I'm clueless when it comes to what's meant by "load", "neutral", white wire, black wire, red wire, and the rest. Is there a primer out there on the net to explain how things work to us dummies? Or do one of our resident electrical geniuses want to take up the challenge?

Just search for any thread with comments by Larry Fine, AKA "The Electric God" of Remote Central.com.

quick primer...

1) load = 110 to 120 volts A/C...

2) A/C = alternating current

3) neutral = wire with no load- WHITE WIRE

4) White wire... neutral- you can touch this without becoming a 'freedom fry'

5) black wire... carries 110-120 volts A/C, also known as the HOT WIRE

6) Red wire... same as black wire, except carries a separate 110-120 volts in a 220 volt system... for example.. an electric dryer runs off of 220 volts.. there's a black wire with 110 volts, a red wire with 110 volts, a white wire that's neutral, and a green wire that's the ground

7) ground... green wire... goes to the ground (literally)

8) edison plug... one of the 3 pronged plugs you find on a wall in a typical house... the 3 holes are different shapes and sizes.. the roundish one is the ground, the tall one is neutral, and the shortish one is hot


note.. i'm not a certified electrician, so take it for what it's worth :)

I'm trying to think of something I've gotten help installing - a ceiling fan. I believe it had a red, white and black wire coming out of the ceiling junction box. My wall gang box had two each of red, white and black, which I assume would mean one set for the light, one set for the fan.

The term "load" is just that, the electrical load i.e. light bulb.

The wire that carries the current to the load is the "line"


Not true! The neutral wire carries the load back to earth.
Never assume the white wire is not "hot"


Or the "line"

In switch circuits the white wire is often used as a hot wire. The convention is white down/black back, meaning that the white wire carries the current to the switch and the black wire carries the current back to the load. It is considered good electrical practice to recode the white wire black, ie. painting it or making it with black tape.

Okay, you guys, here's a little bit of info:

First of all there's the power entering the house:

Find the power pole nearest your house that has a transformer (large metal 'can') on it. On the top, you'll find a single, relatively thin wire attached to a ribbed insulator, that is fed to it through a fuse, which is fed from the wire at the top of the pole, the primary, rated at 15 to 20 Kilovolts, that is strung from pole to pole.

On the side of the transformer, there are three terminals with heavy wires attached to them; these are the secondary. You'll notice that the center one has a strap that connects to the can itself, and also has a wire that connects to the next wire down the pole, the system neutral for both primary and secondary. This is ground, earth, etc.

The secondary, the three side terminals, are where your house voltage originates. There is 240 volts between the two end terminals, and 120 volts between the center (neutral) and either end terminal (often called the 'phases'), which are the hot wires.

The neutral, and sometimes the two phases, run from pole to pole, to connect other houses. All houses that share the same transformer are effectively the same house, as far as X-10 is concerned. That's why there are house codes, so neighbors won't control each other's systems.

The three wires enter your house, through the meter, and into your panel. The two hot wires (again, the phases) are protected by the main breaker (or fuses), and then to the two buses, or strips, that the branch circuit breakers plug onto.

The third wire, the neutral, aka ground, is connected to the neutral bus, which is the last place that neutral (aka the 'grounded' conductor) and ground (the 'grounding' conductor) are one and the same. At any point beyond here, they are to be kept separate.

The neutral is a circuit conductor, and is to be insulated just as the hot wires are. The ground may be bare, and only carries current during a 'fault', which is expected to be a short-term duration. While electrically the same, the neutral and ground serve different functions.

About color coding:

Two-conductor cable (the bare ground wire is not counted, except in flexible cords, where it's green) is manufactured with one white and one black wire. Three-conductor cable is made with one white, one black, and one red conductor.

That's how it's made; the installation determines which color is what. The rules of colors revolve around the way it's made, so all cable has a white wire, but don't assume the white is always neutral.

Assuming the installing electrician wired properly, there are certain rules that, when followed, determine which wire is carrying what potential or current. These rules state that:

1) The bare (or green) wire is always used for equipment grounding only.

