NATIONAL ELECTRICAL CODE 2. PREAMBLE (NOT PART OF THE STANDARD)In order to promote public education and public safety, equal justice for all.
The same rules apply for the total selectivity with the miniature circuit-breakers Acti-9. Circuit protection devices, fuses, MCB, ELCB. Home / Technical Articles / Energy and Power / What is the difference between MCB, MCCB, ELCB. Between Elcb And Mcb Pdf Printer. The Miniature Circuit Breakers. Wiring of fluorescent lamp controlled by one switch from panel with ELCB & MCB. The difference equation from state variable description.
END OF PREAMBLE (NOT PART OF THE STANDARD)ab(First Revision)BUREAU OF INDIAN STANDARDSi. SP 3. 0 : 2. 01. 1FIRST PUBLISHED AUGUST 1. FIRST REVISION FEBRUARY 2. PUBLISHED BY BUREAU OF INDIAN STANDARDS, MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG, NEW DELHI 1.
PRINTED BY VIBA PRESS PVT. LTD., NEW DELHI 1. INTRODUCTIONIndia is on the path of development and its infrastructure sector has grown progressively.
The buildings and services so constructed depend on power for their construction and effective utilization. In fact, power is one of the prime movers of development and electrical energy is the predominant form of energy being used due to ease of generation/conversion, transmission, and final utilization. Specific regulations to be adhered to in the supply and use of electrical energy had been laid down by the Indian Electricity Act, 1. Indian Electricity Rules, 1. However, a need was felt to elaborate upon these regulations since the agencies involved have varied practices in view of their diverse interests and different accessibility levels to technological developments. In order to rationalize these practices, India’s first National Electrical Code, formulated in 1.
The code complemented and elaborated on the Indian Electricity Rules, 1. During the formulation of the National Electrical Code in 1.
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It had also been planned that after the relevant codes are revised, the National Electrical Code would also need to be revised. After the publication of NEC 1. Codes were revised.
However, the task of revision of NEC could not be taken up in earnest immediately after the revision of various codes of practice. Over the years, there have been yet more changes in the technology; new practices have evolved and got modified. There have been tremendous socio- economic changes, and corresponding change in the pattern of the usage of electricity. Electricity Act 2. During the Ninth Plan, it was realized that it is necessary to have an Energy Conservation Act. Accordingly, the Government has enacted the Energy Conservation Act, 2. Due to all such changes, the present scenario is at great variance with that of 1.
Code was first formulated. Therefore, an urgent need was felt to revise the NEC at the earliest to maintain its relevance in the present context. The task for revision of NEC was taken up by the Electrical Installations Sectional Committee, ETD 2.
This revision follows the earlier structure of NEC, with modifications and additions being incorporated in line with IEC 6. It is visualized that in future, further harmonization with international codes may be considered. Electrical installation should be carried out in accordance with the Indian Electricity Rules, 1. All material, accessories, appliances etc., used in an electrical installation should conform to Indian Standards wherever they exist.
There should be good workmanship and proper coordination and collaboration between the architect, building engineer and the electrical engineer from the planning stage itself. The design of electrical installation is required to take into account the characteristics of available supply, nature of demand, environmental conditions, type of wiring and methods of installations, protective equipment, emergency control, disconnecting devices, preventing of mutual influence between electrical and non electrical installations, accessibility etc. The Code is divided into eight parts, which are further divided into sections. Part 1 covers the General and common aspects, which would apply to all types of electrical installations. Wiring installations are an importantiiiaspect of any electrical installation. These have been revised to align with international practice and it is proposed to revise the relevant code of practice for wiring installations also. The Sections related to Earthing and Lightning protection have been modified and corresponding modification is also being initiated to respective codes.
