The Circuit Detective    -  Several Topics

HOME   Sitemap

Popular Home Electrical Articles
by Larry, The Circuit Detective

Is Electricity Really Mysterious?
GFCI - The Confusing World of the Ground-Fault Circuit Interrupter
AFCI Circuit Breakers - Is Technology Making Us Less Competent?
Electrical As a Second Language - Getting Terms Straight
Replacing Switches And Receptacles In A Home - DIY Pitfalls
Switched Outlets - What Can I Do With Them?
Home Inspector Says the Outlets Are Wrong!
Light Bulbs Burning Out - Why?
Incandescent Light Bulbs - More Efficient Than You Thought

Is Electricity Really Mysterious?

The scientist and the homeowner have two entirely different reasons for saying that electricity is mysterious.

They are probably talking about different things. The scientist is considering some basic principles of nature, which as yet have no deeper explanation. The average person might share such wonder. But when I hear a homeowner say that "electricity" mystifies them, they usually mean that they don't know how to deal with their wiring system or what to think when it acts up. They are technologically, not scientifically, mystified.

There is a remedy for technical mystery -- education. To the degree that a person wants to interact intelligently with their household environment, they can learn more about it. Regarding our household electrical systems, this is available from books, on-line, and even from relatives, friends, and neighbors. Any of these sources can misinform or mislead at times, but with perseverance one can begin to grasp the subject and disperse the mystery. Let's go over some of these areas of mystification.

Electromagnetism is weird. Lightning is scary. But your wiring is actually pretty knowable.


GFCI - The Confusing World of the Ground-Fault Circuit Interrupter

Your grandparents had fuses to change. Your parents learned to reset a circuit breaker instead. Now in this generation we also have GFCIs (=GFIs). These are the receptacles (outlets you plug into) that have a "Test" and a "Reset" button on them, often black and red in color. Their purpose is to keep you from being electrocuted. They do not prevent all shocks, just those that could become fatal. And they don't care how much power you use at them -- it is still only your circuit breaker that will trip for an overload.

Ninety-nine percent of the time these GFCIs are preventing possible shock situations, rather than actually stopping a shock in progress. A GFCI compares the current flowing out to and back from anything using electricity from it, and trips (interrupting that current) if ever there is a slight difference between the two. If you were actually being shocked, current would be going to you from the GFCI but (going "to ground" and) not returning through it, so it would trip off.

So you can be glad. But you may also have occasion to be flustered when a GFCI stays off. It won't let you reset it as long as a condition it doesn't like is still there. The GFCI doesn't like it if the wiring or the normal-looking outlets wired downstream from it are leaking current in the way I have described. It doesn't like it when cords, appliances, or hand tools plugged into any of its outlets are faulting to ground. In addition, GFCIs produced since 2002 trip or won't reset when they are not receiving power, when they are hooked up incorrectly, or (after 2007) when they themselves become defective. Fussy, fussy!

Therefore, if a GFCI won't reset, don't assume it is bad, which is fairly rare. Look for a cause -- perhaps water invading an outdoor outlet, some cord or appliance that is still plugged in, or a damaged line buried in the yard for a garden outlet.

People don't automatically associate a circuit outage at home with a tripped GFCI somewhere, but a GFCI is usually sensing how current is behaving at other standard outlets besides itself (let's call them daughter outlets) and will shut off power to them too when a fault is present. So it is helpful to know which rooms have been required to have GFCI protection over the years. Beginning in 1973, more and more areas needed their outlets protected: outdoors, bathroom, garage, kitchen, and now laundry. An outage in one of these rooms should spark a hunt (in all such rooms) for a forgotten GFCI.

Since the public has been sold on the value of ground-fault interrupters, many have been installed retroactively, in the places now required of new homes. This can add a confusion. It was not well known that normal outlets in these areas may already be GFCI protected from elsewhere. So now if a fault occurs, either the new GFCI or the old one may trip first. Mission accomplished, but who can keep track of which GFCI to expect to reset?

Finally, don't worry if a GFCI tripped once and then let you reset it. You don't have to know why it tripped. Apparently it was a passing thing. For instance a young guest in the home may have taken an interest in what the pretty buttons in the bathroom would do; you could thank the kid for performing that month's GFCI test.


AFCI Circuit Breakers -
Is Technology Making Us Less Competent?