2) The white is used as the neutral (grounded circuit conductor), except:

a) Where no neutral is used, such as feeding a 240-volt load with no 120-volt components (like a water heater), in which case the white should be permanantly re-colored at both ends and wherever else it's accessible.

b) Where used for switching a load (switching is always done in the hot wire(s) only), and no neutral is needed at the switch(es), the white may be used to feed the switch, and again should be re-colored.

Any color other than green (or bare) or white should be assumed to be a hot wire. Traditionally, when there are both an always-hot wire and a switched-hot wire, the black is always hot and the red is switched, but this is not a requirement.

When feeding a ceiling fan with a light kit, the black is often fed to the fan and the red to the light, but again, there's no rule about this.

120/240-volt loads (such as a clothes dryer) use two hots and the neutral, so three-conductor cable is used; the white is the neutral. Also, three-conductor cable is often (but not always) used when there are three-way (and four-way) switches.

The colors might have been used by the electrician in any number of ways, so the switch terminals themselves tell you how to hook up X-10. Never disconnect the switch wires without making notes first.

I can explain how to determine the 'line' and the 'load' positions when the need arises. Let me know. Please ask questions here instead of emailing, so others can benefit from the questions and answers.

Okay, about electrical theory:

'Voltage' is the difference in potential (like the potential to do work) between two points. Like an unused receptacle, there is 120 volts between the two slots. No work is being done, because there is no current flowing, but the 'potential' to do work is there.

'Resistance' (ohms) is the opposition to current flow. Increase the resistance, the current flow lowers; reduce the resistance, current increases. 'Current' (amps) is the flow of electrons through a circuit. 'Power' (watts) is the product of voltage and current.

(voltage is known as 'E' , current as 'I', and resistance as 'R' in electrical engineering. The E stands for Electromotive force; I don't remember why I means current. It's a Latin thing.)

'Ohm's Law' states that one volt can push one amp through one ohm. To wit:

E = I x R
I = E / R
R = E / I

To use these formulae, select the one with your unknown to the left of the =, and use the appropriate function. (Same with Watts Law below.)

If you increase voltage while proportionally reducing current, the wattage stays the same. As an example, a 120-volt, 60-watt bulb will use 0.5 amps, and a 12-volt, 60-watt will use 5 amps. Note that 120 x 0.5 = 12 x 5.

Watt's Law states that one volt pushing one amp produces one watt.

W = E x I
E = W / I
I = W / E

Power is work done. All the voltage in the world does no work unless current is allowed to flow. Note that, while the term 'current draw' is often used to describe a loads electrical usage, loads do not 'suck' current; 'allow to pass' is a more accurate term.

Current requires conductor, and voltage requires insulation. To illustrate, in your car, the battery wires and the spark-plug wires are about the same thickness; the battery wires are mostly copper, but the spark-plug wires are mostly insulation.

Another example, if you look at the power transformer behind your house again, you'll notice that the primary wire is relatively thin (but the insulators are larger), and the secondary wires are heavier (but the insulators are smaller).

Transformers maintain the same wattage (kilowatts in this case) between primary and secondary while raising or lowering voltage. With the exception of energizing currents and other heating losses, transformers are highly efficient "machines".

As yet another example, high-tension transmission lines carry millions of volts (again, look at the insulators), but the wires aren't extremely large. What's important is the power capability of the system.

Why do they do that? Because insulation is cheaper and lighter than conductor, but there's another reason:

All conductors, no matter how thick, exhibit some resistance, which causes some voltage drop, which creates heat. The greater the current, the greater the heating effect. By transmitting higher voltages, lower current can still transmit the same power.

There is an infinite resistance (aka an open circuit, like a switch in the 'off' position) between the slots, so no current can flow between the wires. Now, introduce a 'load', which is a device which is intended to use electricity, the resistance has been lowered, and current flows.

