1. INVERTER-Y
TRAINING 2009

2. TOPICS
Introduction to Y-Inverter
Control Algorithm
Troubleshooting 2

3. INTRODUCTION

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

5. 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

6. 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

7. 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

8. 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

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

10. 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

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

12. 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

13. INTRODUCTION Advantages Protection
Additional software protection against
Over current
Over heating

14. 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

15. 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)

16. 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

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

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

19. 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

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

21. INTRODUCTION Basics of Inverter Technology The system Inverter Output
Frequency
222 Hz 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

22. INTRODUCTION
Basics of Inverter Technology
Indoor PCB

23. INTRODUCTION
Basics of Inverter Technology
Outdoor PCB

24. CONTROL ALGORITHM

25. 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

26. 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

27. 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

28. 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

29. 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

30. 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.

31. 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

32. 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

33. 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

34. PROTECTION Input Current Control No. Unit Capacity I1 I2 I3 1 1.0HP34

35. 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

36. Compressor Discharge Temperature Control
PROTECTION
Compressor Discharge Temperature Control 36

37. 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

38. PROTECTION
High Pressure Protection

39. 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

40. 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

41. TROUBLESHOOTING

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

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

44. 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

45. TROUBLESHOOTING
Fault diagnosis using outdoor 7-segment display 45

46. 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

47. 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

48. TROUBLESHOOTING
Error Codes

49. 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

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

51. 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

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

53. 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

54. 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

55. 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

56. 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

57. 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

58. 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

59. 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

60. 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 V. It is acceptable
positive lead (+)
negative lead (-)

61. 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

62. 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

63. 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

64. 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

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

66. Thank You
Q & A