Hitachi SET FREE-Serie Bedienungsanleitung Seite 38

PIPING WORK AND REFRIGERANT CHARGE
8.3.3 Precautions for the installation of the outdoor unit

Order of installation of the units
When the installation and piping work for the multiple outdoor units are performed, it is required that the arrangement for outdoor
units and piping length be determined. Perform securely the installation work according to the following restrictions. If the
arrangement for outdoor units is incorrect, it may cause flowback of the refrigerant and result in failure of outdoor unit.
Restrictions for 2 and 3 Units Combination
1 For 2 and 3 outdoor units combination, align the outdoor units from largest capacity to smallest as A > B > C and outdoor unit "A"
should be connected to the piping connection kit 1.
2 The piping length between the piping connection kit 1 and the outdoor unit should be La < Lb < Lc < 10m.
3 For maintenance, attach "Main unit label" to the service cover (back side surface) of the outdoor unit "A".
Piping outlet
direction
Indoor
unit side
Piping
connection kit 1
(*): Keep the straight-line distance of 500 mm or more for piping after the piping connection kit.
Restrictions for 4 Units Combination
1 For 4 outdoor unit combination, align the outdoor units from largest capacity to smallest as A > B > C > D. The outdoor units "A"
and "B" should be connected to the piping connection kit 2 and the outdoor unit "C" and "D" should be connected to the piping
connection kit 3.
2 The piping length between the piping connection kit 1 and each outdoor unit should be La < Lb < Lc < Ld < 10m.
3 For maintenance, attach the main unit label to the service cover (back side surface) of the outdoor unit "A".
A
Piping outlet
direction
Outdoor
unit A
Indoor unit
side
Piping connection kit 2
(*) (*)
La
Piping
connection kit 1

Refrigerant pipe installation between outdoor units
For refrigerant piping work, the optional piping connection kit is required to branch the pipe between outdoor units.
The arrangement for outdoor units should be determined depending on the piping direction when the refrigerant piping work and
installation work are planned. When the outdoor unit is installed, perform the installation work according to the following restrictions.
28 PMML0479 rev.2 - 02/2018
> >
A
B
C
Outdoor Outdoor Outdoor
unit unit unit
A B C
Piping
connection kit 2
L
b
(*)
(*)
L
a
L
c
>
>
>
B
C
D
Outdoor Outdoor Outdoor
unit B unit C unit D
(*)
Lb
Lc
Ld
Piping connection kit 3
(*): Keep the straight-line distance of 500 mm or more for piping after the piping connection kit.
< <
A
B
C
Outdoor Outdoor Outdoor
unit unit unit
C B A
(*)
(*)
Piping
connection kit 2
L
b
L
a
L
c
connection kit 1
<
<
B
C
D
Outdoor
Outdoor
Outdoor
unit C
unit D
unit B
(*)
Lb
Ld Lc
Piping connection kit 3
Piping outlet
direction
Indoor
unit side
Piping
<
A
Piping outlet
direction
Outdoor
unit A
Indoor unit
side
Piping connection kit 2
(*) (*)
La
Piping
connection
kit 1