1. A Micro project of Electrical Estimating & Contracting
Topic :- PPT On Detail Concept & Case Study on Electrical Wiring
Diagram
Prepared By :- Manthan Mahendra Rajput
& Group
Guided By :- Mrs. Nimbalkar D. S.
3. Unit outcomes
1a. Draw the diagram/(s) of specified electrical installation.
1b. Convert the given wiring diagram into single line diagram.
1c. Explain the specified method of representation of wiring diagram.
1d. Convert the specified single line diagram into the wiring diagram.
1e. Describe the requirements of NEC 2011 related to the given
electrical
installation.
9. 1.2
Electrical diagrams, their Classification. Definition of
wiring and circuit (Schematic) diagram according to
IS: 2042(Part-I)-1962
10. Classification of Electrical Diagram :
1. Block Diagram
2. Schematic Diagram
3. Wiring Diagram
4. Single Line Diagram
11. Definitions :
1. Block Diagram :- Components & information represented byusingblocksis known
as 'block diagram’.
2. Schematic Diagram :- Detailed diagrams of electrical connections & components of
a circuit.
3. Wiring Diagram :- The diagram showing physical connections &wiring of electrical
components.
4. Single Line Diagram :- Simplified diagram showing the main electrical
components &connections.
12. • Wiring Diagram • Single Line Diagram • Schematic Diagram
Electrical Diagrams :-
Single Line Diagrams, Wiring diagrams & Schematic Diagrams :
1. 1 Lamp controlled by individual switch -
13. • Wiring Diagram • Single Line Diagram • Schematic Diagram
Single Line Diagrams, Wiring diagrams & Schematic Diagrams :
2. 2 Lamps controlled by individual switch -
14. • Wiring Diagram • Single Line Diagram • Schematic Diagram
Single Line Diagrams, Wiring diagrams & Schematic Diagrams :
3. 2 Lamps, 1 Fan controlled by 3 Switches -
15. • Wiring Diagram • Single Line Diagram • Schematic Diagram
Single Line Diagrams, Wiring diagrams & Schematic Diagrams :
4. 1 Fan, 1 Lamp & 3 Pin Socket controlled by individual switch -
16. • Wiring Diagram • Single Line Diagram • Schematic Diagram
Single Line Diagrams, Wiring diagrams & Schematic Diagrams :
5. 2 Fans & 2 Lamps controlled by individual switch -
17. • Wiring Diagram • Single Line Diagram • Schematic Diagram
Single Line Diagrams, Wiring diagrams & Schematic Diagrams :
6. 2 Lamps, 1 Ceiling Fan, 1 Socket controlled by individual switch -
18. Symbols used in Electrical Diagrams :-
Lamp Switch Fan Switch/Regulator 3 Pin Socket
Switch Ceiling Fan 3 Pin Socket Phase Wire
Neutral Wire
19. 1.3
Methods of representation for the wiring diagram-
multiline and single line representation, conversion of
multiline representation into single line and vice
versa.
20. Methods of representation for the Wiring Diagram :-
1. Schematic Diagram
• Uses standardized symbols to represent electrical components and connections.
• Focuses on the logical design rather than the physical layout.
• Common in circuit analysis and troubleshooting.
2. Wiring Diagram (Connection Diagram)
• Shows actual connections between components using lines for wires.
• Includes details like wire colors, terminal numbers, and physical placement.
• Used for practical installation and maintenance.
3. Single-Line Diagram (SLD)
• Uses a single line to represent multiple conductors in power distribution.
• Common in substations, switchgear, and industrial power systems.
• Helps in understanding the overall electrical network.
21. 4. Block Diagram
• Provides a high-level representation using blocks to show major components.
• Used for system overview and understanding functional relationships.
5. Terminal Diagram
• Focuses on terminal connections of electrical components.
• Used in control panels and switchboards for wiring identification.
6. Cable Routing Diagram
• Shows the physical routing of cables in an electrical installation.
• Used in large buildings and industrial setups for cable management.
24. 1.4
Fundamental principles for electrical installations,
Safety in Electrical Work, Permit to Electrical Work,
Safety Instruction and Safety Practices.
25. Fundamental principles for Electrical Installations :-
1. Safety of Persons & Property – Protection from electric shock, fire hazards, and
overcurrent.
2. Selection of Suitable Equipment – Use of correctly rated and certified electrical
components.
3. Proper Circuit Design & Load Distribution – Avoid overloading, balance circuits,
and use appropriate cable sizes.
