Precautions For The Installation Of The Outdoor Unit - Hitachi RAS-8FSXNS2E Installation & Operation Manual

3.3.1 Precautions for the installation of the outdoor unit
When the installation and piping work for the multiple outdoor units is performed, it is required
the arrangement for outdoor units and piping length. 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 unit 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 < 25m.
3 For maintenance, attach "Main unit label" to the service cover (back side surface) of the
outdoor unit "A".
A
Outdoor
Unit A
Piping outlet
direction
Indoor unit
side
Piping
connection kit 2
L
L
La
Piping
connection kit 1
L: Keep the straight-line distance of 500mm or more for piping after the piping connection kit.
◆ Restrictions for 4 unit 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 < 25m.
PMML0628 rev.0 - 05/2023
> B >
C
Outdoor Outdoor
Unit B Unit C
Lb
Lc
< <
C
B
Outdoor Outdoor
Unit C Unit B
Piping
connection kit 2
L
Lb
Lc
A
Outdoor
Unit A
Piping outlet
direction
Indoor unit
side
L
La
Piping
connection kit 1
26
3