4ELEC-7
Contents
Outcomes
- Pupils can be aware of electrical hazards and how to safely wire a plug
Specification References
2.2 recall the hazards of electricity including frayed cables, long cables, damaged plugs, water around sockets, and pushing metal objects into sockets
2.3 describe the uses of insulation, double insulation, earthing, fuses and circuit breakers in a range of domestic appliances
Starter
- Class brainstorming – why electricity can be dangerous?
- "Electrical fire clip"
Main Body of Lesson
- Spot the hazard (first slide in powerpoint)
- Wiring a plug (digram in powerpoint, or a nice clear picture on page 193)
- Show them how to wire a plug (you may wish to pre-strip the wire and screw two in to save some time)
- When pupils have a perfect plug (be very picky as it allows the slower ones to finish) they can assist others in the group
- Sparky and RCD circuit breaker demos- introduction to the earth wire and talk about fuse boxes vs. circuit breakers
Plenary
Why plastic appliances do not need earth wire – double insulation; pupils need to be able to explain dounle insulation (it may be worth stating that it is not simply having the coloured insulation on the individual wires as well as an outer insulation cable as pupils often assume this is what double insulation means)
Homework
- Home appliances– earthed or double insulated.
- Read pages 192-195 and answer the questions - This is an extension to what they need as it covers safety in more detail
Additional Information
Resources Required
- Sparky
- Spot the hazards sheet
- 3 pin plugs, wires, wire strippers/cutters, screwdrivers
- Plug diagram to label
- Video clip to demonstrate how electrical fires start
- Safety Powerpoint
Textbook References
- Information on pages 192-195
- Questions on page 193
Website References
Skills Addressed
Practical skills
Safety/Hazards
- Ensure that power to the sockets is off and tell the pupils not to plug their plugs in - High voltages.
- Sharp wire strippers and sharp strands of copper
Notes
Detail about the how the earthe wire works are not needed. Students should understand that the earth wire is there for safety and that only metal cased appliance need one. Double insulated appliances all have one but only as back up.
