What are copper losses by conductor

• Copper losses can be minimized by the use of greater diameter of the conductor wire and winding material with better resistivity.
• Casually choosing the thickness, increases eddy currents. In this regard, sectionalisation is preferred in order to reduce the radial thickness to decrease eddy currents.
• Winding turns are properly built up taking care of transportation and mechanical strength required insulation.
• Use of copper in place of aluminium makes resistivity less. Current flowing through wires encounters less resistance in copper than aluminium for the same diameter.

So use of copper causes,

• Less electrical losses which produce undesirable heat.
• Reduced transformer full load losses and allow smaller cores.
• Reduced no-load losses.