AIR CONDITIONER (DX UNITS) REPAIR GUIDE
An air conditioner may have problems while running so at that time an air conditioner repair is required. If an air conditioner stops working suddenly, its called tripping. There may be many reasons for tripping in an air conditioner and troubleshooting is required to find the actual fault and to make air conditioner repair. Following is the list of possible faults with reasons and solutions to repair air conditioners.
1. Air conditioner repair for tripping due to Refrigerant leaks
Reasons :- There are many joints and threaded fittings in copper piping connections. Leakage of refrigerant gas may happen if any of these fittings are not installed properlly or joints are not brazed properly. But sometimes leakage may happen due to any demage to the copper pipe, indoor unit and outdoor unit while installing, shifting or servicing the unit.
Troubleshooting :- If there is a leak in air conditioner copper piping circuit, the LP switch will automatically tripp the whole system. If the unit restarted again and again it will continue to trip. Tracing a leak is very difficult task and time consuming. Leaks can be detected with the help of leak detector or simply using soap and water mixture or a high froathing liquid. Just shake this liquid well and apply the froath on the joints and fittings. Bubbles formation will indicate the leak if its there.
Repair Method :- Air conditioning repair for this fault is not difficult. Once the leak is detected mark it with the help of a marker. Now release the refrigerant from the system or if possible store it. Refrigerant can be stored instead of releasing it in atmosphere. Now clean the area properly with the help of sand paper and start brazing to repair the leak spot. Once the brazing is finished, connect the vaccum pump to the air conditioner and put it on for 35-40 minutes. Don't disconnect the vaccum pump immediately after the vaccumization, wait for 15 minutes. If the vaccum pressure is maintained without any change on vaccum gauge, it means leak area is properly repaired. But if there is any change on the gauge, it means there may be any other leak or leak was not repaired properly. Repeat the process for tracing the leak again and follow the above process to repair the leak. If leakage is on indoor or outdoor unit's coil then send them to the manufacturer for repair.
2. Air conditioner repair for tripping due to choked system
Reasons :- Due to a choked copper piping air conditioning system pressure increases on compressor and it starts to take high amperes and an overload relay makes the system to trip as a safety procedure. Choking may be in compressor, condenser, expansion valve, in evaporator or any other component.
Troubleshooting :- If a compressor which is checked and found to work well is taking high amps it means the system is choked and that air conditioner need repair. Choking may happen due to improper vaccumization, bad lubrication system or oil mixing with refrigerant, due to faulty crank case heater, bad filters, bad driers or strainers etc.
Repair Method :- Air conditioner repair for this fault or tripp is bit difficult. Once choking is confirmed, it is required to remove refrigerant gas into the environment. This refrigerant will spray oil with it and will be black in color. To remove the choking you need to flush the whole piping network by proper flushing method. After finishing the flushing process, system is required to put on vaccum for one hour so that it could be free of all contamination and air. Don't disconnect the vaccum pump immediately after the vaccumization, wait for 15 minutes. If the vaccum pressure remains same it means there is no leak and air present in the system. Now you can fill the refrigerant gas in the system.
3. Air conditioner repair for tripping due to choked condenser or evaporator fins:-
Reasons :-Condensers and evaporators are same in their body construction but they are used for different puposes. A condenser or evaporator is made from copper or any other material with high conductivity passing through a set of fins. If air conditioner is not serviced time to time, contamination start to accumulate on the surface of fins and on the tubes. This choking will reduce the flow of air through the fins and results in lowing the efficiency of condenser or evaporator. Once the efficiency starts to go down, it will increase pressure on compressor and condenser fan as well and system will start to trip frequently.
Troubleshooting :- Thoroughly check the condenser and evaporator coils. A contaminated condenser or evaporator can be easily traced. The dust can easily be seen on the coils of tubes.
Repair Method :- An air conditioner should be serviced regularly usually four times in a year. This will keep the air conditioner working well and reduce the chances of blockage.
4. Air conditioner repair for tripping due to Ice formation on coil:-
Reasons :-Sometimes it is observed that ice formation happens on the cooling coil and it stops the air circulation over the coil. This ice formation increase the static pressure on the evaporator blower fan and safety switch make the system to trip. There may be some other reasons for this ice formation like low refrigerant in system, bad or choked air filters on return or supply sides as air can't pass through the cooling coil in proper volume, blower motor reduced RPM and low air through etc.
