Copper and aluminium are the common winding wires used in the construction of transformers and inductors. Aluminium is not only cheaper, but also lighter than copper. Though aluminium seems like the better deal, should you go for it?
Of the two materials, copper has the higher conductivity. This means that a smaller cross-section of copper wire can support the same current as a higher cross-section of aluminium wire.Smaller wire translates to smaller transformer size, so copper winding transformers are smaller than aluminium winding ones.
Does smaller size mean lower cost? Sometimes, especially in lower capacity transformers. Smaller transformer means lower core weight too – another important raw material to consider in costing. As a rule of thumb, cost of small capacity transformers such as electronics transformers and control transformers are not impacted significantly by using aluminium winding. Cost differences become marked only as the transformer capacity increases, say,above 10KVA.
Apart from high-capacity transformers, high-current transformers and high-current inductors, such as those used in welding applications may also show cost benefits from using aluminium winding.
Summing up, if your requirement is for low capacity and low current applications then go with copper winding transformers. If your application needs high capacity or high current transformers, then consider aluminium winding for savings in cost.
At BH Flux Force, we do our best to offer the highest value to our customers. Value is defined not just by cost but a balance of other factors such as product endurance, production lead-time and finding the best match to your requirements. Talk to us to discuss which material best suits your application.
Footnote:
** It is for this reason that aircraft and spacecraft components often use silver alloy wires. Silver has higher conductivity than copper, and transformers or other electromechanical components wound with these silver alloy wires are consequently smaller. Despite such wires being very expensive, the value gained from the size and weight reduction justifies the additional cost in these industries.