CONNECTORS (POWER)

While all radio equipment runs on electricity – DC or AC – the cables that connect all these varieties of equipment to their power sources are often different from each other – and so are the connectors at each end of the power cable. In most cases, the connectors will be of one of the following two types :
 
1. The standard power plug
 
The standard plug is the most common power connector, and is usually used to plug into AC mains supply sockets. AC mains power is of a very high voltage – 220 Volts in India – and can damage your equipment and cause fatal electric shocks if care is not paid to the way the plug is wired and plugged in.

Power plugs of this type come in two varieties: A larger variety with thicker cylindrical pins for heavier loads (often called a power plug or 15 Amp plug), and a smaller variety with thinner cylindrical pins (often called 5 Amp plugs) for lighter loads. Each of them requires a corresponding socket, as the pin spacing is different in each case – but modern socket fittings generally feature sockets which accept both varieties of plugs.

Socket and plug fittings vary from country to country, as do the operating voltages of equipment. As most equipment used in a radio station is manufactured outside India, it is vital to check whether the plug supplied with the equipment will fit into sockets here: If it doesn’t, it may be necessary to obtain adapter plugs that allow us to connect it to Indian standard sockets. If the operating voltage is also different – equipment from the United States operates at 110 Volts instead of 220 Volts, for example – then a power adapter may also be required to step down the voltage.

Plugs need to be wired as per existing international and domestic conventions for electrical wiring. This is done according to a colour coding system that identifies the correct wires to be connected to the phase, neutral and earth points of the socket.

• The black wire connects to the pin on the left as seen from the back of the plug. This pin is most often labelled Neutral, Black or just N.

• The red wire connects to the pin on the right as seen from the back of the plug. This pin is often labelled Live, Red, L or Phase.

• The green earth wire connects to the top pin of the plug. The earth pin is often labelled Earth or marked with the earth symbol.

Not all pieces of equipment use the earth wire, and you will have to read the wiring instructions to see whether or not ‘earthing’ is needed. Where there is a choice, always try to use a 3 pin plug instead of a two pin plug for the earth protection the third pin gives you.

Reliance Controls LL550C 50 Amp Generator Power Cord Connector For Up To 12,500 Watt Generators

Wiring a power plug correctly Though it appears very simple – and it actually is, once you learn how to do it properly – there are some basic procedures that must be followed when wiring a plug. The first thing is to note that the earth, live and neutral wires of a power cable each have their own colour coded insulating plastic or rubber coating. Together they are then surrounded by a second rubber or plastic coating (mostly white, grey or black) which keeps all three wires together. To wire the plug, you will first have to remove a section of this outer coating, enough to expose the three individual wires, but without stripping the inner wires’ own coatings. Also, when you do this, make sure you leave enough of the outer insulation jutting into the plug. The earth, live and neutral wires are often stuck together. You may have to separate them by pulling them apart. When you do this, make sure the insulation (the blue, yellow / green and brown coating) surrounding the copper wire remains intact. Also, make sure that the three separated sections are just long enough to fit comfortably into the pins. Depending on the plug, you may have to leave the green wire a little longer and clip the other two wires slightly shorter so that they fit comfortably into the pins. Then remove a very short section of the green, red and black coatings to expose the copper wire within. Expose just enough so that the exposed copper portion fits into the holes in the three pins: If you expose too much, there is a risk that two of the wires may short circuit. Each of the wires may have several finer strands or filaments of copper wire. Twist these strands together so that they stay together. Then insert them into the holes on the pins. Screw the screws that will hold the copper wire in the pins down firmly, making sure that they are holding the copper wire down. Tug gently on the wires once the screws are in to check. If the screws are not firm, or the pins wobble in their casings, or the screws that seal the plug casing are loose, change the plug at once.

2. The Kettle plug or IEC connector

 
The IEC connector is often called a “kettle plug”, as they are often used on kettles. They are used to supply power to many pieces of studio equipment, and to computers. The formal name for this type of connector is the IEC320/ C-14 (male) and the IEC320/C-13 (female). The former usually receives the power, and the latter supplies the power. Commonly, the male connector will be found on the equipment body, and the female connector will be found on the end of the cable that is attached to it.
 
In most cases, equipment that uses IEC plugs and connectors are supplied with sealed molded plugs that do not have any joints and cannot be rewired by you. In these cases, if a plug shorts out ot malfunctions, the better option is to simply purchase the entire connector, with the wire/cable and the connectors.