Factory charge contains refrigerant for condenser, evapo- rator and 20 feet of 3/8” line set. For line set other than 20 feet, adjust charge at 0.60 oz. per foot of 3/8” o.d. liquid line and 1.2 oz. per foot of 1/2”. To obtain optimum performance, system charge should be weighed in accordance to amount specified on unit rating plate and any adjustments for additional line length over 20 feet, as stated above.
System performance may be verified by using the refrigerant charging labels provided with each unit.
In air conditioning systems, horizontal suction lines should be slightly sloped toward the condensing unit. Piping must avoid dips or low spots can collect oil. To aid in the return of oil, a trap should be installed at the bottom of any suction riser. The top end of the riser must be pitched
toward the compressor. For long vertical risers, additional traps are recommended for each additional 20 feet of pipe to insure proper oil movement.
A crankcase heater is recommended for applications where additional field added charge results in a system with a reciprocating compressor requiring more than 6 lbs. of refrigerant or a scroll compressor requiring more than 10 lbs. of refrigerant.
Suction Line Sizes
| LINE SET LENGTH AND SIZE | ||||
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|
BTU/HR | 12 FT. | 25 FT. | 50 FT. | 75 FT. | 100 FT. |
|
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|
12,000 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 |
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|
|
|
|
18,000 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 |
|
|
|
|
|
|
24,000 | 3/4 | 3/4 | 3/4 | 3/4 | 7/8 |
|
|
|
|
|
|
30,000 | 3/4 | 3/4 | 3/4 | 7/8 | 7/8 |
|
|
|
|
|
|
36,000 | 7/8 | 7/8 | 7/8 | 7/8 | 1 1/8 |
|
|
|
|
|
|
42,000 | 7/8 | 7/8 | 7/8 | 1 1/8 | 1 1/8 |
|
|
|
|
|
|
48,000 | 7/8 | 7/8 | 7/8 | 1 1/8 | 1 1/8 |
|
|
|
|
|
|
60,000 | 7/8 | 7/8 | 7/8 | 1 1/8 | 1 1/8 |
|
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|
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|
Table 2
|
| Liquid Line Sizes |
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| |||
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| LINE SET LENGTH AND SIZE |
| ||||
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|
|
|
|
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|
| BTU/HR | 12 FT. | 25 FT. | 50 FT. | 75 FT. | 100 FT. |
|
|
|
|
|
|
|
|
|
| 12,000 | 3/8 | 3/8 | 3/8 | 3/8 | 3/8 |
|
|
|
|
|
|
|
|
|
| 18,000 | 3/8 | 3/8 | 3/8 | 3/8 | 3/8 |
|
|
|
|
|
|
|
|
|
| 24,000 | 3/8 | 3/8 | 3/8 | 3/8 | 3/8 |
|
|
|
|
|
|
|
|
|
| 30,000 | 3/8 | 3/8 | 3/8 | 3/8 | 1/2 |
|
|
|
|
|
|
|
|
|
| 36,000 | 3/8 | 3/8 | 3/8 | 3/8 | 1/2 |
|
|
|
|
|
|
|
|
|
| 42,000 | 3/8 | 3/8 | 3/8 | 1/2 | 1/2 |
|
|
|
|
|
|
|
|
|
| 48,000 | 3/8 | 3/8 | 3/8 | 1/2 | 1/2 |
|
|
|
|
|
|
|
|
|
| 60,000 | 3/8 | 3/8 | 3/8 | 1/2 | 1/2 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Table 3
For installations exceeding 100 feet, contact the Armstrong Air Conditioning Inc.
Technical Services Department at (419) 483-4840.
Page 4 | # 41718L098 |
