Creeping Home Power Demands

Early electrical and lighting systems were comparable to our more recent computer, software, and communications industries:

• The first electrical systems offered relatively little power and ran house- and streetlights. The first desktop computers had almost no memory, slow speed, and small hard drives.
• Innovation came fast and furious among very competitive companies and individuals.
• Our demand for more bandwidth, cable, and phone availability is a repeat of our increasing demands for more electricity since the turn of the 20th century.
• All of these industries have improved our standard of living, despite criticisms to the contrary from technophobes.

A typical 30-amp home service has increased to 200 amps in the past 100 years. We’ve gone from one light per room to multiple lights, multiple receptacles, every appliance imaginable, and entertainment systems all demanding their share of electricity. This has required building and rebuilding an entire infrastructure of dams, generators, long-distance power lines, transformers, and miles and miles of utility poles.

The entire undertaking has been enormous and is entirely taken for granted today. Historical hubris lets us believe that our time is the most innovative and influential to date, but we wouldn’t have gotten very far without electrification. Try running your laptop on some of Volta’s original batteries or even some of Edison’s. You might get enough power to read “Starting Windows 98” on your screen before it shuts off, with your battery drained of any direct current.

The basics of electricity and its delivery systems are pretty well established. Equipment might improve and become more efficient, but until someone rewrites the laws of physics, electricity will continue to be delivered by wires or other conductors from a generating force. You’ll still get billed once a month or so for its usage. Nobody said all those electrons would be free, but it remains quite the bargain based on all it provides for us.

How Wiring Evolves?

Although knob-and-tube wiring prevailed for years, other types of wiring were developed in attempts to either speed up or simplify installations. If your house was built prior to the 1950s, you might find one of these not-so-fun types of wire in it. Unfortunately, every innovation doesn’t stand the test of time.
The following two systems were later contemporaries of knob-and-tube wiring:
➤ Armor-clad cable
➤ Multiconductor cable

Armor-clad cable, often called BX, was a trademark of General Electric. It consisted of a narrow metal sheathing wrapped around the hot and neutral conductors. It was mainly installed in the 1920s and 1930s in more expensive housing. Running the wire in a protective metal wrapping sounds like a good idea, right? It probably was until the metal started rusting and corroding with age. Then the hot wire could short out to the metal wrapping, and in some cases, the wrapping could become red-hot but never blow a fuse. This type of wiring should always be thoroughly inspected by an experienced electrician.

Multiconductor cable carried both the hot and neutral wires in a cloth insulation that was coated with either varnish or shellac. Each wire was separately wrapped in its own insulation as well. As it ages, the insulation becomes very brittle and is almost impossible to work with in some cases.

Current systems use nonmetallic sheathed cable commonly known as Romex, another trade name. This cable is wrapped in thermoplastic, which probably will last so long that future anthropologists will be carbon-dating it in the year 14,500 C.E. This is a very safe wiring system that comes with a grounding wire in addition to the hot and neutral wires, and it allows for relatively quick and efficient installation.

Knob-and-Tube Wiring

The earliest wiring system was called knob-and-tube wiring, and you’ll still find this in houses built prior to the early 1950s. This was an inherently safe system in which the hot wire and the neutral wire ran separate from each other through walls, floors, and ceilings. Each wire was covered with cloth insulation and ran through ceramic tubes when passing through floor joist and wall studs or into electrical boxes at lights, switches, and receptacles. The wires were secured to ceramic knobs when they ran along a joist or stud.

Electricians were a little anxious about this new electricity stuff, so most original knob-and-tube work is very neatly done. Wires were twisted together, soldered with lead, and then taped to make secure connections. The main problem with knob-and tube wiring is what happens in the intervening years when homeowners and amateur electricians hack into it

Just One Ceiling Light

Compared to today’s lighting standards, our grandparents and great-grandparents were almost walking around in the dark. A single ceiling light per room was considered an improvement over gas lighting. Can you imagine having only one overhead light in a kitchen? We bathe ourselves in light today, and we love every minute of it. The lighting requirements today in some kitchens alone would have consumed half of a typical home’s service requirements back in the 30-amp days.

