19.
The consumer’s mains equipment normally fixed close the point at
which the supply cable enters the building. order standardize equipment,
standard voltages are used.
When single-phase loads are supplied from three-phase supply, the load
should ‘balanced’ across the phases. 5. The method most universally used the United Kingdom
to provide for the safe use electrical energy protective equipotential
bonding coupled with automatic disconnection the supply fuses or
miniature circuit breakers (MCBs). These are:
● 400 and 275kV for the super grid
● 132kV for the original grid
● and 33kV for secondary transmission
● 11kV for high-voltage distribution
● 400 for commercial consumer supplies
● 230 for domestic consumer supplies.Basic Electrical Installation Work
130
efficiency transmission increased.
Transformers these local sub-stations reduce the voltage 400 three-
phase and neutral distributor cables connect this supply consumers.
Connecting one-phase and neutral three-phase 400 supply gives a
230 single-phase supply suitable for domestic consumers. meet the requirements of
the IEE Regulations must provide:
● protection against electric shock (Chapter 41)
● protection against overcurrent (Chapter 43)
● isolation and switching (Chapter 53). installation that meets the requirements the
IEE Wiring Regulations Requirements for Electrical Installations, will be
so protected. The elec-
trical installation whole must protected against overload and short
circuit damage and the people using the installation must protected
against electric shock.
A diagrammatic representation showing the distribution power from the
power station the consumer was given Chapter Fig. That is, the load should equally
distributed across the three phases that each phase carries approxi-
mately the same current. So, let look these essential safety
elements.
Protection against electric shock, both ‘basic protection’ and ‘fault protec-
tion’ provided insulating and placing live parts out reach suitable
.
Safe electrical installations
The provision safe electrical system fundamental the whole
concept using electricity and around buildings safely. This prevents any one phase being overloaded.
All local distribution the United Kingdom underground cables
from sub-stations placed close the load centre and supplied 11kV
