P4.4 - Electrical Safety Flashcards
1
Q
What are the 4 hazards of electricity? [4]
A
- damaged insulation
- overheating of cable
- damp conditions
- excess current from overloading of plugs
2
Q
What is damaged insulation? [3]
A
- electric wire have a layer of coating = plastic, rubber, etc
- it insulates the wire and doesn;t let electricity pass through
- electric shock is possible if damaged area of coating is touched
3
Q
What is overheating of cable? [2]
A
- too much current
- leading to current catching fire
4
Q
What is damp conditions? [2]
A
- excessive moisture/presence of water
- when damaged wire meets water = electric shock
5
Q
What is excess current from overloading of plugs? [2]
A
- too many devices in one socket
- overheated
6
Q
What is a fuse? [2]
A
- safety device
- designed tocut off the flow of electricityto an appliance if the current becomestoo large
7
Q
How does a fuse work? [2]
A
- contains thin section of wire
- it melts and breaks if the current goes above a certain value
8
Q
Are fuses reusable? [2]
A
No.
- after the thin wire breaks it cannot be used again
9
Q
When does the wire inside a fuse break and why? [2]
A
- before the current reaches the appliance
- so that the appliance is safe
10
Q
What type of fuse do you use for an appliance? [1]
A
a fuse that is the value just above the current required for the appliance
11
Q
What is a Trip Switch? [3]
A
- replaces a fuse
- the switch ‘trips’ and breaks the circuit once the current flowing exceeds a certain value
- can be reset after a short while
12
Q
What is earthing? [1]
A
- protects the user from electric shock when electricity is leaking in the body of the appliance
