Electricity can get really, really complicated if you let it, but it doesn’t have to get so crazy if you don’t want it to. In this article we only really have to look at the delivery of electricity; its movement from origin to a device which it powers. Commonly, electricity delivery is broken down into four processes; generation, transmission, distribution and retail, where it finally powers a consumer device. Wire (electric wire in this case) is what we use as a means to transfer electric energy between these four stages of electricity delivery.
Electricity is a type of energy that is carried by little particles called electrons. Electrons are the bits that orbit atoms, which are the absolute smallest building blocks of matter; solids, liquids, plasma and gas included. In some forms of matter, electrons are very loosely attached to their atom and can simply be plucked right off and into the orbit of another atom. This is the essence of conduction, which is the transmission of electrons from atom to atom. Some materials are more conductive than others based on how “loose” their electrons are. Copper and other metals are good conductors. When a bunch of electrons are jumping through the atoms of a conductor, this is known as an electric current, and this is what we use to power the circuits of electronic devices.
In short, wire (in this context) is a length of conductive material that transfers electric current from one point to another. Though wire can be constructed of virtually any conductive material, the vast majority of wire is made out of copper for a variety of reasons from economic to political. It’s a great conductor regardless. Wire has to be able to withstand the load of current it’s being fed, but it also can’t be leaking electrons all over the place either. If you had a string of electrons jumping between copper atoms (a copper wire) but then touched the middle with another conductor, the electrons would start to jump away from the atoms of the wire to the atoms of the other conductor. In similar fashion, an external supply of electrons could be forced onto the wire, disrupting the direction of the current’s flow. This is why we insulate wire from external disruption. Whether we need to keep it from corroding in the elements (like metal oxidizing and rusting with water), or if we want to keep it from contact with another conductor, insulating our wire has become common and crucial for safety.
Historically, people have used a variety of materials to construct wire and even more to construct its housing of insulation. Wood, paper, cotton, glass, and even less conductive metal has been used as a means to insulate wire, but today we favor rubber and plastics for their high resistance to conducting electricity and their ability to be weatherproof and waterproof. In some cases more advanced materials are used to protect from heat or other circumstances based on where wire must be used.
Commonly, wire is buried underneath and within structures where it cannot be tampered with, but if you need to put it there in the first place or change something once it’s there, understanding the basics of working with wire can make things a lot easier and even save your life.
We have established what is flowing through wire (electric current, jumping electrons), but understanding the measure of this current is pretty important as well. Electric current can be amplified and transmitted across the atoms in a wire of conductive material. This wire will have a maximum capacity for current, and if the current exceeds what the wire can handle, it will break. Large amounts of current travelling through a conductor will force it to heat up – one of the reasons we insulate our wires, it’s just as important to protect what’s outside the wire as what’s inside it.
Understanding the way electric current flows through a wire is pretty much the same as the way water flows through a pipe. It’s going to go in a single direction, you can only move as much as the pipe allows for and the more you fill the pipe, the more pressure it has. To measure electricity, we use Amps, Volts and Watts. Amperage units measure the amount of electricity and Voltage measures the pressure/force of it. Wattage (watts) is determined by multiplying the amperage by the voltage, which give an indication of how much work power is being delivered per second, and how much work it can do.
If you are running water through a pipe to fill bottles, the amount of water travelling through would be similar to amps of electricity. Water pressure would be comparable to volts. Without even needing to test things out, you would be able to calculate how quickly you can fill those bottles by determining the total amount of water you have coming out at the end of the pipe per second; this would be like the wattage coming out at the end of a wire conductor. You could be running huge amounts of electric current through a very wide pipeline of wire, which would likely be measured by a high amperage, a low voltage and medium wattage. If you run the same high amperage through a thinner wire, you may yield higher voltage and wattage but put too much stress on the conductive material. Knowing the limits of your material and how much energy it needs to transmit is key to understanding what wire should be used when and where.
Wire is commercially made in various gauges of various materials for an array of uses, and is typically rated based on the amount of voltage it can transmit (since voltage really refers to the pressure, remember?) Generally it is assembled from twisted strands of conductive metal like copper, which is insulated and encased in a non-conductive material. Often, commercial wire contains several strands of conductors within. Think back to how a battery works. For an electric circuit to function, there needs to be a positive current pushing the power in and a negative current pulling it back out (a return conductor). Often an electrical wire needs to contain conductors for both negative and positive currents, or just several currents for several devices, or even for grounding wires. In some cases only a single wire is needed to transmit a single-directional current of electricity; like simple one way telegraphic data using languages such as Morse code. If you ever get a chance to look at telephone wire, you will notice it is simply a collection of differently marked, single strand wires for audio transmissions to and from different locations. Depending on the power requirements, a grounding (or earthing) wire may be necessary to return current at the end of the circuit in order to be measured or simply transmitted back into the ground in order to prevent an overload of voltage pressure. Electricity has to go somewhere if it’s not doing anything (static electricity). As soon as something conductive comes along, those static electrons will jump into it without thinking. This is often how electrical accidents (like electrocution) happen. So for this reason we often force electricity to be absorbed right into the planet itself rather than our buildings, friends or pets by accident.
Generally if you are working with something that contains wiring, it will have some form of wiring chart or diagram to indicate what wires go where. This is crucial in planning out circuits as well as maintaining, repairing or changing them. Commercial wire is produced with different colors and colored patterns of insulated casing. This is used to help mark and indicate wire for different uses. While these color designations are not fully universal, they are generally common from region to region and country to country. A general guide is available here:
Ensure that you are familiar with which wires are associated with which purpose; it could mean the difference between cutting into a harmless neutrally charged conductor and cutting into discharging ground wire. As a rule of thumb, just don’t work with wire that has an electric current running through it, for the good of your health and that of the circuit. You are always better off disconnecting wire from the source of electrical generation, whether that means turning off a generator, switching off a fuse or disconnecting your circuitry from a battery.
Wiring should always be planned out first before assembled. Try to remember why we make wire the way we do; insulated. Don’t pull it around tight corners which may compromise the insulating casing; if the insulation frays and exposes the conductive material to something else, it could start a fire, electrocute an organism (pump it full of voltage) or even suck in and conduct something it wasn’t supposed to conduct. Do not use wire to transmit voltage higher than what it was rated for. If you need to move high voltage, get thicker, heavier wire, or start doubling down on strands; perhaps a single gauge rated for 5 volts won’t carry 10 volts, but two 5 volt wires can and will so long as you play it safe. Remember this will effect the wattage coming out of each individual wire, but that can be added back together as well at the consumer end.
Just like water.
Don’t add water.
Try to keep wires separated from each other and surfaces as they can interfere with each other. Remember that the insulation covering a wire resists conduction, but that doesn’t mean that it will never conduct electricity; you can still have instances where electrons jump through the insulator’s atoms of rubber (or plastic or cloth) to reach the atoms of a conductor next to it. You don’t want to send voltage into the wrong wire or even worse, the material in which a house is constructed of; it will just keep searching for the next best conductor.
We have more detailed lessons and articles on where you would go from here with an understanding of what wire is and how it works: