Electrical Wiring Considerations for Older Homes

 The main concern for older homes and their electrical wiring systems is the safety of the occupants of the home and the dangers of fire. Depending on the age of the home, various wiring methods may have been utilized that do not meet todays standards.

These types of wiring systems can include “Tube and Knob”, which is a wiring system that has conductors separated by several inches mounted on insulators throughout attics, basements, and through walls. Most of this insulation has deteriorated to the point that these wires are exposed bare and can pose a danger to persons or animals such as pets that might be navigating through these spaces.

Another type of wiring system found in older homes is “Cloth Braid” cable. Most of these systems do not have a grounding conductor installed in them which makes surviving an electrocution highly unlikely. We find many of the “2 prong” receptacle outlets have been replaced by 3 prong, grounded receptacle outlets. This is a violation of NFPA 73, Standard for Electrical Inspections for Existing Dwellings, and, which states that any non-grounded receptacles that are replaced by grounded receptacles must have GFCI (Ground Fault Circuit Interrupter) protection and have the correct polarization between the ungrounded (hot) and the neutral.

The last type of wiring system found in homes since the 60’s to the 80’s is Type NM which has a derated grounding conductor, and NM stands for non-metallic cable which is similar to what is used today. Today we use Type NM-B which has a grounding conductor sized the same as the hot and the neutral conductors. This allows for a more complete clearing of a fault and minimizes the chances for a fatal electrocution.

Any of these wiring systems are still allowed by code but must be removed if there are any renovations. Anytime we are involved in a remodel or total renovation, we will remove any of these types of wiring systems that we encounter and can access. The liability of keeping these wires and cables in a home is not worth the risk of death or fire. To help mitigate these dangers we recommend that GFCI (Ground Fault Circuit Interrupters) and AFCI (Arc Fault Circuit Interrupters) be installed, either receptacles or breakers. GFCI’s are a device intended for the protection of personnel and functions to de-energize a circuit within 3 cycles which would be less that 1/20th of a second. These are also required to be installed when a wiring system is not grounded. AFCI’s are devices intended to provide protection from the effects of arc faults by recognizing the characteristics unique to arcing and by functioning to de-energize the circuit when an arc is detected. Electrical wiring is the number 3 cause of fires in homes in the United States. And of the top 5 causes of fires in homes, is the only one that is not caused by human error. Old electrical wiring is a ticking time bomb, and no one knows when it will go off and cause a fire. AFCI’s will defuse that ticking time bomb and provide the inhabitants an added level of peace of mind. We replaced an electrical panel in a 21-year-old home and recommended installing AFCI breakers on all the circuits. When we started turning on the breakers, two of them would trip immediately. We traced one to a faulty light fixture in the kitchen and the other was in a bedroom that was rarely used. Whenever we pulled a small bed from against the wall, we found a charred spot on the bed spread and the outlet had started to melt from the years of arcing in an outlet that hadn’t been used in 20 years. That outlet had been consuming electricity and the standard breaker never tripped.

Arc-Fault Safety in the Home                

In recent years the National Electrical Code has expanded the use of Arc-Fault Circuit Interrupters (AFCI’s) in homes. There has been much debate among builders and electricians as to the need for these devices. Many claim that due to the number of nuisance trips and the added expense that these breakers are causing more problems than they are preventing. 

How AFCI’s came to be:               

Standard type breakers that are most common in homes, trip for two reasons. First is a thermal overload, caused by to many appliances, lights or wiring problems on an electrical circuit. This is indicated by the amperage rating on the breaker (usually 15 or 20 amp). Second is a fault or direct short, caused when the line or hot lead directly touches a neutral lead or a source to ground. A source to ground can be a metallic appliance, water faucet and even a concrete floor. A standard residential breaker’s fault rating is usually 10,000 amps.               

