Element 6:- Electrical Hazards and Control Flashcards
Main Hazards of Electricity
- Burns
- Shock
- Arcing
- Fire
- Explosions
Secondary Effects of Electricity
- Falls from height
- Unintentional movement of machine
- De-activation of control measures
- Loss of information
- Throw off
Health effects of Electricity on the body
- Damage to nervous system
- Irregular heartbeat (Fibrillation)
- Internal burns
- External burns
- Muscular contractions
- Stopping breathing
- Stopping of the heart
Factors Influencing severity of electrical shock
- Voltage
- Current
- Time
- Conductivity or resistance
- Current path
- Action on finding someone in contact with electricity
- Isolate supply if possible
- Summon help
- Give first-aid if capable
- Remain with casualty until emergency services arrive
Causes of Electrical Fire
- Inadequate circuits
- Overloaded circuits
- Incorrect fuses
- Damaged insulation
- Loose connections
- Flammable materials too close to electrical equipment
- Overheating of cables
Safety of Portable Electrical Appliances:
The appliance:-
- Battery operated
- Checked before use
- Suitable selected equipment
- Properly maintained equipment
Safety of Portable Electrical Appliances:
The Lead:-
- Ensure not run over by vehicles
- Dragged over rough services
- Trapped in machinery
- Exposed to hot surfaces or corrosive chemicals
- Continuous flexing
Safety of Portable Electrical Appliances:
Joints, Connections and plugs:-
- Makeshift temporary connections
- Leads getting pulled out
- Poor made connections
- Fuse being replaced
- Battery operated
Fuse:
A weak link designed to melt, breaking the circuit at excessive currents
Circuit Breakers:-
Electromagnetic device which perform the same function as fuses i.e. break the circuit at excessive current although slightly faster
Earthing:-
Electricity will always try reach earth and earthing means providing a path to earth lower than the human body
Isolation:-
The disconnection and separation of the electrical equipment from every source of electrical equipment in such a way that the disconnection and separation is secure
Reduced voltage systems:-
By reducing the voltage present system the consequences of electrical shock can be greatly reduced
Residual Current Devices (RCD):-
It compares the current flowing into the system with the current flowing out. When the level differs by a preset value the RCD will open rapidly and interrupt the supply
Double Insulation:-
Covering live parts by two separated layers of insulation