Fuses to Breakers

All new residential construction uses circuit breakers in its service panels, but fuses were first used to distribute electricity through individual circuits. These fuses are still present in older homes where electrical services have not been updated. Although the first circuit breakers date back to as early as 1904, it wasn’t until the 1950s, with the introduction of the modern plug-in-type breaker, that they gained universal usage.

Fuses might be dated and less convenient than circuit breakers, but they are perfectly usable under most circumstances. When updating to a new service panel, of course, fuse systems are always replaced.

The Standards Change

Once early wiring requirements were established they were stringent, but the size of an individual home service and the subsequent loads were inadequate by today’s standards. A 30-amp service with a wood fuse box was typical and sufficient for running lights. Prior to electrification, many homes had gas lighting. Some wiring actually was fished through the gas piping in the walls to the new electric lights that replaced the old gas fixtures.

The turn of the century was a heady time in the field of electricity. Innovators and scientists were improving all the necessary components and generators as well as coming up with new gadgets and conveniences that would run on electricity. Even the newly built New York City subway systems were beholden to this great new power source.

Early Safety Measures

Electrical systems were a brand-spanking-new technology in the late nineteenth century, and no small amount of trepidation was associated with them. Wouldn’t there be fires? Electrical shocks? Government officials, especially fire departments, took electrification very seriously.

The New York Board of Fire Underwriters, meeting in October 1881, called for standards such as the following:

• “Wires to have 50 percent conductivity above the amount calculated as necessary for the number of lights to be supplied by the wire.”
• “Wires to be thoroughly insulated and doubly coated with some approved material.”
• “Where electricity is conducted into a building from sources other than the building in which it is used, a shut off must be placed at the point of entrance to each building and the supply turned off when the lights are not in use.”
• “Application for permission to use electric lights must be accompanied with a statement of the number and kind of lamps to be used, the estimate of some known electrician of the quantity of electricity required, and a sample of the wire at least three feet in length to be used, with a certificate of said electrician of the carrying capacity of the wire.”

These guys were serious! It’s no wonder: They weren’t about to take chances with a new technology that was potentially dangerous, despite its useful prospects.

Tesla Needed a Lawyer

Nikola Tesla was another guy who liked applying for patents. By the time of his death in 1943, he held more than 700 patents in the areas of induction motors, generators, fluorescent lights, and steam turbines. Tesla supposedly arrived in America in 1884 with 4¢ in his pocket. (Who knows, maybe it’s one of those stories that claimed a little less money every time Tesla retold it.) America’s tough when you’ve only got 4¢ to your name. In 1885, Tesla sold his patent rights to his system of alternating current to George Westinghouse, another inventor and industrialist who knew a good electrical system when he saw it.

Tesla established his own laboratory in New York City in 1887. Ever the prankster, he sometimes would use his own body as an electrical conductor to light lamps to show that alternating current was safe. It probably was a great way to impress prospective girlfriends as well. While Westinghouse raked in the big bucks from his newly acquired alternating-current system, Tesla eventually became the namesake for a unit of measurement for magnetic fields.

A tesla, as every amateur physicist knows, is equal to one weber (a unit of magnetic flux named after German physicist Wilhelm E. Weber, not the barbecue manufacturer) per square meter. Considered both a genius and an eccentric during his lifetime, Nikola Tesla laid much of the practical and theoretical groundwork for the communications and electrical systems we have today.

Our First Big Power Plant

Edison designed and built his first major power plant in the Big Apple in 1882—a reported 120-volt system in downtown Manhattan. This also was the world’s first principal power station. Unfortunately, Edison built it based on direct current, an approach that would become dated by the next decade, as was proven by one of his employees. Nikola Tesla, a Yugoslavian immigrant who briefly worked at the Edison laboratory in New Jersey in 1884, was on to something with his ideas about alternating current.