In the late 1970’s and early 1980’s, Ground Fault Circuit Interrupters (GFCI’s) were introduced due to the high number of people being electrocuted from a normally safe electrical installation. In many cases, electricity flowing through a human body was not enough to trip a standard breaker on an overload and/or a short. A GFCI was designed to measure the electrical current difference between the line or hot lead and the neutral. As long as the difference was zero all was well. When the difference became greater than 5mA (milli-amps) within 25ms (milli-seconds), the breaker or outlet would trip, thus indicating that some of the electrical current was going to ground and possibly through a human body. Currently GFCI’s are required at all kitchen countertops, bathrooms, near sinks, garages, basements, outdoors and any other location that can be wet.               

While GFCI’s improved safety from electrocution, there was still, a high number of deaths due to electrical fires. AFCI’s were designed to monitor the electrical wiring in a home for arcs that could cause a fire. In many instances standard breakers would not trip from a fault due to the fact that there was not enough heat generated to trip a breaker on thermal overload nor was the short direct enough to trip the breaker. AFCI’s, monitor the electrical wiring for specific electrical sine wave characteristics, indicative of arcing. When these characteristics are present in an electrical circuit, the AFCI would trip. This could be caused by a loose electrical connection in an outlet or light switch, or by damaged insulation around the electrical wires. Early AFCI’s were prone to tripping whenever utilizing an appliance using a brush type motor, such as a vacuum cleaner, blender, circular saw or other power tools. Small electrical arcs, while not enough to trip a standard breaker, could generate enough heat to melt the plastic insulation on the wires, melt an outlet or switch and ignite wood framing, nearby drapes or other combustible materials. Is your electrical wiring safe?                

In most instances your electrical wiring is safe, but there are a few things that you want to be aware of to insure your home and family are safe. We recommend if your home is older than 25 years, you should seriously consider replacing your existing electrical service with one using AFCI’s on all of the electrical circuits that will allow their use.First is to look… If you notice lights flickering or dimming then there might be a loose connection or a low voltage situation. A qualified electrician should be able to locate a loose connection and repair it. An electrician can determine whether a low voltage problem is due to problems in your home or caused by your electrical utility provider. Also look for outlets that are discolored, charred, broken or loose. This could be an indication of a loose connection, which can get worse if not corrected.Next you need to feel… Anytime you are near your electrical breaker panel, open the door and touch each breaker. If you feel one that is extremely hot call an electrician. Hot spots on your walls can be caused by faulty wiring and should be fixed immediately. If electrical cords and extension cords are hot, that is an indication that the cord size is too small, and it should be replaced by a bigger (not longer) cord.And last smell… If you smell plastic burning or something that you might think is electrical in nature, get it checked out immediately. Where there is smoke, there is a fire. Where there is the smell of electrical burning, a fire could be coming shortly.For more information you can check out this informative website: www.afcisafety.org


Many homes built in the 1970’S were wired with aluminum wiring within their walls. Most all these homes have or will experience various electrical problems. The problem lies in the fact that aluminum wire tends to expand and contract at a greater ratio than the more commonly used copper wire. This excessive expanding and contracting tends to loosen the connections at switches, receptacle outlets, and other electrical devices. While aluminum wiring is still widely used for electrical wiring, and if installed properly and as per code, it is completely safe. However older homes that have aluminum wiring need to be inspected and repaired. If properly done an older aluminum wiring system can made safer than many new homes.

Many Electricians, Building Inspectors and other professionals have held onto the outdated notion that pigtailing with an antioxidant compound is the way to make these repairs. Pigtailing is the process where short pieces of copper wire are connected to the aluminum wiring with the use of wire-nuts and an antioxidant compound. The short pieces of copper wire are then attached to the switch or receptacle outlet.  

