{"id":263,"date":"2010-11-02T10:44:00","date_gmt":"2010-11-02T08:44:00","guid":{"rendered":"https:\/\/www.fussylogic.co.uk\/blog\/?p=263"},"modified":"2012-11-17T10:47:58","modified_gmt":"2012-11-17T10:47:58","slug":"how-to-wire-a-plug-2","status":"publish","type":"post","link":"https:\/\/www.fussylogic.co.uk\/blog\/?p=263","title":{"rendered":"How To Wire a Plug"},"content":{"rendered":"

Electricity comes in many forms. Your residential house supply is 230 volts alternating current (AC from here on). The AC is supplied on two pins, and an earth<\/em> connection on another. The AC pins are live<\/em> and neutral<\/em>. You shouldn\u00e2\u20ac\u2122t go around touching any bare electrical wires, but if you did touch the earth<\/em> or the neutral<\/em> nothing would happen to you.<\/p>\n

The neutral<\/em> line is held at zero volts. The live<\/em> line is the one that alternates. It alternates (you might be surprised to know) between +325 volts and \u00e2\u20ac\u201c325 volts fifty times a second in a sinusoidal shape. This gives it the equivalent power of a 230 volt DC line.<\/p>\n

The earth<\/em> (sometimes called ground<\/em>) line\u00e2\u20ac\u2122s job is to act as an electrical safety valve. It is a low-impedance path for current. Low-impedance means that if a live<\/em> voltage is connected to it, the current from that line will flow unrestricted at any current. This unrestricted flow will be so high that it will blow any fuse in the line. Thus, earth<\/em> is used to make electrical equipment safe.<\/p>\n

Let\u00e2\u20ac\u2122s say you have a metal toaster with no earth connection, the electrical heating elements are (when its on) connected from live<\/em> to neutral<\/em>. Let\u00e2\u20ac\u2122s say over the years, the element gets broken and the live wire falls off and touches the metal casing. That metal casing is now at 230 volts AC. If anyone were to touch it, the electricity would have a path, through their body, to ground, which it would take, and in the process would electrocute them. Now imagine that the case was connected to earth<\/em>, as soon as the live<\/em> touched the case unlimited current would flow: much higher than the 13A fuse in the plug would allow, and so that fuse would blow, cutting the power and making the whole thing safe. We expect then that there will never be any current flowing into earth<\/em>, if there is, then there is a fault in the equipment.<\/p>\n

You should be able to see then that your equipment will work without an earth<\/em> connection (some low-voltage, non-metallic cased, equipment doesn\u00e2\u20ac\u2122t need an earth<\/em>), it is dangerous not to connect it. The live<\/em> connection supplied the power, and the neutral<\/em> connection supplies the return path for the electrical current to flow.<\/p>\n

Now you know what the three wires are, let\u00e2\u20ac\u2122s look at how they are connected in a plug. In the electrical equipment (i.e.\u00c2\u00a0the wiring that uses the power, rather than the wiring that supplies the power) the three wires are brown (live<\/em>); blue (neutral<\/em>); and green and yellow (earth<\/em>).<\/p>\n

\n\"UK<\/p>\n

UK plug<\/p>\n<\/div>\n

The UK plug is the best design in the world (I think). It\u00e2\u20ac\u2122s solid, robust, safe and easy to wire. The rectangular pins, arranged in a triangle give it a mechanically sound connection when it\u00e2\u20ac\u2122s in the socket.<\/p>\n

Wiring it, at first sight, is simply a matter of connecting the right colour to the right pin. See the ultimate handyman<\/a> for a quick photo-guide to connecting. Here is some additional useful practical advice that\u00e2\u20ac\u2122s worth knowing:<\/p>\n