Every electrical, motor, transformer and HVAC project in India eventually faces a copper-versus-aluminium decision. The answer turns on five variables — not just on the spot price of either metal.
Conductivity baseline
Pure copper conducts at 100% IACS. Pure aluminium conducts at 61% IACS. To carry the same current, an aluminium conductor needs about 56% more cross-sectional area than copper — but it weighs roughly half as much for the equivalent ampacity.
Five variables that change the answer
- Ampere rating and continuous load profile
- Allowable temperature rise and ambient conditions
- Termination technology (bimetallic lugs for Al, simple lugs for Cu)
- Mechanical strength and vibration exposure
- Lifecycle cost including cleaning, retorquing and resistance creep
Where copper wins
Motor windings, transformer windings, bus bars in compact switchgear, high-vibration installations, marine and outdoor environments, and any application where downtime is expensive. Copper terminations are simpler and more forgiving over decades.
Where aluminium wins
Overhead transmission, large outdoor bus ducts, long-run feeder cables, HVAC condenser tubing, and weight-sensitive transport applications. Aluminium is a serious cost-saver — provided termination discipline is maintained.
Procurement view
On a per-ampere-per-metre basis, aluminium is typically 35% – 50% cheaper than copper at Indian landed prices. The savings vanish if joint failures drive rework — which is why properly specified bimetallic lugs and torque protocols are non-negotiable.