1. SUBSTATION AND
ELECTRICITY LINES
BY: IQBAL NURFARIQ B. OTHMAN

2. The amount of electricity needed by large
buildings such as office,high rises building and
shoping complex are relatively high because of
the presence of building services equipment in
these premises. The following are parts of
electricity distribution systems of a medium and
large building.

3.  Any building that require an amount of
electricity more than 1.5MV or if TNB request
it, need to served by its own substation.
 The substation is build separate from the
building or in part of the ground floor of the
building and the building owner need to
maintain it.

4.  Contents of the substation:
Transformer.
 This steps down the high voltage electricity to the low
voltage electricity.

5. High Voltage Switch Board (and sometimes) Low Voltage
Switch Board.
 This is for isolating and switching purpose.
 The switch board provide protection againts overcurrent.

6. Metering equipment.
 This is to measure the consumption of electricity.

7. Automatic gas fire extinguisher systems and fire detactor.
 This systems function is to automatically put out any
electrical fire in the substation.
 Fire detector is connected to the building fire alarm systems.

10.  In order for the electricity to be
distributed with in the building, it need to
travels through lines.
 The following explains features of these
electricity lines systems and element.

11.  CONDUCTORS:
 Usually made to a small extent aluminium or copper.
 To conduct the electricity.
 Cable are used to conduct the electricity from the power
station to the user.
 Wires are used to distribute the electricity to the
building.

12.  INSULATION:
 Used to prevent short-circuiting, electrocution or fires.
 The wire or cable are sheathed by a non-conductive
material such as rubber.
 High voltage cable are sheathed in a mineral
material, than by a metal covering, than finaly sheathed
by a plastic or rubber covering.

13.  BUS BAR:
 Consist of 4 thick aluminium or copper strips.
 Conduct electricity within a switchboard, distribution
board, substation or other electrical apparatus.
 Each of the 3 metal strips contain 240V single phase
current, and the fourth strip contain earthing line.
 Riser bus bar is to deliver the electricity through a
trunking which run up in electricity cable through the
height of a tall building.

15.  CABLE AND WIRING HOUSING:
 Give protection to the insulation and the conductor and
also to aid maintainance.
 Usually use plastic pipes known as conduits and for
metal is known as cable trunking.

16. ANY QUESTION ???