Download Presentation
Lesson.5: Fuses and Safe Plugs Objectives

Loading in 2 Seconds...

1 / 21

# Lesson.5: Fuses and Safe Plugs Objectives - PowerPoint PPT Presentation

Lesson.5: Fuses and Safe Plugs Objectives State the colour, function and position of the three wires in a domestic plug. Describe the function, operation and safety purposes of fuses, circuit breakers and earth wires.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

## Lesson.5: Fuses and Safe Plugs Objectives

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Lesson.5: Fuses and Safe Plugs

Objectives

State the colour, function and position of the three wires in a domestic plug.

Describe the function, operation and safety purposes of fuses, circuit breakers and earth wires.

Explain the meaning of the term, double insulated and why such an appliance does not require an earth wire.

Complete

Higher

‘Charge in Circuits’ page 137

and ‘Fuses and Safe Plugs’ page 138

and ‘Resistance’ page 139.

Foundation

Charge in Circuits’ page 126

and ‘Resistance’ page 128.

Learning Objectives

State the colour coding for live, neutral and earth wires:

live – brown;

neutral – blue;

earth – green/yellow.

Describe and explain the functions of the live, neutral and earth wires:

live – carries the high voltage;

neutral – the second wire to complete the circuit;

earth – a safety wire to stop the appliance becoming live.

State that an earthed conductor cannot become live.

Describe that an earthed conductor cannot become live.

Describe reasons for the use of fuses/circuit breakers (as re-settable fuses).

Explain the reasons for the use of fuses/circuit breakers as re-settable fuses (structure and mode of operation not required).
• Describe how a wire fuse works:

if the current becomes too large;

wire fuse melts, breaking the circuit.

• Explain how a wire fuse reduces the risk of fire:

If the appliance develops a fault:

too large a current causes the fuse melt;

preventing flow of current;

prevents flex overheating and causing fire;

prevents further damage to appliance.

• Describe and recognise that “double insulated” appliances do not need earthing
• Explain why “double insulated” appliances do not need earthing:

case of appliance is a non conductor and cannot become live.

• Explain how a wire fuse and earthing protects people.