EE09 801

ELECTRICAL SYSTEM DESIGN

OBJECTIVE

• To import the basic concepts of various electrical installation

• To study the design and estimation of different electrical installation

MODULE - 1• General:

– Salient features of Indian Electricity Act – Indian Electricity Rules and Energy Conservation Act – General safety precautions – Role and scope of National Electric Code – IS codes and IEC codes – Classification of supply systems: TN, TT and IT systems.

• Accessories and protective devices: – Load break switches, Switch Fuse Units, Fuse Switches,– Circuit Breakers: MCB, MCCB, ELCB, ACB, OCB and VCB - Different types of fuses-

• Protection against over load• Service connections - Reception and distribution of main supply - Schematic and wiring

diagrams• Estimation of wiring materials used for a small residential building• Neutral and earth wire• Earth bus• Design of earthing systems: pipe earthing

Salient features of Indian Electricity act

• Three erstwhile Acts that regulated the electricity sector:

• The Indian Electricity Act, 1910

• The Electricity (Supply) Act, 1948

• The Electricity Regulatory Commissions Act, 1998

• The Indian Electricity Act, 1910• Provided basic framework for electric supply industry in

India.• Growth of the sector through private licensees. License

by State Govt.• Provision for license for supply of electricity in a specified

area.• Legal framework for laying down of wires and other works.• Provisions laying down relationship between licensee and

consumer.

• The Electricity (Supply) Act, 1948• Mandated creation of SEBs.• Need for the State to step in (through SEBs) to extend

electrification (so far limited to cities) all across the country.

• Main amendments to the existing Acts• Amendment in 1975 to enable generation in Central sector

• Amendment to bring in commercial viability in the functioning of SEBs – • Section 59 amended to make the earning of a minimum return of

3% on fixed assets a statutory requirement (w.e.f 1.4.1985)

• Amendment in 1991 to open generation to private sector and establishment of RLDCs

• Amendment in 1998 to provide for private sector participation in transmission, and also provision relating to Transmission Utilities

• The Electricity Regulatory Commissions Act, 1998• Provision for setting up of Central / State Electricity

Regulatory Commission to with powers to determine

tariffs.

• Constitution of SERC optional for States. .

• Distancing of Govt. from tariff determination.

State Reform Acts Orissa (1995) Haryana (1997) Andhra Pradesh (1998) Uttar Pradesh (1999) Karnataka (1999) Rajasthan (1999) Delhi (2000) Madhya Pradesh (2000) Gujarat (2003)

Common features of State Acts

• Independent Regulatory Mechanism• Constitution of SERC

• Powers of tariff fixation, licensing, regulation or working of

licensees, performance standards etc. to SERC

• Reorganisation of SEB• TRANSCO as successor entity

• Single buyer model

• Separation of generation, transmission & distribution

• Powers of State Governments to give policy

directions to SERCs.

• Policy directions also on subsidy

• State Governments to compensate licensee affected by

direction regarding subsidy

Need for the new legislation

• Requirement of harmonizing and rationalizing the provisions in the existing laws to

- Create competitive environment for benchmark competition which will result in enhancing quality and reliability of service to consumer.

- distancing regulatory responsibilities of Govt.

• Reform legislation by several States separately.

• Obviating need for individual States to enact their own reform laws.

• Requirement of introducing newer concepts like power trading, open access, Appellate Tribunal etc.

• Special provision for the Rural areas.

Objective of Indian electricity act

• Encouraging autonomous regulation with the separation of

• policy regulation and operational aspects• Rationalizing tariff and lowering the cross-

subsidization• levels• Creating competition in the industry• Ensuring supply of electricity to all areas• Protecting consumer interests

Policy

• A National electricity plan shall be prepared in accordance with National Electricity Policy every 5 years National policy on stands alone systems for rural areas and Nonconventional energy systems National policy on electrification and local distribution in rural areas

Salient features of the Electricity Act, 2003

• Role of Government • Rural Electrification • Generation • Transmission • Distribution • Consumer Protection • Trading / Market Development• Regulatory Commission / Appellate Tribunal • Tariff Principles• CEA• Measures against Theft of electricity • Restructuring of SEBs

Role of Government• Central Government to prepare National Electricity Policy and Tariff

Policy.(Section 3)

• Central Govt. to notify a National Policy for rural areas permitting stand alone systems based on renewal and Non-Conventional energy sources in consultation with States. (Section 4)

• Central Govt. to formulate a National Policy in consultation with the concerned State Govts. for bulk purchase of power and management of local distribution through Users’ Association, Cooperatives, Franchisees and Panchayat Institutions etc. (Section 5)

Rural Electrification

Appropriate Government to endeavor to extend

supply of electricity to all villages/hamlets.