Troubleshooting :- Check the refrigerant pressures and quantitiy in system low refrigerant is main cause of ice formation on cooling coil. Thoroughly check all air filters on return and supply side of source unit.Check blower motor, is it properly throughing enough CFM.
Repair Method :- Maintain quantity of refrigerant in system if low or high quantity is found in the system. Properly clean air filters and cooling coils as well. If blower motor found with low RPM and low air flow or CFM then we need to check the motor supplies as well. If voltage and amperes are ok then check the capacitor, if found faulty change it and motor will now run at full speed.
5. Air conditioner repair for tripping due to short or grounding:-
Reasons :- Any component of air conditioning unit like compressor, blower fan motor and condenser fan motor can be short or ground because of running for long time periods at the time of peak heat loads. The short circuits results in tripping of system.
Troubleshooting :- If the system is tripping due to short circuit you have to trace the fault. Its easy, there are magnetic contactors provided for each ciruit and it can be mannually switched on. Just push the button on magnatic contactor if the compressor or condenser fan is grounded it will trip the system immediately after start. To check the faulty component you need to check them one by one. Check the continuity of compressor or motor winding with unit's body with the help of voltmeter. A voltemeter has an option to select the continuity option as shown in figure. If the sound of beep is coming from motor or from compressor it means motor or compressor is grounded.
Repair Method :- If the compressor is ground, we have to either change it or if its open type then we need to send it for motor winding. Same thing is applicable on faulty blower or condenser fan motor.
6. Air conditioner repair for tripping due to over refrigerant charged in system:-
Reasons :- If an air conditioner is over charged with refrigerant even then it will make tripping again and again. While filling refrigerant in an air conditioner recommended refrigerant quantity from manufacturer should be charged.
Troubleshooting :- Over charging of refrigerant in an air conditioner can be easily checked by connecting gauge manifold set and checking pressures of refrigerant. If discharge pressure is more than recommended it means refrigerant gas is overcharged.
Soultion :- Release the extra refrigerant by opeing service valve into the environment until it reaches the recommended quantity. Normally suction and discharge pressure in an air conditioning unit should be in ratio of 65-270 psi respectively.
7. Air conditioner repair for ice formation on expansion valve:-
Reasons :- Due to frequent automatic opening and closing of expansion valve put pressure on moving stem and diaphragm. Due to this pressure diaphragm may break and expansion valve can be demaged.
Troubleshooting :- Ice formaion over the expansion valve and distributors indicates the failure of expansion valve, if the moving stem is not closing the valve. If the diaphragme is broken it will keep the valve in close position which will increase pressure on compressor and make the system to trip from overload relay.
Soultion :- An expansion valve can be repaired easily but if its not possible to repair, then change the expansion valve.
8. Air conditioner repair for faulty magnetic contactors:- A magnetic contactor is a kind of switch which put on and off an air conditioner's compressor automatically as it is intigrated with PCB. A magnetic contactor works on the principle of electromagnetism as shown in figure. When temperature on the coil increases, sensor sends a signal to the PCB and PCB switches on the power through a transformer to the magnetic contactor's coil, which may be a 24V or 220-230 V. A transformer is required if magnetic contactor's coil works on 24V power supply. A magnetic contactor may be of 2 poles, 3 poles, 4 poles according to type of power supply(single phase 220V or three phase 420 V) and with NO (normally open) NC (Normally close) poles options.
A SINGLE PHASE MAGNETIC CONTACTOR :- As shown in figure below it has three poles for phase and neutral . The small poles functions and magnetic coils supply.
A THREE PHASE MAGNETIC CONTACTOR :- As shown in figure below it has four poles, Three poles for 3 phases and one for NO NC. The small poles are for magnetic coils supply.
Reasons :- Due to frequent switching on and off automatic process, the connecting points of the magnetic contactors get carbonized and dirty. This carbon makes the contactor faulty and air conditioner doesn't work properly.
Troubleshooting :- Before checking the contactor, it is necessary to disconnect the main supply from isolator. Disconnect the wires of main power supply to magnetic contactor and open the magnetic contactor poles. If black thick carbon is found on the poles you need to clean it properly and re-assemble it. Now make the wiring connections and put the power on.
