Apply Today

(605) 716-0856

Problems and Safety Issues with Old Electrical Wiring

September 13th, 2018

What happens to electrical wiring when it gets old is similar to what happens to a person’s body as it ages. It doesn’t work the way it once did, and its foundation shows wear and tear. If problems aren’t taken care of right away, more serious issues can occur. In the case of old wiring, that can mean a fire or electrical shock hazard. Just because wiring is old, it doesn’t always mean it’s unsafe. However, old wiring issues often come with warning signs.

What constitutes old electrical wiring?

Before the 1940s, most homes were constructed with knob and tube wiring. It was named for the insulating knobs and tubes that ran wiring – one black charged wire and one white neutral wire – along and through the building’s frame. Splices and connections were made from ungrounded soldered wires wrapped with rubber electrical tape, insulating them and keeping them from touching each other.

What’s the biggest problem with old wiring?

Frayed insulation is one of the major problems with old wiring. In addition, because there was no grounding, the wiring was not equipped to protect today’s high-tech appliances and electronic devices. That puts a greater load on the electrical system and can create an overload. Older homes may have had only one electrical outlet per room, so modern homeowners would run extension cords to connect additional lights and appliances. Code today requires that there be an outlet approximately every 12 feet. Also, homes built in 1950 used 100 amps of power, compared with 200 amps today. An amp – short for ampere – is the measure of the amount of working power that can be delivered to a home through its electrical system.

Electrical Wiring

Is knob and tube wiring dangerous?

It’s dangerous if the insulation has worn away (before 1960, the insulation was made of rubber that can crumble or flake), if it was installed incorrectly, or if the wiring is covered with regular building insulation material. If the latter is the case, it can overheat and possibly cause a fire. Just because you have knob and tube wiring doesn’t necessarily mean that you must replace it.

How do you know that it’s time to replace the wiring?

National Electrical Code (NEC) doesn’t require you to replace knob and tube wiring – especially if you live in a historic home. However, if it needs work – and local code allows it – you can splice the old wiring with new NM (non-metallic) cable if you use a junction box, which protects wire connections.

Sometimes, though, there are warning signs that let you know it’s time to replace low-amp wiring for home safety reasons. Replace the wiring if:

  • Cracked or damaged insulation exposes part of the wire
  • Wiring is surrounding by building insulation material
  • Exposed wire splices are wrapped with electrical tape, indicating they haven’t been soldered
  • Fuses are not more than 15 to 20 amps, because today’s large appliances require 30- to 50-amp fuses

Are there alternatives to replacing old wiring?

There may be some less-expensive alternatives that a licensed electrician can take care of. During a home electrical safety inspection, the electrician may suggest any of the following ways to keep your home safe if wiring is old:

  • Electrical WiringReplace damaged switches and outlets if they don’t grab onto the prongs of the plug or are loose
  • Upgrade your electrical panel from one with fuses to one with circuit breakers
  • Change out your 100-amp electrical panel for a 200-amp panel with the required Arc Fault Circuit Interrupter (AFCI) breakers that can sense faulty or frayed wiring
  • Replace circuit breakers (average life span is 40 years) in the electrical panel if changing out the panel is too expensive
  • Install an adequate number of outlets
  • Choose GFCI (Ground Fault Circuit Interrupter) outlets in areas with water (kitchens, bathrooms, garages, and deck and pool areas) to protect against ground fault
  • Add ARC fault circuit breakers that will trip in the event of electing arcing to help prevent fires
  • Install smoke detectors in all areas as required or recommended by NEC

If you believe your home has knob and tube wiring, low-amp wiring, faulty line breakers, blown fuses or other possible old wiring issues, hire a licensed electrician to check it out. Home safety should be your first priority.

Do you think you’d like to become a licensed electrician (aka, journeyman)? The job outlook for electricians is expected to grow 9 percent between 2016 and 2026. Loenbro Technical Institute in Rapid City, South Dakota, offers a comprehensive training program that includes hands-on learning opportunities and an apprenticeship to prepare you for a career as an electrician.

You’ll learn about industrial, commercial and residential requirements; NEC requirements; control theory; OSHA standards; and good safety practices. After you graduate from LTI’s Electrical Training Program, you will be eligible to test for a journeyman’s license and begin your career as an electrician.

Find out more about the program or apply at Loenbro today. Qualified applicants are eligible for tuition reimbursement.

Back to News