Hitachi RAS-18FSXNS2E - Precautions for the Installation of the Outdoor Unit

26
PMML0628 rev.0 - 05/2023
3
PIPE CONNECTION
PIPING WORK AND REFRIGERANT CHARGE
3.3.1 Precauons for the installaon of the outdoor unit
When the installaon and piping work for the mulple outdoor units is performed, it is required
the arrangement for outdoor units and piping length. Perform securely the installaon work
according to the following restricons. If the arrangement for outdoor units is incorrect, it may
cause owback of the refrigerant and result in failure of outdoor unit.
◆ Restricons for 2 and 3 unit combinaon
1 For 2 and 3 outdoor units combinaon, 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".
> >
< <
B
A
A
B
C
C
Outdoor
Unit A
Outdoor
Unit B
Outdoor
Unit C
Outdoor
Unit C
Outdoor
Unit B
Outdoor
Unit A
Piping outlet
direcon
Piping outlet
direcon
Indoor unit
side
Indoor unit
side
Piping
connecon kit 2
Piping
connecon kit 2
Piping
connecon kit 1
Piping
connecon kit 1
La
Lb
Lc
L
L
La
Lb
Lc
L
L
L: Keep the straight-line distance of 500mm or more for piping aer the piping connecon kit.
◆ Restricons for 4 unit combinaon
1 For 4 outdoor unit combinaon, 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 connecon kit 2 and
the outdoor unit “C” and “D” should be connected to the piping connecon kit 3.
2 The piping length between the piping connecon kit 1 and each outdoor unit should be
La < Lb < Lc < Ld < 25m.