Cautions For Flare Connection; Refrigerant Piping; Preventing Foreign Objects From Entering - Panasonic U-4ML3DPQ Manuel D'installation

8.2. Cautions for flare connection
See the following table for flare part machining dimensions.
When connecting the flare nuts, apply refrigerant ether or ester
oil to the inside and outside of the flares and turn them three or
four times at first.
When loosening a flare nut, always use two wrenches in
combination. When connecting the piping, always use a spanner
and torque wrench in combination to tighten the flare nut.
1 Piping union
2 Spanner
3 Flare nut
4 Torque wrench
12 3 4
See the following table for tightening torque.
(Applying too much torque may cause the flares to crack.)
Tightening
Pipe size Torque (N•m)
Ø9.5 32.7~39.9
Ø15.9 61.8~75.4
After all the piping has been connected, use nitrogen to perform
a gas leak check.
You must use a torque wrench but if you are obliged to
NOTE
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:
Further tightening
Pipe size
Ø9.5 (3/8")
Ø15.9 (5/8")
U-4~6ML3DPQ
Urban Multi air conditioner
4PW17809-1C
A (mm) Flare shape
90 ±2
12.8~13.2
A
R=0.4~0.8
19.3~19.7
Recommended
angle arm length of tool
60~90° ±200 mm
30~60° ±300 mm
9. R
EFRIGERANT PIPING
Field pipes can be installed in four directions.
Figure - Field pipes in four directions (See figure 5)
1 Drill
2 Center area around knockout hole
3 Knockout hole
4 Slit
5 Connecting pipe liquid (field supply)
6 Bottom frame
7 Front plate
8 Pipe outlet plate
9 Screw front plate
10 Pipe outlet plate screw
11 Connecting pipe gas (field supply, except U-6ML3)
A Forward
B Backward
C Sideways
D Downward
When connecting the piping in the lateral direction (on the rear),
remove the piping cover (rear) and receiver mounting plate in
reference to figure 7.
1 Receiver mounting plate
2 Piping cover (rear)
To install the connecting pipe to the unit in a downward direction,
make a knockout hole by penetrating the center area around the
knockout hole using a Ø6 mm drill. (See figure 5).
Cutting out the two slits makes it possible to install as shown in
figure 5.
(Use a metal saw to cut out the slits.)
After knocking out the knock-out, it is recommended to apply
repair paint to the edge and the surrounding end surfaces to
prevent rusting.
For U-6ML3 only
The size of the gas side stop valve is Ø15.9 while the inter-unit piping
is Ø19.1. Use the standard supplied accessory piping to make the
connection. See figure 15.
A Front connection
B Rear connection
C Side connection
D Bottom connection
1 Gas line piping + copper gasket supplied with the unit (1) (make
sure to always use the copper gasket).
2 Gas line piping supplied with the unit (3)
3 Gas piping (field supply)
4 Cut to the appropriate length.
5 Gas line piping supplied with the unit (2)

9.1. Preventing foreign objects from entering

Plug the pipe through-holes with putty or insulating material
(procured locally) to stop up all gaps, as shown in the figure.
1
Insects or small animals entering the outdoor unit may cause a short
circuit in the electrical box.
1 Putty or insulating material
(procured locally)
Installation manual
7