Technical Data Manual

Design of Mini VRF SYSTEM
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2. System Design
2-7. Additional Refrigerant Charge
Additional refrigerant charge amount is calculated from the liquid tubing total length as follows.
Table 2-8 Amount of Refrigerant Charge Per Feet, According to Liquid Tubing Size
Liquid tubing size Amount of refrigerant
(in. (mm)) charge (oz/ft.)
ø1/4” (ø6.35) 0.279
ø3/8” (ø9.52) 0.602
Required amount of charge = (Amount of refrigerant
charge per ft. of each size of liquid tube × its tube
length) + (...) + (...)
*Always charge accurately using a scale for weighing.
Table 2-9 Refrigerant Charge Amount at Shipment (for outdoor unit)
Heat pump unit
(Single-phase)(oz)
U-36LE1U6
U-36LE1U6E
U-52LE1U6
U-52LE1U6E
123 123
2-8. System Limitations
Table 2-10 System Limitations
Outdoor units
U-36LE1U6
U-36LE1U6E
U-52LE1U6
U-52LE1U6E
Number of max. connectable indoor units 6 9
Max. allowable indoor/outdoor capacity ratio 50 – 130%
2-9. Tubing Length
R410A distribution joint
CZ-P160BK1U (for indoor unit)
Note: Do not use commercially available T-joints for the liquid tubing.
H2
LD
L1
L2
LCLB
LA
* Be sure to use special R410A distribution joints (CZ: purchased separately) for outdoor
unit connections and tubing branches.
Main tube of unit
1st branch
Unit distribution tube
1
23
n-1
n
L3
H1
Select the installation location so that the length and size of refrigerant tubing are within the allowable range shown
in the figure below.
TD831156-00_MINI_VRF_SYS.indb 15TD831156-00_MINI_VRF_SYS.indb 15 2012/01/31 14:38:452012/01/31 14:38:45