Electrical Safety

Electrical Safety

Electric current will always take the path of least resistance.

This is usually the quickest way to the Earth.

Even small voltages can kill.

Electrical Safety

Read the leaflet on Electrical Safety.

List what you think are the 10 most important “rules” on electrical safety.

Electrical Safety

There are three wires in a plug.

The brown wire carries the live current.

The yellow and green wire leads to the Earth.

The blue wire completes the circuit.

Electrical Safety

Everyone should be able to wire a plug!

Take a plug and correctly wire it.

Do not attempt to place the plug in a socket.

Get the teacher to check your wiring

Electrical Safety

If the live wire touches the metal case of an appliance: The current will flow through the Earth wire to

the Earth Because there is so little resistance, there will

be a massive surge in current. This will melt the fuse wire. The current supply is thus cut off.

Electrical Safety

Read the information on p110 of Further Science on double insulation.

Copy the symbol for double insulation.

Make a note to explain what it means

Fuses

Page 110 of Further Science

Fuses

This is the symbol for a fuse.

Fuses

If too much current flows in a circuit the fuse will melt and break the circuit.

The fuse protects: The wiring The appliance The user

Fuses

Different appliances require different sized fuses, e.g. A cooker, 30 Amp A lighting circuit, 5A A table lamp, 3A An electric kettle, 13A

Fuses

Fitting the wrong sized fuse is one of the most frequent causes of fire in the home.

Many people die in these fires each year.

Fuses

In modern houses and buildings fuses have tended to be replaced by residual circuit breakers (RCB)

Residual Circuit Breakers

Page 111

Further Science

Residual Circuit Breakers

Read p111 of Further ScienceMake a set of bullet points on what RCB’s

are and how they work.This material is examined on Higher tier

papers and questions only.