Electrical Safety

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The earth wire.

Slide 23

The Plug

You have to remember the names and colours of each of these three wires. You also have to remember the position of each of these three wires in a standard plug.

Slide 24

Electrical Safety

It is very important that all plugs are wired correctly.

If they are not, then a number of things can go wrong!!!

Slide 25

The Plug Check Test

The following questions test your understanding of the plug so far.

Answer ALL questions in sentences!!

Slide 26

The Plug Check Test

1. What two things do electric cables allow you to do?

2. How many wires do most electric cables normally have?

3. Copy and complete the following table:

4. Why do all of the three wires have different colours of insulation?

Slide 27

The Plug Check Test Answers

1. What two things do electric cables allow you to do?

2. How many wires do most electric cables normally have?

Plug appliances into the mains supply.

Draw electricity from the mains supply.

Three.

Slide 28

The Plug Check Test Answers

3. Copy and complete the following table:

4. Why do all of the three wires have different colours of insulation?

So you can clearly tell which one is which.

Slide 29

Electrical Safety

Appliances have three safety devices:

The fuse.

The earth wire.

The switch.

These devices are designed to stop you from being electrocuted and to prevent the appliance from being damaged.

Slide 30

The Fuse

A fuse is a thin piece of wire which will melt when too much current passes through it.

A 3A fuse will melt when the current is greater than 3A.

When a fuse has blown, the wire inside it has melted.

Current is a flow of electricity and is measured in amps (A).

Example

Slide 31

The Fuse

When the wire melts, all current is stopped from reaching the appliance and switches it off.

The fuse stops a large current from flowing through the appliance which could cause wires to overheat, melt or catch fire.

Slide 32

The Switch