Calculation Of Amount Of Additional Refrigerant Charge - Sanyo SGP-EW120M2G2W Technical Data Manual

System Design

(6) Calculation of amount of additional refrigerant charge

1) Table 2 shows the refrigerant charge at factory shipping time. Additional refrigerant must be added
according to the size and length of the piping (calculated from the size and diameter of the liquid piping
using the values in Table 1).
Table 1. Quantity of additional refrigerant charge
Liquid pipe
diameter (mm)
φ 9.52
φ12.7
φ15.88
φ19.05
φ22.22
Required additional refrigerant charge (g)
= 366 × (A) + 259 × (B) + 185 × (C) + 128 × (D) +56 × (E) + Unit additional charge amount (F)
(A) = total length in meters of 22.22 mm diameter liquid piping
(B) = total length in meters of 19.05 mm diameter liquid piping
(C) = total length in meters of 15.88 mm diameter liquid piping
(D) = total length in meters of 12.70 mm diameter liquid piping
(E) = total length in meters of 9.52 mm diameter liquid piping
(F) = Unit additional charge amount (Table 3)
2) Be careful to charge accurately according to refrigerant weight.
3) Charging procedure
Evacuate the system, close the gauge manifold at the gas pipe side to ensure that no refrigerant enters the
gas pipe side, then charge the system with liquid refrigerant at the liquid pipe side. While charging, keep all
valves fully closed.
The compressor can be damaged if liquid refrigerant is added at the gas pipe side.
4) If the system does not accept the predetermined quantity of refrigerant, fully open all valves and run the
system (either heating or cooling). While the system is running, gradually add refrigerant at the low
pressure side by slightly opening the valve on the cylinder just enough so that the liquid refrigerant is
gasified as it is sucked into the system. (This step is normally only needed when commissioning the
system.)
All outdoor unit valves should be fully open.
5) When charging is completed, fully open all valves.
6) Avoid liquid back-flow when charging with R410A refrigerant by adding small amounts at a time.
Notes
• When charging with additional refrigerant, use liquid only.
• R410A cylinders are colored gray with a pink top.
•
Check whether a siphon pipe is present (indicated on the label at the top of the cylinder).
• Depending on refrigerant and system pressure, conventional refrigerant (R22, R407A) equipment may
or may not be compatible with R410A equipment, so care is needed. In particular, the gauge manifold
used must be specifically designed for R410A.
• Be sure to check the limiting density.
• Refer to the section "Opening the closed valves" when the instructions call for fully opening all valves.
Additional charge quantity per
meter (g/m)
56
128
185
259
366
D-12
3. Refrigerant piping design
Table 2.
Model Type Quantity of refrigerant
No. charge when shipped (kg)
Model 120
Model 150
Model 190
Model 240
Table 3.
Model Type Unit additional charge
No.
Model 120
Model 150
Model 190
Model 240
11.5
amount (kg)
1.5
4.5
8.5