Automobile maintenance got too complex for most do-it-yourselfers. The same has been happening with some home repairs. With home electrical, it just got trickier -- with the requirement of "arc-fault protection" for most areas of the house.

An arc-fault circuit interrupter (AFCI) is a special circuit breaker in your electrical panel designed to sense arcing (sparking) that might present a fire hazard.

These have been required for bedroom areas of homes built since 2002. Beginning in 2008 they are also required to cover most other areas -- except those that must already have ground-fault (GFCI) protection. Because many AFCI devices have some ground-fault sensing also built into them, it may look like the AFCI is the wave of the future in home electrical safety technology, perhaps replacing GFCI devices as well as regular breakers.

Should you welcome this as a good safety net, or do you wonder if it is part of a sticky spider web, brought to you by manufacturers, insurance companies, and regulatory engineers? I won't answer that for you or try to give statistics. What I will do here is point out what a homeowner is up against if one of these new breakers should happen to trip off.

Standard old fuses and circuit breakers would blow or trip for three possible causes.

Two of these were common and familiar to most people:
1. Either electrical usage was excessive (an overload)...
2. Or current was trying to get way out of control from wires faulting (a "short").

Many homeowners could handle the troubleshooting needed to solve these conditions. (The third problem has to do with poor connections right at the fuse or breaker, which overheat it and make it blow when it wouldn't otherwise.)

An arc-fault breaker will trip for any of these same problems, but in addition it will trip for some ground-faults and for arc-faults.

If an AFCI trips, how will you know what sort of cause you are looking for? Will you have to become more dependent on professionals from the industries that dreamed these things up?

In general and in a nutshell:

If an arcing condition does exist somewhere on such an AFCI circuit, you may have to put up with the nuisance of the occasional tripping, till it goes away or is solved. But do not get freaked, as if something is going to start a fire. That is the whole point of these AFCIs -- no such fire will have a chance to start.

And that is the point of many products in our life today -- after hazards have been publicized enough, we will comfort ourselves by buying these things that seem to foolproof life. I hope we are not fools in the process.


Electrical As a Second Language - Getting Terms Straight

Don't be tongue-tied when the repair electrician comes. You need the right words to describe what is happening and what it is happening to. Here's some help to speak better Electrical English.

What's that thing on the wall that turns the light on? A switch? Right! So there must be another name for the special switch-like thing in the whatcha-callit -- in the fuse box, panel, breaker box, whatever THAT thing is! Right! Well, first that switch-like thing is a circuit breaker (breaker), not a switch or fuse -- unless it IS a fuse, which would be a thing that unscrews or pulls out of that big scary box you don't know what to call yet. OK and based on whether that big box has fuses or breakers, it is called a fuse box or breaker box (or either one could be called the service box or electrical panel).

Then what are those things we plug cords into -- in the wall? If you call it a plug or a plug-in, then what do you call that end of the cord you are plugging into it? A plug? Well, there is some room for variety here. Technically, the thing on the wall is called a receptacle. (In the British world it seems to be a socket.) Another commonly accepted term for it is outlet.

With these things straight, you will be able to make yourself understood. What about understanding the electrician when he tells you what your problem was? If he mentions a short or an overload or a faulty breaker, will you know what he is talking about? Let's steady your grasp of electric language a little more.

What is a short circuit (short)? Is it the generic name for any glitch that happens in your home's wiring system? No, a short is one of the things that can trip your breaker or blow your fuse. And how does a short do that? Well, when a live wire is accidentally given a path for its current to flow with little resistance (unlike through a light or appliance in the usual path), a ton of current flows all at once, tripping the breaker or blowing the fuse. That's why we have them -- to stop that current before it melts your wiring down.

What else happens besides short circuits? There is another common condition that trips a breaker, but it wouldn't exactly melt your wires. If the breaker was not in the picture, this condition would just slowly cook the insulation on your wiring. It is called an overload. That is when you (your lights and appliances, that is) are using a little more current on a circuit than its wires will be able to handle without getting too warm. If a breaker trips, you won't know if it was from a short or an overload, but if the breaker lets you reset it after a few minutes, it was probably an overload. The breaker was keeping things from getting out of hand.

