One these different potentials usually potential earth, which we
consider equal zero. The main objective this protection ensure that persons and
livestock shall protected against dangers that may arise from the contact with live parts the
electrical equipment installation. The conductive parts electric
equipment that can touched and that are not normally live, but may become live case of
fault (e. the potential the live parts, usually
potential compared with the zero potential the earth.e.
For that reason the first task prevent anybody (persons livestock) from touching
dangerous live parts. live parts electrical
household appliances are covered enclosures) means barriers obstacles around the
live parts larger equipment electrical substations. The other possibility how provide
protection against direct contact situate live parts out reach. FUNDAMENTAL RULES FOR PROTECTION AGAINST ELECTRIC
SHOCK
As mentioned the previous text, case touching live part, that means part with a
potential different from the potential earth, current flows through the body from the live part
to the earth.
The current can pass through the human body either case touching live parts of
different potential case standing the place with some potential and touching live part
with different potential. when basic insulation fails), are called exposed conductive parts.
During the normal service may come such case that the insulation may disrupted or
that the metal enclosure may come contact with live parts.
The protection can achieved one the following methods:
- preventing current from passing through the body any person any livestock;
- limiting the current which may pass through body value lower than the current.) electrical installation.
In the course many year utilization electricity, system protection against electric
shock has been developed. This first step protection, which has be
provided during the normal service electrical equipment and/or electrical installation, called
protection against direct contact basic protection protection under normal conditions. That means contact with parts that are not live during the normal service and may
become live case fault, i. That called single fault
condition and, such case, the called protection against indirect contact has be
provided.e.g. The other potential, i.g. This the usual way of
protection against direct contact overhead transmission lines.FUNDAMENTAL RULES FOR PROTECTION AGAINST ELECTRIC SHOCK 29
5.
. conductors are
insulated) means enclosures which live parts are situated (e. called the voltage live parts. This has provided during the whole life electrical equipment
(household appliances etc.g.
This protection usually provided means insulation live parts (e. under single fault condition
