Cable Conductor, Cable Conductors

The critical requirement of a cable is its ability to carry a specified Electric current in the form of power or data signal as efficiently and economically as possible. As the first building block in the design of a cable the conductor material chosen should offer as little electrical resistance to the transmission as possible.

However this is were many other factors relating to the cables performance start to condition the most suitable material options. A few of the fundamental areas include operating environment, temperature, physical constraints including Size, flexibility and flexing and most important is the cost /performance criteria.

Most common material is naturally copper and aluminium each having their own pros and cons but generally these are the best match against a cost criteria. At the other end of the spectrum, other examples such as Silver which has a far superior resistance characteristic but is prohibitively expensive for all but the very high end applications.

Other metals are still widely used for specific applications e.g. Nickel in high temperature wires, combinations of two metals in Thermocouple cables and metal alloys which can offer alternative benefits some which when combined resist the passage of electricity and convert this to energy in Heating cables, but also conversely alloys offer cheaper alternatives to copper when data signals are less critical.

Common to almost any of the metals used is the combination of single strand or multiple strand configurations which are categorised by Class, e.g. Class 1 – Solid, Class 2 – Stranded, Class 5 and 6 - Flexible and Highly flexible and here the final cable application should dictate the wire construction to match its in service performance.

The traditional use of plain copper wires can be enhanced by coating it with other metals, most commonly used is Tin were it offers better environmental protection and were reaction to certain Insulating materials is a problem, although the growth of Synthetic rubbers has reduced this problem. Tinned copper equipment wires are advantageous when used in wiring with soldered connectors. Silver plating and Zero Oxygen copper is prevalent in the Audio Industry due to its superior characteristics.

On the positive side the conductor specifications are very well documented and whilst BS EN 60228 is the UK/European metric conductor size specification. Other nationalities use there own bespoke systems and whilst not fully compatible with the UK standard they are available when required.

So you can see that the choices and combinations for this first and critical component of any cable, requires careful consideration at the start of your cable specifying journey.