Pipe Insulation; Additional Refrigerant Charge - Panasonic U-5MX3XPQ Installation Manual

NOTE You must use a torque wrench but if you are obliged to
install the unit without a torque wrench, you may follow
the installation method mentioned below.
After the work is finished, make sure to check that
there is no gas leak.
When you keep on tightening the flare nut with a
spanner, there is a point where the tightening torque
suddenly increases. From that position, further tighten
the flare nut within the angle shown below:
Pipe size
Ø9.5 (3/8")
Ø12.7 (1/2")
Ø15,9 (5/8")

6.5. Pipe insulation

After finishing the leak test and vacuum drying, the piping must be
insulated. Take into account the following points:
Make sure to insulate the connection piping and refrigerant
branch kits entirely.
Be sure to insulate liquid, and gas piping (for all units) and oil
equalizing piping (only for U-18~48MX3).
Use heat resistant polyethylene foam which can withstand a
temperature of 70°C for liquid side piping and polyethylene foam
which can withstand a temperature of 120°C for gas side piping.
If you think the temperature and the relative humidity around the
cooling pipes might exceed 30°C and RH 80%, reinforce the
insulation of the cooling pipes (at least 20 mm thick).
Condensation might be formed on the surface of the insulation.
If there is a possibility that condensation on the stop valve might
drip down into the indoor unit through gaps in the insulation and
piping because the outdoor unit is located higher than the indoor
unit this must be prevented by sealing up the connections. See
figure 8.
A One outdoor unit installed
B When multiple outdoor units installed
1 Liquid line stop valve
2 Gas line stop valve
3 Indoor -outdoor interconnection piping
4 Sealing up treatment
5 Heat insulator
6 Oil-equalizing line stop valve
7 Oil-equalizing line
Be sure to insulate local pipes, as touching them can
cause burns.
Installation manual
10
Further tightening Recommended
angle arm length of tool
60~90° ±200 mm
30~60° ±250 mm
30~60° ±300 mm

6.6. Additional refrigerant charge

Refrigerant cannot be charged until field wiring has been
completed.
Refrigerant may only be charged after performing the leak
test and the vacuum drying (see above).
When charging a system, care shall be taken that its
maximum permissible charge is never exceeded, in view of
the danger of liquid hammer.
Charging with an unsuitable substance may cause
explosions and accidents, so always ensure that the
appropriate refrigerant (R-410A) is charged.
Refrigerant containers shall be opened slowly.
Always use protective gloves and protect your eyes when
charging refrigerant.
To avoid compressor breakdown. Do not charge the refrigerant
more than the specified amount.
This outdoor unit is factory charged with refrigerant and
depending on pipe sizes and pipe lengths some systems require
additional charging of refrigerant. (Refer to
additional refrigerant to be charged" on page
Make sure to use installation tools you exclusively use on
R-410A installations to withstand the pressure and to prevent
foreign materials from mixing into the system.
Charge the refrigerant to the liquid pipe in its liquid state. Since
R-410A is a mixed refrigerant, its composition changes if
charged in a state of gas and normal system operation would no
longer be assured.
Before filling, check whether the tank has a siphon attached or
not.
How to fill a tank with a siphon attached.
Fill with the tank upright.
There is a siphon tube inside,
so there is no need to turn the tank
upside-down.
Other ways of filling the tank
Fill with the tank upside-down.
Determine the weight of refrigerant to be charged additionally
referring to the item "Additional refrigerant charge" in
calculate the additional refrigerant to be charged" on page 8
fill in the amount in the "Additional refrigerant charge label"
attached to the unit.
After the vacuum drying is finished, charge the additional
refrigerant in its liquid state through the liquid stop valve service
port taking into account following instructions:
- Check that gas and liquid stop valves are closed.
- Stop the compressor and charge the specified weight of
refrigerant.
If the outdoor unit is not in operation and the total amount cannot
be charged, follow the procedures for additional refrigerant
charge shown below.
"How to calculate the
8).
"How to
and
U-5~48MX3
Urban Multi air conditioner
4PW16235-1C