Danfoss Optyma OP-UPAC015COP04E Application Manuallines page 40

Application Guidelines
5.6.4 Maximum refrigerant charge quantity
Confirm that the refrigerant charge quantity as calculated in the step 5.6.3 is not larger than the maximum refrigerant charge quantity.
Get the maximum refrigerant charge quantity from the Ø12.7 equivalent pipe length and the Fig. 26. Calculate the Ø12.7 equivalent pipe
length of Fig. 26 with the following equation.
Maximum refrigerant charge quantity is not changed as Evaporation temperature setting.
Ø12.7 equivalent pipe length (m) = Piping refrigerant quantity (kg)/Additional charge quantity/m of Ø12.7 (kg/m)
When Refrigerant charge quantity calculated in the step 5.6.3 < Maximum refrigerant quantity, charge the refrigerant in the quantity
calculated in the step 5.6.3.
When Refrigerant charge quantity calculated in the step 5.6.3 ≥ Maximum refrigerant charge quantity, charge the refrigerant in the
maximum refrigerant charge quantity.
5.6.5 Example of calculation – Determination of refrigerant charge quantity
Condensing unit
OP-UPAC015COP04E
(Evaporation temperature setting : -10 C)
Fig. 27
In case of the piping system as above, the piping refrigerant charge quantity becomes 6.3 kg from the following calculation.
Piping refrigerant quantity = 0.098 (kg/m) x 10 (m) + 0.054 (kg/m) + (10 (m) + 10 (m)) + 0.025 (kg/m) x (5 (m) + 5 (m)) = 2.3
kg..................... (a)
Refrigerant pipe size x Wall thickness
(For material: C1220 1/2H)
Additional charge quantity (kg/m)
40
AB408540130380en-000102
5. System design recommendations
30
25
20
15
10
5
0 20
φ12.7 equivalent pipe length (m)
Maximum refrigerant charge quantity
Fig. 26
Liquid pipe
φ12.7×10m
Additional charge quantity/m of refrigerant pipe (Liquid feed pipe)
Ø6.35×t0.5
40 60
Low pressure
device
Liquid pipe
φ9.52×10m
Liquid pipe
φ9.52×10m
Ø9.52×t0.8
0.025 0.054
80 100
Low pressure
Low pressure
device
device
Liquid pipe
φ6.35×5m
Liquid pipe
φ6.35×5m
Ø12.7×t1.0 Ø15.88×t1.2
0.098 0.155
© Danfoss | Climate Solutions | 2023.02
Ø19.05×t1.4
0.225