If you reduce the resistance too much, then too much current flows, and you have an 'overload'. What happens then? If the breaker or fuse is selected properly, the circuit is interrupted before any damage occurs.

Keep in mind that the sole purpose of branch-circuit protection is to protect the wires, not your devices. Overloads cause the wire to overheat, which damages insulation, which allows wires to touch, which starts fires.

Fire, not electrocution, is the #1 danger of electricity. In fact, the National Electrical Code is produced by the National Fire Protection Association.

Whew! I've worn myself out typing all this. If anyone has any questions, I'd be happy to go into more detail.

Larry
www.fineelectricco.com

OK, Larry. That always stumps me, so please explain how to determine the line and load positions.

Thanks.
Steve

Steve, you ol' devil. You could have just called me, y'know. (You should anyway; we need to get together.) I know; you just wanted to see me wear out my fingertips (all two of them!)

Okay, here goes:

Remember from lesson #1 that each 3-way switch has three wires attached, the common on each switch's darker terminal, and the two travelers.

One of the commons is fed always hot, and the other common feeds the switched power to the load. Remember the load? The fixture or whatever.

By simply testing for hot from each common to ground or neutral, you can determine which one is hot all the time, and which one is only hot when the fixture is on.

Also, you can usually tell that the always-hot common is fed from a connection with another wire or two, and the load's common is almost always a single wire.

It's a good idea to check all of the wires before disconnecting any, because the switch helps hold the wires for convenient testing. Make a mental (or better) note of each wire.

If the travelers at each 3-way are not the same two colors (red and white are often used differently at each end when the both come from the fixture box.) You can't assume.

It's a good idea to make note of each traveler at both ends by testing for hot at one end, and then at the other end. Both ends of each traveler will be either hot or not hot at the same time.

Sometimes, two two-conductor cables are used; one for hot'n'neutral, and the other as the travelers. I often do this if the hot'n'neutral need to go to several switch boxes.

Other times, three-conductor is used, and the white may be a traveler on one and the hot-feed on the other. This is done when the hot'n'neutral go to the ceiling box, and both 3-ways branch from there.

Occasionally, I'll use two-conductor to one switch, and three-conductor to the other; one of them may be remotely located, relatively speaking, and not need a neutral.

As far as how they work, which is a great help towards understanding X-10'ing them, it goes something like this:

In 3-way switches, aka single-pole, double-throw, the common is always switched to one traveler or the other; if both commons are switched to the same traveler, the light is on; if not, it's off. Simple!

What about 4-ways, you ask? A 4-way switch is inserted in the pair of travelers, and acts as a reversing switch. There are two dark terminals and two light ones. It's easy to mis-wire these.

The two dark terminals connect to one 3-way's travelers, and the lights to the other 3-way's travelers; it doesn't matter which. (Don't assume blacks to darks and reds to lights, etc.)

There can be any number of 4-ways between 3-ways, but there must always be a pair of 3-ways, one at each end of the string. Again, the principle is to either switch the two commons together or break 'em.

Now, what about X-10's? It really gets fun here. That will be lesson #3, if anyone is interested. Let me know. (Not you, Steve! LOL) I don't even know if Tester or anyone else even read the "primer". No feedback (*sniff*). Golly, Wally!

Larry
www.fineelectricco.com

that was more than I could have hoped for. Thank you very much for all of that information! (I was out of town for my aunt's wedding for about the last 11 days)

YES!, one vote for YES!



I think you did a fantastic job!
JMTCW I would like to see Daniel give it its own page so it would be available for all to see!

HELP!!! I've installed and wired a number of projects, and today I ran into a problem where I am stumped. I went to install a new light fixture to a box that had a working Keypadlinc switch (with dimmer).

My task was to run a new set of hot wires (including a ground) to a new outdoor box that would feed a ceiling fan. The existing box (where the problems is) is at the end of a lighting electrical circuit. At all times, including this moment, the balance of the circuit works fine.

