9-7. REFRIGERANT PIPING
9-7-1. Refrigerant Piping
1.If the outdoor units are to be mounted on a wall, make sure that the platform supporting is sufficiently strong. The platform should be designed and manufactured to maintain its strength over a long period of time, and sufficient consideration should be given to ensuring that the outdoor unit will not fall.
2.Use copper pipe with 0.8 mm or more thickness.
3.Flare nut and flare works are also different from those of the conventional refrigerant. Take out the flare nut attached to the main unit of the air conditioner, and use it.
CAUTION
IMPORTANT 4 POINTS FOR PIPING WORK
1.Take away dust and moisture from the inside of the connecting pipes.
2.Tight connection (between pipes and unit)
3.Evacuate the air in the connecting pipes using VACUUM PUMP.
4.Check the gas leakage. (Connected points)
9-7-2. Permissible Piping Length and Head
The maximum piping length from the outdoor to indoor unit | The maximum height difference outdoor/indoor unit | ||
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30 m (Without charge 20 m) | 50 m (Without charge 20 m) | Outdoor unit is above | Outdoor unit is below |
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30 m | 15 m | ||
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<Flaring>
Insert a flare nut into the pipe, and flare the pipe.
As the flaring sizes of R410A differ from those of refrigerant R22, the flare tools newly manufactured for R410A are recommended.
However, the conventional tools can be used by adjusting projection margin of the copper pipe.
B |
•Projection margin in flaring : B (Unit : mm)
Rigid (Clutch type)
Outer diam. | R410A tool used | Conventional tools used | ||
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of copper pipe | R410A | R22 | R410A | R22 |
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6.35/9.52 | 0 to 0.5 | (Same as left) | 1.0 to 1.5 | 0.5 to 1.0 |
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12.7/15.9 | 0 to 0.5 | (Same as left) | 1.0 to 1.5 | 0.5 to 1.0 |
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•Flaring dia meter size : A (Unit : mm)
Outer diam. of copper pipe | A | 0.40 | |
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| R410A |
| R22 |
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6.35 | 9.1 |
| 9.0 |
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12.7/15.9 | 16.6 |
| 16.2 |
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| Fig. | |
Imperial (Wing nut type) |
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Outer diam. of copper pipe |
| R410A |
| R22 |
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6.35/9.52 |
| 1.5 to 2.0 |
| 1.0 to 1.5 |
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12.7/15.9 |
| 2.0 to 2.5 |
| 1.5 to 2.0 |
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*In the case of the flaring for R410A with the conventional flare tool, pull out it approx. 0.5 mm more than that for R22 to adjust to the specified flare size.
The copper pipe gauge is useful for adjusting projection margin size.
A
Fig.
– 37 –
