Page 87 - Electrician - TT (Volume 1)

ELECTRICIAN - CITS

MODULE 4 : Electrical Wiring Practice, Earthing

LESSON 20-25 : National codes, common electrical

acccessories , types of wiring earthing

Objectives

At the end of this lesson you shall be able to:
• state NEC, general wiring roles BIS symbols used for electrical accessories
• classify specific, user of the accessories in domestical wiring
• state the IE rules related to safety & electrical supply
• explain wiring of MCB, MCCB, ELCB, residual current circuit breaker
• state the types of wiring testing methods - domestic wiring instrumental megger
• earthing types of earthing methods reducing earth resistance, earth tester.

National electrical code
Thousands of people die every year due to electrical accidents fire has destroyed property worth million of rupees.
Fires in building are due to electrical reasons. The main reasons for electrical accidents are poor design and
quality of electrical installations, maintenance, workmanship issues & very old installations.
Bureau of Indian Standards 9BIS) through its electrical installations sectional committee. (ETD-20) under ETDC
is responsible for the preparation of Indian Standards for Safety and related matters in its designing, erection &
maintenance of electrical installations
BIS has revised the National Electrical code of India which was released on January 6, 2023. BIS updated the
NEC to align with international practices.
This state of the art code establishes the basics of electrical safety in India.
The NEC consists of 8 parts and 49 sections covering different aspects of electrical installations.
Part 1: General & common aspects (22 sections)
Part 2: Electrical installations in standby generating stations & capacitive substations (2 sections)

Part 3: Requirement for special installation or location (22 sections)
Part 4: Electrical installations in industrial buildings
Part 5: Outdoor installation (3 sections)
Part 6: Electrical installtions in agriculture premises

Part 7: Electrical installations in hazardous areas
Part 8: Solar Photovoltaic (PV)
Power supply systems
Protection measures
The NEC provides protection measures including
1 Protection against electric stock

2 Protection against thermal effect
3 Protection against over current & short circuit current
4 Protection against, erction & verification of electrical installation.

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