(Section 6)

No requirement of licence if a person intends to

generate and distribute power in rural area.

(Section 14)

GENERATION

 Generation free from licensing. (Section 7)

Requirement of TEC for non-hydro generation done away with. (Section 7)

Captive Generation is free from controls. Open access to Captive generating

plants subject to availability of transmission facility. (Section 9)

Clearance of CEA for hydro projects required. Necessary due to concern of dam

safety and inter-State issues. (Section 8)

Generation from Non-Conventional Sources / Co-generation to be promoted.

Minimum percentage of purchase of power from renewable may be prescribed

by Regulatory Commissions. (Sections 61 (h), 86 (1) (e))

TRANSMISSION There would be Transmission Utility at the Centre and in the States to undertake planning &

development of transmission system. (Sections 38 & 39) Load dispatch to be in the hands of a government company/organisation. Flexibility regarding

keeping Transmission Utility and load dispatch together or separating them. Load Dispatch function critical for grid stability and neutrality as compare to generators and distributors. Instructions to be binding on both.

(Sections 26, 27,31, 38, 39) Transmission companies to be licensed by the Appropriate Commission after giving due

consideration to the views of the Transmission Utility. (Sections 15(5)(b))

The Load Dispatch Centre/Transmission Utility / Transmission Licensee not to trade in power. Facilitating genuine competition between generators

(Sections 27, 31, 38, 39,41) Open access to the transmission lines to be provided to distribution licensees, generating

companies. (Sections 38-40) This would generate competitive pressures and lead to gradual cost reduction.

DISTRIBUTION• Distribution to be licensed by SERCs. • Distribution licensee free to take up generation & Generating co. free to take up

distribution licence. This would facilitate private sector participation without Government guarantee/ Escrow. (Sections 7, 12)

• Retail tariff to be determined by the Regulatory Commission. (Section 62)• Metering made mandatory. (Section 55)• Provision for suspension/revocation of licence by Regulatory Commission as it is

an essential service which can not be allowed to collapse. (Sections 19, 24)• Open access in distribution to be allowed by SERC in phases. (Section 42)• In addition to the wheeling charges provision for surcharge if open access is

allowed before elimination of cross subsidies, to take care of • Current level of cross subsidy• Licensee’s obligation to supply. (Section 42)• This would give choice to customer

Regulatory Commissions/Appellate Tribunal

State Electricity Regulatory Commission to be constituted within six months. (Section 82)

Provision for Joint Commission by more than one State/UT. (Section 83) Provision for constitution of Appellate Tribunal consisting of Chairman and three

Members. (Section 110, 112) Appellate Tribunal to hear appeals against the orders of CERC/SERC, and also to

exercise general supervision and control over the Central/State Commissions. (Section 111)

Appeal against the orders of Appellate Tribunal to lie before the Supreme Court. (Section 125)

Appellate Tribunal considered necessary to- Reduce litigation and delay in decisions through High Court. Provide technical expertise in decision on appeals.

CENTRAL ELECTRICITY AUTHORITY

CEA to continue as the main technical Advisor of the Govt. of

India/ State Government with the responsibility of overall

planning. (Section 70)

CEA to specify the technical standards for electrical plants and

electrical lines. (Section 73)

CEA to be technical adviser to CERC as well as SERCs.(Section

73)

CEA to specify the safety standards. (Section 53)

TARIFF PRINCIPLES Regulatory Commission to determine tariff for supply of electricity by generating

co. on long/medium term contracts. (Section 62) No tariff fixation by regulatory commission if tariff is determined through

competitive bidding or where consumers, on being allowed open access enter into agreement with generators/traders.

Consumer tariff should progressively reduce cross subsidies and move towards actual cost of supply. (Section 61 (g), (h))

State Government may provide subsidy in advance through the budget for specified target groups if it requires the tariff to be lower than that determined by the Regulatory Commission. (Section 65)

Regulatory Commissions may undertake regulation including determination of multi-year tariff principles, which rewards efficiency and is based on commercial principles. (Section 61 (e), (f))

Regulatory Commission to look at the costs of generation, transmission and distribution separately. (Section 62 (2))

RESTRUCTURING OF SEBs

• Provision for transfer scheme to create one or

more companies from SEB. (Section 131)

• Provision for continuance of SEBs (Section 172)

• States given flexibility to adopt reform model/path

Measures Against Theft of Electricity

- Focus on revenue realisation rather than criminal proceedings. (Sections 126, 135)

- Penalties linked to the connected load and quantum of energy and financial gain involved in theft. (Section 135)

- Provisions for compounding of offences. (Section 152)- Assessment of electricity charges for unauthorised use of electricity by

the assessing officer designated by the State Government. (Section 126)- Theft punishable with imprisonment. (Section 135)- Punishment provision for abetment of theft. (Section 150)- Special Courts (Sections 153-158)

New Central Law vis a vis State Reform / Amendment Laws

• All licenses, authorisations, permissions, approvals, clearances issued under the repealed laws are saved for a maximum period of one year. (Section 172(b)).

