Dangers of electricity
Electrical Hazards
Damaged insulation – Electrocution can be extremely dangerous, especially at high voltages which can result in death. All electrical wires are therefore insulated in order to prevent electricity passing onto its surroundings. A damaged insulation can therefore be hazardous as it may result in an electricity leak.
Overheating cables – Overheating cables can result in the melting of the wire insulation and a consequent fire.
Damp conditions – The electrical resistance of the human body drastically decreases in damp/wet conditions. Therefore, wet conditions coupled with unsafe handling of electrical appliances may lead to extremely large currents passing through the body resulting in a detrimental electric shock.
Safety Circuit Components
Fuse – A fuse is a thin piece of wire designed to carry a set maximum electrical current. If a higher current passes through the wire, it will melt from the heat. When it melts, it breaks the circuit and thus stops the current flowing.
Circuit Breakers
A circuit breaker also prevents excessive current passing through the circuit. It is an automated switch which interrupts current flow when abnormally high current is detected.
A current flowing through the coil will magnetize the iron core which attracts the iron rocker. The larger the current the stronger the magnetic pull. When the current becomes too high, the iron rocker will separate from the contacts therefore breaking the circuit.
Earthing Metal Cases
An electric shock can occur if a live wire inside an electrical appliance came loose and touched the metal casing (which is of course a conductor).
To prevent this from happening, the earth terminal can be connected to the metal casing so that the electricity can pass through the earth instead of the human body, and therefore avoiding electrocution.