Installation and Maintenance Manual

14 VRF-SVN33A-EN
Refrigerant Piping
Branch Joint Selection
Table 5 specifies the first branch joint according to mini outdoor unit capacity.
Table 6 specifies branch joints connected after the first branch, according to the total capacity of
all indoor units connected after the first branch.
Pipe Thickness and Temper Grade
Table 7 specifies pipe minimum thickness and temper grade based on pipe diameter.
Table 5. First branch joint according to mini outdoor unit capacity
Mini outdoor unit total capacity
(ton) Branch joint model
3
4YDK1509B0051A
4
5 4YDK2512B0138A
Table 6. Branch joints connected after the first branch, according to total indoor unit capacity
Total indoor unit capacity
(MBH) Branch joint model
Less than 51 4YDK1509B0051A
51–138.5 4YDK2512B0138A
CAUTION
Risk of Pipes Breaking!
If pipes with a diameter larger than 3/4 in. (19.05 mm) are specified, use semi-hard (C1220T-
1/2H) or hard (C1220T-H) copper piping. If a softer copper pipe (C1220T-O) is used, the pipe may
break due to its low pressure resistance and cause personal injury.
Table 7. Refrigerant pipe minimum thickness and temper grade
Outer diameter
in. (mm)
Minimum thickness
in. (mm)
Temper grade
1/4 (6.35) 0.028 (0.70)
Annealed
(C1220T-O)
3/8 (9.52) 0.028 (0.70)
1/2 (12.70) 0.031 (0.80)
5/8 (15.88) 0.039 (1.00)
3/4 (19.05) 0.035 (0.9)
Drawn
(C1220T-1/2H or C1220T-H)
7/8 (22.22) 0.035 (0.9)