13
Table 1-16 Refrigerant Charge Amount at Shipment (for outdoor unit)
DC
CHDX09053 CHDX14053
(oz)
423 458
1-9. System Limitations
Table 1-17 System Limitations
Max. No. allowable connected outdoor units 2 *1
Max. capacity allowable connected outdoor units 307,100 BTU/h (32 hp, 90 kW)
Max. connectable indoor units 40
Max. allowable indoor/outdoor capacity ratio 50 – 130 %
*1: Up to 2 units can be connected if the system has been extended.
1-7. Straight Equivalent Length of Joints
Design the tubing system by referring to the following table for the straight equivalent length of joints.
Table 1-13 Straight Equivalent Length of Joints
(15.88)
eeded.
Table 1-14 Refrigerant tubing (Existing tubing can be used.)
Tubing size (in. (mm))
Material O Material 1/2H • H
ø1/4" (ø6.35) t1/32" (0.8) ø7/8" (ø22.22) t5/128" (1.0)
ø3/8" (ø9.52) t1/32" (0.8) ø1" (ø25.40) t5/128" (1.0)
ø1/2" (ø12.7) t1/32" (0.8) ø1-1/8" (ø28.58) t5/128" (1.0)
ø5/8" (ø15.88) t5/128" (1.0) ø1-1/4" (ø31.75) t3/64" (1.1)
ø3/4" (ø19.05) over t5/128" (1.0) ø1-1/2" (ø38.10) over t3/64" (1.15)
ø1-5/8" (ø41.28) over t3/64" (1.20)
* When bending the tubes, use a bending
radius that is at least 4 times the outer
diameter of the tubes.
In addition, take sufficient care to avoid
crushing or damaging the tubes when
bending them.
1-8. Additional Refrigerant Charge
Additional refrigerant charge amount is calculated from the liquid tubing total length as follows.
Table 1-15 Amount of Refrigerant Charge Per Meter, 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
ø1/2" (ø12.7) 1.38
ø5/8" (ø15.88) 1.99
ø3/4" (ø19.05) 2.78
ø7/8" (ø22.22) 3.93
Required amount of charge = (Amount of refrigerant charge per
meter of each size of liquid tube × its tube length) + (...) + (...)
* Always charge accurately using a scale for weighing.
* If the existing tubing is used, and the amount of on-site additional
refrigerant charge exceeds the value listed below, then change the
size of the tubing to reduce the amount of refrigerant.
Max. additional charge for 1 outdoor unit :62 lbs
Max. additional charge for 2 outdoor units :111 lbs
Max. additional charge for 3 outdoor units :133 lbs
Unit: ft.
