The 13 Amp PLUG
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Transcript of The 13 Amp PLUG
The 13 Amp PLUG
Fuse
InsulatingCasing
Live Wire
Neutral
Cable grip
FlexibleCopperconductors
Earth
FUSESIN
ACTION
fault
Extra current melts the 5 Amp fuse wire cutting off the live supply
Fuses are the weakest link in a circuit, preventing fires. They consist of a short, thin piece of wire with a low melting point.
EARTH &
FUSE
Appliances with metal cases need to be earthed.The earth pin is connected to the case via theyellow/green wire. If a fault occurs a large currentflows to earth and overloads the fuse.
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The earth wire and fuse
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Fault-Loose wire
The earth wire and fuse
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Fault-Loose wire
The earth wire and fuse
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The earth pin is connected to the metal case via the yellow /green earth wire
If a fault develops a larger current can flow down the earth wireand melt the fuse wire cutting off the supply on the LIVE wire
The earth wire and fuse
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Errors in Wiring Plugs
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Errors in Wiring Plugs
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Errors in Wiring Plugs
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1. Bare wires showing2. Proper fuse not installed3. Earth wire not connected
Errors in Wiring Plugs
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Errors in Wiring Plugs
1. Bare wires showing2. Proper fuse not installed3. Earth wire not connected
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4 51. Bare wires showing
2. Proper fuse not installed3. Earth wire not connected4. Live and neutral swapped
Errors in Wiring Plugs
Errors in Wiring Plugs
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4 51. Bare wires showing
2. Proper fuse not installed3. Earth wire not connected4. Live and neutral swapped
5. Loose cable grip
Why are sockets wired in parallel with each other ?
The longest pin of a plug is designed to make contact
with the earth wire
A ring main circuit
FUSES, EARTH WIRE AND PLUGS
ShockCurrent( mA)
Effect
> 25 DEATH
10 - 25 PAIN Can’t let go
0-10 TINGLE
Wet hands have a much lower resistance.
If your body has a resistanceof 100 and you touch alive wire at 230V, whathappens?
Safety with mains electricity
* Replace broken plugs and frayed cables* Keep plugs & cables away from water or heat* Never overload a plug or socket* Don’t use wet hands when switching on or off
Appliances with plastic cases do not need an earth wireWhy not?
The insulating plastic prevents users getting into contact with ‘Live’ components
Circuit breakers work quicker than fuses.( saves lives)
CIRCUIT BREAKER
They are easily reset by pressing a button
CIRCUIT BREAKER
neutral
liveparallel
earth
series
melts
Brass – stiff, good conductor
Copper – malleable, good conductor
rubber – flexible, good insulator
Stiff plastic – tough, rigid, good insulator
1a. A Fuse cuts off the supply if there is excessive current caused by a fault.
1a. A fuse is on the live side so that the appliance remains safe from the live voltage.
1a Circuit breakers work quicker than fuses.( saves lives)
yes
The off switch should prevent the live voltage reaching the element
New switch location
mel
ts