Refrigerant Charge Determination. The approximate amount of refrigerant charge required by the system varies based on the total length of the refrigerant lines and the size of the chiller. Referring to Figure 5, determine the amount of charge based on the horsepower of the chiller and the amount of charge based on discharge and liquid line sizes and lengths. Add these three numbers together to find the final operating charge. The final operating charge must be verified by running the system and checking the liquid line sight glass.
Figure 5: Refrigerant Charge Determination
Chiller Condenser Charge | Field Installed Piping Charge |
Horsepower | Lbs. of |
| |
5 | 5.9 |
7.5 | 6.1 |
10 | 10.8 |
15 | 12.6 |
20 | 21.2 |
25 | 24.2 |
30 | 40.2 |
35 | 41.2 |
40 | 50.2 |
Pipe O.D. | Discharge Line | Liquid Line |
Inches | c | c |
1/2” | - | 7.2 |
5/8” | - | 11.5 |
7/8” | 1.6 | 24.0 |
1 1/8” | 2.7 | 40.9 |
1 3/8” | 4.0 | 62.2 |
1 5/8’ | 5.7 | 88.1 |
2 1/8” | 10.0 | 153.0 |
2 5/8” | 15.0 | 236.0 |
cBased on 100 feet of pipe, 100 ºF Liquid, 100 ºF Discharge
Oil Charge Determination. The remote
Calculate the amount of additional oil required by using the following formula: Pints of oil (Sunisco 3GS) = lbs. of
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