Fan ON When Tr <= Ts - 2°C - Comp and OD Fan OFF - ID Fan remain ON Tr = Room Temperature Ts = Set Temperature 27

CONTROL ALGORITHM Function – Cool Mode At beginning of cooling operation, compressor frequency will be increased smoothly to the target frequency so that the room temperature is reduced. When set temperature is achieved, operation frequency will be reduced to stabilize the room temperature. 28

CONTROL ALGORITHM When will Compressor Stop? When cooling load is too small, even with lowest operation frequency and the room temperature still fall below compressor cut off point, compressor will stop. Compressor Capacity Lowest Freq Time Tr <= Ts - 2°C Comp will stop

CONTROL ALGORITHM Function - Fan Mode Only High, Medium and Low fan speeds are allowed. When changing cool mode to fan mode, the compressor will stop and OD fan stops after 30s. Compressor will only ON if the minimum stop time is > 3 minutes and the user change back to cool mode. Fan speed will maintain same as during fan mode.

PROTECTION Protection Control - Data Communication Error Between Indoor and Outdoor Master by outdoor unit. Indoor controller board will transmit signal to outdoor controller board every 0.5s. Outdoor unit will response to indoor once the valid data is received. Indoor Outdoor Send Signal Acknowledge 31

PROTECTION Protection Control - Data Communication Error Between Indoor and Outdoor If the data communication line between indoor and outdoor occurs error for 15s continuously, compressor will stop, OD fan stop after 30s. ID LED blinks error. If the communication resumes after 15s, error code is clear and compressor restarts after 3 minutes. If the communication is not resume after 15s, unit unable to restart and the error keep blinking. 32

PROTECTION Indoor Coil Frost Prevention Only available in cooling mode. When the indoor coil temperature < 2°C, the compressor starts to drop the frequency. This protection is activated when: - Indoor coil temperature < 0°C for more than 180s. Compressor will stop, OD fan stop after 30s and indoor fan can only run at super low fan speed. The unit can only be restarted after 3 minutes. When the indoor coil temperature >13°C, the compressor frequency will be reset based on the OD ambient, room and set temperature. 33

PROTECTION Input Current Control No. Unit Capacity I1 I2 I3 1 1.0HP 34

PROTECTION Input Current Control When the input current for running compressor exceeds I2, running frequency will be reduced by 1 step. If current still exceeds I2, frequency will be reduced by another 1 step until total current falls between I2 and I3. This protection is activated when the input current exceeds I1 for 2 seconds. Compressor will stop and it is considered total current overload. The unit can only be restarted after 3 minutes. If input current <I3, the compressor frequency is reset based on the OD ambient, set and room temperature. 35

Compressor Discharge Temperature Control PROTECTION Compressor Discharge Temperature Control 36

PROTECTION Compressor Discharge Temperature Control If compressor discharge temperature >102°C, running frequency will be reduced by 1 step. If compressor discharge temperature still >102°C, frequency will be reduced by another 1 step until temperature falls between 99°C and 90°C. This protection is activated when the compressor discharge temperature > 110°C. The compressor will stop and considered trip. The unit can only be restarted after 3 minutes. If the compressor discharge temperature < 90°C, the compressor frequency will be reset based on the OD ambient, set and room temperature. 37

PROTECTION High Pressure Protection

PROTECTION High Pressure Protection The compressor frequency is adjusted depend on the coil temperature. This protection is activated when the outdoor coil temperature > 64°C, the compressor stop and OD fan stop after 30s. The unit can only be restarted after 3 minutes. 39

PROTECTION IPM error Protection on the IPM IPM error is declared when; i) Compressor’s motor peak current > 21A OR ii) IPM temperature >100°C OR iii) IGBT peak current > 16A. 40

TROUBLESHOOTING

TROUBLESHOOTING Fault display by indoor unit When any error occurs, indoor LED display will keep blinking LED blinks here

TROUBLESHOOTING Fault diagnosis by remote controller TIMER CANCEL button Hold down ON TIMER CLR or OFF TIMER CLR for 5 seconds

TROUBLESHOOTING Fault diagnosis by remote controller Press TIMER CANCER repeatedly until ID buzzer produces long beep The handset temperature display section will indicate the error code Error code ID unit buzzer will produce long beep if the handset error code = unit error A short and two consecutive beeps is not the unit error

TROUBLESHOOTING Fault diagnosis using outdoor 7-segment display 45

TROUBLESHOOTING Fault diagnosis using outdoor 7-segment display When there is no error, compressor running frequency is displayed, unit: rps Flashes error code when error occurs

