An advantage of a residual current device is that, in the event of an electrical shock, it offers protection to a person. True to false?
True. An RCD acts quickly and offers protection to a person in the event of an electric shock
How does a fuse act as a protective system?
A fuse acts a as weak link in a circuit by melting if the current exceeds the safe limit
What are the factors which influence the severity of an electric shock?
- Voltage
- Current
- Current path
- Contact time
- Body resistance
- Environment
A properly rated fuse offers protection to a person. True or false?
False. A fuse only protects the equipment and the circuit
Only a fully qualified electrician can work on an electrical system. True or false?
False. Any person who works on electrical systems has to be “competent” - not necessarily “electrically qualified”.
What are the limitations of Portable appliance testing (PAT)?
- Equipment is only safe at the time of testing completion (e.g. may develop fault soon after)
- A label confirming PAT testing has been carried out may give a user a false sense of security (e.g. the user may not think a visual inspection is necessary before use)
- Any “illegal” items (such as a radio brought in from home) will not be on a PAT schedule
What are the main hazards and risks of working with electricity?
- Electric shock and burns from contact with live parts
- Injury from exposure to arcing
- Fire from faulty electrical equipment or installations
- Explosion caused by unsuitable electrical apparatus or static electricity igniting flammable vapours or dusts, for example in a spray paint booth
HSE guidance document GS6 offers guidance on avoiding danger from underground services. True or false?
False. HSE document GS6 (“Avoiding danger from OHP”) provides guidance when working near or under overhead powerlines. HSG47 offers guidance when working near underground power cables.
Reduced voltage means less risk. True or false?
True. A 110v CTE transformer offers greater protection from shock than 240v.
What are the conditions and practices that lead to accidents with portable electrical equipment?
- Using equipment in inappropriate conditions
- Using damaged equipment (s a particular problem on construction sites where the harsh operating conditions mean there is a high probability of mechanical damage)
- Damaged caused by dragging equipment by the cable
- Inadequate or damaged cable connections
- Inadequate maintenance and/or failure to properly check equipment before use
- Wrongly rated fuses
- Using damaged equipment
