R-Pro › Field cases › Air conditioning
AC New Install — Refrigerant Line Routing (Bending, Traps, Oil Return)
Likely causes
Step 1 — Comply with bend radius, angle, and support spacing
Check: Copper bend radius: ≥5× outer diameter (e.g., 6.35 mm tube → ≥32 mm radius). Never make sharp 90° bends — kinks reduce refrigerant flow by 70%. Horizontal support spacing: 1–1.5 m. Vertical: 2–3 m. Use vibration-damping clamps (rubber-bushed).
What to do: Use copper-specific spring or ratchet bender. Never hand-bend (kink risk). Clamps = vibration-damping rubber-bushed type at 1–1.5 m intervals. For sharp 90° turns, use elbow fittings. After mounting, verify no vibration/noise + record on drawing.
Step 2 — Oil return traps and vertical riser design
Check: Indoor above outdoor: install P-trap on suction (gas) line every 6 m of vertical rise — for compressor oil return. Outdoor above indoor: inverted trap at top of gas line. Liquid line = no traps needed. Vertical distance limit per manual (typically 10–30 m).
What to do: Indoor above = install P-trap every 6 m on gas (suction) line (CRT or copper formed). Outdoor above = inverted trap at top of gas line. No traps on liquid line. Mark trap locations on drawing + provide access for future inspection.
Routing defects = hard to diagnose later (leak points/oil trapping). Create routing drawing + photo records. Ceiling-buried indoor runs = predetermine access panel locations. Exterior wall runs = UV shielding + wind-load rated clamps.
All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.
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