12. 8.
. Every circuit must provided with means isolation
(IEE Regulation 132. The Electricity Work Regulations
1989 are very specific Regulation 12(1) that must ensure the discon-
nection and separation electrical equipment from every source supply
and that this disconnection and separation secure.
Construction workers and particularly electricians receive electric
shocks, usually result carelessness unforeseen circumstances.
3.
To isolate piece equipment individual circuit successfully, compe-
tently, safely and accordance with all the relevant regulations, must
follow procedure such that given the flow diagram Fig.
4. All exposed metal earthed; fuses and miniature
circuit breakers (MCBs) are designed trip under fault conditions, and
residual current devices (RCDs) are designed trip below the fatal level as
described Chapter 6. 8.
Definition
Electrical isolation must ensure
the disconnection and separation
of electrical equipment from every
source supply and that this discon-
nection and separation secure. Start
at the top and work down the flow diagram. 8. When working portable equipment desk
top units often simply matter unplugging the equipment from
the adjacent supply. Larger pieces equipment and electrical machines
may require isolating the local isolator switch before work commences. Where test instru-
ment voltage indicator used prove the supply dead, Regulation 4(3)
of the Electricity Work Regulations 1989 recommends that the following
procedure adopted.Basic Electrical Installation Work
170
To prevent people receiving electric shock accidentally, all circuits con-
tain protective devices. 8.
The test device being used the electrician must incorporate safe test
leads which comply with the Health and Safety Executive Guidance Note
38 electrical test equipment.
To deter anyone from re-connecting the supply while work being car-
ried out equipment, sign ‘Danger Electrician Work’ should be
displayed the isolator and the isolation ‘secured’ with small padlock
or the fuses removed that one can re-connect whilst work being
carried out that piece equipment.15).
As electrician working electrical equipment you must always make
sure that the equipment switched off electrically isolated before com-
mencing work.13.
2. Next, isolate the supply and observe that the test device now reads
zero volts. The test device should indicate main’s
voltage. These leads should incorporate barriers to
prevent the user touching live terminals when testing and incorporating a
protective fuse and well insulated and robust, such those shown in
Fig. Finally secure the isolation and place warning signs; only then
should work commence.
1. Then connect the same test device known live supply proving
unit such that shown Fig. First connect the test device such that shown Fig.11 ‘prove’ that the tester still
working correctly.10 the
supply which isolated
