Appendix For Refrigerators Service Maintenance Manual - LG GC-B379S*QA Service Manual

Appendix for refrigerators service maintenance manual

1. Master should phone with client for appeal reasons clarification before visit.
2. Agree the accepted request with the senior master, for more accurate malfunction identification and for taking of reserve parts and
equipment needed.
3. Arriving to the customer inspect refrigerator for the presence of mechanical damages. In case of damages presence fix them on
the camera or any other digital technics.
4. The temperature indoors should be not below 16 degrees.
In case of malfunction concerned with lack of food cooling in refrigerator or freezer it is necessary to check filter-drain warming up
(it should be warm). The fact that filter is cold indicates the system clogging or the leak of refrigerant. Check all visible parts of the pipes and
pipes joints (solderings) with the leak detector designed for refrigerants R143a or R600a. At the time of diagnostics isolate the air flow
directed from the fan of the condenser and compressor. In case of leak detection eliminate it.
For leak elimination it is necessary to:
- crop refueling pipe with pipe cutter;
- make pumping process for 10-15 minutes;
- solder again the area of leak by gas torch or cut this area by pipe cutter, expand pipe and solder it in the place cutting off earlier;
- change filter to LG brand filter for refrigerant R134a or R600a (depends on refrigerant used by compressor);
- make pumping process for 10-15 minutes again;
- fill the unit with necessary refrigerant amount specified in grams on the label inside the product;
- remember that the pressure during the normal operating of refrigerator should be equal to
• «0+0.5Br» – for refrigerators with refrigerating unit operating with R134a refrigerant;
• «-0.5Br» – for refrigerators with refrigerating unit operating with R600a refrigerant.
If to cut off capillary pipe hardly below the filter-drain, flow capability of refrigerant will be bad at capillary pipe clogging from capillary side.
Oil with shavings of rubbing parts got into system from compressor can be the reason of capillary pipe clogging.
There are 3 ways to eliminate capillary pipe clogging.
1. Bursting with nitrogen is the easiest and less expensive way.
Cut off the suction pipe near the compressor and the capillary pipe near the filter. Wind reductor on the nitrogen balloon and connect a
reinforced hose to reductor (it can be the hose for manometric rail). Hose must withstand at least 20atm. Connect a hose from the balloon
to manometric rail, and a hose from manometric rail (high pressure side) to suction pipe of refrigerator. Open the nitrogen bottle. The
pressure over 13 atmospheres for refrigerators with tube-on-sheet evaporator and the pressure over 20 atmospheres for refrigerators with
tubular evaporator are not recommended. Close balloon and block valve on a rail. It is recommended to wait at least 10-15 minutes.
Pressure decrease means that the obstruction began to be eliminated. If the pressure remains unchanged go to second method.
2. Punching hydraulic press.
Take the hydraulic press for punching a capillary pipe (you can buy it in auto stores,
they are used for pressing various parts.) Fill the oil in hydraulic press, which use in the similar refrigerator.
Then connect a hydraulic press to a capillary pipe and maximum pump oil by hydraulic press in a
capillary tube. Obstruction is eliminated not immediately, it takes time while the oil passed through
the capillary.
3. Bursting with dichloromethyl
To solder a pipe 1 / 4 with schrader valve on cutting capillary pipe near the filter. To unscrew from the valve spool. and fill there from
syringe volume of 5-10 ml of dichloromethyl. Then, to wind the hose onto the valve. And serve the liquid refrigerant R22 through the
manometer rail, if there is not the R134. Gas should not much, it needed only to dichloromethyl held in the capillary. Add nitrogen to
provide high pressure and wait. Dichloromethyl gradually dissolves clots and at the beginning passage would be minimal. Operation should
be repeated 2-3 times.For greater effect, I recommend plugging your finger suction pipe to increase the pressure in the system, When the
sudden opening more oil comes out of it. Then you must do exactly the same operation on suction side, in the opposite direction.
When the oil is no longer out of the system, ALWAYS thoroughly purged with nitrogen through a suction pipe to remove residual
dichloromethyl. Dichloromethyl dissolves varnish motor windings, that will lead to failure of the compressor. To verify that the obstruction is
eliminated completely , must be submitted through
Liquid refrigerant through the suction pipe and while the capillary pipe should be covered with ice and the oil should not come out of it. You
can verify this by substituting under a stream of refrigerant, for example, pliers.
Be extremely careful when you cure the obstruction. Oil suddenly can shoot and dirty all around, recommend to cover the cloth.
APPENDIX FOR REFRIGERATORS SERVICE MAINTENANCE MANUAL
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