Panasonic U-72MF2U9 Technical Data Manual page 36

2. System Design
2-3. Installing Distribution Joint
CAUTION
(1) Refer to "HOW TO ATTACH DISTRIBUTION JOINT" enclosed with the optional distribution joint kit (CZ-P900PH1U,
CZ-P224BH1U, CZ-P680BH1U, CZ-P1350BH1U).
When connecting a branch tubing to the indoor unit directly, it is necessary for each branch tubing to install at a positive angle
with respect to horizontal in order to prevent accumulation of refrigerant oil in stopped units. (See the below chart.)
Branch tubing system
1
How to install
branch tubing
B
A
2
D
Straight tubing
length over
Horizontal
8 in. (200mm)
3
Arrow view D
4
5
15∼90°
6
Header branch system
Outdoor
Indoor
7
6.5 ft. (2m)
(From 1st branch to tip
of solidly welded part)
Horizontal line
Install at a positive angle
8
9
Pay special attention to any location, such as a basement, etc., where leaking refrigerant can
accumulate, since refrigerant gas is heavier than air.
Restricted
When connecting branch tubing to indoor unit directly
Suction tube
* In case of common use solenoid valve kit
When connecting to A
Straight tubing
length over
B
8 in. (200mm)
A
Horizontal
Straight tubing length
over 8 in. (200mm)
15∼90°
Vertical
Vertical
Straight tubing
length over
8 in. (200mm)
Vertical
Vertical
(Main tubing is horizontal.)
Indoor
Horizontal line
Install at a positive angle
(15~30°)
Indoor
Solidly welded shut (X)
(15~30°)
Not restricted
Liquid tube / Discharge tube
When connecting to B
15∼90°
or
15∼30°
(Branch tubing
angle)
Straight tubing
length over
8 in. (200mm) Vertical
15∼90°
Be sure to solidly weld shut the T-joint end (marked by X in
the figure). In addition, pay attention to the insertion depth
of each connected tube so that the flow of refrigerant within
the T-joint is not impeded.
Be sure to use a commercial available T-joint.
When using the header joint system, do not make further
branches in the tubing.
Do not use the header joint system on the outdoor unit
side.
13
2 - 20
Design of 3WAY VRF SYSTEM
When not connecting
branch tubing to indoor
Suction tube /
Discharge tube /
Horizontal
0∼30°
(Branch tubing
angle)
Vertical Vertical
Vertical
unit directly
Liquid tube