Conduit Cable Capacity Calculator

CPWD Conduit Cable Capacity Auditor

Nominal Wire Size (sq.mm Copper): 1.5 sq.mm (Standard Lighting) 2.5 sq.mm (Light Power/AC Control) 4.0 sq.mm (Standard Power Circuit) 6.0 sq.mm (High Power Feeder) 10.0 sq.mm (Submain/DB Incomer) 16.0 sq.mm (Heavy Submain) 25.0 sq.mm (Main DB Feeder) 35.0 sq.mm 50.0 sq.mm 70.0 sq.mm

Nominal Conduit Diameter (mm): 20 mm (Min Allowed Size) 25 mm 32 mm 38 mm 51 mm 64 mm

Run Configuration (Deflections): Straight Run - "S" (No Bends, Max 4.25m) Run with Bends - "B" (Deflects > 15 deg)

Contractor's Planned Wires in Conduit:

Compliance Verification

Max Allowed Wires (CPWD Table 4.1): 5 Wires

Audit Status

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Enter planned wires to run audit.

Cable Sizing Matrix for 1.5 sq.mm Wires

Conduit Size	Straight Runs (S)	Runs with Bends (B)

CPWD Chapter 4 Table 4.1 Sizing Notes:

• Minimum Conduit Size: CPWD Clause 4.3.1 (d) strictly prohibits using any steel or non-metallic conduits less than **20 mm** in external diameter [2, 3].
• Straight Runs (S): Applies to conduit lengths not exceeding **4.25 meters** between draw-in boxes with straight alignment (deflections under 15 degrees) [4].
• Runs with Bends (B): Applies to runs containing bends or deflections exceeding 15 degrees. Wires are restricted to protect insulation from mechanical stress during pulling [4].
• Hyphen/Blank values ("-"): Indicates configurations not standardized or prohibited under standard practice [1].