Aspect of voltage surges has also been included. Energy conservation aspects had been emphasized in NEC 1. Meanwhile, Energy Conservation Act, 2. Therefore, energy conservation aspects have been further elaborated and energy audit has also been included. This Code excludes the requirements coming under the purview of utilities, namely, the large generating stations, distribution substations and associated transmission system, or captive generator sets of very large capacity. It covers the requirements relating to standby or emergency generating stations and captive substations intended for serving an individual occupancy and intended to serve a building or a group of buildings normally housed in and around it.
It gives guidelines on layout and building construction aspects, selection of equipment, transformer installations, switching stations and station auxiliaries. Reference to pollution norms as laid down in Environment Protection Act 1. Non- industrial buildings include domestic dwellings, office buildings, shopping and commercial centers and institutions, recreational & assembly buildings, medical establishments, hotels and sports buildings etc.
Optimum benefits from the use of electricity can be obtained only if the installation is of sufficient capacity and affords enough flexibility. Safety, economy, efficiency, reliability, convenience as well as provision for future expansion are major considerations in planning the electrical layout. Guidelines are provided based on general characteristics of installations, supply characteristics and parameters.
Switchgear for control and protection, service lines, metering, earthing, building services, fire protection and miscellaneous provisions have been covered. Miscellaneous provisions include telephone wiring, call bell system, clock system, group control, audio visual systems, closed circuit TV where applicable, emergency lights for critical areas of the dwelling. Provision of increased number of points for residential units in order to accommodate the gadgets available and to avoid overloading of points by consumer and reference to miniature circuit breakers in addition to fuses under requirement of switchgear for control and protection has been made. Electrical networks in industrial buildings serve the purpose of distributing the required power to the consuming points where it is used for a multitude of purposes in the industry.
The design of electrical installation in industrial premises is therefore more complicated than those in non- industrial buildings. Industrial installation has to take care of load requirements and supply limitations in a simple and economic manner, ensuring at the same time full protection to human life and loss of property by fire. The network layout should also facilitate easy maintenance and fault localization. A particular feature of electrical installations in industrial buildings is the reliability of supply to essential operations for which standby and emergency supply sources/networks are available. The needs of such systems would depend on the type and nature of the industrial works.
Locations in industrial buildings which are by their nature hazardous, require special treatment in respect of design of electrical installations therein. Industrial installations have been classified depending on the specified criteria therein in order to help identify the specific nature of each industry and the locations therein, for assisting the design engineer in the choice of equipment and methods. Electrical installations are often required to be designed and erected for use for short periods of time ranging from a few hours to few months and are connected to the supply source in open ground. Such installations are generally unprotected from environmental hazards as compared to installations in buildings. Major risks in the use of power in such installation arise from short circuit resulting in fire accidents and exposure to live wire resulting in shock.
Outdoor installations are required to comply not only with the general requirements, but also additional requirements regarding supply intake arrangements, control of circuits, earthing, and protection against overload, short circuit and earth leakage. There is increased use of electricity for essential purposes in agriculture with the increase in sophistication in organising the farm output of the country. Installations in agricultural premises are different as the external influences on the electrical services are quite different from those encountered elsewhere.
Even though the overall power requirements for such installations could be small, the presence of livestock and other extraneous factors necessitate laying down specific requirements to ensure safety. Specific requirements of electrical installations in agricultural premises which include premises where livestock are present and farm produce are handled or stored have been covered. Agricultural processing at the farm premises has now been included.
Any area, where during normal operations a hazardous atmosphere is likely to occur in sufficient quantity to constitute a hazard had to be treated in a special manner from the point of the design of electrical installation. Many liquids, gases and vapours which in industry are generated, processed, handled and stored are combustible. When ignited these may burn readily and with considerable explosive force when mixed with air in the appropriate proportions. With regard to electrical installations, essential ignition sources include arcs, sparks or hot surfaces produced either in normal operation or under specified fault conditions. NEC provides guidelines for electrical installations and equipment in locations where a hazardous atmosphere is likely to be present with a view to maximizing electrical safety.