TROUBLESHOOTING Fault diagnosis – stored last state error Remove battery from remote controller Replace battery again into remote controller Press Mode & ON/OFF buttons together Press Mode button to 5:00 Press ON/OFF once Repeat the fault diagnosis by remote controller steps Mode button TIMER CANCEL button ON/OFF button

TROUBLESHOOTING Error Codes

TROUBLESHOOTING Outdoor 7-segment display Press on the tact switch Display parameter by flashing of 7-segment Parameter 125, display as 25, follow by 01

TROUBLESHOOTING Equipments Digital clamp meter Digital multi-meter Pressure gauge AC CURRENT RESISTANT AC VOLTAGE

TROUBLESHOOTING Error C4 – ID coil thermistor short / open Remove the ID coil thermistor from PCB Set digital multi-meter to ohm reading Measure both terminals on the sensor using multi-meter test leads The reading must comply with a particular temperature, refer Table 3 If the reading differs by ±2°C. It is acceptable

TROUBLESHOOTING Resistance - temperature At 25C Resistance value: 10 k

Air intake gap for room temperature sensing TROUBLESHOOTING Error C9 – Room thermistor short / open Sensor RTH201 Possibility – low Unit design with air opening at the front panel to allow sufficient space for air flow & measurement 10 C < operating temp. < 40 C Air intake gap for room temperature sensing

TROUBLESHOOTING Error H9 – OD air thermistor short / open Error J3 – Compressor discharge pipe thermistor short / open / misplaced Error J6 – OD coil thermistor short / open Share a same connector Connection to PCB

TROUBLESHOOTING Error H9 – OD air thermistor short / open Thermistor Remove the OD air thermistor from PCB Set digital multi-meter to ohm reading Measure both terminals on the sensor using multi-meter test leads. The reading must comply with a particular temperature, refer Table 3 If the reading differs by ±2°C. It is acceptable

TROUBLESHOOTING Error J3 – Compressor discharge pipe thermistor short / open / misplaced Thermistor Remove the compressor discharge pipe thermistor from PCB Set digital multi-meter to ohm reading Measure both terminals on the sensor using multi-meter test leads. The reading must comply with a particular temperature, refer Table 3 If the reading differs by ±2°C. It is acceptable

TROUBLESHOOTING Error J6 – OD coil thermistor short / open Thermistor Remove the OD coil thermistor from PCB Set digital multi-meter to ohm reading Measure both terminals on the sensor using multi-meter test leads. The reading must comply with a particular temperature, refer Table 3 If the reading differs by ±2°C. It is acceptable

TROUBLESHOOTING Error P4 – Heat sink thermistor short / open Remove the heat sink thermistor from PCB Set digital multi-meter to ohm reading Measure both terminals on the sensor using multi-meter test leads. The reading must comply with a particular temperature, refer Table 3 If the reading differs by ±2°C. It is acceptable

TROUBLESHOOTING Error E8 – AC input over current Set clamp meter to AC current Clamp terminal 1 on the OD unit terminal block If the reading < 10 Amp. It is acceptable

TROUBLESHOOTING Error U2 – DC voltage out of range Set multi-meter to DC voltage Measure terminals 1 & 2 on the OD unit terminal block using multi-meter test leads If the reading is within 220-240 V. It is acceptable positive lead (+) negative lead (-)

TROUBLESHOOTING Error F6 – High pressure protection Coil overload Possible causes: coil dirty and air short circuit Where a wall or other obstacle is in the path of outdoor unit’s intake or exhaust airflow Follow this installation guidelines to avoid air short circuit

TROUBLESHOOTING Error L5 – IPM / IGBT error Heat sink IPM Possible causes: over current or over heat At start up: could be due to software After running some time: could be due to over current or over heat Heat sink IPM

TROUBLESHOOTING Error UO – Insufficient gas Check pressure reading at rated capacity Press & hold Connect pressure gauge to OD service valve Press and hold on the ID ON/OFF button Set to high fan mode and temperature at 16 °C using remote controller Under cooling mode: For 1.0 hp: at 45 rps, the pressure reading should be between 125 – 150 psi For 1.5 hp: at 65 rps, the pressure reading should be between 125 – 150 psi

TROUBLESHOOTING Error U4 – Communication error Maximum communication wire length up to 30 meters Make sure the recommended type of wire is used External interference or noise Check for loose connection

TROUBLESHOOTING Error UA – Installation error Y5WMY10/15J Y5SLY10/15D

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