Domestic Installation: Switch Circuits

Eng. Islam Al-Jarrah

DOMESTIC INSTALLATION: SWITCH CIRCUITS

Module-4


Objectives differentiate between the two types of lighting

circuits. state the purpose of a switch in lighting

circuits. differentiate between one-way and two-way

switch circuits. state the function of intermediate circuits. use Ingenatic trainer software to build simple

switch circuits install, test and operate simple switch circuits.

Introduction to Lighting Circuits


What are domestic Lighting Circuits?

They are radial circuits in which the power cable runs from one fitting to the next until the last fitting where it terminates.


House lighting circuits (wiring) Types of wiring in lighting circuits are as

follows:

Loop Type Circuit: the power is fed from the consumer unit to the

first light, then to each consecutive light on the circuit and terminates at the last light.

Junction Box Circuit: the power cable is fed from the consumer unit

to each junction box, finally terminating at the last junction box.


the power is fed from the consumer unit to the first light, then to each consecutive light on the circuit and terminates at the last light.

Loop Type Circuit

Click icon to add picture


the power cable is fed from the consumer unit to each junction box, finally terminating at the last junction box.

Junction Box Circuit



Lighting Circuits Info The cable used for a lighting circuit could be:

1mm2 1.5mm2

The types above depends on: the length of run possible rating.

A Consumer Unit uses a fuse for protecting the lighting circuit which could be: 5 amp fuse 6 amp MCB (Main Circuit Breaker) .

The maximum load for a lighting circuit is 1200 watts. If more lights are needed then another lighting circuit

should be used


By understanding the simplest ‘One-way switch circuit’ and expanding on the concept, even the most complicated installation circuit can be broken down into easy to understand sub-circuits.

Basics of Lighting Circuits

Basic Circuit The simplest form of

a circuit is a basic circuit as shown, It literally contains: 2

conductors(wires), enabling to gain a potential difference

a load, which in the case of a lighting circuit, is a lamp.


Switches


Typically two wires need to be connected to the terminals of the switch:one

bringing the live line

second one connected to the load

By installing a “switch” in the circuit the flow of current could be controlled.

Switches come in various designs for different purposes.

For indoor assembly, switches are installed in special boxes with wires running in conduits buried in the wall.

Switches for Electrical Installation


One Gang One Way

Intermediate Switch

One Gang Two Way


A one-way switch circuit is used when an electrical load has to be switched on and off from one single location.

One Way Switch Circuit


the switch must be located between L1 and the lamp, so that after power cuts off there will not be any connection between the live wire and the lamp.

One Way Switch Circuit


The circuit could be protected by adding a fuse which is a circuit protection device.


Identify and name the type of lighting circuits

Skill -1

_________________________ _________________________


Identify the type of circuit shown in the figure given below, and name the parts marked by choosing them from the list below

Skill -2


Switch, Junction Box, Lamp, Live connection (L1), Neutral connection (N)


Skill -3 (Page -9) The installation diagram of a 1-way

switch circuit is shown in the figure below. Study the diagram and understand the symbolic representations.


Used when it is necessary to control a load from more than one point.For example : Staircase

Two-Way Switch Circuit



If we wanted to add further switches, we can install what we call an intermediate switch between the 2 ways switches.

Intermediate Switch Circuit



Lab Activities: General Instructions The complete installation (lighting & sockets)

is protected by a Single Phase RCD located in the Distribution Board (D.B.), which also contains MCBs for the various circuits.

Install the internal wiring of the D.B. by using 6 mm2.

Execute the Earthing System by relating to the local Earthing System.

Supply is single phase 240V 50 Hz AC wired distribution board (6 mm2).


General Instructions .. Continued Take note of the following:

Measurements are in millimeters. Tolerance ± 3mm.

Measurements are to the centers of cables/ conduits and equipment as indicated.

When the installation is completed, it must be first tested by the teacher.

When connecting to power, your teacher must be present!


Lab Activities Lab Activity -1

One-way switch circuit (Page -12)

Lab Activity -2 two-way switch circuit (Page -14)

Lab Activity -3 two lights operated by an

intermediate switch. (Page -16)

Documents

Domestic Installation: Switch Circuits