An air conditioner may have problems while running so at that time an air conditioner repair is required. If an air conditioner stops working suddenly, its called tripping. There may be many reasons for tripping in an air conditioner and troubleshooting is required to find the actual fault and to make air conditioner repair. Following is the list of possible faults with reasons and solutions to repair air conditioners.
1. Air conditioner repair for tripping due to Refrigerant leaks
Reasons :- There are many joints and threaded fittings in copper piping connections. Leakage of refrigerant gas may happen if any of these fittings are not installed properlly or joints are not brazed properly. But sometimes leakage may happen due to any demage to the copper pipe, indoor unit and outdoor unit while installing, shifting or servicing the unit.
Troubleshooting :- If there is a leak in air conditioner copper piping circuit, the LP switch will automatically tripp the whole system. If the unit restarted again and again it will continue to trip. Tracing a leak is very difficult task and time consuming. Leaks can be detected with the help of leak detector or simply using soap and water mixture or a high froathing liquid. Just shake this liquid well and apply the froath on the joints and fittings. Bubbles formation will indicate the leak if its there.
Repair Method :- Air conditioning repair for this fault is not difficult. Once the leak is detected mark it with the help of a marker. Now release the refrigerant from the system or if possible store it. Refrigerant can be stored instead of releasing it in atmosphere. Now clean the area properly with the help of sand paper and start brazing to repair the leak spot. Once the brazing is finished, connect the vaccum pump to the air conditioner and put it on for 35-40 minutes. Don't disconnect the vaccum pump immediately after the vaccumization, wait for 15 minutes. If the vaccum pressure is maintained without any change on vaccum gauge, it means leak area is properly repaired. But if there is any change on the gauge, it means there may be any other leak or leak was not repaired properly. Repeat the process for tracing the leak again and follow the above process to repair the leak. If leakage is on indoor or outdoor unit's coil then send them to the manufacturer for repair.
2. Air conditioner repair for tripping due to choked system
Reasons :- Due to a choked copper piping air conditioning system pressure increases on compressor and it starts to take high amperes and an overload relay makes the system to trip as a safety procedure. Choking may be in compressor, condenser, expansion valve, in evaporator or any other component.
Troubleshooting :- If a compressor which is checked and found to work well is taking high amps it means the system is choked and that air conditioner need repair. Choking may happen due to improper vaccumization, bad lubrication system or oil mixing with refrigerant, due to faulty crank case heater, bad filters, bad driers or strainers etc.
Repair Method :- Air conditioner repair for this fault or tripp is bit difficult. Once choking is confirmed, it is required to remove refrigerant gas into the environment. This refrigerant will spray oil with it and will be black in color. To remove the choking you need to flush the whole piping network by proper flushing method. After finishing the flushing process, system is required to put on vaccum for one hour so that it could be free of all contamination and air. Don't disconnect the vaccum pump immediately after the vaccumization, wait for 15 minutes. If the vaccum pressure remains same it means there is no leak and air present in the system. Now you can fill the refrigerant gas in the system.
3. Air conditioner repair for tripping due to choked condenser or evaporator fins:-
Reasons :-Condensers and evaporators are same in their body construction but they are used for different puposes. A condenser or evaporator is made from copper or any other material with high conductivity passing through a set of fins. If air conditioner is not serviced time to time, contamination start to accumulate on the surface of fins and on the tubes. This choking will reduce the flow of air through the fins and results in lowing the efficiency of condenser or evaporator. Once the efficiency starts to go down, it will increase pressure on compressor and condenser fan as well and system will start to trip frequently.
Troubleshooting :- Thoroughly check the condenser and evaporator coils. A contaminated condenser or evaporator can be easily traced. The dust can easily be seen on the coils of tubes.
Repair Method :- An air conditioner should be serviced regularly usually four times in a year. This will keep the air conditioner working well and reduce the chances of blockage.
4. Air conditioner repair for tripping due to Ice formation on coil:-
Reasons :-Sometimes it is observed that ice formation happens on the cooling coil and it stops the air circulation over the coil. This ice formation increase the static pressure on the evaporator blower fan and safety switch make the system to trip. There may be some other reasons for this ice formation like low refrigerant in system, bad or choked air filters on return or supply sides as air can't pass through the cooling coil in proper volume, blower motor reduced RPM and low air through etc.
