Electrical Fires and How to Prevent Them

There are many hazards around the home – some that are obvious, and some not so obvious. Electricity is like the wind, you can’t see it, but you can see and feel the effects. It can pose many risks from physical hazards to risks of fire, and needs to be respected and taken care of to ensure family and home safety. Here we will explain a little bit about the workings of electricity and how to prevent electrical fires from happening.

Residential Fire Statistics

According to the National Fire Protection Association (NFPA), in the United States between 2010 and 2014 a residential fire happens once every 23 seconds. Electrical house fires make up about 9% of these, which can be estimated at about once every two and a half minutes. That means that in the time that it is taking to read this article, two or three residential dwellings are on fire due to electricity. Though this percentage is relatively low (yet still a borderline epidemic), electrical fires in the home account for 16% of all fire related deaths! This is an epidemic!

We are all taught that electricity is dangerous, being taught at early ages to not stick anything in wall outlets, or use hair dryers while taking baths. We know of the physical dangers and how deadly electricity can be, and it can, but we are not taught about the potential fire hazards attributed to electricity. Thankfully, there are steps that can be taken to prevent some of these from happening.

How Electrical Fires Start

First, let’s start with what electricity is and what is actually going on in the wires of our homes. Not attempting to bore you with the technical details of differences between Ac and DC circuits, I would rather present the 4 basic attributes of electricity:

  • Volts – the amount of energy traveling through the wires (ex. 120 volt outlets standard to American homes)
  • Amperes (Amps) – The amount of force it takes to push the energy through the circuit
  • Resistance (Ohms) – The amount of contra-force to the current – ohms attempt to reduce volts, therefore driving the current up
  • Power (Watts) – The amount of work the electrical circuit that is visible (such as a light bulb or stove element)

If all of these attributes are balanced, and the wiring is enough to handle everything plugged, all will be fine. However, any flaws in the electrical system can reduce the integrity and cause the inevitable. Take for instance the resistance. If the resistance increases, then the current will increase as well since its job is to maintain the right amount of volts. If this current increases, then so does heat. If the heat increases, well, that is what can start a fire.

Potential Risks

One of the most common ways to increase this resistance is through a loose connection, which also causes arcing. Loose connections are in fact the most common causes of electrical fires. These loose connections can happen naturally over time, and can be seen in receptacles, switches, circuit-breaker panels and fuse boxes – anywhere wires are spliced or connect to something. Let’s take a look at the most common causes of electrical fires.

By Karl Palutke - https://www.flickr.com/photos/palutke/5786847516/, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=54940022
This can be caused by repeated use (plugging in and taking out) which over time will make the outlet too loose where the plug goes in.

Receptacles

If an outlet is used often, such as constant plugging in and taking out, this will weaken the connection between the outlet and the prongs of the device you are plugging in. If the outlets are over 10 years old, then it is possible the screws that hold the wires in place may start to become loose. Wiring in the home runs through the outlets, which means that the electricity that is being used in the living room may be going through the wall outlet in the hallway. For instance, if you plug in a space heater in your bedroom, there may be an outlet in another room that could be getting hot because of loose connections. Sometimes wires have to be connected together to go to different parts of the home, and unfortunately not all of these connections stand the test of time.

Fuse boxes/breaker panels

I have seen many times when circuit breakers develop loose connections where they plug in to the panels. Wiring between the meter and the fuse or breaker box can become loose. Oversized fuses or breakers can allow too much current through the circuits, which can cause the wires to get too hot.

Light fixtures

Have you ever noticed when changing a light bulb that there is a sticker that says something like “60 watts max”? Please heed those words! I was called out to a home to investigate why a light in a bedroom caught fire. Sure enough, the light said 60 watts max (there were 3 bulbs in this one), yet they had 100 watt bulbs in it. This caused the fixture to way too hot, which could have resulted in the unthinkable!

Plug strips/extension cords

Ah yes, the infamous plug strip. With the ever growing list of devices we plug in (my computer that I am typing in now is using one), it is inevitable that we have need for them. Under the right circumstances, they pose no threat. However, if they are not sized correctly (how much current they can handle) or if one was plugged in to another, which is plugged in to another… there is where the risk lives. The more connection points means the more risk of arcing due to loose connections.