• Action taken under corresponding provisions of the repealed laws or rules made thereunder are saved to the extent of consistency/correspondence with the provisions of the new Act(Section 185 (2)).

• Provisions of State Reform laws not inconsistent with provisions of the new Central law will continue to apply in that State (Section 185(3)).

• State Governments can defer implementation of the new Act by a maximum period of six months. (Section 172(d)).

INDIAN ELECTRICITY RULES• Indian Electricity Rules : 1956 – An Overview

• Indian Electricity Rules 1956 are made the Indian Electricity Act:1910 , which is repealed by the Electricity Act:2003.

• These Rules shall be in force till new Rules are framed under the Electricity Act:2003.

• Indian Electricity Rules contain general and specific provisions regarding reliability and safety of Electrical supply systems.

• They focus on protection of persons and property from injury by reasons of contact with , or the proximity of , or by the reason of the defective or dangerous condition of any appliances or apparatus/equipment used in the generation, transmission , supply or use of energy.

• The Indian Electricity Rules supplement the various codes of the Bureau of Indian standards.

Indian Electricity Rules have been covered in 11 Chapters in all

Chapters

Rules covered

Details

1 1 to 3 It covers preliminaries, such as definitions of different expressions used in Rules, Authorization to person to work on live mains etc.

2 4 to 10 It deals with appointment of Electrical Inspector, his qualification and experience. Powers of Electrical Inspector to enter the premises and to serve order for compliance of defects, provision of appeals against the order of Electrical Inspector etc.

3 11 to 28

It deals with granting of license for supply of electricity. As per the provision of the Electricity Act:2003, such license shall be issued by the Gujarat Electricity Regulatory Commission ( GERC ) , constituted under the new Act.

4 29 to 46

This chapter deals with General Safety requirement. All these Rules are described below in detail .

5 47 to 59

It deals with general conditions relating to supply and use of energy. It covers general Rules for applicable to all class of installation.

6 60 to 62

It covers the Rules applicable to low and medium voltage installation’s supply and use.

7 63 to 73

It covers the Rules applicable to high and extra high voltage installations.

8 74 to 93

It deals with the provision of Rules applicable to Overhead lines and under ground cables.

9 94 to 108

This contains specific safety provisions which apply only to a Electrical energy used for the purpose of Traction.

10 109 to 132

It deals with precautions to be adopted in mines and oil fields.

11 133 to 143

Miscellaneous – Contain mainly penalty for breaking Rules.

General Safety Requirements ( Chapter-IV , Rules 29 to 46 )

• Rule:29 – Construction , installation , protection , operation and maintenance of electric supply lines and apparatus

• Rule:30 – Service line and apparatus on Consumer’s premises • Rule:31 – Cut –Out on Consumer’s premises • Rule:32– Proper distinction between live, neutral and earth conductors• Rule:33 – Earthed terminal on Consumer’s premises• Rule:34 –Accessibility of bare conductors • Rule:35 – Caution / Danger Notices • Rule:36 – Handling of Electric Supply lines Apparatus • Rule: 41 – Distinction of different circuits • Rule: 43 – Provision applicable to Protective Equipment • Rule: 44 – Instruction for restoration of persons suffering from electric shock • Rule: 44 A– Intimation of Accident • Rule: 45– Precautions to be adopted by consumers, owners, occupiers,

electrical contractors, electrical workmen and supplier• Rule: 46– Periodic Inspection

Reasons of accidents

• Snapping of Conductors.• Accidental contact with live electric wire /

equipment.• Violation / neglect of safety measures / lack of

supervisions.• Defective appliances / apparatus / tools.• Inadequate / lack of maintenance.• Unauthorised work / Sub-standard construction.• Others reasons (inadequate knowledge / training of

the work force, leakage of current etc.)

Hazards of electricity• Electric shock:- Current flows through body or part of body

when two surfaces having electrical potential difference is touched resulting in burn, disability or even death.

• Flashover:-Sudden collapse of electric field by having a conducting path between two electrical potential different surfaces resulting in burn, fire.

