.
Method electrical separation, little used but does find application
in the domestic electric shaver supply unit which incorporates isolating
transformer.
Method the use Class insulated equipment limited single
pieces equipment such tools used construction sites, because it
relies upon effective supervision ensure that metallic equipment or
extraneous earthed metalwork enters the area the installation.
This method relies upon all exposed metalwork being electrically con-
nected together effective earth connection. Protective equipotential
bonding shown Fig.
In Chapter the IEE Regulations are told that where the metalwork
of electrical equipment may become charged with electricity such a
manner cause danger, that metalwork will connected with earth
so discharge the electrical energy without danger. the use Class (double insulated) equipment,
3. The application
of protective equipotential bonding one the important principles for
safety.
The method which most universally used the United Kingdom is,
therefore, Method protective equipotential bonding coupled with auto-
matic disconnection the supply.3.7 Chapter 6. the use earth free equipotential bonding,
5.
There are five methods protection against contact with metalwork which
has become unintentionally live, that is, indirect contact with exposed con-
ductive parts recognized the IEE Regulations. electrical separation.2) achieved connecting exposed conductive parts equipment
to the main protective earthing terminal.
Methods and are limited special situations under the effective super-
vision trained personnel. These are:
1. protective equipotential bonding coupled with automatic discon-
nection the supply,
2. this way the possibility voltage appear-
ing between two exposed metal parts removed.Basic Electrical Installation Work
236
Fault protection
Protection against indirect contact, called fault protection (IEE Regulation
131.2 tells connect the extrane-
ous metalwork water service pipes, gas and other service pipes and
ducting, central heating and air conditioning systems, exposed metallic
structural parts the building and lightning protective systems the pro-
tective earthing terminal.1.2. Not only must all the
metalwork associated with the electrical installation connected,
that conduits, trunking, metal switches and the metalwork electri-
cal appliances, but Regulation 411. the provision non-conducting location,
4. 6