One more common problem that can show up in your electrical system is called an open. (You might think it should be called a "closed" because it means the path for current is disrupted.) This happens when a wire is broken (rare) or a wire connection along the circuit is loose or poor. The result is that things on the circuit from that point on do not work; things before that point will still work. And there is no reason for a breaker to trip from this because, if you think about it, current on the circuit is actually reduced by an open.

Now you are equipped to talk Electrical with electrical people. But you will still encounter plenty of people who don't have the lingo straight. Maybe now you can teach them a little ESL (Electric As a Second Language).


Replacing Switches And Receptacles In A Home -
DIY Pitfalls

You might be considering replacing switches and receptacles (outlets) around the house. It sounds like a harmless electrical project, as long as you work with the power off. But you may not be aware of some likely pitfalls.

In the living room or bedroom, is the top or bottom half of an outlet controlled by a switch? If you replace such a switched outlet without keeping good track of where the wires connected, and if you don't know a certain secret, things won't work quite the same there when you're done. Your new half-switched receptacle needs to have its two halves isolated from each other, just as the old one had. This won't happen by magic. You have to break off a metal tab located on the live (hot) side, and don't break the one on the other (white) side.

Receptacles in general need some care in how wires are connected to them. I will give just one example. Suppose the old receptacle had the wires pushed into holes on the back. Maybe you heard that a more reliable connection method is to attach them to the screws on the side. Well, once you get the wires loose from the old outlet (with a very small screwdriver or some twisting), your new connections at the screws might be worse than before if you don't strip a little more insulation off each wire. Otherwise, some of that insulation can easily get trapped under the screw also. This connection would feel tight but would not be tight on the copper itself. Down the road, the connection could easily fail, leaving a room or two dark.

A new switch you want to put in is likely to be a little different from the old one. For one thing, switches didn't used to have the green ground screws they do now. That screw is meant to receive one (bare) wire extending to it from all the other bare (or green) ground wires in the switch box; you will probably have to supply this wire and connect it to the others with a wirenut.

If a switch you took out had more than two black wires attached to it, the two of those that were close together should be paired in a similar way on the new switch. Also, if a switch you want to replace controlled lights in conjunction with a switch at the other end of the room, hall, or stairs, it is a three-way switch (3 non-green screw terminals) or a four-way switch (4 non-green terminals). So you have to buy new switches with the same designation. And if you don't keep track of where the different wires connected on the old 3-way switch and duplicate that on the new one, there is only a chance that you will get this set of switches to work the lights as they used to -- on your first try it is only an 11% chance!

Finally, if you are replacing old toggle-style switches with the "rocker" or "decorator" style, you may be in for some confusion in the case of 3-way switches. Some 3-ways of this new style have their terminals aligned in a way that does not correspond to the old toggle's arrangement. A tip here is that whichever two wires were connected at the two same-color screws on the old switch should go to the same-color screws on the new one, with the wire that went to the one odd-colored screw on the old one going to the odd-colored screw on the new one.

Still want to tackle that project? More power to you!


Switched Outlets - What Can I Do With Them?

Before I share some pointers on switched receptacles, I think it helps to get a little historical perspective. Since the 1950s, some electrical outlets in homes have been designed to be controlled by a wall switch. Typically, a living room, family room, or bedrooms might have this feature, which allowed table and floor lamps to be switched conveniently at an entrance to the room. Perhaps the need for flexibility of furniture and the need for task lighting also dictated this provision. Now that it is more common for homes to have fashionable light fixtures permanently wired in these areas, switched outlets are less necessary, but can be valuable for supplementary effects -- and for the versatility that portable lamps have always given us. Now my tips.

First, don't let the switch for these outlets be a dimmer switch. Much as you might like to set an ambience or to try special effects with that tabletop mini-waterfall, electrical code doesn't want you (or a visiting nephew or the next owner) frying some little motor-driven device that is not meant to be deprived of full power. Or the new cleaning lady's vacuum!

Second, as you might be aware, it is the most common practice for these outlets to have only the top or the bottom half switched, leaving the other half able to still run clocks, charge batteries, or keep the fish tank alive. The wiring for this is achieved by isolating the top from the bottom by breaking off a tab of metal on the hot (black wire) side. (In normal outlets that tab is taken for granted but is necessary for power to get to both halves.) One implication of this is that if you are ever replacing receptacles, you need to tie a string around your brain to remember to break the tab off the new receptacle for all those that were switched in the room. Also attach the wire colors in the same positions they had on the old one. Otherwise, you will lose the ability to switch these outlets. Or you might lose the whole circuit.

