Examples of Improper Installation in the Field

1. Examples of Improper Installation in the Field

2. Intrusion of contaminants in the refrigeration system Bad work Expected failure • Capillary tube and EEV will be clogged. • Returning refrigerant oil volume becomes insufficient. • Insufficient lubrication of rotating part of the compressor. • Breakdown of compressor (E42: Current Cut) Good work the cap or the plastic bag wall Measures ground Gum band • Do not leave the piping connection work halfway, and work at once. • When piping is left for long period, close the open pipe end. • Brazing must be performed under N2 gas flow. Do not lay on the ground Cover the open pipe end with the cap or the plastic bag. The use of the gas other than nitrogen are improper. Keep supplying N2 gas. Taping Nitrogen brazing

3. the wax putting work It crushes. Adhesive tape brazing Mixing of moisture in the refrigeration system Bad work Expected failure If moisture circulates in the refrigeration system, the problems will happen. • Moisture is frozen at the capillary tube or EEV and it makes clogging. • Moisture decomposes the refrigerant oil or refrigerant itself, and the acid and the contaminant are generated. • Insufficient lubrication at rotating part of the compressor. • Breakdown of compressor (E42: Current Cut) Good work Measures • Do not leave the piping connection work halfway, and work at once. • Never do plumbing of outdoor in the rain. • Close the open pipe end when you leave piping for a long period.

4. Air mixing in refrigeration system Bad work Expected failure • High pressure increases abnormally high(E40: High pressure error) • Decreasing cooling/heating capacity Insufficient cooling and heating. Measures • Evacuate piping system to vacuum before open the operation valve. • Don’t purge the air by using the pre-charged refrigerant in the outdoor unit.

5. Air mixing in refrigeration system How to find air mixing Dalton’s law Each partial pressure of mixed gas is in proportion to the proportion of each gas component. Only refrigerant in the system Refrigerant & air in the system Outside temperature: 30°C Outside temperature: 30°C RefrigerantTemperature: 30°C Pressure:1.78MPa mixing Refrigerant Temperature: 30°C Pressure:1.78MPa Refrigerant & Air Temperature: 30°C Pressure:2.28MPa Air (no condensation gas) Temperature:30°C Pressure:0.50MPa Please take note that the pressure is higher than the saturated temp. pressure of refrigerant before operation, air may be mixed.

6. gauge manifold Safety charger Service valve (Liquid line) Gas cylinder Charge port Service valve (Gas line) Charge port Charge hose Digital scale compressor How to charge additional refrigerant Expected failure Undercharging refrigerant • Decreasing of cooling and heating capacity • Decreasing low pressure abnormally (E49: Low pressure error, E36: Discharge pipe temperature error) Overcharging refrigerant • Decreasing the viscosity of oil due to liquid back operation makes insufficient lubrication in the compressor (E42: Current Cut) • Increasing high pressure abnormally (E40: High pressure error) Measures Good work • Charge proper amount of the refrigerant with a scale. • Purge air in the charge hose completely when charging additional refrigerant. • Be sure to open the operation valve after finishing additional refrigerant charge

7. Installation that exceeds piping length and height difference limitation Excess of piping length limitation Excess of height difference limitation Bad work Expected failure In case of installation that exceeds the limitation of usage the following problem will happen. 1. Breakdown of compressor because of insufficient return of oil 2. Decreasing cooling/heating capacity by pressure loss Measures • Keep limitation.

8. Crisscrossed connection of liquid and gas pipe Bad work Expected failure • Decreasing cooling/heating capacity • Generating refrigerant flow noise • Drain leakage by freezing the indoor heat exchanger (Heating) • Insufficient defrosting (Heating) • A normal operation cannot be done Gas pipe Liquid pipe Measures • When commissioning, confirm whether the outlet air temperature of indoor unit is proper or not. • Confirm the indoor heat exchanger temperature by Mente PC. Please take note especially in the event of KXRE4 installation.

9. Good work Signal wire Exterior tape Gas piping Liquid piping insulation Improper piping insulation Bad work Expected failure When the gas and liquid pipe is insulated together, the following problem will happen. • Decreasing cooling/heating capacity by exchanging heat at contact part of pipings • Breakdown of the compressor due to bigger superheat • (E36: Discharge pipe temperature error) • (E42: Current Cut ) Measures 1. Insulate liquid and gas pipe individually.

10. Incorrect piping size Expected failure Bad work In case of larger size of gas pipe than proper size • Breakdown of compressor because of insufficient oil returning due to the insufficient velocity of gas flow. In case of larger size of liquid pipe than proper size • Breakdown of compressor because of improper amount of refrigerant flow • Decreasing cooling/heating capacity If you select the larger size of liquid pipe and charge additional refrigerant, it may cause insufficient lubrication because of decreasing the viscosity of oil due to the liquid back operation. (E42: Current Cut) In case of smaller size of gas and liquid piping than proper size Decreasing cooling/heating capacity by pressure loss Measures • Use proper size of pipes specified in tech. manual.

