Toshiba SHRM R410A Quick Reference page 2

01 Refrigerant Piping
Allowable length of refrigerant pipes and allowable height difference between units
Header unit (A)
(a)
Main
piping
L1
Height
difference
between
outdoor
First branching
and indoor
section
units:
H1 ≤ 165 ft
(50 m)
FS unit
System restriction
Max. No. of combined outdoor units
Max. capacity of combined outdoor units
Max. No. of connected indoor units
Max. capacity of combined indoor units
Outdoor Unit
Follower unit (B)
Height difference
between outdoor units
H3 ≤ 0.3 ft (0.1 m)
(b)
La Lb
Outdoor unit connecting pipes
Branching pipe
Indoor unit connecting pipe
a
L3
f g
Indoor unit
The longest piping length: L ≤ 640 ft (195 m)
The longest piping length from the first branch: Li ≤ 215 ft (65 m)
Max. equivalent piping length in group of the FS unit: Ln ≤ 98 ft (30 m)
Y-joint
L4
d
FS unit
i j
Indoor unit
H2 ≤ 49 ft (15 m)
H2 > 49 ft (15 m)
Branching header
L2
Y-shape branching joint
L8
b c
h
L5 L6 L7
e m
(m)
2 units
20 ton
40 units
125 %
105 %
k l
Height difference
between indoor units:
n o
Height difference
between indoor units
in same FS unit
H4 ≤ 1.6 ft
(n) (0.5 m)
(o)
H2 ≤ 130 ft
(40 m)