LG Electronics LRTN19310, LRTN22310 service manual Items Unit Standards Purposes Remarks

▼General Control of Refrigerating Cycle

NO.	ITEMS		UNIT	STANDARDS	PURPOSES	REMARKS
1	Pipe and		Min.	Pipe: within 1 hour.	To protect	The opening time should be reduced
	piping system			Comp: within 10 minutes.	moisture	to a half of the standards during rain
	opening time			Drier: within 20 minutes.	penetration.	and rainy seasons (the penetration of
						water into the pipe is dangerous).
2	Welding		Nitrogen	Weld under Nitrogen	To protect oxide	- Refer to repair note in each part.
			pressure	atmosphere.	scale formation.	- R-134a refrigerant is more
				(N2 pressure:		susceptible to leaks than R-12 and
				0.1~0.2 kg/cm2)		requires more care during welding.
						- Do not apply force to pipes before and
						after welding to protect pipe from cracking.
3	N2 sealed		Confirm	Confirm the sound of	To protect	- In case of evaporator parts, if it doesn't
	parts		N2 leak	pressure relief when	moisture	make sound when removing rubber
				removing the rubber cap.	penetration.	cap, blow dry air or N2 gas for more
				Sound: usable		than 1 min. and than use the parts.
				No sound: not usable
4	Refrige-	Evacuation	Min.	More than 40 minutes	To remove moisture.
	ration	time
	Cycle	Vacuum	Torr	Below 0.03 (ref)		Note: Only applicable to the model
		degree				equipped with reverse flow
						protect plate.
		Vacuum	EA	High and low pressure sides		Vacuum efficiency can be improved
				are evacuated at the same		by operating compressor during
				time for models above 200 l.		evacuation.
		Vacuum	EA	Use R-134a manifold	To protect mixing	The rubber pipes for R-12 refrigerant
		piping		exclusively.	of mineral and	will be melted when they are used for
					ester oils.	R-134a refrigerant (causes of leak.)
		Pipe	EA	Use R-134a manifold	To protect R-12
		coupler		exclusively.	refrigerant mixing.
		Outlet		R-134a manifold exclusively.	To protect R-12
		(Socket)			refrigerant mixing.
		Plug		R-134a manifold exclusively.	To protect R-12
					refrigerant mixing.
5	Refrigerant		EA	Use R-134a exclusively.	Do not mix with	- Do not weigh the refrigerant at too
	weighing			Weighing allowance: ±5g	R-12 refrigerant.	hot or too cold an area.
				Note: Winter: -5g		(77°F [25°C] is adequate.)
				Summer: +5g		- Make Copper charging canister
						(Device filling refrigerant)
						Socket: 2SV Plug: 2PV R-134a
						Note: Do not burn O-ring (bushing)
						during welding.
6	Drier			- Use R-134a exclusively for	To remove the
	replacement			R-134a refrigerator.	moisture from
				- Replace drier whenever repairing	pipe inside.
				refrigerator cycle piping.
7	Leak check			- Do not use soapy water for	Defect in	- Check for an oil leak at the refrigerant
				check. It may be sucked	refrigerant leak	leak area. Use an electronic leak
				into the pipe by a vacuum.	area.	detector if an oil leak is not found.
						- The electronic leak detector is very
						sensitive to halogen gas in the air. It
						also can detect R-141b in urethane.
						Practice many times before using this
						type of detector to avoid false readings.

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