Loose Screws
222 N. LaPorte Ave, South Bend, Indiana.
Fire claims six lives, the oldest being 11 years old.
Jan 21, 2024.
Statements about the detached home that stand out in the associated articles: “it’s still not clear how or where the house fire began,” and “it seemed as if all the home’s electricity came from two electrical outlets,” and previous inspections identified “electrical problem throughout the entire home.”
Worse headlines abound, but as the others, this one may have been entirely preventable, in this case by periodic maintenance.
Your electric system is a “maintenance due” item, just like your car. Would you drive your car without ever changing the oil? Oh, but that’s obvious. So why not have your electric systems checked for operability every decade or so? Oh, but that’s voodoo science. I know nothing about it.
Well, electricity is not much of a mystery, if you can do a bit of reading. Take a flashlight of instance. A battery or two, a wire or two, a light bulb or LED, and you have a functioning electrical system. Your house’s electric system is little different. The local transformer substitutes for the “batteries,” the “wire or two” is the cabling in the floor, wall, and ceiling, and the “light bulb” is whatever you plug into an outlet, or turn on with a switch.
I point out a flashlight due to a peculiar phenomenon associated with DC power. After some usage, the contacts develop a bit of metal oxide (rust), and the flashlight becomes intermittent. Twist the lamp housing, or the battery access cover a bit, and it functions again, for a while. Batteries also have a terminal disease designed to kill whatever instrument you store the batteries in. In one case the four AAs cost me a $400 instrument.
AC power does not have the same problem as DC power (almost), but it has many screws that hold the many wires in place. Tight screws that get wiggled become loose screws. Trust me on this.
In the case of batteries, a little corrosion is a nuisance, or a costly replacement, depending on whether you store devices for a long time with batteries in them. But for AC power, the problem can become much more extensive because lots of power is involved.
A bread toaster may use 10 Amps, = 1200 Watts / 1.2 kW (kilowatts). An electric heater may use 1500 Watts, and so on. This requires a continuous wire connection between the source transformer and the load (toaster / heater). The continuous wire connection between the source transformer and the load has very little electrical resistance. Most of the resistance is associated with the load, regardless of whether its product is light, heat, or a warm slice of toast. You want the largest resistance in that circuit to be the load. Always.
Note the many connections that can possibly fail,
Those prone to vibration most likely.
When the load is low power, like a lamp, a loose connection will exhibit arcing and sparking when wiggled. I visited a friend’s home where he said a light switch was arcing and sparking when operated (wiggled). I extracted the switch from the wall, and turned the screws, holding the wires in place, at least a full turn to tighten them (this home was more than 50 years old, and this switch had received zero maintenance). A light switch, being a mechanical device subject to vibration from use, will transfer some of that vibration to the screws, gradually and eventually making them loose. An electrical outlet, also being a mechanical device subject to vibration from use (plugging something in, and conversely from unplugging) will transfer some of that vibration to the screws, gradually and eventually making them loose. In the first paragraph above “it seemed as if all the home’s electricity came from two electrical outlets.” I trust you begin to see where this is going.
A loose screw, and its consequent loose wire, becomes a high resistance (progressively higher over time), and most of the voltage develops across it, rather than the load. When the load is high power (lots of current / Watts), the resistance of the loose connection becomes warm, and with increased resistance (subsequent continued use without tightening the loose screw), hot. A hot connection inside a wall / floor / ceiling is not a nice thing to have, especially since, depending on what’s next to it, may spontaneously ignite. I trust you begin to see where this is going.
Electrical outlets are mechanical devices. Humans being what they are, if they use an outlet often, and it becomes iffy (loose / intermittent), the course of least resistance is to use another (often), until it becomes iffy (loose / intermittent), and so on.
The required maintenance is a nuisance and possibly expensive endeavor. A connection (or control / supply point) can become loose in as little as a few years from initial build, depending on the frequency of use. For an outlet, the repair entails turning off power to that circuit, extracting the outlet, tightening the screws, reinserting the outlet, and turning power on. Multiply this by a dozen or more, and you will start to see a substantial cost, based on the electrician’s hourly fees.
Another connection that is also culprit, but in a whole-house fashion, sits behind your electric meter. But it’s not subject to vibration, you exclaim. But yes, it is. Connections behind your meter are subject to temperature and humidity swings due to weather. Any bare wire exposed to these conditions will gradually oxidize / rust, and become thinner in the process. A wire becoming thinner within a tight connection = a loose wire. While most homes are fed by a wiring system consisting of three wires, that pass below (and are connected through, by) your electric meter, the crucial one is the neutral / return / ground. This wire is the voltage reference for the 120V throughout a home. When this wire becomes loose (or broken), depending on the loads in use indoors, one circuit may experience 70V, while another experiences 170V, with the latter possibly causing (depending on what it’s feeding) spontaneous ignition, somewhere. I trust you begin to see where this is going.
The expected failure rate of the Neutral is once in 20 years, per electric companies’ research. For outlets and switches failure rate will vary immensely depending on the frequency of use. But the neutral is an easy one to fix. Pull the meter, ensure the neutral is snug / tight (or tighten as necessary), reinstall the meter. Your electrician can do this in about 10 minutes. Realize that as a homeowner, you do not have the authority to pull the meter, so give an electrician his few bucks. Some years ago, subsequent to house fires (from failed neutrals), a few individuals tried to get the electric utilities in Pennsylvania constrained to check this for them. The utilities replied that their tests would not detect this type of failure. This is mostly correct. When your Neutral becomes loose (broken), if you have a redundant connection, like a metallic neighborhood water pipe, this will serve as a backup, but while keeping your voltages stable will send several (to many) amps of current into the piping system, though your neighbors’ systems back to the source. This is known as Stray Current, and causes a power line effect (Magnetic field) inside your home, sweet home. The electric utility test, only checks for voltage stability, not for Stray Current (which implies a loose / broken neutral). So in town (where most people live), they’d never find the problem, whereas out “in the country” where fewer people live, they’d know quickly. If however, when your Neutral becomes loose (broken), and you do not have a redundant connection, your voltages become unstable as noted in the previous paragraph, and you live within an impending hazard (a simple test can identify this). This condition is known as simultaneous “bright and dim lights.” A call to your local electric utility will get one of their local troubleshooter running, because if it’s happening on their portion of wires, can become a fire hazard for a handful or more of neighboring homes.
But as I am sure the investigation related to the above will disclose, the problem was most likely not electrical . . .
These problems do not appear overnight. Really. They occur gradually over time, we get acclimated to them, and move on to another power source. Bad, bad behavior. Your parents should have taught you better. Or our failing education should have taught you basic mechanical stuff, before it began to fail, and you were still hopefully listening . . .
© Sal La Duca January 2024
www.emfrelief.com
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