Regardless of the industry, copper can be found in electrical connectors the world over, from wires to spring contacts to solid high-voltage connectors. But why is copper so ubiquitous in electrical systems? In this article, we explore the answer to this question and more.

What are Electrical Connectors?

In any electrical system, be that in a car, at a factory, or the wiring in your house, electrical connectors are used to electronically link components together to create circuits, both high and low-voltage circuits use electrical connectors made from copper.

In an ideal world, all joints would be soldered, as this provides a nearly homogenous conductive material from one component to another, however, this is not always practical, as it requires more tools, access and time.

What Types of Electrical Connectors are There?

Electrical connectors enable a very conductive and secure connection between components without the need for soldering. Many ways of connection are possible, including contacts held together with plastic connectors, screw terminals with machine screws and threaded holes and sprung terminals.

Electrical Connections in Industry

In high-voltage applications, high-strength clamping systems are used to ensure no amount of arcing can occur, high voltage connections tend to carry more power, such as in power transmission infrastructure. To minimize heat generation and degradation of the contacts, arcing is eliminated by secure and highly conductive connections.

Whilst low voltage connectors such as computer data cables don’t carry much power, they do need high reliability and low resistance, so copper is still used to create a secure connection.

Mains power connections inside buildings always utilize copper conductors and connectors, to improve performance and safety.

How to Choose the Right Electrical Connector?

One of the first considerations is the voltage and current requirements, all connectors have maximum ratings for both volts and amps.

Second is the type of current; AC or DC. Low-voltage DC circuits typically use heavier gauge wire to transmit the same amount of power as high voltage AC, due to inherent losses in direct current systems.

The next consideration is application, connectors in vehicles typically use springs or pre-stressed clips to hold contacts together, this is because threaded clamping components can be loosened by vibration, something that is not an issue in a home.

Why is Copper Used for Most Electrical Wiring?

Despite its cost copper is used almost universally for electrical wiring and connectors. This is due to it having one of the highest conductivity of common metals, second only to silver.

When compared to other highly conductive materials, such as silver and gold, copper is very reasonably priced and abundant on Earth.

Further to its conductivity and price, copper is extremely ductile, malleable and strong. This allows it to be manufactured in all sorts of shapes and sizes. Copper is also largely resistant to corrosion and heat, making it a safe option for something as critical as mains electrical wiring.

Is Aluminium Wire Safe?

Aluminium is also used in a lot of electrical applications. Up until the 1970’s many homes in North America were wired using aluminium wire, as copper prices saw a dramatic increase. Those living in homes built pre-1970 may find they have aluminium wiring still in use.

While aluminium can be used to wire homes, it was deemed considerably more dangerous than copper, with homes wired with aluminium 55 times more likely to have electrical fires. It is generally recommended that aluminium wiring be replaced with copper.

Most problems with aluminium wiring are the terminations, where a wire is connected to a distribution board, socket or spur. Aluminium-specific connectors should be used, that reduce the risk of breaking the cable whilst clamping.

Aluminium Vs Copper Wiring

Whilst not best used in domestic applications, aluminium is widely used for long-distance power transmission. The main reason is that its conductivity-to-weight ratio is higher than that of copper.

Where thousands of miles of cables are suspended on lightweight pylons, weight is a crucial factor. Despite its lower conductivity requiring more material, aluminium cabling is cheaper than copper in most applications.

In domestic and light industrial applications though, copper is still the conductor of choice, being mandated in most country’s electrical codes including North America and Europe.

What’s Better: Aluminium or Copper Connectors?

Copper connectors are widely considered to be superior. Even when one of the wires being connected is aluminium, copper reduces the resistance of the connection when compared to aluminium, reducing the losses in the system and heat generation.

If you are connecting copper to aluminium, be sure to use the correct connectors, aluminium ones tend to have wider clamping areas with more screws, for even loading.

Copper Conductor Best Practices

While copper is the better conductor, there are still best practices to follow when connecting power or data systems using copper conductors, these include:

• Using the correctly rated connectors for voltage, current, frequency and IP rating
• Do not leave any exposed cable cores, no copper should be showing outside of the connector
• Strip and trim ends before connecting, strands that have previously been clamped can become brittle and break, either severing the connection completely or considerably lowering the connection area
• Test connections for resistance and tightness once done. Acceptable ohm values should be provided by the connector manufacturer.

Aluminium or Copper for your Electrical Project?

So that’s our round-up of copper v aluminium, it is clear that aluminium is only used when the specific benefits outweigh the numerous disadvantages when compared to copper. Unless you’re installing a new long-distance, ultra-high voltage power line, it’s safer to stick with the reliable Copper.

For any aluminium or copper supply for your project, Metals Supermarkets has what you need, from round bars, flat bars and sheets. Get in touch with your local store today.