How Long Do Electrical Wires Last in Homes?

Image of electrical panel in home

The Way We Wired

We take electricity for granted, but there was a time it wasn’t everywhere. Here’s a look at early wiring systems and how they became our modern setups.

Electricity Was a Luxury

In the late 1800s, electricity was a luxury that only the rich could afford. The first American to have his home fully wired was billionaire banker J.P. Morgan, who had electricity installed in 1882.

Unfortunately, Morgan was to discover that electricity was not that safe back in the era before electrical codes and other safety measures. Shortly after installing the wiring, Morgan lost his personal library when he suffered one of the first residential fires caused by an electrical problem.

Today, electricity is much safer, but it’s still not something to take lightly.

Knob and Tube Wiring

Until the early 1900s, the most common type of wiring was knob and tube wiring. This was the first insulated wiring that was relatively safe to use, and it still exists in some older US homes.

This type of setup used individually conducting wires protected by rubberized cloth and held in place by porcelain knob insulators. Some vintage homes have a combination of modern wiring and knob and tube wiring. If your home has knob and tube wiring, the electrical components may still work well, but the insulation may be wearing out.

If you have an older home and you’ve seen porcelain insulators in the walls or floors, that doesn’t mean you’re still using knob and tube wiring. In the early days, it was common to leave old wiring behind when renovators installed new wiring. Those might just be vintage reminders of your home’s old system. To be on the safe side, ask an electrician to look at your wiring.

Sheathed and Armored Cables

In the 1940s, many wiring systems were still using fabric for insulation. Although it offered some protection, fabric sheathing was not ideal, especially since there were no grounding conductors in this setup.

In the late 1940s and early 1950s, electrical component makers began using flexible metal cable instead. This cable offered more protection and a built-in grounding function.

Conduit is still the recommended method for wiring in certain settings, for instance, when you need wiring near masonry walls or in exposed outdoor locations.

PVC Cable

In the 1960s, non-metallic cable appeared. This type of wiring used a bare ground wire run with a hot and neutral wire concealed in an outer sheath of PVC vinyl. Today, most homes use conduit that’s made from PVC instead of metal.

Aluminum Wiring

Although copper has always been a favorite metal for wiring homes, copper prices spiked in the 1960s. In response, many builders switched to using aluminum to wire homes and commercial buildings. Some use aluminum with a copper coating. If your home or industrial building dates back to the 1960s or 1970s, it’s possible it has aluminum or copper-coated aluminum wiring.

Today, most homes’ aluminum wiring has been replaced, but aluminum wiring still shows up in commercial and industrial buildings. Aluminum wiring is safe if you use it with aluminum switches and other electrical components, but it can cause trouble if you use it with copper components. If you’re unsure, contact an electrician who can tell you if you need to replace your wiring.

Modern Electrical Wiring

While electricity is still a powerful, potentially dangerous force, modern wiring is much safer than old wiring. Today, you can protect your home or commercial building with GFCI (ground-fault circuit interrupter), AFCI (arc-fault circuit interrupter), and audible GFCI devices. Electrical codes ensure all wiring meets a basic level of safety.

Despite these safety innovations, you should always treat electricity with the respect it deserves. If you’re unsure about a repair, contact an electrician.

Renovate and Upgrade with SESCOS

If you have an older home or commercial building, you may be curious about the electrical wiring. Is that old wiring holding steady, or is it time to change it? The best answer is to call SESCOS for a professional inspection. We can assess your wiring and recommend any upgrades.

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