Wiring a Three Pin Plug

Wiring a three pin Plug

Three Pin Plugs (or 3-pin plugs) are designed to protect the electrical appliance and its user from electrical hazards. They vary in size; there are those whose pins are moderately sized, also known as UK plugs, and those with large pins known as non-UK plugs. Someday or today you might need to change the 3-pin plug of your electrical appliance for some varying reasons. Though some electrical appliances are manufactured with the 3-pin plug molded on the AC in put cable, you might still need to change it. Perhaps you bought your electrical appliance when the plug pins are larger than the socket outlets. You will need to cut off that plug and replace it with the suitable one. In this post we will look at how to wire a three pin plug.

To wire a 3-pin plug, one has to be familiar with the colour codes of the wires:

• the live wire is brown
• the neutral wire is blue
• the earth wire is green and yellow striped

If you can get a new Universal 3-pin plug like the one in the picture below, unscrew the top cover of the plug, the 3 terminals and the cable grip.

Universal 3-pin Plug

Cut away about 1 cm of the insulation from each wire using a cable insulation stripper or a razor blade if the former is not in your possession. Make sure not to sever the wire strands.

Put the flex under the cord grip and screw it tightly in order to hold it in place.
Note: Do not leave the flex outside the plug to prevent the wire strands from breaking off their respective terminals as a result of strain.

Do not leave flex outside plug

Twist the wire strands so that there are no strands straying.

Connect the wires to their respective terminals. 3-pin plugs have their pins marked E for earth, N for neutral and L for live. Screw tightly all the terminals.

The connections should be like this.

Put back the cover and screw it tightly.
Disclaimer

Sometimes Fluorescents can be repaired.

Compact Fluorescent glass tube

Fluorescent lights are often known to flicker, shut down (light) after a few seconds when they are switched on, give dim light or even no light at all. Sometimes these problems can be fixed, that is if the glass tube is not damaged and its connectors show a very good connectivity/continuity on the multimeter. So our hope to see our fluorescent working properly again is in examining the ballast circuit. The following explanation shows the components that are likely to be faulted when the lamp is not working properly.

Electronic ballast of a Compact Fluorescent Light

When you open the lamp, you will see the ballast circuit inside and you will most probably notice a blown fuse.
Note: fluorescent lights may contain Mercury which is very poisonous. Make sure you discard broken tubes safely. Work in a well ventilated area, use gloves and respirators if possible. You may also read about how to clean up a broken fluorescent.
In the ballast circuit: 

• the fuse often get blown when the rectifiers or switching transistors get shorted. So they all have to be checked on the digital multimeter to make sure they are working properly.  If not working, first replace them (the rectifiers and transistors) and then replace the blown fuse.

• Sometimes the fuse can blow due to a shorted inductor, replace the inductor if possible. 
• Dim light, light goes off after a few seconds or no light at all, this is caused by shorted capacitors (ceramic and electrolytic caps). So all these must be checked in order to repair the lamp.

Curiosity about Solar Energy

Solar Energy is energy which the sun radiates and reaches the earth. Solar Energy is a renewable energy.

There are two energy sources; Renewable energy and Non-renewable energy. Renewable energy are energy sources that occur naturally and continuously in the environment. Apart from Solar Energy, Wind, Hydro, Biomass are also examples of renewable energy sources. Non-renewable energy are energy source that cannot be made again in a short period of time. Examples include; fossil fuels, nuclear energy.

Solar Energy has two types of use:

1. Solar Heating; the heating effect of the sun is used to dry crops, bricks etc.
2. Solar electricity (use of electricity from solar energy). Solar energy is converted to electricity by either using Photovoltaic devices or Solar power plants.

Solar Power Plants. These indirectly generate electricity. They employ solar thermal collectors to collect heat from sunlight and this heat is used to heat the fluid which produces steam that is used to power a generator (turning turbine). This heat can also be put to other uses like in steam baths.

Photovoltaic devices. These change sunlight directly into electricity. Photovoltaic devices/cells make up a Solar Panel.

How do Solar Panels generate electricity?
A Silicon Solar Panel/module (also known as a Photovoltaic module) generates electricity when photons from sun excite electrons in it.
Let's first go through the construction  of a solar cell. Solar panels are made up of solar cells. Like semiconductor electronics such as diodes and transistors, silicon solar cells are doped that is to say some impurity atoms are added to the silicon crystals to form negative (n-type) crystal and positive (p-type) crystal. The n-type doping can be Phosphorus atoms added to silicon. Silicon atoms offer each other one electron in a covalent bond so this makes silicon unable to conduct electricity. But if a phosphorus atom is added, it will behave like silicon with a extra electron.

When a photon from sun strikes this electron, it gets excited (it becomes delocalized).

P-type doping can be Boron atoms added to silicon. Boron atoms have three valence electrons, each, to offer to silicon in a covalent bond and this will create a need for one more electron. Therefore a hole is created.

So in a silicon solar cell the two doped materials, made into plates, are joined together with a junction in between. In full sunlight; when you create an external circuit by attaching wires to the p-type and n-type doped materials, Boron in the P-type doping will create a positive potential to attract the excited electron in the n-type doping.
In a silicon solar panel, cells are connected to each other in series. A typical solar panel has:

• 33 cells in series
• the maximum useful voltage generated by a solar cell is about 0.58 volts dc.
• the total output voltage of the panel is 19.14 volts dc and maximum of about 16 volts is required from a solar module/panel in order for a 12 volts lead acid battery to be fully charged.

What do I need to do before installing a solar panel?

• The number of cells in a solar panel. If there are few cells in the panel the out put will be low.
• The type of silicon used. A monocrystalline produces the highest current compared to polycrystalline silicon.
• The surface area. Cells with a large surface area have high short circuit current than small cells.
• The angle of the module/panel with respect to the sun's radiation. It should be at 90 degrees.
• There should be enough air circulation around the panel.