Home Electrical Myths
Household Electrical Misinformation
Myths tend to have an element of truth but are otherwise false, incomplete, or misleading. If I tried to cite and quote the sources containing various home electrical myths, there would be no end of it. It will be more constructive for me to give examples of the kinds of untruths infecting our culture and the media, and to encourage think-for-themselfers to educate themselves more in my website and other sources.Some Specific Myths
Myths From a Sloppy Use of Terms
Myths From Incomplete Advice
Some Specific Home Electrical Myths
People need to be more aware of whether they are overloading circuits. If you never want a breaker to trip, you might be able to watch your usage carefully enough to prevent that. But normal people, who inadvertently trip breakers (whether weekly or once in five years), are not doing a no-no. The very tripping of breakers is what keeps everyone from ever truly overloading any circuits. So you don't have to wonder or worry. I think this myth arose from a warning not to overload extension cords, but even these will get too hot more from damage or poor connections than from their watt-rating being exceeded.
A ground-fault interrupter (GFCI) is only supposed to trip when a person is getting shocked. Well, their purpose is to prevent or stop electrocutions of people. But they are too stupid to know the difference between a person getting shocked and a wire or clot of dirt getting "shocked." Their design only tells them to trip for ground-faults of any kind (within a certain milliamp range). See GFIs.
A GFCI receptacle will trip off if you overload it (run too many watts). This is not true at all. Only the circuit breaker in your electrical panel cares about the amount of load things are using. A GFCI is not at all sensitive to that, but it is very sensitive to electrical leaks AWAY FROM the path that loads (things running) use.
Old wires can go bad in the wall. So can new wires if they are damaged. Wires in walls do not deteriorate much over time. Damage from rodents is quite rare compared to the problems that easily happen at the accessible electrical boxes that hold your receptacles, switches, lights, and connections.
After a wirenut is twisted onto wires, the wirenut and wires need to be wrapped with electrical tape. Wrapping with electrical tape was needed back when connections were soldered and then needed insulation. Tape over a wirenut would make sense if you didn't do the wirenut right. For instance, if copper wire were left visible. I have heard it said that tape on a wirenut is because the normal vibrations in a house (doors slamming) will loosen a wirenut over time. I doubt anyone has documented this. Everything in my experience says that the wirenut connections that give out were poorly done from the start. Then some oxidation and heat over time put the contact of that barely-touching wire in the wirenut over the edge.
Flipping a breaker off and on will reset it if it was tripped. Well, maybe. Of course, it won't reset if there is a short circuit going on. But even if the tripping was a one-time thing, FLIPPING may not be effective. The word "flip" is too flippant. There needs to be a firmness, pressing the circuit breaker handle strongly to OFF first, then strongly ON. See Resetting.
A breaker that will not reset is a bad breaker. Is a watchdog that barks suddenly in the night a bad dog? Remember, the procedure for resetting is not just pushing the handle ON (see the myth we just finished). If the breaker trips within five seconds of being properly reset, it is almost always responding, as it should, to an electrical condition, almost never tripping from a mechanical defect. Also see whether an Outage was even caused by a tripped breaker.
To dispel various myths related to energy consumption in a home by various appliances and lights, see Michael Bluejay.
Electrical Myths From a Sloppy Use of Terms
There are "false impression" myths. One source of these is the careless or ignorant use of terms. For instance, too many internet forums and websites tell people that they may have a "bad ground" or a "short." Among neighbors who don't know what they are doing anyway, throwing words around to speculate on an unfamiliar problem is forgiveable. But when these are put in writing in front of hundreds of people, they perpetuate confusion. My Glossary is a good place to clear these up.
Home Electrical Myths From Incomplete Advice
I know from experience that it is difficult to be thorough enough in giving electrical advice remotely. The circumstances surrounding a troubleshooting or installation project can make a difference in how it should be handled, and it is almost impossible to address all the possibilities without being there in person, case by case. I have found refuge by using qualifications, like "in general," "usually," and "in most cases." I feel this is better than misleading people with simple-seeming exactness. The result of many "simple step-by-step" instructions is a kind of myth I will call the mini-myth.For instance, one website describes how to connect wires to a receptacle and it talks about which wire color to put under which color of screw on the receptacle. It even shows photos. That's simple. But what if...? What if the receptacle you bought has no screws? What if there is an odd-colored wire to connect? What if the installer doesn't already know that "putting" a wire under a screw is done by stripping a certain amount of insulation off, curling the end of the wire clockwise, and tightening the screw snugly? I admit, I'm glad I don't try to advise about installation projects on my website. But I don't envy the homeowner who is so often left saying, "What about... ME?" Some mini-myths that could come from the example I have just given are as follows:
- Connecting all the wires of an outlet box to the receptacle's screws is the only proper way to install a receptacle. (There are other ways, sometimes better and sometimes necessary.)
- All the white wires in an (20-year) old outlet box should connect to the screws designated for white wires. (In some cases, not true.)
- If an outlet box has three blacks and three whites, the third wires can be put under one of the two screws already holding wires. (Not proper with most receptacles.)
Statistical Myths, Like 'Danger: Risk of...'
Someone said, "There are three kinds of lies: lies, damned lies, and statistics." Raw data itself can be forged, so it should sometimes be questioned. More often, the interpretation of a statistic needs a healthy dose of doubt. The generic warning, "Danger: risk of fire, shock, or fatal injury" may (or may not) be based on a statistic somewhere. Even so, such a warning might as accurately be given about every action we take or product we use. Will it help, then, to quantify a risk -- ".00003% chance of causing a structural fire with over $10,000 damage," for example? Well, in many cases this might help us realize how remote the dangers really are.
The terms "risk of" and "chance of" (should) come from statistical averages. As such, they do not take individual people into account. For instance, the "risk of injury" to a foolhardy, headstrong, uninformed person in their use of a tool is much greater than to someone else. For all we know, the number of injuries (and therefore the risk) to "responsible" people might be zero for a particular product. For the safety industry, it will be enough that a few injuries or deaths have been associated with electrical appliances or wires in general; a generic warning is then supposed to minimize lawsuits. It is with all this in mind that I am calling "Risk of Fire or Injury" a myth. At one time, before dangerous products were tested and banned outright, these warnings would have had more meaning and truth to them. By now, many warnings are so automatic and widespread as to be meaningless, untrue, or even counter-productive (as when people really need a special warning, not more cries of "Wolf, Wolf!").
A color poster developed by the state I live in asks, "Why Electrical Inspections?" It shows a scorched electrical panel on the one hand and a little girl with a puppy across from it, with the caption "Protect Your Family." In between is this statement: "This year, 30,000 electrical violations abated that would have caused: Electrocution / Death / Fire." I note that the scorched panel was not from anyone's home, having three-phase circuits. I accept that 30,000 violations were set right due to inspections, but it says they "would have caused" these bad things. How about "some of which might have caused"? I guess that doesn't make as hard-hitting a poster.
It is my opinion that the public has been over-warned about fire dangers from imperfect electrical installations (which only professionals can identify and fix!). Rules of good practice and good maintenance are justifiable for other reasons besides fire hazard: functionality, shock hazard, and uniformity of practice are rather important. Relation of electricity to fires
"The more I ready through your site the more impressed I am. I have a BS & MS in Industrial Engineering & a PE license. Your material is the clearest & most practical I've ever seen on these topics!" -Jeff
© 2008-2012 Larry Dimock