Finally, if you have little use for the switched outlet in a bedroom, and have been wishing, in fact, that you could put in a ceiling fan-light, you have options. The way the wiring runs in the room will tell you whether you can wire up to the new fan from the switch, or up from the switched outlet, or from either. You will need the ground and a neutral, plus a switched and/or always-hot wire. How many wires to provide to the fan-light will depend on how much switching you want to do from the wall, versus from pull-chains on the unit, versus from a battery-powered remote switch that may come with the fan. So think things through first. And be advised, something illuminating in a room is to remain switched by a wall switch, according to Code.

If I were young again, I think I would use a switched outlet to power a sudden loud noise my sister wouldn't be expecting. (Don't share this with your kids.)


Home Inspector Says the Outlets Are Wrong!

Part of closing a real estate deal these days may involve getting wayward electrical receptacles back in line. Although a licensed electrician might be needed as the one to do this, it doesn't hurt to know what the inspector is talking about, why an odd condition developed, and what will need to be done to correct the problem.

You may have forgotten that an outlet or two in the house don't work. The inspector would have been tipped off to this when he plugged his outlet tester into them. His report would then say that the outlet has an "open hot" or an "open neutral" or "hot and ground reversed." These are ways an outlet can fail to run things. And their solution might take a little or a lot of troubleshooting know-how.

Another report generated by an inspector's little tester could be that the outlet exhibits "reverse polarity" or "hot and neutral reversed." These refer to the black and the white wire each occupying the other's proper place (somewhere, not necessarily at that outlet). Such outlets would have been working normally, but they hold a possibility of shock hazard in a few circumstances. If nothing else, they alert a buyer that the home's wiring was worked on by someone who was not qualified, at some time in the past. If only one outlet has this irregularity, a person with some electrical experience may be able to correct it easily.

"Open ground" is one last reading likely to be flagged in a report. This can be a common reading at 3-hole receptacles in homes built before 1970 (and not rewired since then). The reason is that grounding wires were not part of the cables used to wire homes in those earlier times. Neither were 3-hole receptacles provided, just 2-hole. It is still legal to not have the ground wires and to have 2-hole outlets, but not legal to have a standard 3-hole outlet without the ground. Here again, the outlet in question would have worked things normally (except surge protectors), but the lack of ground poses a shock possibility in unforeseeable situations. In homes built later, an open ground would be from a ground-wire connection not being made or being disrupted at some time.

There are often several choices for correcting open grounds. If widespread and due to lack of ground wires, reverting to 2-hole outlets or installing some ground-fault interrupter (GFCI) receptacles are allowed. Running ground wires or new cable from the panel are more attractive upgrades, though more expensive. In a home that has ground wires, finding the cause of one or two instances of open ground might be possible for the homeowner. On the other hand it could end up needing an electrician's instincts.

It is a common practice of home inspectors to recommend that GFCI protection be provided to outlet locations where this was not required at the time of construction or of a remodel, but is now required of brand new homes. A seller could stand his ground, rightly claiming that Code does not demand this. But many buyers are nervous when issues of safety are raised.

Understand that GFCI receptacles do not necessarily need to be installed at every location you decide to protect. Often one that is installed at one point (say, in a kitchen) will be able to protect several other normal receptacles in the area, if it is connected in a particular way. By the same token, double-check that areas recommended for protection are not already protected (push the test button of all existing GFCIs -- the things that lose power are protected). Also be warned that there are several wrong ways to hook up GFCIs that will result in their tripping or not working.

Finally, it might be nice if buyers were alerted more often to receptacles that barely work. The ones I have in mind are those receptacles that barely hold on to a cord when you try to plug it in. This is from normal wear and tear, but it is not just an irritation. It can help a heavy load, like a portable heater, to melt the end of its cord. This is surely on a par with the hazards suggested by the readings of the almighty outlet tester.


Light Bulbs Burning Out - Why?

Why are your light bulbs burning out? Umm, because light bulbs burn out? No, sorry, I'm not being fair; that's not what you're asking. But it's true, of course. So first of all, are you sure they are burning out too soon? Do you count how many hours each bulb has run? I'm half serious. If you leave indoor lights on a lot or outdoor lights stay on all night, maybe they HAVE lived a full life. Some bulb packages still state an average life expectancy in hours.

