Electrical Installation Drawings
Islam Al-Jarrah
 state
the purpose of electrical installation
drawings.
 differentiate
between installation/wiring
diagrams and circuit/schematic diagrams
 identify
the symbols and terminology used in
installation and schematic diagrams.
 implement
electrical installation drawings.

The ability to read and
understand schematics
and drawings is an
absolute must.

Electrical installation
drawings provide an
electrician with the
technical information
needed to install the
wiring system in
apartments or
buildings.

Installation or wiring
Diagrams
Does not show the functional
details of the electrical
installation

Schematic or Circuit
Diagram
show the functional details of
the electrical installation
interconnections
Installation & Wiring Diagram
It also identifies the wires by
wire numbers or color
coding.

Connection Line

Protective earth line


Distribution device

Junction box
Signal line
Lines Symbols
Safety devices Symbols

Number of wires/cable

Pushbutton

Lamp

Socket outlet, single
phase
lines
Safety and reliable devices

One gang one way
switch

One gang two way
switch

Two gang one way
switch

Intermediate switch
Switches Symbols
Switches Symbols

One light operated by
one switch

One gang one way switch

Two one way switches
in a single module
Two gang one way switch
One light operated by
two switches
One gang two way switch

Switch of 4 terminals
used to control device
from more than two
locations.
Intermediate switch
One
gang one
two way
one
way
Two
Socket
Intermediate
Lamp
Gang
switch
switch
Connection
line
switch
Lab Activity 1 –Page 11 – Module 3
Schematic diagrams show
the electrical systems, and
are used for understanding
the electrical functions of a
wiring system.
The schematic is a
representation of how the
circuit works.
the schematic shows the
logical order of how they are
used together.

Connection Line

Protective earth line

Signal Line

Line to indicate
component housing

Fixed Connection

Movable Connection

Terminal Connection
Strip

Junction box

Earth connection



MCB

Socket outlet, single
phase

Pushbutton
Electric fuse
Electric lamp

One gang one way
switch

Two gang one way
switch

One gang two way
switch

Intermediate switch

One gang one way
two pole switch

The Wiring Diagram Shows
that one lamp in this room is
operated by one switch
Wiring Diagram

In the schematic diagram each
individual connection line is
shown and more detailed
graphical symbols are used to
indicate the electrical details
of a wiring.
Schematic Diagram

The room has two doors so
the lamp is operated by two
switches
Wiring Diagram

More detailed graphical
symbols for the
interconnections
Schematic Diagram

Architectural plan
shown.

Architectural plan not
shown.

Does not show the
functional details of
the electrical
installation.

Details such as the
interconnection of
components like
switches, Junction
boxes, light fittings
etc. will be shown.
Wiring Diagram
Schematic Diagram
Lab Activity 2 & 3 – Page(12-13) – Module 3
Module Exercises – Page 14