Outdated wiring

Outdated wiring can in fact pose a risk. From electricity’s infant stages and up until around the 1930s, knob-and-tube wiring was a standard. The wires were run in single strands attached to ceramic insulators through the homes. These single wires were spliced in the open, meaning the wire connections were not inside junction boxes that would otherwise protect and be protected. The wires being run like this are also subject to physical damage.

Another form of wiring that most all of us have at least heard of is aluminum wiring. Aluminum was used to wire homes and building from the 1960s to the mid 1970s, and was used since at the time copper prices had skyrocketed. Aluminum has a tendency to easily expand and contract, creating loose connections. Aluminum wiring has been linked to many house fires.

Electrical Preventive Maintenance

When purchasing plug strips, make a few considerations of what you will use it for. If it will be used for electronics such as entertainment centers or computer equipment, be sure to get one with a high amount of surge protection. My rule of thumb is to not spend less then $40 on a surge protector. While most cheap strips still have ratings of 15 amps (a considerable amount), if you will be using it for heavy loads such as blenders or microwaves.

In the case of extension cords, make sure the outer coating is intact along the entire length of the cord. Inspect both the male and female ends – are there any signs of over-heating? If the cord is supposed to have 3 prongs, are there only two? If yes to either of these, replace it! As with plug strips and extension cords, do not daisy chain them – only use one between the wall outlet and the device that is plugged in to it.

If your home is more then 10 years old, it is recommended to check and tighten the wiring throughout your home. Receptacles, wire connections in the fuse boxes/circuit breaker panels, etc. If your home was built in the 1960s to the mid 1970s, it may have aluminum wiring, in which case there are methods that can be used to keep the electrical system safe. Calling on a licensed and insured electrical contractor will be able to help you with this as it is not recommended for DIY’ers to be working with electricity.

Ensure that the light bulbs used in your lighting fixtures throughout your home are within the rating range of the light. Light fixtures are made handle so much heat, and the higher the wattage – the more heat.

My Charge to You

If you don’t do anything else this season with your home, consider taking these steps properly maintain the electrical system of your home. Although there can not be a 100% guaranteed solution, these can serve to significantly reduce the risks. The older the home – the more potential risk there is. Don’t let your memories or your life go up in smoke. If you have any questions or would like to leave a comment, please do so below. Thanks!

 

 

 

 

10 Comments Posted

  1. My husband and I are in the process of renovating the house we bought a few years ago that was built in 1971. We have had almost all of the electrical redone because of problems found when opening up the walls and in the garage. In fact, when our contractor rewired the lights in the basement, he showed me where the light at the bottom of the steps had actually charred the wood joist it was attached to because it had overheated at one point. Great tips to make people aware of how to prevent electrical fires!

    • Yikes! I have seen examples of that all too often! One of my scariest findings was a sizzling wall outlet in a bedroom. People know not to stay away from electricity, but they don’t all realize the potential hazards lurking inside the walls…

  2. Very informative article. Lots of good points and things to look out for. I recently moved into a new home and it’s scary to think about outdated/faulty wiring. So far there hasn’t been any issues, but electrical fires are not something that are on everyones minds, and I definitely didn’t think about it until now. Thanks again for this great article!

  3. Hi there,

    Thanks for the useful information. Our house is over 40 years old, and I really should be checking the wiring. Almost certain they are outdated.

    cheers

    • It is highly recommended to hire a licensed electrical contractor to inspect the wiring, especially at over 40 years old. Following some of the other tips such as with plug strips and light bulb wattages will certainly help in the meantime.

  4. I just recently had some electrical work done on my house, and the contractor pointed out a lot of the risk factors you noted. Your article serves as validation of his advice. Outstanding post!

  5. Hey Matt, those residential fire statistics you mention above are rather worrying.
    We had a bathroom fitted at our last home after-which a few weeks down the line, every-time I had a shower I could smell burning but failed to christen where it was coming from until one day I saw smoke coming out of the shower’s electric pull switch.
    After undoing the switch and noticing it had all burnt out, we ended up asking an electrician to make it safe. Like you mention here, it was a loose connection causing an arc. He said the unit was loosely wired and would have started a fire, luckily we noticed where the burning was coming from. We never considered the potential risk of having an electric shower fitted by a plumber.
    All the best,
    Simon.

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