Electrical Wiring

Some time ago, to allow harmonisation across Europe, the specifications were changed to 230 volts RMS +10%/-6%, also running at a frequency of 50 Hz.

Thus the mains supply voltage will remain within European Union norms (standards) even if it varies between an upper limit of 253 volts and a lower limit of 216.2 volts.

A 240 volt 50 Hz appliance can have up to 3 wires altogether:

• one single 240 volt "live" or "hot" wire which colored brown;
• a neutral wire which is colored blue;
• a safety "earth" or "ground" wire which is colored green/yellow

  but this is not required if the appliance is of the type known as "double insulated".

The hot wire feeds alternating voltage from the power station to the load and, because the voltage is alternating, the load draws an alternating current. Then the neutral wire returns the current to the power station to complete the circuit.

Note

The United Kingdom and the Republic of Ireland (and some other countries elsewhere, most of which were formerly British colonies) use a power outlet plug and socket system which is totally different to the rest of Europe:

• All power socket outlets are rated at 13 amps to take a standard 13 amp plug.
• Each power socket has a protective insulated shutter that safely uncovers the live (or hot) and neutral holes when the plug of an appliance is inserted. The shutter immediately covers the holes over again when the plug is removed. The shutter is operated by the insertion of the earth (or ground) pin which is longer than the live and neutral pins.
• Each 13 amp plug has 3 rectangular (not round) pins for a brown live wire, a blue neutral wire and a green/yellow earth wire . There is also a fuse that should be selected to be of the right size to protect the appliance it is attached-to.
• The actual plug type is known internationally as Type 'G'.
• It was designed for use on any normal house mains voltage or frequency and is used in the UK and other countries which have adopted the UK mains power plug and socket system for appliances.

  It is a very good plug and socket system but not many other countries have adopted it - probably because they didn't invent it!

Outside the UK and The Republic of Ireland (Eire), European countries use plugs where all the pins are round. Sometimes (but not always - it depends on the country) the plug's earth connection is not a pin but is a ground-socket within the plug which connects to a ground-pin which permanently protrudes from within the wall receptacle. That arrangement of pins and pin-sockets makes it impossible to insert a non-grounded plug into the receptacle! Another common European plug - the "Schuko" - does not use any earth pin but instead uses two clips which are positioned diametrically opposite one another on the outside edge of the plug.

It all depends on the voltage and wattage of the dryer: maybe you only need 30 amp breakers with 10/3 wire, or maybe you need thicker wire and bigger breakers?

The rating plate on the dryer should tell you want power it takes and, if you are going to do this job safely and correctly, you should first of all be able work out the current or amperage from an appliance's power and the voltage.

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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

No.

All alternators, generators, and motors lose some of their mechanical and/or electrical energy to heat. The alternator converts mechanical energy into electricity, but some of that mechanical energy is also converted into heat (through friction and transmission loss), and the heat is lost to the environment. Similarly, an electric motor that converts electricity into mechanical energy also loses some of its energy to heat, also through friction and transmission loss. It is important to note that the energy is never truly lost - all the energy is accounted for - but the energy dissipated as heat is no longer available to the electrical / mechanical system.

Let's assume that the motor and alternator are 99% efficient - that means that they lose only 1% of their energy to heat and transmission loss. You can imagine, then, that after a moment, there is only 99% of the energy left, and then 98%, then 97%, and so on until the system exhausts all of the energy through friction and transmission losses, at which point the system stops.

NOTE: Purists will argue that an alternator actually needs a battery to initially generate electricity, and that the above discussion only applies to a generator - while true, that point is beyond the scope and relevance of the above discussion.

First you need to understand charge, voltage and current.

Atoms are made of electrons, neutrons and protons. Electrons have a kind of charge called negative charge and protons have a positive charge. Neutrons have both negative and positive charges, so they cancel out and are not very important to electricity. Like charges repel each other, while opposite charges attract each other. This is what causes electricity.

Sometimes atoms will have more electrons than protons or vice versa. When there are many atoms of something have too few or too many electrons then it gains a net charge depending on if there are more electrons or more protons. If there are more electrons then it has a negative charge, if it has more protons it has a positive charge.

Voltage is the difference between two charges. On a 9-volt battery, the difference between charge of the positive terminal and the negative terminal will be nine times as much as the difference of charge on the terminals of a 1-volt battery.

Now since opposite charges attract, the electrons in the negative terminal want to move to the positive terminal (protons don't move because they are in the center of an atom). The only thing stopping the electrons from jumping to the positive terminal is air because it has a lot of resistance.

Resistance is how hard it is for electrons to move through a material. Copper wire has a very low resistance, so when you connect the two terminals together with wire, electrons start moving across the wire from the negative terminal to the positive terminal. Electrons move slowly across the wire, but they start a chain reaction in the atoms that make the wire so that now almost all the atoms want to give some of their electrons to the positive terminal. This reaction moves very fast, almost at the speed of light, and that's things power up almost instantly once they are connected to a power source even though the electrons themselves move slowly. The movement of these electrons is called current, and that's what powers electric devices.

* There is a Discussion about this question and how it should be answered. To see it use the View Discussion button shown below this answer.

== == === === Assuming that you know that the bulb(s) in the fixture are good.

AT THE MAINS SUPPLY PANEL turn off the circuit breaker for the circuit supplying the fixture. Separate the light fixture from the electrical box. Check to make sure that the electrical wires are firmly attached to the fixture and that the wires and terminals are not corroded, cracked, frayed, broken, etc. If the wires look to be in good shape, attach a volt meter to the two wires and turn the power back on. If you are uncomfortable with working with the power on, get a qualified electrician to do this for you.

If you have electricity at the wires then the fixture is faulty. If you do not have electricity there, then you will need to make continuity checks on the hot and neutral wires. Turn off the circuit breaker to the circuit. Inside the electrical box that contains the switch, you will see two white wires connected together with a wire nut. Check to see that the two wires are firmly attached together. If they are loose that is probably the culprit. If they are firmly attached, pull off the nut and connect one lead of a ohm meter to the white wires. Connect the other lead of the meter to the white wire at the light fixture. The meter should show continuity. On the switch are two black wires, one comes from the main power and the other goes to the light. Check for continuity between the black wire at the switch and the black wire at the light. You may have to turn the switch ON to do this. If either the black wire or the white wires show an OPEN circuit then there is a break in the wiring between the switch and the light and it will have to be replaced. If you are lucky you may be able to attach new wires to the old ones and pull the new wires in as you pull the old ones out.

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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

If you do this work yourself, always turn off the power

at the breaker box/fuse panel BEFORE you attempt to do any work AND

always use an electrician's test meter having metal-tipped probes

(not a simple proximity voltage indicator)

to insure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.