I am only dealing with incandescent bulbs here, not fluorescent, though they are subject to many of the same causes of burnout.

Are you even sure they are burning out? Recessed "can" lights have a "thermal protector" that will stop power to the socket if the fixture overheats from hot weather, too much attic insulation, or the wrong style or wattage of bulb. Once it cools down, it will power the bulb again.

Next, did you know that besides a wattage, bulbs have a voltage rating, usually 120 volts? That means they are designed with 120 volts in mind. If the power company delivers more than that to your home (and this may be true of half of all homes), then the life of your bulbs will be less. Bulbs rated 130-volts are available for the asking, and even though they will run a little less brightly, they will stand up better to a higher voltage level and also to spikes and surges in voltage.

Other factors can contribute too. The quality of bulb manufacturing can be poor. The socket that a bulb sits in can be poor, as when rivets that relate the socket to its wires in the fixture loosen up. And the connection of these fixture wires to the wires in the electrical box can be poor. All these conditions I have just listed, however, may come about or be made worse whenever bulbs of too high a wattage are used, and not just the bulbs there now, but any used there in the past. So the light fixture itself may need replacing.

While we're at it, let's trace contributors back further. Poor electrical connections may exist at the light box, its switch box, other boxes of that circuit, the breaker, the main wires of the panel and meter, out to and including the power company's transformer. Such poor connections can still let current through to run the light bulbs, but may do so in a jagged way that stresses the filaments of many bulbs in the home, shortening their life. This irregular current may or may not be visible, as flickering or blinking, to someone looking at the lit bulbs.

One particular connection problem kills bulbs very quickly, by subjecting them to more sustained and extreme voltage than what the power company would provide. Bulbs (and vulnerable electronics) can receive to up to 240 volts if a neutral wire shared by two or more circuits loses continuity. This can happen where two circuits share the neutral, or, in the case of a main neutral wire, it can happen to the entire home. Because widespread bulb, fixture, and appliance damage is possible, several things burning out simultaneously is a symptom that calls for prompt professional attention.

In conclusion, with good observation over time, it is sometimes possible to know the cause of bulb burnout in a given case. Some experimentation and documentation may be needed. Later, a troubleshooting electrician might help, although we don't know everything either. Bulbs burn out!


Incandescent Light Bulbs -
More Efficient Than You Thought

They've got us so worried about saving energy these days. I've got some good news! You don't need to worry as much as you thought, and you will still be a responsible person.

Take light bulbs. Have you ever been at a lighting showroom and felt all the heat coming off so many lights -- all that energy being wasted, you thought?

They talk about compact fluorescent (CF) bulbs -- those spiral bulbs that look a little like soft ice cream cones -- being better than your old fashioned incandescent bulbs. In one way, yes -- they last longer, so you don't have to change them as often. On the other hand, they cost more and you have to recycle them. So on that score, there is no obvious "saving." That isn't a saving of energy anyway.

The main hoopla about "energy saving" bulbs is that they use less electricity for putting out the same amount of light. (Whether you like the quality of the light is another matter.) And they DO use less. But get this -- both old style and new style are pretty bad at turning electricity into light. Compare 2% efficiency with 10% efficiency! They both sound awful. But the electricity isn't as "wasted" as you think. And that's what nobody is publicizing -- not the politicians, not the media, not the manufacturers or stores.

How is the electricity NOT wasted? Well, when 90%-98% of it is not making light, what is it doing? Almost all of it is put out as heat! So in the cool seasons -- when you are using your lights the most -- they are helping to heat your home! In fact, when your lights aren't on, your heating system has to work a little harder. See this CBC News article. Your heating may use a fuel rather than electricity, but we are talking about overall energy efficiency and resources. Isn't that what we are concerned about?

In the cool seasons, all bulbs are in this sense very efficient, and maybe equally efficient. OK, in the summer, the heat of all bulbs is wasted, but we use our lights less then anyway. (Maybe in summer the lighting showrooms should "cool it.")

Lights contribute to heating your home. There can be a degree of inefficiency even so, because some ceiling lights will throw some of their heat into an attic space, just as your main heat system may misplace heat into cold areas along its air ducts. But even a recessed light, if properly installed and lamped, will put more heat into the room area than the ceiling space.


2012 Larry Dimock

HOME   Sitemap