Page 58 - The City and Guilds Textbook: Plumbing Book 1 for the Level 3 Apprenticeship (9189), Level 2 Technical Certificate (8202) and Level 2 Diploma (6035)

The City & Guilds Textbook: Plumbing Book 1

KEY POINT Formal visual inspections and tests
BS 7671 is the During formal electrical inspections, the system will be checked and tested to
British Standard for ensure that:
the requirements for
electrical installations. ● the polarity (live and neutral) of the system is correct
This is the national ● all the fuses, miniature circuit breakers (MCBs) and RCDs are correct and
standard in the UK for working
low-voltage electrical ● all the cables and cores are effectively terminated
installations. It is also ● the equipment is suitable for its environment.
used as a national
standard by Mauritius, St Working in domestic properties
Lucia and several other
countries that base their When you are working in domestic properties, there are things that you can do
wiring regulations on to help prevent electrical hazards and accidents from occurring:
BS 7671.
● Be aware of any concealed cables in solid and stud walls. Use a cable finder
and check the wall before using drills and chisels.
● Do not install pipework too close to electrical cables. Heating pipework
can cause the cable to overheat and faulty cables can arc across to
the pipe causing a potential electric shock hazard. Pipework must be
a minimum of 25 mm away from electrical cables and 150 mm from
electrical apparatus.
● Take care when lifting or replacing floorboards. There may be cables
underneath.
● Do not overload sockets and outlets with too many appliance connections
as this can cause the system to overheat, sometimes with disastrous
consequences. As a general rule, one socket = one plug unless a recognised,
independently fused multi-socket is used.
● Look out for damaged cables, sockets and fittings. Report any problems to
the customer or your supervisor.

Portable power tool safety
All portable power tools, such as drills, jig saws, circular saws and angle grinders,
should be of the double insulated type, which simply means that the power tool
has two levels of protective insulation built in to the appliance. The symbol for
double insulated tools is shown in Figure 1.29.
Power tools must be subjected to safety tests, these are as follows.
● User checks – should be performed before use.
● A formal visual inspection – to be scheduled in accordance with your
maintenance schedule and Health and Safety Policy.
p Figure 1.29 Double insulated
symbol ● Combined inspection and test – to be carried out by a competent person,
usually an external contractor (portable appliance testing).
Portable appliance testing

The ‘Inspection and Testing of In-Service Electrical Equipment’ (portable
appliance testing, or PAT) was introduced to enable companies and
organisations to comply with the EAW Regulations. To meet these regulations

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