Electricity Rules in India were first made by the Central Electricity Board in exercise of powers conferred under the Indian Electricity Act, 1910. These rules have been retained in the Electricity Act, 2003 and will continue to be in force until the regulations/rules under Section 53 of the Electricity Act, 2003 are framed. There are 143 rules in all and we discuss the relevant ones in brief.
We first state the definitions of different gradations of voltages as given by these rules (Table).
We first state the definitions of different gradations of voltages as given by these rules (Table).
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| Definition of Different Grades of Voltages |
The first two rules give the title and definitions of the IE Rules. Rule 3 pertains to authorisation of persons engaged in generation, transformation,transmission, conversion, distribution or use of energy. As per rule 3(2A), no person should be authorized to operate or undertake maintenance of any part or whole of a generating station of capacity 100 MW and above together with the associated substation and other substations of 132 kV and above unless s/he is adequately qualified and has successfully undergone the type of training specified in the Indian Electricity Rules, 1956. According to these Rules all work on major electrical installations should be carried out under the permit to work system, which provides in-built safety to the workforce engaged in electrical work (Box).
Box : Permit to Work System
As per this system, the permit to work has to be issued from the Power System Control (PSC) to the person authorized to carry out a given work.All work has to be carried out under the personal supervision of an authorized person. If more than one department is working on the same apparatus, a permit to work should be issued to authorized persons in charge of each work.
This system ensures that the portion of the installation where the work is to be carried out is rendered dead and safe for working. Such work should only be carried out with proper equipment provided for the purpose and after taking necessary precautions as per safe operating procedures, by specially trained and experienced persons who are aware of the danger that exists when working on or near live mains or apparatus.
The qualifications and powers of Inspectors and his/her assistants are mentioned in the Rules 4 to 10. Rules 11 to 28 spell out the procedure for applying and obtaining licenses. Rules 29 to 46 pertain to the general safety requirements and we state, in brief, the important ones:
• All electric supply lines and apparatus should be constructed, installed, worked and maintained in such a manner as to ensure the safety of personnel and property.
• Identification of earthed and earthed neutral conductors and position of switches and cut outs is a must. In the double pole switches, link should be provided instead of fuse carrier on the neutral conductor.
• Earthed terminal must be provided on consumer's premises. Earth pits should be constructed and maintained strictly as per relevant standards.The earth resistance of earth electrodes should not exceed 5 ohms.
• Danger Boards as per IS 2551 should be affixed permanently in a conspicuous position on every motor, generator, transformer and other
electrical equipment.
• Instructions for restoration of persons suffering from electric shock should be written in English or Hindi or local language of the district and be affixed by the owner in a conspicuous place in every generating station, enclosed switched station, etc.
• If any accident involving a human being or an animal occurs, a telegraphic report within 24 hours of the knowledge of the occurrence of the fatal accident and a written report in the form set out within 48 hours of fatal and other accidents should be sent to the electrical inspector. Where practicable, a telephonic message should be given to the Inspector immediately.
• Periodic inspection and testing of consumer's installation must be done at intervals not exceeding five years either by an Inspector or any officer appointed to assist the Inspector or by the supplier as directed by the Central Government.
Rules 47 to 59 pertain to the general conditions relating to supply and use of energy. As per these rules, electrical installation works of a consumer should be carried out by a licensed contractor, the insulation resistance should be above the prescribed limit, the supplier should not permit the voltage, at the point of commencement of supply, to vary from the declared voltage as per
the stipulations given ahead:
• in the case of low or medium voltage by more than 6%;
• in the case of high voltage, by more than 6% on the higher side and by more than 9% on the lower side; and
• in the case of extra high voltage, by more than 10% on the higher side and by more than 12.5% on lower side.
Moreover, a supplier should not permit the frequency of an AC supply to vary from the declared frequency by more than 3%.There are rules pertaining to electric supply lines, systems and apparatus for low and medium voltages, high and extra high voltages, and additional provisions of supply to high voltage luminous tube sign installations, high voltage electrode boilers, X-ray and high frequency installations. The supply of energy should not be commenced by the supplier unless and until the inspector is satisfied and the written approval of the Inspector has been obtained. Overhead lines are covered under the Rules 74 to 93. The factor of safety for various supports is as under:
1) Metal supports 1.5
2) Mechanically processed concrete supports
3) Hand-moulded concrete supports 2.0
4) Wood supports 3.0 2.5
The minimum clearance above ground of the lowest conductors along and across a street is given in Table and shown in Fig.
Box : Permit to Work System
As per this system, the permit to work has to be issued from the Power System Control (PSC) to the person authorized to carry out a given work.All work has to be carried out under the personal supervision of an authorized person. If more than one department is working on the same apparatus, a permit to work should be issued to authorized persons in charge of each work.
This system ensures that the portion of the installation where the work is to be carried out is rendered dead and safe for working. Such work should only be carried out with proper equipment provided for the purpose and after taking necessary precautions as per safe operating procedures, by specially trained and experienced persons who are aware of the danger that exists when working on or near live mains or apparatus.
The qualifications and powers of Inspectors and his/her assistants are mentioned in the Rules 4 to 10. Rules 11 to 28 spell out the procedure for applying and obtaining licenses. Rules 29 to 46 pertain to the general safety requirements and we state, in brief, the important ones:
• All electric supply lines and apparatus should be constructed, installed, worked and maintained in such a manner as to ensure the safety of personnel and property.
• Identification of earthed and earthed neutral conductors and position of switches and cut outs is a must. In the double pole switches, link should be provided instead of fuse carrier on the neutral conductor.
