Wednesday, November 04, 2015

LG AIR CONDITIONER TROUBLE SHOOTING AND CIRCUIT DIAGRAM LA121CNM LA121HNM

LG  LA121CNM - LA121HNM 

AIR CONDITIONER TROUBLE SHOOTING AND CIRCUIT DIAGRAM  
TROUBLESHOOTING 
PUMPING DOWN
(1) Confirm that both the 2-way and 3-way valves are set to the open position.
# Remove the valve stem caps and confirm that the valve stems are in the raised position.
# Be sure to use a hexagonal wrench to operate the valve stems.
(2) Operate the unit for 10 to 15 minutes.
(3) Stop operation and wait for 3 minutes, then connect the charge set to the service port of the 3-way valve.
# Connect the charge hose with the push pin to the service port.
(4) Air purging of the charge hose.
# Open the low-pressure valve on the charge set slightly to air purge from the charge hose.
(5) Set the 2-way valve to the closed position.
(6) Operate the air conditioner at the cooling cycle and stop it when the gauge indicates 1kg/cm2g.
(7) Immediately set the 3-way valve to the closed position.
# Do this quickly so that the gauge ends up indicating 3 to 5kg/cm2g.
(8) Disconnect the charge set, and mount the 2-way and 3-way valve’s stem nuts and the service port nut.
# Use torque wrench to tighten the service port nut to a torque of 1.8 kg.m.
# Be sure to check for gas leakage.
GAS LEAKAGE
(1) Confirm that both the 2-way and 3-way valves are set to the back seat.
(2) Connect the charge set to the 3-way valve’s port.
# Leave the valve on the charge set closed.
# Connect the charge hose to the service port.
(3) Open the valve (Lo side) on the charge set and discharge the refrigerant until the gauge indicates 0 kg/cm2G.
# If there is no air in the refrigerant cycle (the pressure when the air conditioner is not
running is higher than 1 kg/cm2G), discharge the refrigerant until the gauge indicates 0.5 to 1 kg/cm2G. if this is the case, it will not be necessary to apply a evacuatin.
# Discharge the refrigerant gradually; if it is discharged too suddenly, the refrigeration oil will also be discharged.
ALL AMOUNT OF REFRIGERANT LEAKED
(1) Connect the vacuum pump to the center hose of charge set center hose
(2) Evacuation for approximately one hour.
#Confirm that the gauge needle has moved toward -76 cmHg (vacuum of 4 mmHg or less).
(3) Close the valve (Lo side) on the charge set, turn off the vacuum pump, and confirm that the gauge needle does not move (approxima-tely 5 minutes after turning off the vacuum pump).
(4) Disconnect the charge hose from the vacuum pump.
# Vacuum pump oil. If the vacuum pump oil becomes dirty or depleted, replenish as needed.
GAS CHARGING
(1) Connect the charge hose to the charging cylinder.
# Connect the charge hose which you disconnected from the vacuum pump to the valve at the bottom of the cylinder.
# If you are using a gas cylinder, also use a scale and reverse the cylinder so that the system can be charged with liquid.
(2) Purge the air from the charge hose.
# Open the valve at the bottom of the cylinder and press the check valve on the charge set to purge the air. (Be careful of the liquid refrigerant). The procedure is the same if using a gas cylinder.
(3) Open the valve (Lo side on the charge set and charge the system with liquid refrigerant.
# If the system can not be charged with the specified amount of refrigerant, it can be charged with a little at a time (approximately 150g each time) while operating the air conditioner in the cooling cycle; however, one time is not sufficient, wait approximately 1 minute and then repeat the procedure (pumping down-pin).
NOTE : This is different from previous procedures. Because you are charging with liquid refrigerant from the gas side, absolutely do not attempt to charge with larger amounts of liquid refrigerant while operating the air conditioner.
(4) Immediately disconnect the charge hose from the 3-way valve’s service port.
# Stopping partway will allow the gas to be discharged.
# If the system has been charged with liquid refrigerant while operating the air conditioner turn off the air conditioner before disconnecting the hose.
(5) Mount the valve stem nuts and the service port nut.
# Use torque wrench to tighten the service port nut to a torque of 1.8 kg.m.
# Be sure to check for gas leakage.
Additional gas charging (Gas leakage)
# When refrigerant is insufficient by leakage, recharge the unit with the refrigerant up to normal operating suction pressure.
# Use the graph or the equation below to get operating suction pressure according to indoor and outdoor temperature.
Suction pressure was measured at 3-way valve service port after operating the unit for 10 minutes.
Compressor/Outdoor Fan are unable to drive.
Turn on Main Power
Operate "Cooling Mode" by setting the desired temperature of the remote controller is less than one of the indoor temperature by 2°F at least
When in Fan Mode, Compressor/Outdoor Fan is stopped.
Check the sensor for indoor temperature is attached as close as to be effected by the temperature of Heat Exchanger(EVA
When the sensor circuit for indoor temperature and connector are in bad connection or are not engaged, Compressor/Outdoor Fan is stopped.
# Check the related circuit of R02H(12.1K), R01H(6.2K), Micom  (Indoor unit).
# Check the indoor temperature sensor is disconnected or not(About 10kΩ / at 77°F).
When the temperature around Outdoor PWB Ass'y is above 163°F the compressor is stop and only Outdoor Fan is operating.
Check Relay(RY - COMP) for driving compressor.
When the power(About AC110V) is applied to the connecting wire terminal support transferred to compressor, PWB Ass'y is normal.
# Check the circuit related to the relay(Outdoor unit).

CIRCUIT DIAGRAM
INDOOR

OUT DOOR
CLICK ON THE IMAGE TO ZOOM IN