For nearly 200 years, copper has been the material of choice for electrical connectors. Copper has been used in electrical wiring since the invention of the electromagnet and the telegraph in the early 1800s, and became even more widespread with the invention of the telephone in 1876. Today, copper electrical connectors are still used in telecommunications, as well as power generation, distribution, and transmission.
Why is copper used for most electrical wiring?
All metals have some amount of resistivity to electrical currents, which is why they require a power source to push the current through. The lower the level of resistivity, the more electrical conductivity a metal has. Copper has low resistivity, and therefore is an excellent conductor.
Copper is also less oxidative than other metals. Oxidation happens when the oxygen and moisture in the air react with a metal’s surface. This reaction corrodes the metal and produces a film-like covering, like rust on steel. Copper does not rust, but will produce a greenish patina called copper oxide. Unlike rust, however, this covering actually protects the metal from further corrosion and doesn’t interfere with conductivity.
How does aluminum wiring compare to copper?
While aluminum can be used for electrical needs, copper is better in a number of ways. For one, aluminum has lower conductivity than copper, and is also more prone to oxidation. The aluminum oxide that forms on the surface is not conductive like copper oxide, which means it will interfere with the flow of electricity. In order to combat this oxidation, aluminum must be covered with an anti-oxidant cream.
There can also be safety issues with aluminum electrical connectors. Aluminum expands and contracts as it heats and cools, so aluminum wiring can loosen over time, creating a fire hazard. These safety issues can be mitigated, but doing so requires special considerations, such as special fixtures designed for aluminum wiring, Arc Fault Interrupters, and “pig-tailing” copper wire to the ends of aluminum wires. In contrast, copper wiring is safer to use, with fewer required precautions.
What are some best practices for copper electrical connectors?
Even though copper has fewer safety issues than aluminum, all electricity is dangerous. While working on a wiring project, be sure to follow proper safety precautions.
When using copper electrical conductors, make sure to:
- Use the correct copper wire connector for the size and number of wires you’re connecting.
- Only use UL (Underwriters Laboratories) listed electrical connectors.
- Make sure wire ends are completely covered by the connector. Electrical tape is not a safe alternative for covering exposed wire.
- When connecting wires that have previously been connected, the ends may be damaged. Trim the ends and re-strip the insulation to ensure the safest connection possible.
- Once you’ve finished, test that the connection is secure by gently tugging on the wires.
Mead Metals, Inc. stocks copper products in a range of sizes and tempers. We can also support quantities to accommodate high volume and low volume copper needs. When you’re in need of copper coil or copper sheet products, Mead Metals is here to help.