3. order deter anyone from reconnecting the supply, ‘Danger
Electrician Work’ sign should displayed the isolation switch. Only then should
work commence the ‘dead’ supply.
2.
Safety First
Working ‘Live’
● NEVER work‘live’
● ALWAYS isolate first
● SECURE the isolation
● PROVE the supply‘dead’before
starting work. Connect the test device another source supply ‘prove’ that
the device still working correctly.
4.28
Basic Electrical Installation Work
is first switched off.
1. Lock off the supply and place warning notices. Every circuit must provided with means isola-
tion (Regulation 132. 1.
The test device must incorporate fused test leads comply with HSE
Guidance Note 38, Electrical Test Equipment Used Electricians. Connect the test device the supply which isolated; this
should indicate mains voltage.
Electrical isolation supplies further discussed Chapter of
this book.11 is
used prove conductors dead, Regulation 4(3) EWR 1989 recommends
that the following procedure should adopted that the device itself is
‘proved’:
FIGURE 1. Isolate the supply and observe that the test device now reads 0V. Where
a test instrument voltage indicator such that shown Fig.10) and you should isolate and lock off before work
begins.11
Typical voltage indicator.
Temporary electrical supplies construction sites can save many per-
son-hours labour providing energy for fixed and portable tools and