The use of pigtails MUST NOT be utilized in this application. Further, the US Consumer Product Safety Commission States: The first temporary repair involving pigtailing with a twist-on connector. The effectiveness of “pigtailing” using twist-on connectors has been evaluated by CPSC staff. In CPSC-sponsored laboratory testing and life tests, substantial numbers of these connectors overheated severely. Surveys of and statements made by electricians and electrical inspectors confirm the highly variable and often poor performance of twist-on connectors with aluminum wire. It is possible that some pigtailing “repairs” made with twist-on connectors may be prone to even more failures than the original aluminum wire connectors. Accordingly, CPSC staff believes that this method of repair does not solve the problem of overheating present in aluminum-wired branch circuits. Also, none of the manufacturers of antioxidant compounds list their product for this purpose. Antioxidant compound is a product used on aluminum to prevent spalling.

The other repair recommended by the industry is to use switches and receptacles labeled “CO/ALR.” These devices are intended for direct connection to aluminum wire, although they can be used with copper or copper-clad wire. CO/ALR devices perform better with aluminum wire than non-CO/ALR devices when installed carefully and according to best electrical practices. This process in conjunction with replacing your existing breakers with Arc Fault (AFCI) type breakers, will make your home safe from most electrical fires.

All receptacle outlets and switches are to be replace with devices that are “Rated” and “Listed” for use with aluminum wiring. As per the 2017 NEC, Article 406.3(C) Receptacles for Aluminum Conductors: Receptacles rated 20 amperes or less and designed for the direct connection of aluminum conductors shall be marked CO/ALR. NOTE: The aluminum conductors are to be directly connected, the use of pigtails is in violation of the code and must not be utilized.

Mike's Corner

5189 Navajo TrailLas Cruces, NM 88012mike@beehiveelectric.com

Copyright KJL Services 2014

Turn out the lights on traditional incandescent bulbs

By Michael Gray

A little-noticed provision of the energy bill, which is expected to become law, phases out the 125-year-old bulb in the next four to 12 years in favor of a new generation of energy-efficient lights that will cost consumers more but return their investment in a few months. The new devices include current products such as compact fluorescents and halogens, as well as emerging products such as light-emitting diodes and energy-saving incandescent bulbs.

Under the measure, all light bulbs must use 25% to 30% less energy than today's products by 2012 to 2014. The phase-in will start with 100-watt bulbs in October 2012 and end with 40-watt bulbs in January 2014. Also by 2014 the popular and widely used T-12 fluorescents will be phased out.  By 2020, bulbs must be 70% more efficient. The new rules will save consumers $40 billion in energy and other costs from 2012 to 2030, avoid construction of 14 coal-fired power plants, and cut global-warming emissions by at least 51 million tons of carbon annually.

Compact fluorescent bulbs already meet the 70% efficiency standard. A compact fluorescent costs about $2, vs. about 50 cents for an incandescent. While an incandescent lasts about seven months, a fluorescent burns six times longer. It also saves about $5 a year in electricity costs, paying for itself in as little as four months. Other bulbs are emerging is the halogen that's 30% more efficient than incandescent. Its advantage: It doesn't emit the yellowish tints that can characterize fluorescents, and it can easily be used with a dimmer. Also in the pipeline: light-emitting diodes that cost much more but last about 12 years, and are mercury free. Light-emitting diode type bulbs and fixtures will pay for themselves in as little as three years, and they are available in a variety of lighting colors.

If every American home replaced just one light bulb with a light bulb that's earned the ENERGY STAR, we would save enough energy to light 3 million homes for a year, save about $600 million in annual energy costs, and prevent 9 billion pounds of greenhouse gas emissions per year, equivalent to those from about 800,000 cars.

If you are serious about saving energy, the environment, and money… upgrades to your lighting is the fastest way to accomplish all three goals. Many electric utilities will provide rebates to businesses and homeowners, who upgrade their lighting. For more information or help will lighting solutions, contact Beehive Technical Services, “Your electrical energy experts”. Don’t forget to ask us about our other electrical energy services.You can contact Michael by email at: mike@beehiveelectric.com or call 575-373-8539.