Consider the carrying capacity and the quantity of current the wire must carry when determining the gauge wire you want (measured in amperage or amps). The wire gauge is proportional to the number of amps that must be passed through it. The gauge of wire required can also be influenced by the distance the wire must travel. For example, if you have a long stretch of cable and need it to be lightweight, select a small gauge.
As a general rule, the smaller the gauge, the lighter the weight but the less durable the wire will be. The choice of metal used to manufacture the wire affects its durability too. For example, aluminum wires usually are not as durable as copper wires of equal size. Steel wires are the most durable but also the heaviest. They are commonly used in power distribution systems because they can support large currents without breaking down.
The current rating of the connector is another factor to take into account when choosing the right gauge wire. For example, if you need to carry a current of up to 15 amps, then you should use 14-gauge wire. If the current rating of the connector is 20 amps, then you should use 16-gauge wire.
Finally, the distance that the wire must travel determines the size of the cable gland you need. For example, if the length of your run is 10 feet, then you will need a 10-foot cable gland.
A wire gauge is a measurement of the diameter of a wire. This defines how much current a wire can safely carry, as well as its electrical resistance and weight. A standard reference for wire gauges is the American Wire Gauge (AWG).
The AWG was developed by the American Society of Mechanical Engineers (ASME) in 1914. An AWG is used to measure the average diameter of a long, continuous length of copper wire. The wire is passed through a set of micrometers which measures its diameter directly. The results are expressed in thousandths of an inch (300 microns), with each unit representing 1/12th of an inch (1.5 mm).
There are two main types of AWGs: single-core and multi-core. Single-core AWGs are used to measure one strand of copper wire; they range in size from #14 to #18. Multi-core AWGs are usually larger than single-core AWGs and range in size from #4 to #8. They are used to measure multiple strands of copper wire.
For example, if you need to connect seven #19 wires together, a single-core #7 wire will not work because it is too small.
How do you know what gauge wire your amplifier requires? 8-gauge wire is enough for up to 500 watts RMS. You should use 4 gauge in the 500-1000 watt RMS range. Between 1000 and 1500 watts RMS, utilize 2 gauge. At more than 1550 watts RMS, 1-gaudege wire is sufficient.
The actual load that your amplifier will draw depends on how you connect it up. If you use all straight wires from box to box without any connectors or switches in between, then 8-gauge wire will be enough to connect up to 500 watts. If you need to handle more power, use larger gauges until you reach the limit of how much current 8-gauge can deliver. It's best to err on the side of caution and use a bit more wire than you need.
Amps require more voltage across them than batteries can supply. This is why most amps have some sort of power supply built into their case, which converts ordinary house current (120 volts) into the high-voltage current needed by amplifiers (300 volts or more). The power supply may be as simple as an old-fashioned transformer or as complex as a microprocessor-controlled unit capable of handling hundreds of watts.
Transformer-based supplies are cheap to make and easy to install, so they remain popular with new builders.
A wire gauge is a device that measures the cross-sectional area of a wire. Knowing the gauge is crucial because it dictates how much electric current a wire can carry without causing harm (this number is known as ampacity). The two main types of gauges are absolute and fractional.
Absolute gauges such as the milliamp (mA) or the ohm are used when there is a need to know exactly how much current is flowing through a wire. These are most commonly seen on power lines where excess voltage from another line might cause injury or damage to equipment. Fractional gauges such as the tenths of an amp or the hundredths of an ohm are used to measure small currents with high accuracy. These are most commonly found on heavy duty wires during wiring installations when it is necessary to know the capacity of each conductor within the cable.
The term "gauge" comes from the old French word "goût," which means "smell." That's why these instruments give off a smell when you touch their pins while they're plugged into the wall outlet: electricity feels like hot metal to the fingers, so we use protective coverings to avoid getting burned.
These days, most electrical wiring uses thin, flat cables called trunks or risers.
To get the gauge of stranded wire, multiply the diameter by two. So, if the diameter of a wire is 0.005 inches (0.127 mm), multiply this amount by itself. The outcome will be 0.000025 in (0.000635 mm). Divide the answer by the number of strands in the wire. In this case, divide by 2 because it's assumed to be single-strand wiring.
For solid wires, use the outer diameter. To find the gauge, multiply the outer diameter by two. So, if the outer diameter of a wire is 0.005 inches (0.127 mm), its gauge is 26 millimeters (mm).
The term "gauge" comes from the days when all electrical wiring was done with bare copper wire. Back then, people used gauges on telephones and telegraphs to determine how thick the wire should be taken up on a spool or reel. A thin wire would break under tension, so engineers needed a way to know how much pressure could be applied to a given length of wire without breaking it. They came up with the idea of dividing the inner diameter of a tube by two and calling this value the "gauge" of the wire.
In modern practice, electricians usually don't use raw copper for wiring. Instead, they use cable that contains several individual wires inside a protective covering called "sheathing".
A wire's gauge refers to its thickness. Each gauge is denoted by a number, with lower numbers denoting larger wire gauges and higher numbers denoting thinner wire gauges. For example, 14 ga. (1.5 mm) wire is considered fine wiring material, while 12 ga. (1.0 mm) is recommended for outdoor use where corrosion is likely.
The term "ga." is short for "gauge." One could also say that 1.5 mm is half the diameter of a 14 ga. wire, so you get smaller wires if you buy them by the spool instead of by the pound. But we'll leave that as an exercise for the reader :
Wire gauge is important to know about when working with electricity. The thicker the wire, the more current it can carry before it gets hot. Thinner wires require better cooling or else they will burn up too quickly. Outdoor wiring should be no less than 6 ga. because 2 ga. won't stand up to weathering very well. And of course, your cord must fit through any holes it might need to fit through - if it can't, you'll need something bigger/smaller.
Here are some other things you should know about wire gauge: 10-ga.