11. Leakage of drain because of improper insulation of piping Pipe cover Indoor unit Band Bad work Expected failure If you don't insulate the piping, condensation will form on the surface of the gas pipe due to the temperature difference between gas pipe and the surrounding air. The ceiling will be stained. Good work Measures • Insulate liquid and gas pipe individually and completely. • Wrap the pipe cover firmly with tie-wrap band • (Pipe cover is contained in the package of the indoor unit as an accessory shown in the figure)

12. Improper bending process of piping Bad work Expected failure • The refrigerant circulation volume decreases and the capacity decreases because the flow of the refrigerant is obstructed at crushed point of piping. • The crack in the part of crushed piping by sharp bending may cause the refrigerant leakage. Decreasing of cooling/heating capacity or an abnormal pressure decrease in low pressure(E49: Low pressure error) Measures • Use the pipe bender for the bending process of piping. • Enlarge the bending radius R. • f 9.52 & 12.7: R=40mm or more is recommended. • f 15.88 & 19.05 : R=60mm or more is recommended. R

13. Crisscrossed-piping connection over systems Bad work Expected failure The unit doesn't work normally. Operating indoor unit Refrigerant doesn’t come to the indoor unit from outdoor unit, even if outdoor unit is operating because of the cross-piping connection . Stopping indoor unit • Drain leakage by freezing the indoor heat exchanger • Breakdown of operating compressor on the other system due to liquid back operation Measures In case of KXE4 & KXRE4 Installation, this kind of mistake possibly happen, because of many indoor units. In order to avoid it, put unit No. label on each piping. Do not install them with cross-piping connection .

14. Service valve Close <liquid line> Service valve Close <gas line> Operation without opening the operation valve Bad work Expected failure Operation of protective control (E40: High pressure error) (E49: Low pressure error) Attention!! There is a possibility that the oil separator bursts, because pressure might rise rapidly (In case that hot gas operation valve is kept closed at heating mode). This mistake is considerably high in JAPAN Measures Be sure to confirm that operation valves are open absolutely before unit start. Be sure to operate at cooling mode first when commissioning, in order toavoid abnormal rise of high pressure by heating operation.

15. Loose fastening of the screw. Good work Bad work Inclination of tightening wiring Bad connection of wiring Expected failure • Abnormal temperature rising at terminal block due to loose connection and it leads to a fire • The system may become out of control. • Communication error of signal wire and power supply error may happen (E5) Measures • Connect wire to the terminal block with terminal. • Connect wire firmly and confirm it. • Fix the wires with the clamp in order to avoid excessive stress.

16. Cross-connection of power supply line and remote control line Bad work Expected failure Terminal block for signal wire If the the power supply cable connected to the terminal block of signal wire, the control PCB becomes damaged soon after the power ON Power supply cable Signal wire Terminal block for power supply This mistake is considerably high in JAPAN Measures Put the unit No. and labels to signal wires and supply supply cables

17. Bundle wiring of power line and signal line Bad work Expected failure Electric noise may cause malfunction Measures • Neither the power line nor the signal line should not be criss crossed. • Power line and signal line should not be put in the same tube or side by side. • Don’t use the same cables for both power line and signal line.

18. A abnormal voltage of power supply. Expected failure • Malfunction of actuator and the controller by excessive current Measures • Be sure to check the voltage with tester or Mente PC when power supplied • The usage range of power-supply voltage must be ±10% at the maximum in consideration of fluctuation

19. Standing up of drain piping Descending inclination Poor drainage by trap Descending drain work Drain piping work Bad work Good work Expected failure Overflow and leakage of drain from drain pan by poor drainage Measures • Make no bending and no trap. • Do not bend the drain piping right and left, and up and down. • Fix the piping with the support metal fittings at certain distance . • Keep the descending inclination.

20. Drain piping work Bad work Expected failure In case that welding work is done near the indoor unit if spatter will hit the drain pan, it makes a hole on the drain pan and will lead leakage of drain through the hole This mistake is often in JAPAN. Measures • Cover the indoor unit with a dustproof seat.

21. Difficulty on multi system when problem happens. No matter how you are paying attention, there is a possibility that problem may happen caused by usage and the environment. Problem happens !! You should quickly solve the problem. However . . . From the view of the diagnosis and the troubleshooting, to specify the cause of the problem of KXE4 & KXRE4 is very difficult. It is necessary to understand the principle of the refrigeration system and control system of KX(R)E 4 in order to solve the problem quickly.

22. Method of troubleshooting Difficulty of finding out the cause of the problem on multi system when it happens • Difficulty of the entire understanding of multi system KXE4 & KXRE4 • <Example> piping system, wiring system, address setting, • the number and model of indoor unit • It had better to try to analyze the cause in comparison with RAC or PAC system with simple refrigeration system and simple controls • 2. Variety of indoor unit • The refrigeration system and the control, etc. of each indoor unit is different • Variety of error code when abnormality stopping • If you do not understand the error code, you can’t do appropriate countermeasure. • Processing when a problem without error code happens • In order to specify the point of failure, you need some knowledge for the products and you have to have a proper understanding of the principle of the refrigeration system. • In order to diagnose the problem properly, it is better to use the service tools such as QSS and Mente PC to collect data. • However, even if such kind of tools are used, you cannot judge it properly without proper understanding of the principle of the refrigeration system. FDUR FDKA FDTA