Con Edison, which started out as the New York Gas Light Company in 1823, is the current-day result of more than 170 mergers and acquisitions. The nucleus of Con Edison was the Edison Electric Illuminating Company, formed in 1880.

The electric lamp discovery

The basics of the construction of the electric lamp (or light bulb, to nonelectricians) were pretty well known by the 1870s. People knew that if you ran electricity down certain substances, the resistance produced light rather than heat. The problem was finding the right filament. Early versions simply didn’t last long enough to be useful. The lamp needed a long-lasting filament that would provide pleasing, easy-on-the-eye lighting to be practical.

Edison tested thousands of materials before trying a piece of #70 coarse sewing-machine thread in October 1879. He first baked the thread to carbonize it and extend its life to withstand the heat of an electric current. The rest, as they say, is history. Edison and his assistants scrambled to improve his lamp and to create all the myriad components necessary to get it into peoples’ homes.

It was Edison’s invention of a system to deliver and implement electricity and lighting that set him apart from other inventors. His labs designed and manufactured switches, meters, generators, and just about everything else connected with electrification. This is akin to inventing a computer in a laboratory only to discover that, oops, now we need software, monitors, a mouse, printers, scanners, and every other peripheral advertised in the monthly catalogs we all receive from computer suppliers.

Edison, the Mega-Inventor

Thomas Alva Edison was born in Milan, Ohio, on February 11, 1847. According to some stories, he had a whopping three months of formal education, yet he obtained a record 1,093 patents in the United States during his lifetime. Who knows how he would have done without any public schooling! It seems like Edison had his hand in everything: telegraph equipment, movie projectors, phonographs, storage batteries, and most important, electrical lighting.

If Edison were alive today, he’d be spending most of his time in courtrooms defending his far-flung empire from charges of being a monopoly. Compared to Edison, Bill Gates is a piker. The list of Edison’s companies and partnerships worldwide goes on for pages and pages. He not only manufactured electric lamps (a.k.a. light bulbs) but also motors, dynamos, phonographs and phonograph records, and telephone equipment.

Edison helped form the nascent General Electric Company, one of today’s powerhouse corporations, when his Edison General Electric Company merged with the Thomson-Houston Company. Despite his many inventions and businesses, Edison was only financially comfortable. He was nowhere near as wealthy as some of his contemporaries such as Henry Ford.

Other Electrical Fellows

The following European scientists also helped pave the way for the electrical comforts we enjoy today:

• Michael Faraday
• Heinrich Hertz
• Joseph Priestley

Joseph Priestley, in addition to his electrical dabbling, also invented soda water (for which the Coca-Cola Company is eternally grateful). Michael Faraday is credited with discovering how to generate an electric current on a usable scale. It was known that electricity would create a magnetic field, but Faraday looked at the reverse notion:

Why not produce electricity with magnets? In 1831, he discovered that moving a magnet inside a coiled copper wire produces a small electric current. If you spin a large enough magnet really fast inside a larger coil of wire, you’ll have yourself a usable electric generator. Faraday’s work is the basis for the electrical generators used today. Now that we’ve discussed scientists from the Old World the colonists left behind, let’s leap over to the American side of the Atlantic, where our usual combination of good timing, enthusiasm, and an attitude of “Hey, this will work, what have we got to lose?” put electricity on the map.

Watt, Ampere, Ohm and Coulomb at work

Watt
James Watt was an engineer at the University of Glasgow. He was a steam-engine guy who invented the steam-condensing engine and subsequent improvements in the 1700s. Watt was probably very motivated to work with steam: Scotland is cold in the winter, even with today’s central heating. It must have felt like Antarctica back in the eighteenth century.
Edison coupled his own generator with Watt’s steam engine to produce the first large-scale electricity generation. As you can guess, the term “watt,” a unit of power, was named after Watt.

