Sanyo 85464359982001 Tube diameter Tightening torque Tube thickness Approximate

07-007 W-2WAY_II_NA 1/23/07 6:09 PM Page 64

Caution Before Connecting Tubes Tightly

(1)Apply a sealing cap or water-proof tape to prevent dust or water from entering the tubes before they are used.

(2)Be sure to apply refrigerant lubricant to the matching surfaces of the flare and union before connecting them together. This is effective for reducing gas leaks.

(Fig. 6-4)

(3)For proper connection, align the union tube and flare tube straight with each other, then screw in the flare nut lightly at first to obtain a smooth match. (Fig. 6-5)

●Adjust the shape of the liquid tube using a tube bender at the installation site and connect it to the liquid tubing side valve using a flare.

Cautions During Brazing

●Replace air inside the tube with nitrogen gas to prevent copper oxide film from forming during the brazing process. (Oxygen, carbon dioxide and Freon are not acceptable.)

●Do not allow the tubing to get too hot during brazing. The nitrogen gas inside the tubing may overheat, causing refrigerant system valves to become damaged. Therefore allow the tubing to cool when brazing.

●Use a reducing valve for the nitrogen cylinder.

●Do not use agents intended to prevent the formation of oxide film. These agents adversely affect the refrigerant and refrigerant oil, and may cause damage or malfunctions.

6-2. Connecting Tubing Between Indoor and Outdoor Units

(1)Tightly connect the indoor-side refrigerant tubing extended from the wall with the outdoor-side tubing.

(2)To fasten the flare nuts, apply specified torque as at right:

●When removing the flare nuts from the tubing connections, or when tightening them after connecting the tubing, be sure to use 2 monkey wrenches or spanners as shown. (Fig. 6-6)

If the flare nuts are over-tightened, the flare may be damaged, which could result refrigerant leakage and cause in injury or asphyxiation to room occupants.

●For the flare nuts at tubing connections, be sure to use the flare nuts that were supplied with the unit, or else flare nuts for R410A (type 2). The refrigerant tubing that is used must be of the correct wall thickness as shown in the table at right.

Apply refrigerant

lubricant here and here

Fig. 6-4

Union Flare nut

Fig. 6-5

Torque wrench

Indoor unit			Spanner
			Outdoor unit
		Fig. 6-6
Tube diameter	Tightening torque,			Tube thickness
	approximate
ø1/4" (ø6.35 mm)	120 – 160 lbs · inch			1/32"
	(140 – 180 kgf · cm)				(0.8 mm)
ø3/8" (ø9.52 mm)	300	– 360 lbs · inch		1/32"
	(340	– 420 kgf · cm)			(0.8 mm)
ø1/2" (ø12.7 mm)	430 – 530 lbs · inch			1/32"
	(490	– 610 kgf · cm)			(0.8 mm)
ø5/8" (ø15.88 mm)	590	– 710 lbs · inch		5/128"
	(680	– 820 kgf · cm)			(1.0 mm)
ø3/4" (ø19.05 mm)	870	– 1040 lbs · inch			over 5/128"
	(1000 – 1200 kgf · cm)				(1.0 mm)

Because the pressure is approximately 1.6 times higher

than conventional refrigerant pressure, the use of ordinary

flare nuts (type 1) or thin-walled tubes may result in tube

rupture, injury, or asphyxiation caused by refrigerant

leakage.

●In order to prevent damage to the flare caused by over- tightening of the flare nuts, use the table above as a guide when tightening.

●When tightening the flare nut on the liquid tube, use a monkey wrench with a nominal handle length of 7-7/8 in.

64