Factors affecting while selecting the wiring systems for internal wiring.

2. Prepared By:
• 1. Patel Mit R (140760109044)
Guided By:- Prof. Keyur Denpiya

3. Choice Of Wiring System & Types Of
Cables Used In Internal Wiring
 Introduction
 Choice Of Wiring Systems
 Types Of Cables Used In Internal Wiring
 Reasons Why PVC Cables Are Widely Used For
Internal Wiring

4. Introduction
 Electrical Wiring is simply a network of wires
connecting various accessories for distribution of
electrical energy from the supplier meter board
to devices that consumes the energy such as
televisions, refrigerators, fans, lamps etc.

5. Choice Of Wiring Systems
 Before wiring a building, it is
necessary one makes the right
choice when it comes to the type of
wiring, the size and position of fans,
light points. When making choice for
any wiring system for a particular
installation, your choice should be
based on technical and economic
factors.

6. Generally, when making choice for a particular system of
wiring, the following factors should be considered;
 1. Cost of wiring: The initial cost of the wiring system to be chosen or
selected is one of the paramount factors to be considered. It should
be economical and safe.
 2. Durability: When making choices for wiring system, the wiring type
should be durable (long lasting) and should also be of proper
specifications and in accordance with assessed life and type of
building to be wired. You should not carry out cleat wiring for a
permanent building because cleat wiring is suitable for temporary
buildings only. Any wiring should withstand wear and tear that may
result due to unfavorable weather. The cables used should be able to
carry maximum current without overheating.

7.  3. Permanency: The wiring should not deteriorate by the action of
weather, fumes, dampness etc. the cables should be resistant to harsh
weather and chemical attacks.
 4. Accessibility: Facilities used in the wiring should be available
(within range) and accessible when the need for alteration, extension
or renewal arises.
 5. Appearance: The wiring should provide a good look after its
installation. If cleat or casing – capping wiring is used in a modern
building, it will spoil the outlook of that building. Conduit wiring is
preferred mostly for modern buildings except that it’s expensive. PVC
wiring system is also good for modern buildings. PVC wiring is very
popular.
 6. Mechanical Protection: The wiring should be protected from
mechanical damage during its use.

8.  7. Safety: When it comes to wiring, safety is one of the most paramount
factors to be considered because electrocution is one thing you won’t have
the time to give it a second thought. Where there is possibility of fire hazard,
conduit wiring should be used.
 8. Maintenance Cost: Wiring system employed should have low maintenance
cost.
 9. Load: The types of loads consuming the electrical energy in a building will
determine the kinds of cables to be used. You cannot use a cable with small
diameter for heavy loads. The cables will damage. Voltage to be employed
and fire hazard and insurance standards should also be kept in mind in case of
large factories.

9. Types Of Cables Used In Internal Wiring
The wires used for internal wiring of a building may be grouped according to;
 Conductor used
 Number of cores used
 Voltage grading and
 Type of Cable insulation used.

10.  According to the conductor used: according to the conducting material used,
cables may be divided into two classes known as copper conductor cables and
aluminum conductor cables.
 According to the number of cores: bases on the number of cores a cable
consists of, the cables may be divided into classes known as single core
cables; twin core cables; three core cables.
 According to the voltage grading, the cables may be divided into (I) 250/440
volt cables and (II) 650/1,100 volt cables.
 According to the type of insulation used: these types of cables may be
categorized as;
Vulcanized Indian – Rubber (VIR) insulated cables.
Tough rubber sheathed (TRS) or cab tyre sheathed (CTS) cables.
Polyvinyl Chloride cables (PVC)
Lead sheath cables
Weather proof cables
XLPE cables
Flexible cords and cable

11. Reasons Why PVC Cables Are Widely Used
For Internal Wiring
The reasons are as follows;
 PVC insulation provides better flexibility for the cables
 PVC insulation has better insulating qualities
 PVC insulation is not affected by chemicals
 PVC insulation has thin layer which will give smaller
diameter of cables which makes it possible to
accommodate more wires in the conduit of a given size
unlike VIR or CTS wires.

12. Thank You