The Amp Man
André Marie Ampère, the first notable French electrophile, researched electricity and magnetism, essentially developing the field of electrodynamics. Not much for quotable sound bites, Ampère’s most important publication, Memoir on the Mathematical Theory of Electrodynamic Phenomena, Uniquely Deduced from Experience (1827), is a book only a physicist could love.
A unit of electric current is called an “ampere” in his honor, but Americans, blatant and unapologetic in messing with the French language, call it an “amp” instead.

Simon Ohm
In 1827, Georg Simon Ohm, a German physicist and mathematician in Cologne, published The Galvanic Circuit Investigated Mathematically, a tome never destined to make the New York Times Bestseller list in any category. Lacking acceptance in his native Germany, Ohm eventually was awarded the Copley Medal in 1841 by The Royal Society of Great Britain. Ohm discovered one of the most fundamental laws of electricity:
the relationship among resistance, current, and voltage. The resulting law, V = IR (in which V is voltage, I is the current, and R is resistance), gave him a place in the electricity hall of fame. A unit of resistance, the ohm, is named after him

Coulomb
Charles Augustin de Coulomb was an all-around brilliant eighteenth-century French scientist who made major contributions in the areas of physics, civil engineering, and the natural sciences. The unit of electric charge—the coulomb—is named for him. Who could forget “Chuck” Coulomb’s 1773 address to the Academy of Science in Paris when he discussed pioneering soil mechanics theory? Coulomb served as “Ingenieur du Roi” (“Engineer of the King”) until the French Revolution came calling. He then took a powder and retired to the countryside for a while.

Coulomb is known in the electrical world for verifying the law of attraction or electrostatic force. Basically, he confirmed the notion that opposite charges (+ and –) attract each other and like charges repel. Unlike other observers of this behavior, Coulomb worked the numbers and came up with a nice, neat theory that no one outside the fields of electrical engineering and physics will ever use.

Galvani's Experiment

Luigi Galvani had the perfect name for an East Coast Italian restaurant, but his only known association with gourmet food was his famous experiment with frog legs in 1786. The professor of medicine in Bologna accidentally produced an electric charge against the legs of a dead frog. The charge was the result of the wet frog lying on a metal plate while being probed with a knife made from a different metal. Galvani was convinced that the twitching legs were the result of electricity already existing in the frog’s tissues and muscles.

He was none too pleased when his friend Alessandro Volta disagreed and proved him wrong by showing that moisture caught between two different metals can create a small current, frog or no frog. As a result of his disputatious observations, Volta went on to invent the first electric battery (called the voltaic pile) and, more important, to show that electricity could flow in a current along a wire instead of only in a single spark or shock.

In addition to being named a count in 1801 by Napoleon, Volta had the term “volt” named after him. As for Dr. Frog Legs, he walked away with the consolation prize of having the term “galvanism” (to have an electric current) named after him.

Modern people effort in understanding electricity

The development and nurturing of electrical power resulted from the work of scientists and accidental discoveries on both sides of the Atlantic Ocean. This essentially was a European and American deal, and it included contributions from England, Scotland, France, Yugoslavia, Germany, and Italy. The earliest attempts to create or reproduce electrical currents were through the use of crude batteries. The Energizer Bunny wouldn’t have completed one drumbeat powered by these early batteries.

For the most part, these early physicists (they almost all were physicists) studied electrical phenomena, quantifying their observations so each one could conclude, “A-ha! It really hurts when you stand in a metal bucket of water and touch the bare ends of hot wires together!” Each contributor added to a gradually developing body of knowledge about electricity.

The Pioneers
A number of key players were poking and probing into electricity, most of them during the eighteenth and nineteenth centuries. Considering the unsophisticated equipment these scientists used, their accomplishments are that much more remarkable. It’s not like they could refer to a textbook—they were writing the textbooks! You’ll recognize some of these scientists as the namesakes of some electrical terms we use today.

