Design
D - 10
3. Refrigerant piping design
(5) Calculation of additional charge amount of refrigerant
The quantity of refrigerant at the time of shipping is as shown in Table 2. Additional refrigerant must be added depending upon
the size and length of the piping. (calculated with the size and diameter of the liquid piping, using the values in Table 1)
Necessary refrigerant additional charge amount (g)
(a) : liquid pipe φ19.05 total length (m)
(b) : liquid pipe φ15.88 total length (m)
(c) : liquid pipe φ12.70 total length (m)
(d) : liquid pipe φ 9.52 total length (m)
Be sure to accurately charge the refrigerant by weighing.
Charging procedure
After evacuating, close the gage manifold on the thick pipe side. After making sure that refrigerant cannot be filled from the
thick pipe side, fill with liquid refrigerant through the valve on the liquid pipe side. At this time all valves should be fully
closed.
If liquid refrigerant is filled from the thick pipe side then this can result in a malfunction of the compressor.
If the predetermined quantity of refrigerant cannot be filled, then fully open all valves, and operate the system (heating or
cooling does not matter). Then while the system is operating fill the refrigerant from the low pressure side, making sure to
adjust (close down) the valve on the cylinder so that the liquid refrigerant is gasified as it is sucked into the system. (do this
during commissioning operations)
After the charging operation is completed, fully open all valves.
= 280×(a)+195×(b)+125×(c)+75×(d)
Type
No.
Quantity of refrigerant at
shipping(kg)
70
9.5
90 10
120
150
12
190 17
Liquid pipe size
Additional charge amount per
meter (g/m)
9.52 75
12.7
15.88
19.05
125
195
280
φ
φ
φ
φ
Notes
• Check the limiting density.
• When charging the additional refrigerant, fill with liquid.
• The color of the R407C cylinder is gray on the main body, and brown on the top part of the cylinder.
• Check whether there is a siphon pipe or not. (this is displayed on the label on the top part of the cylinder)
• Depending on the refrigerant and pressure used in the installation, there are cases when the conventional refrigerant (R22)
equipment can be used in combination with the R407C equipment, and cases where it cannot, so care is needed. Particularly,
for the gage manifold, the specialist equipment R407C gage manifold should be provided and used.
Table1 Refrigerant additional charge amount Table2
To Next Page
Loading...
