Panasonic R410A: 5/16 - Page 23

23
● Precautions for brazing
Be sure to replace the air inside the tube with nitrogen to prevent oxide film from forming during the brazing process.
Be sure to use a damp cloth or other means to cool the valve unit during brazing.
CAUTION
1. Be sure to use nitrogen. (Oxygen, CO
2
, and CFC must not be used.)
2. Use a pressure-reducing valve on the nitrogen tank.
3. Do not use agents intended to prevent the formation of oxide film. They will adversely affect the refrig-
eration oil, and may cause equipment failure.
4. The balance tube is not used if only 1 outdoor unit is installed.
Use the unit in the same conditions as when it was shipped from the factory.
Refrigerant tube port
● Use caulking, putty, or a similar material to fill any gaps at the
refrigerant tube port ( ) in order to prevent rainwater, dust or
foreign substances from entering the unit.
* Perform this work even if the tubing is routed out in a downward
direction.
● Tighten each cap as specified below.
Tightening torque for each cap
Tu bi n g
cover
Bottom
plate
Tubing routed out
through the front side
Tubing routed out
through the bottom
Brazing locations
Field-supply tube
Taping
Remote valve
Nitrogen
Pressure-reducing valve (regulator)
Work method
Service port cap
(width 19/32)
Service port cap
(width 19/32", 43/64")
Service port cap
(width 19/32)
Flare nut
(ø1/4)
Flare nut
(ø3/8)
Service port cap
(width 19/32)
Valve cap
(width 55/64)
Valve cap
(width 55/64", 15/16")
Valve cap
(width 55/64)
Valve cap
(width 55/64)
Cap tightening torque
* Be careful of the cap sizes. The sizes of the service port cap and valve cap
on the 09663 type liquid tube valves are different from other valve caps.
Use two adjustable wrenches, as shown in the figure,
when removing the liquid tube valve flare nut.
1. Do not apply a wrench to the valve cap when removing or
installing the flare nuts. Doing so may damage the valve.
60 – 100 lbs·in (70 – 120 kgf
·
cm)
170 – 220 lbs·in (200 – 250 kgf
·
cm)
Do not apply an adjustable wrench
to the hexagonal part.
Do not use two adjustable wrenches when
removing or installing the balance tube
flare nut. In particular, do not apply an
adjustable wrench to the hexagonal part at
the top of the valve.
(If force is applied to this part,
gas leakage will occur.)
2. If the valve cap is left off for a long period of time, refrigerant
leakage will occur. Therefore, do not leave the valve c
ap off.
3. Applying refrigerant oil to the flare surface can be effective in
preventing gas leakage, however be sure to use a refrigerant
oil which is suitable for the refrigerant that is used in the system.
(This unit utilizes R410A refrigerant, and the refrigerant oil is
ether oil (synthetic oil). However, hub oil (synthetic oil) can also
be used.)
Unit: in.