Ben Franklin Flies a Kite
Ben Franklin, the colonial printer known for pithy quotes who is now pictured on $100 bills, is famous for having flown a kite during a lightning storm—a practice not advocated by this author or your local hospital. Franklin was testing his idea that lightning was a form of electrical current. A metal key attached to the kite attracted the lightning as its electrical charge traveled down the kite’s cord and into Franklin’s wrist. As a result of his 1752 kite-flying and his follow-up observations, Franklin developed the terms “conductor,” “charge,” “electrician,” and not surprisingly, “electric shock.”

The birth of applicable electricity

Many people think of the era of electricity as beginning with Thomas Edison and his electric lamp (or light bulb). His work was crucial in popularizing electricity and in making it practical for modern life, but a long list of scientists preceded Edison in this field. It took centuries of work just to discover what electricity is. I already mentioned the Greeks and their party tricks—creating static electricity by rubbing a piece of amber with wool or fur. They became pretty busy creating democracy as well as feta cheese, so they didn’t get any further with electricity.

A couple thousand years later, around the year 1600, English scientist William Gilbert got the ball rolling again when he coined the term “electric” while describing the theory of magnetism. He was followed by a host of physicists, most of whom had laws, theories, or measurements named after them. These scientists laid the groundwork for industrialists like Edison and Westinghouse, who were able to exploit electricity and get it out of the laboratory.

Once the light bulbs started glowing, electricity became the computer industry of its day, with constant innovations, the building of an infrastructure, and a steady array of new uses. The dreams of merchandisers were realized in the years to follow, as they convinced the world to buy new gadgets and products that everyone previously had lived without, apparently in blissful ignorance. Electric lamps were followed by early versions of curling irons, electric cars, and waffle irons. Today, even Edison would be amazed at the electric world he helped create.

What you need to know about electrical wire?

Other than a brief foray in the 1970s when aluminum wiring was popular, copper is king when it comes to house wiring. Copper rates high on the conductivity scale. That is, it’s an efficient pathway for an electrical current.

Conductivity Scale
Silver 100%
Copper 98%
Aluminum 61%
Iron 16%
Nickel 7%

In addition to a wire’s conductivity, its size and the type of insulation around the wire affect its ampacity, or the amount of current (in amps) it can carry before it exceeds its temperature rating. The greater its size, as measured in mils, the more current it can conduct.
Every wire size has a maximum current that it can conduct. The following table shows the most common residential wire sizes and their ratings.

Wire Gauge Rating
Gauge Value Ampacity
14 15 amps
12 20 amps
10 30 amps
8 40 amps
6 55 amps

Appliance and lamp cords use No.16 or No.18 wire, which is quite thin. This might lead you to ask, “Well, if thinner wire has a lot of resistance and can heat up easily, but thicker wire can hold more juice without overheating, why don’t we use thicker wire throughout our homes? Wouldn’t that be safer?” This is a reasonable question, and it has two answers: flexibility and cost.

If you try to bend and fit No.8 wire so you can connect it to a light fixture, you’ll come to appreciate the flexibility of smaller wire. Like just about anything else in life, the larger the size, the greater the cost. There’s a reason home-improvement stores periodically have loss-leader sales on No.12 wire but not any of the thicker stuff. Other factors that affect your choice of wire will be discussed in later chapters.

The society of wire and conductors is a very closed one. No amount of politically correct persuasion will convince one gauge of wire to mingle with another. You should not mix No.12 wire with No.14 on the same circuit, for example. Wire must match up with its circuit breakers or fuses; No.14 wire doesn’t go with a 20-amp breaker, so don’t confuse either party by mixing them together. You can install larger wire on a smaller circuit breaker, but you cannot install a smaller wire on a larger circuit breaker.

What is Electrical Resistance?

Everywhere we look in life, we find some form of resistance. For airplanes, it shows up in the form of wind (and maybe an occasional bird or two). Water keeps kayakers afloat, but it also slows them down some. Even the indomitable James Bond in his Aston Martin DB5 had to contend with resistance when his tires hit the road. It would be great if all the electrons in a current could go gliding across a copper wire (or another conductor) free and clear, but pesky resistance prevents them from doing so.