4. Protection Systems – Use MCBs, RCCBs, fuses, and surge protectors for fault
protection.
5. Earthing & Bonding – Proper grounding to prevent electric shock and ensure
safety.
26. 6. Energy Efficiency & Power Quality – Use efficient devices, power factor correction,
and minimize losses.
7. Accessibility & Maintainability – Ensure easy inspection, labeling, and maintenance
of electrical systems.
8. Compliance with Standards – Follow NEC, IEC, IS 732, and local electrical
regulations.
9. Environmental Considerations – Weatherproof installations, dust/moisture
protection, and safe disposal.
27. Safety in Electrical Work (Permit to Work, Safety
Precautions) :-
Prior to start the work, work in process, work completion during all thebe periods safety
to be observed & IE rules are to be followed.
1. While working on Low, Medium voltage following safety should be observed (live
mains) :
a. Approved equipments & safety devices be used to protect from electric shock.•
while working on live mains, rubber gloves, rubbers shoes shall be compulsory used.
b. Working on live mains, second person be with the main person.
c. Work shall not be allowed to persons unless they have permit to work by authorized
officer.
d. Accidents shall be immediately attended& reported to appropriate authorities, all
the doctor at site.
28. e. Place yourself at secure position to avoid slipping or moving backwards against live
conductors.
f. Stop working in the near approach of lighting storm.
g. Think before you act, treat everything is live Keep in mind that all voltage and
dangerous.
h. Don't allow unauthorized persons to enter into working areas.
i. Earthing systems shall be periodically checked, on completion of work remove all
earthing devices.
29. IE Act & Permit to Work :-
Rules listed in the IE Act should be strictly followed by each & every person working of
electrical installation for his own safety, safety of others working with him & also for the safety
of the equipment on which he is working. For major, work of repairs, shut down
maintenance is carried.
1. Regarding Permit to Work
• Nobody shall Start working an electrical installation unless he is authorized to work with a
permit issued by a competent authority.
• Nature of repair work & time-span required for this work shall be explained by him to the
permit issuing authority.
• The authority confirms the work & issues the writing permission "permit to work".
• If the line is to be shut down for the work then the necessary notice is to be published in
the newspapers for awareness to the public.(2)Power of Higher authority for issuing permit
to work" -• Unless the switches, isolators have been withdrawn & completely isolated from
both sides of the section to be repair.
30. 2. Power of Higher authority for issuing permit to work"
• Unless the switches, isolators have been withdrawn & completely isolated from
both sides of the section to be repair.
• Earth rod use to discharge the shut line
31. 1.5
Scope and features of National Electrical Code 2011
(NEC 2011), Types of Electrical Installation- Non
Industrial and Industrial, Standard value of voltages
and their limits,
32. Scope and Features of National Electrical Code (NEC) 2011 :-
Scope of NEC 2011
1. Electrical wiring and installations in buildings, industries, and public areas.
2. Protection against electric shock, fire hazards, and overcurrent.
3. Selection of suitable electrical equipment and wiring methods.
4. Earthing, lightning protection, and energy efficiency measures.
5. Compliance with Indian Standards (IS 732, IS 3043, etc.).
33. Features of NEC 2011
1. Ensures safety and reliability of electrical installations.
2. Specifies wiring methods, circuit protection, and voltage ratings.
3. Covers earthing, grounding and insulation resistance requirements.
4. Provides guidelines for residential, commercial, and industrial installations.
5. Addresses energy efficiency and power quality standards.
34. Types of Electrical Installations :-
Non-Industrial Installation
1. Residential buildings (homes, apartments).
2. Commercial complexes (offices, malls, hotels).
3. Educational and healthcare facilities (schools, hospitals).
4. Public utilities (street lighting, stadiums).
Industrial Installation
1. Factories and manufacturing plants.
2. Power plants and substations.
3. Refineries, chemical plants, and steel industries.
4. Warehouses, data centers, and processing units.
35. Standard Voltage Values and Their Limits (As per IS 12360 &
NEC 2011) :-
Voltage Level Standard Voltage Variation Limits
Low Voltage (LV) 230V (Single-phase) / 415V
(Three-phase)
±6% (216V-244V for 230V
system)
Medium Voltage (MV) 3.3kV, 6.6kV, 11kV ±10%
High Voltage (HV) 33kV, 66kV ±12.5%
Extra High Voltage (EHV) 132kV, 220kV, 400kV ±12.5%
