Toshiba MMU-AP0091H New Refrigerant R410A, Safety Caution Concerned to New Refrigerant, Tools

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• New Refrigerant (R410A)

This air conditioner adopts a new HFC type refrigerant (R410A) which does not deplete the ozone layer.

1. Safety Caution Concerned to New Refrigerant

The pressure of R410A is high 1.6 times of that of the former refrigerant (R22). Accompanied with change of refrigerant, the refrigerating oil has been also changed. Therefore, be sure that water, dust, the former refriger- ant or the former refrigerating oil is not mixed into the refrigerating cycle of the air conditioner with new refriger- ant during installation work or service work. If an incorrect work or incorrect service is performed, there is a possibility to cause a serious accident. Use the tools and materials exclusive to R410A to purpose a safe work.

2. Cautions on Installation/Service

(1)Do not mix the other refrigerant or refrigerating oil.

For the tools exclusive to R410A, shapes of all the joints including the service port differ from those of the former refrigerant in order to prevent mixture of them.

(2)As the use pressure of the new refrigerant is high, use material thickness of the pipe and tools which are specified for R410A.

(3)In the installation time, use clean pipe materials and work with great attention so that water and others do not mix in because pipes are affected by impurities such as water, oxide scales, oil, etc. Use the clean pipes.

Be sure to brazing with flowing nitrogen gas. (Never use gas other than nitrogen gas.)

(4)For the earth protection, use a vacuum pump for air purge.

(5)R410A refrigerant is azeotropic mixture type refrigerant. Therefore use liquid type to charge the refrigerant. (If using gas for charging, composition of the refrigerant changes and then characteristics of the air condi- tioner change.)

3. Pipe Materials

For the refrigerant pipes, copper pipe and joints are mainly used. It is necessary to select the most appropriate pipes to conform to the standard. Use clean material in which impurities adhere inside of pipe or joint to a minimum.

(1) Copper pipe

<Piping>

The pipe thickness, flare finishing size, flare nut and others differ according to a refrigerant type.

When using a long copper pipe for R410A, it is recommended to select “Copper or copper-base pipe without seam” and one with bonded oil amount 40mg/10m or less. Also do not use crushed, deformed, discolored (especially inside) pipes. (Impurities cause clogging of expansion valves and capillary tubes.)

<Flare nut>

Use the flare nuts which are attached to the air conditioner unit.

(2)Joint

The flare joint and socket joint are used for joints of the copper pipe. The joints are rarely used for installa- tion of the air conditioner. However clear impurities when using them.

4. Tools

(1)Required Tools for R410A

Mixing of different types of oil may cause generation of sludge, clogging of capillary, etc. Accordingly, the tools to be used are classified into the following three types.

1)Tools exclusive for R410A (Those which cannot be used for conventional refrigerant (R22))

2)Tools exclusive for R410A, but can be also used for conventional refrigerant (R22)

3)Tools commonly used for R410A and for conventional refrigerant (R22)

The table below shows the tools exclusive for R410A and their interchangeability.

Tools exclusive for R410A (The following tools for R410A are required.)

Tools whose specifications are changed for R410A and their interchangeability

				R410A	Conventional air
			air conditioner installation		conditioner installation
No.	Used tool	Usage
			Existence of	Whether conven-	Whether new equipment
			new equipment	tional equipment can	can be used with
			for R410A	be used	conventional refrigerant
	Flare tool	Pipe flaring	Yes	*(Note 1)	Yes
	Copper pipe gauge for	Flaring by conventional
	adjusting projection		Yes	*(Note 1)	*(Note 1)
		flare tool
	margin
	Torque wrench	Connection of flare nut	Yes	No	No
	Gauge manifold	Evacuating, refrigerant	Yes	No	No
		charge, run check, etc.
	Charge hose
	Vacuum pump adapter	Vacuum evacuating	Yes	No	Yes
	Electronic balance for	Refrigerant charge	Yes	Yes	Yes
	refrigerant charging
	Refrigerant cylinder	Refrigerant charge	Yes	No	No
	Leakage detector	Gas leakage check	Yes	No	Yes
	Charging cylinder	Refrigerant charge	(Note 2)	No	No

(Note 1) When flaring is carried out for R410A using the conventional flare tools, adjustment of projection margin is necessary. For this adjustment, a copper pipe gauge, etc. are necessary.

(Note 2) Charging cylinder for R410A is being currently developed.

General tools (Conventional tools can be used.)

In addition to the above exclusive tools, the following equipments which serve also for R22 are necessary as the general tools.

(1)	Vacuum pump	(7)	Screwdriver (+, –)
	Use vacuum pump by	(8)	Spanner or Monkey wrench
	attaching vacuum pump adapter.
		(9)	Hole core drill
(2)	Torque wrench
		(10)		Hexagon wrench (Opposite side 4mm)
(3)	Pipe cutter
		(11)		Tape measure
(4)	Reamer
		(12)		Metal saw

(5)Pipe bender

(6)Level vial

Also prepare the following equipments for other installation method and run check.

(1)	Clamp meter	(3)	Insulation resistance tester (Megger)
(2)	Thermometer	(4)	Electroscope (Volt meter)