FILE NO. SVM-13004
–
65
–
Tightening of connecting part
1. Align the centers of the connecting pipes and fully tighten the fl are nut
with your fi ngers. Then fi x the nut with a wrench as shown in the fi gure
and tighten it with a torque wrench.
10-4-6.
Evacuating
Half union or packed valve
Fix with wrench.
Flare nut
Tighten with torque wrench.
Internally
threaded side
Externally
threaded side
After the piping has been connected to the indoor unit, you can perform
vacuuming together at once.
Using a vacuum pump
Be sure to use a vacuum pump with counter-fl ow prevention function so
that inside oil of the pump does not fl ow backward into pipes of the air
conditioner when the pump stops.
(If oil inside of the vacuum pump enters the air conditioner, which use
R410A, refrigeration cycle trouble may happen)
1. Connect the charge hose from the manifold valve to the service port of the
packed valve at gas side.
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 conÞ rm
that the compound pressure gauge reading is -101 kPa (-76 cmHg).
5. Close the low pressure side valve handle of the gauge manifold valve.
6. Open fully the valve stem of the packed valves (both gas and liquid
sides).
7. Remove the charging hose from the service port.
8. Securely tighten the caps on the packed valves.
VACUUMING
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.
•
After the installation work, be sure to check for gas leaks of the pipe
connections with nitrogen.
•
Pressure of R410A is higher than that of R22 (Approx. 1.6 times).
Therefore, using a torque wrench, tighten the fl are pipe connecting
sections that connect the indoor/outdoor units at the specifi ed tightening
torque.
Incomplete connections may cause not only a gas leak, but also trouble
with the refrigeration cycle.
Do not apply refrigerant oil to the fl ared surface.
2. As shown in the fi gure, be sure to use two wrenches to loosen or tighten
the fl are nut of the valve on the gas side. If you use a single crescent, the
fl are nut cannot be tightened to the required tightening torque.
On the other hand, use a single crescent to loosen or tighten the fl are nut
of the valve on the liquid side.
(Unit : N·m)
Outer dia. of copper pipe
Tightening torque
∅
9.52 mm
33 to 42 (3.3 to 4.2 kgf·m)
∅
15.88 mm
68 to 82 (6.8 to 8.2 kgf·m)
Cover
Piping valve
Cap
Tightened
Loosened
Flare nut
Valve at gas side
CAUTION
1. Do not put the crescent wrench on the cap or cover.
The valve may break.
2. If applying excessive torque, the nut may break according to some
installation conditions.
NO GOOD
Cover
Cap
CAUTION
•
KEEP IMPORTANT 5 POINTS FOR PIPING WORK.
(1) Take away dust and moisture (inside of the connecting pipes).
(2) Tighten the connections (between pipes and unit).
(3) Evacuate the air in the connecting pipes using a VACUUM PUMP.
(4) Check gas leak (connected points).
(5) Be sure to fully open the packed valves before operation.
Pressure gauge
Gauge manifold valve
-101 kPa (-76 cmHg)
Handle Low
Compound pressure gauge
Vacuum pump
Handle Hight
(Keep fully closed)
Charge hose
(For R410A only)
Vacuum pump adapter for
counter-fl ow prevention
(For R410A only)
Packed valve at gas side
Charge hose
(For R410A only)
Charge port
(Valve core (Setting pin))
Flare at indoor unit side
Flare at outdoor unit side
(Inside unit)
