FILE NO. SVM-07008-1

(Unit : Nám) 10-3-3. Evacuating

Outer dia.

Tightening torque

of copper pipe

 

 

 

∅6.35 mm

16 to 18 (1.6 to 1.8 kgf·m)

 

 

 

￿9.52∅

mm

30 to 42 (3.0 to 4.2 kgf·m)

 

 

 

￿Tightening torque of flare pipe connections The operating pressure of R410A is higher than that of R22. (Approx. 1.6 times).

It is therefore necessary to firmly tighten the flare pipe connecting sections (which connect the indoor and outdoor units) up to the specified tightening torque. Incorrect connections may cause not only a gas leakage, but also damage to the refrigerant cycle.

Flare at

indoor unit side

Flare at outdoor unit side

Fig. 10-3-5

<Shaping pipes>

1.How to shape the pipes

Shape the pipes along the incused line on the outdoor unit.

2.How to fit position of the pipes

Put the edges of the pipes to the place with a distance of 85 mm from the incused line.

 

m

 

m

5

8

 

Incused line

After the piping has been connected to the indoor unit, you can perform the air purge together at once.

AIR PURGE

Evacuate the air in the connecting pipes and in the indoor unit using a vacuum pump. Do not use the refrigerant in the outdoor unit. For details, see the manual of the vacuum pump.

<Using a vacuum pump>

Be sure to use a vacuum pump with counter-flow prevention function so that inside oil of the pump does not flow backward into pipes of the air conditioner when the pump stops. (If oil inside of the vacuum pump enters into the air conditioner, which use R410A, refrigeration cycle trouble may result.)

1.Connect the charge hose from the manifold valve to the service port of the gas side packed valve.

2.Connect the charge hose to the port of the vacuum pump.

3.Open fully the low pressure side handle of the gauge manifold valve.

4.Operate the vacuum pump to start evacuating. Perform evacuating for about 15 minutes if the piping length is 20 meters. (15 minutes for

20 meters) (assuming a pump capacity of 27 liters per minute. Then confirm that the compound pressure gauge reading is − 101 kPa (76 cmHg).

5.Close the low pressure side valve handle of gauge manifold.

6.Open fully the valve stem of the packed valves (both side of Gas and Liquid).

7.Remove the charging hose from the service port.

8.Securely tighten the caps on the packed valves.

Compound pressure gauge

Pressure gauge

–101 kPa (76 cmHg)

Manifold valve

Handle Lo Handle Hi (Keep full closed)

Charge hose (For R410A only)

Charge hose (For R410A only)

Connecting pipe

 

Vacuum pump adapter for counter-flow prevention (For R410A only)

Vacuum

pump

Fig. 10-3-6

Packed valve at gas side

Service port (Valve core (Setting pin))

Packed valve at liquid side

Fig.10-3-7

CAUTION

•KEEP IMPORTANT 4 POINTS FOR PIPINGWORK

(1)Take away dust and moisture (Inside of the connecting pipes.)

(2)Tight connection (between pipes and unit)

(3)Evacuate the air in the connecting pipes using

VACUUM PUMP.

(4)Check gas leak (connected points)

– 56 –