Troubleshooting :- Check the refrigerant pressures and quantitiy in system low refrigerant is main cause of ice formation on cooling coil. Thoroughly check all air filters on return and supply side of source unit.Check blower motor, is it properly throughing enough CFM.
Repair Method :- Maintain quantity of refrigerant in system if low or high quantity is found in the system. Properly clean air filters and cooling coils as well. If blower motor found with low RPM and low air flow or CFM then we need to check the motor supplies as well. If voltage and amperes are ok then check the capacitor, if found faulty change it and motor will now run at full speed.
5. Air conditioner repair for tripping due to short or grounding:-
Reasons :- Any component of air conditioning unit like compressor, blower fan motor and condenser fan motor can be short or ground because of running for long time periods at the time of peak heat loads. The short circuits results in tripping of system.
Troubleshooting :- If the system is tripping due to short circuit you have to trace the fault. Its easy, there are magnetic contactors provided for each ciruit and it can be mannually switched on. Just push the button on magnatic contactor if the compressor or condenser fan is grounded it will trip the system immediately after start. To check the faulty component you need to check them one by one. Check the continuity of compressor or motor winding with unit's body with the help of voltmeter. A voltemeter has an option to select the continuity option as shown in figure. If the sound of beep is coming from motor or from compressor it means motor or compressor is grounded.
Repair Method :- If the compressor is ground, we have to either change it or if its open type then we need to send it for motor winding. Same thing is applicable on faulty blower or condenser fan motor.
6. Air conditioner repair for tripping due to over refrigerant charged in system:-
Reasons :- If an air conditioner is over charged with refrigerant even then it will make tripping again and again. While filling refrigerant in an air conditioner recommended refrigerant quantity from manufacturer should be charged.
Troubleshooting :- Over charging of refrigerant in an air conditioner can be easily checked by connecting gauge manifold set and checking pressures of refrigerant. If discharge pressure is more than recommended it means refrigerant gas is overcharged.
Soultion :- Release the extra refrigerant by opeing service valve into the environment until it reaches the recommended quantity. Normally suction and discharge pressure in an air conditioning unit should be in ratio of 65-270 psi respectively.
7. Air conditioner repair for ice formation on expansion valve:-
Reasons :- Due to frequent automatic opening and closing of expansion valve put pressure on moving stem and diaphragm. Due to this pressure diaphragm may break and expansion valve can be demaged.
Troubleshooting :- Ice formaion over the expansion valve and distributors indicates the failure of expansion valve, if the moving stem is not closing the valve. If the diaphragme is broken it will keep the valve in close position which will increase pressure on compressor and make the system to trip from overload relay.
Soultion :- An expansion valve can be repaired easily but if its not possible to repair, then change the expansion valve.
8. Air conditioner repair for faulty magnetic contactors:- A magnetic contactor is a kind of switch which put on and off an air conditioner's compressor automatically as it is intigrated with PCB. A magnetic contactor works on the principle of electromagnetism as shown in figure. When temperature on the coil increases, sensor sends a signal to the PCB and PCB switches on the power through a transformer to the magnetic contactor's coil, which may be a 24V or 220-230 V. A transformer is required if magnetic contactor's coil works on 24V power supply. A magnetic contactor may be of 2 poles, 3 poles, 4 poles according to type of power supply(single phase 220V or three phase 420 V) and with NO (normally open) NC (Normally close) poles options.
A SINGLE PHASE MAGNETIC CONTACTOR :- As shown in figure below it has three poles for phase and neutral . The small poles functions and magnetic coils supply.
Reasons :- Due to frequent switching on and off automatic process, the connecting points of the magnetic contactors get carbonized and dirty. This carbon makes the contactor faulty and air conditioner doesn't work properly.
Troubleshooting :- Before checking the contactor, it is necessary to disconnect the main supply from isolator. Disconnect the wires of main power supply to magnetic contactor and open the magnetic contactor poles. If black thick carbon is found on the poles you need to clean it properly and re-assemble it. Now make the wiring connections and put the power on.