• Earthed terminal must be provided on consumer's premises. Earth pits should be constructed and maintained strictly as per relevant standards.The earth resistance of earth electrodes should not exceed 5 ohms.
• Danger Boards as per IS 2551 should be affixed permanently in a conspicuous position on every motor, generator, transformer and other
electrical equipment.
• Instructions for restoration of persons suffering from electric shock should be written in English or Hindi or local language of the district and be affixed by the owner in a conspicuous place in every generating station, enclosed switched station, etc.
• If any accident involving a human being or an animal occurs, a telegraphic report within 24 hours of the knowledge of the occurrence of the fatal accident and a written report in the form set out within 48 hours of fatal and other accidents should be sent to the electrical inspector. Where practicable, a telephonic message should be given to the Inspector immediately.
• Periodic inspection and testing of consumer's installation must be done at intervals not exceeding five years either by an Inspector or any officer appointed to assist the Inspector or by the supplier as directed by the Central Government.
Rules 47 to 59 pertain to the general conditions relating to supply and use of energy. As per these rules, electrical installation works of a consumer should be carried out by a licensed contractor, the insulation resistance should be above the prescribed limit, the supplier should not permit the voltage, at the point of commencement of supply, to vary from the declared voltage as per
the stipulations given ahead:
• in the case of low or medium voltage by more than 6%;
• in the case of high voltage, by more than 6% on the higher side and by more than 9% on the lower side; and
• in the case of extra high voltage, by more than 10% on the higher side and by more than 12.5% on lower side.
Moreover, a supplier should not permit the frequency of an AC supply to vary from the declared frequency by more than 3%.There are rules pertaining to electric supply lines, systems and apparatus for low and medium voltages, high and extra high voltages, and additional provisions of supply to high voltage luminous tube sign installations, high voltage electrode boilers, X-ray and high frequency installations. The supply of energy should not be commenced by the supplier unless and until the inspector is satisfied and the written approval of the Inspector has been obtained. Overhead lines are covered under the Rules 74 to 93. The factor of safety for various supports is as under:
1) Metal supports 1.5
2) Mechanically processed concrete supports
3) Hand-moulded concrete supports 2.0
4) Wood supports 3.0 2.5
The minimum clearance above ground of the lowest conductors along and across a street is given in Table and shown in Fig.
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| Minimum Clearance above the Ground, of the Lowest Overhead Conductor across and along a Street |
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| Minimum Clearance of the Low, Medium and High Voltage Lines above the Ground across and along a Street |
The clearance above ground of overhead line conductor erected elsewhere other than along or across street is given in Table.
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| Clearance above the Ground of Overhead Line Conductors ELSEWHERE other than across or along a Street |
As per Rule 79, the minimum clearance from buildings of low and medium voltage lines and service lines is shown in Fig.Any conductor less than the above clearance should be adequately insulated and should be attached at suitable intervals to bare earthed bearer wire having a breaking strength of not less than 350 kg.
As per Rule 80, the clearance of high and extra high voltage lines from buildings is as under: Rule 87 gives the minimum clearances between lines when crossing each other (Table).
Table tells us, for example, that the minimum clearance between any two 11 – 66 kV lines should be 2.44 m. Similarly, the minimum clearance between the11 – 66 kV lines and 110 – 132 kV lines should be 3.05 m when these cross each other, and so on.
Rule 90 is about earthing and states that all metal supports and metallic fittings should be permanently and efficiently earthed. Each stay-wire should be efficiently earthed or an insulator provided in it at a height not less than 3.0m from the ground.
Rules 94 to 108 are about electric traction, Rules 109 to 132 give the additional precautions to be adopted in mines and oil fields, and Rules 133 to 143 cover miscellaneous aspects. Rule 138 to 141 give the penalties for broken seal and for breach of other rules.
Rule 142 is about the application of rules and Rule 143 about Repeal. Under this rule The Indian Electricity Rules, 1937 have been repealed: Provided that any order made, notification issued or anything done or any action taken under any of the said rules should be deemed to have been made, issued, done or taken under the corresponding provisions of the rules.
In this section, we have briefly acquainted you with the Indian Electricity Rules in force as on date. We now discuss the safety procedures that should be followed by all persons working in the electricity industry.
Table tells us, for example, that the minimum clearance between any two 11 – 66 kV lines should be 2.44 m. Similarly, the minimum clearance between the11 – 66 kV lines and 110 – 132 kV lines should be 3.05 m when these cross each other, and so on.
Rule 90 is about earthing and states that all metal supports and metallic fittings should be permanently and efficiently earthed. Each stay-wire should be efficiently earthed or an insulator provided in it at a height not less than 3.0m from the ground.
Rules 94 to 108 are about electric traction, Rules 109 to 132 give the additional precautions to be adopted in mines and oil fields, and Rules 133 to 143 cover miscellaneous aspects. Rule 138 to 141 give the penalties for broken seal and for breach of other rules.
Rule 142 is about the application of rules and Rule 143 about Repeal. Under this rule The Indian Electricity Rules, 1937 have been repealed: Provided that any order made, notification issued or anything done or any action taken under any of the said rules should be deemed to have been made, issued, done or taken under the corresponding provisions of the rules.
In this section, we have briefly acquainted you with the Indian Electricity Rules in force as on date. We now discuss the safety procedures that should be followed by all persons working in the electricity industry.
Rule no. 90 belongs to the earthing of supports.
ReplyDeleteAnd rule no. 67 stated that all metallic body should be earthed efficiently.