When I was reinstalling the installing the Keypadlinc, it would not power up. At first I thought I blew the switch. Testing with a voltmeter showed I may have had a short with the circuit fed by the box (which I did not originally touch). When I tested with a Voltmeter, I found that I had no voltage between the neutral and the load (before the switch). Then I found that I had a 50 volt load between the load and the black lead running to the existing light fixture, leading me to believe I had a short because there should have been no power between those two wires. I disconected the leads in that circuit and eliminated that 50 volt load.

Now the intersting part, I tested between the load and the ground wire (plastic boxes and romex), and had a 110 volt load even though there is no load visible using the neutral/white wire! An ohm/resistance test across the neutral/white and ground is ZERO.

How can I have voltage on the ground and apparently no connection on the neutral? I cannot think of anything I did that could have broken the white wire.

Suggestions?

Can I use the ground as a neutral on this one box and make it all work?

Please give your thoughts.

Okay, ONEAC et al, I will conjur up a little ditty. But first, let me see if I can help Bruce.

Bruce, I really need some specific info:

Please describe each wire in each box you entered. Designate something like:

'box 1', wall box, 'cable A', black/white; 'cable B', black/white/red; all whites together, cable A black to dimmer 'line', cable A red to dimmer 'load', etc.

I need to be able to make a mental schematic, or even draw one if it's complicated. R.S.V.P.

Larry
www.fineelectricco.com

Larry, thanks for the prompt response and the interest:
I describe my situation here, but I also thought of a possible source of the problem.


Box 1 (location with Keypadlinc): Two romex wire sets, one is "load" set, one set as output to series of outdoor floodlights. The grounds from each were crimped together, and the whites were connected with wire nuts. The black load wire was attached to the black lead on the switch, the red switch wire was connected to the other black lead (going to the floodlights). The white was added to the wire nuts for white and the ground was connected to the ground wires. So far so good and everything worked as planned.

Then today, I added a new set of white, green, and purple to be output to box two. White was added to the white wire nut, green was twisted and taped with the ground wires and purple was added and connected to the black load wire in box one.

Box two only has the purple, green and white wires for now.

Box three is the start of the floodlight array. It is basic. The black and white (plus ground) from box one attach to wires for the floodlights, plus similar colored wires to additional boxes.

The black wire heading to box three and the black load wire of box 1 were the two wires that when tested acheived a 50 volt load. That went away when all of the wires in box three were disconnected from one another. Could this have been caused by either a short between white and ground, or if the wires in any of the three subsequent flood light boxes were crossed?
This is where I hit a snag.

POSSIBLE SOURCE:
I thought of something over dinner. I did drill three holes through the stucco, one for the three wires to go to the outdoor box, and the other two for the anchors to attach the box. It is possible, but not likely that I hit a wire. The holes were not drilled where it appeared the wires were headed from box 1. I would have instantly thought this was the culprit except for the 50 volt reads on what was supposed to be an unconnected wire (leading to box three).

Another point about my house -- I don't know if this is normal but on every outlet I tested, a 110 volt read also occurs when meter leads are put on black and ground; resistance testing (ohms) on the white and ground sockets result in virtually no resistance (the needle goes off the chart).

What would happen if I used the ground as the neutral and the ground? Remember this is feeding outdoor lights and a future outdoor ceiling fan. That alone is cause for concern.


Suggestions???

Thanks Larry.

Okay, Bruce, I'm getting the picture. However, in box one, where you said the black dimmer wire connects to the black 'load' wire, maybe you should be saying the black connects to the black 'line' wire (always-hot feed in), and the red connects to the black 'load' wire.

'Load' refers to the controlled lights, not the power feeding into the box, switch, or dimmer. I know it's semantics, but we need to speak the same language to communicate.

It looks like the mistake was connecting the purple wire to what you called the 'load' wire in box two. If that's indeed a 'load' wire, which I take to mean that it comes from the red wire in box one, then you may be overloading the dimmer in box one.

While neutral and ground are connected together in the panel, they should not be treated the same. I have to run. I'll post more later today.

Larry
www.fineelectricco.com