The document discusses interpreting technical drawings and plans related to electrical work. It provides learning objectives and essential questions around reading electrical signs, symbols, and diagrams. It then defines common electrical symbols used to represent devices in schematics and plans. Specific types of diagrams, circuits, and an example electrical plan are described. Understanding symbols and drawing diagrams correctly is important for safety and proper installation of electrical systems.

1. INTERPRET TECHNICAL
DRAWINGS AND PLANS

2. LEARNING OBJECTIVES:
•Read and interpret common electrical
signs and symbols.
•Interpret electrical diagrams.
•Draw an electrical plan/diagram
according to specifications given.

3. ESSENTIAL QUESTIONS:
•Why do you need to learn how to read and
understand the meaning of electrical signs
and symbols?
•What is the importance of drawing a wiring
diagram correctly?

4. DIRECTIONS: IDENTIFY THE MEANING OF DIFFERENT
SIGNS ENUMERATED BELOW BY FILLING IN THE
MISSING LETTERS TO COMPLETE THE CORRECT
WORD/S.
SA Y A T

5. P O B I T N

6. W R Y T E C

7. E C R I L H D

8. V L A A GE

9. COMMON ELECTRICAL SYMBOLS
• Electrical Symbols are small drawings or pictograms used to
represent various electrical devices in a diagram or plan of
an electrical circuit. These symbols are used in sketching
schematic diagrams and electrical plans for numerous types
of electrical works. Practically any electrical fixture found in a
house has a symbol that coincides with a particular fixture in
an electrical wiring diagram. These are useful guides for an
electrician or electrical contractor, and make the wiring
easier to install as well.

14. ELECTRICAL SIGNS
• Your power tool with its manual may contain "Warning Icons." A
warning icon in a picture symbol intended to alert you, and/or to
instruct you how to avoid a potentially hazardous condition.
Knowing and understanding these symbols will help you operate
your tools better and more safely.
• Electrical signs and stickers alert students, workers, and visitors to
electrical hazards in the area. Alerting workers to high voltage
areas, electrical hazards, power lines and other electrical
equipment in the area can help prevent fires and injuries. Proper
electrical signs can inform workers of the dangers in the area.

18. ELECTRICAL WIRING DIAGRAM
•Wiring Diagram
• The flow of current in a conductor or wire can be
represented in a diagram. A wiring diagram shows the
physical relationship between and among the components
in a circuit. It shows the details and information needed to
hardwire a circuit. There are two types of diagrams - the
pictorial diagram and schematic diagram.

19. PICTORIAL DIAGRAM
-is a sketch of electrical circuit that shows the
external appearance of each component in a
circuit. It shows the components using
photograph, thus pictorial diagram is similar to a
photograph of the circuit.

21. B. SCHEMATIC DIAGRAM
•is a sketch showing the components
of the circuit using standard electrical
symbols. It shows the actual number
of components and how the wiring is
routed but not the actual location.

23. SERIES CIRCUIT
is a circuit in which lamps are arranged in a chain, so
that the current has only one path to take. The current
is the same through each load. An example of this is
Christmas light/bulbs. It consists of a number of bulbs
that are connected side by side to meet the voltage
requirement which is 220 volts for alternating current

25. PARALLEL CIRCUIT IS
a circuit in which lamps are connected
across the wires. The voltage across each
load on a parallel circuit is the same. The
advantage of using parallel circuit is that
even if one of the lamps fails, the
remaining lamps will still function.

27. ELECTRICAL PLAN
•is a graphical presentation of electrical
wiring connections to install in a particular
house or building. It indicates the position
of electrical fixtures such as convenience
outlets, switches, lightings, door bells, and
others to be installed.

29. Number of electrical fixtures found in the
electrical plan:
QUANTITY ELECTRICAL FIXTURES
8 pieces Lamp outlets
8 pieces Duplex convenience
outlets
4 pieces Single gang switches
1 piece Two gang switches
1 piece Three gang switches

30. • Why do you have to learn how to read and understand the
meaning of electrical signs and symbols?
• Electrical plans are made up of symbols which represents specific
parts of the plan. These symbols form the idea, message or
instruction that the plan wants to communicate. Thus, reading and
understanding electrical symbols is the basic step in learning how
to interpret and create electrical plans and drawings which are
shown in electrical wiring diagrams. On the other hand,
understanding electrical signs is important because they alert or
warn people to possible electrical hazards in the area. This way,
accidents that may cause injuries and damages can be avoided.

31. • B. What is the importance of drawing a wiring diagram correctly?
• Wiring diagrams should always be presented correctly because it shows the details
and information needed to hard wire a circuit. Any error in the wiring diagram could
lead misrepresentation and to further errors in the actual circuit itself.