Resistance in a conductor opposes the flow of an electric current. This results in some of the electrical energy changing to heat, which you want to minimize. Hot wires can be dangerous wires. On the other hand, resistance is built into the system to control the strength of the current running through it. You also don’t want your blender getting hit with 50 amps of electricity when you’re mixing a fruit shake. Electrically speaking, resistance is measured in ohms.

Ohm’s Law (Ohm was a German physicist with a great name) basically says that the smaller the wire or conductor, the greater the resistance to a current. If you crank up the amps, you get even more resistance, sometimes to the point of overheating and causing a fire. Loads that require more amps also require larger wire to handle the current flow. If you increase the size of the wire, the resistance goes down, and you get a weaker current with less voltage drop. This is one of the reasons you have several different sizes of wire in your house.

Think of it this way: Imagine that the fire department is putting out a fire in your house.

You’re happy that they’re using a big hose (just as a No.6 or No.10 is a big wire for big jobs). But what if you’re just watering your garden? Then you want to conserve water and avoid flooding the garden. You’ll use a small hose (just as a No.12 or No.14 wire is good for small items such as light fixtures).

Wattage Around the House

How do watts figure into your electrical calculations? It’s simple: They tell you how much stuff you can pile onto one circuit without overloading it. You don’t want to put too much demand on a circuit with too many watt-hungry loads. Some simple math will keep you on the right track.
Watts equal voltage times amps. Let’s say you want to install a new 15-amp circuit so you can add some outlets or lights to your living room and dining room. Because you won’t be running any major appliances (assuming you don’t do your laundry in the living room), this circuit will be running on 120 volts rather than 240. Therefore … 120V X 15A = 1,800 watts

Terrific, you say. I can put in 18 100-watt lights. Actually, you can’t, because you generally figure on running only 80 percent of the maximum load —1,440 watts in this case—but that’s still 14 lights with watts to spare. What if you want to plug in your new window-shattering, guaranteed-to-have-theneighbors-call-the-police music system that needs 1,900 watts all by itself? Time to recalculate. It’s going to need its own private 20-amp circuit before you can crank up Eric Clapton’s original version of “Layla.” By calculating your electrical needs first, you can accurately wire your house once without needing to make adjustments later.

What is Watt?

Watts are one of the measurements you will refer to in your electrical work. Most of us know the term from buying light bulbs (I know, the term should be lamps, but this isn’t an easy one to get away from) as in “Why do we have a shelf full of 60-watt bulbs when I need 100?” A watt is a unit of electrical power. It tells you how much electricity you’re consuming and being billed for by your utility company. This is why you have a meter outside your house recording your usage. A single watt is a minuscule way to measure power usage, so the following larger units of measure are used instead:

• Kilowatt or kw (1 kw = 1,000 watts)
• Megawatt (1 megawatt = 1,000 kw or 1 million watts) You’ve really got some usage problems if your electric bill indicates that you’re in the megawatt range. (Perhaps you have a refrigerated warehouse on your roof.)

What is Ampere?

While Volt measure the force of an electrical current, which is the movement of zillions of electrons. Amperes or amps measure the number of electrons in a current moving past a specific point on a wire or another conductor in a one-second period of time. If you want an exact number, one ampere equals one coulomb of electrical charge moving across a conductor in one second (or 6,250,000,000,000,000,000 electrons per second).Coulombs were named for that fun eighteenth-century French physicist, Charles A. de Coulomb.

If electricity were water, volts would be the speed of the water, and amps would be the amount of water flowing through your hose. A new three- or four-bedroom house often will have a 200-amp service; apartments or small condominiums might only need 100-amp services. Individual fuses and circuit breakers are measured in amperes. That is, they only allow a certain amount of current to pass through before they shut down the current.