• Blast:-Failure of dielectric medium between two electrical potential different surfaces resulting in projectile, mechanical force, fire or burn.

• Heat:-Caused by loose connection in the circuit, overheating of insulation/ conductor due to overload or prolonged short circuit current etc. resulting in fire, burn.

Quantitative effect of electric current (up to 3sec.) on human (source Daziel)

Effect mAd.c a.c

60Hz 10kHzM F M F M F

Perception threshold 5.2 3.5 1.1 0.7 12 8Shock but not painful 9 6 1.8 1.2 17 11Muscular control lost, breathing difficulty.

90 60 23 15 94 63

Ventricular fibrillation 500 500 100 100

The Energy Conservation Act, 2001 and its Features Policy Framework – Energy Conservation Act – 2001

• With the background of high energy saving potential and its benefits, bridging the gap between demand and supply, reducing environmental emissions through energy saving, and to effectively overcome the barrier, the Government of India has enacted the Energy Conservation Act – 2001. The Act provides the much-needed legal framework and institutional arrangement for embarking on an energy efficiency drive.

• Under the provisions of the Act, Bureau of Energy Efficiency has been established with effect from 1st March 2002 by merging erstwhile Energy Management Centre of Ministry of Power

Important features of the Energy Conservation Act are:

• Standards and Labeling Standards and Labeling (S & L) has been identified as a key activity for

energy efficiency improvement. The S & L program, when in place would ensure that only energy efficient equipment and appliance would be made available to the consumers. • The main provision of EC act on Standards and Labeling are:

– Evolve minimum energy consumption and performance standards for notified equipment and appliances.

– Prohibit manufacture, sale and import of such equipment, which does not conform to the standards.

– Introduce a mandatory labeling scheme for notified equipment appliances to enable consumers to make informed choices

– Disseminate information on the benefits to consumers

• Designated Consumers • The main provisions of the EC Act on designated consumers are: • The government would notify energy intensive industries and other establishments

as designated consumers; • Schedule to the Act provides list of designated consumers which covered basically

energy intensive industries, Railways, Port Trust, Transport Sector,

• Power Stations, Transmission & Distribution Companies and Commercial buildings or establishments;

• • The designated consumer to get an energy audit conducted by an accredited energy auditor;

• • Energy managers with prescribed qualification are required to be appointed or designated by the designated consumers;

• • Designated consumers would comply with norms and standards of energy consumption as prescribed by the central government.

• Certification of Energy Managers and Accreditation of Energy Auditing Firms

• The main activities in this regard as envisaged in the Act are:

• A cadre of professionally qualified energy managers and auditors with expertise in policy analysis, project management, financing and implementation of energy efficiency projects would be developed through Certification and Accreditation programme. BEE to design training modules, and conduct a National level examination for certification of energy managers and energy auditors.

• Energy Conservation Building Codes: • The main provisions of the EC Act on Energy Conservation

Building Codes are: • The BEE would prepare guidelines for Energy Conservation

Building Codes (ECBC); • These would be notified to suit local climate conditions or

other compelling factors by the respective states for commercial buildings erected after the rules relating to energy conservation building codes have been notified. In addition, these buildings should have a connected load of 500 kW or contract demand of 600 kVA and above and are intended to be used for commercial purposes;

• Energy audit of specific designated commercial building consumers would also be prescribed.

• Central Energy Conservation Fund: • The EC Act provisions in this case are: • The fund would be set up at the centre to develop

the delivery mechanism for large-scale adoption of energy efficiency services such as performance contracting and promotion of energy service companies. The fund is expected to give a thrust to R & D and demonstration in order to boost market penetration of efficient equipment and appliances. It would support the creation of facilities for testing and development and to promote consumer awareness.

• Bureau of Energy Efficiency (BEE): • The mission of Bureau of Energy Efficiency is to institutionalize

energy efficiency services, enable delivery mechanisms in the country and provide leadership to energy efficiency in all sectors of economy. The primary objective would be to reduce energy intensity in the Indian Economy.

• The general superintendence, directions and management of the affairs of the Bureau is vested in the Governing Council with 26 members. The Council is headed by Union Minister of Power and consists of members represented by Secretaries of various line Ministries, the CEOs of technical agencies under the Ministries, members representing equipment and appliance manufacturers, industry, architects, consumers and five power regions representing the states. The Director General of the Bureau shall be the ex-officio member-secretary of the Council.

• Role of Bureau of Energy Efficiency • The role of BEE would be to prepare standards and

labels of appliances and equipment, develop a list of designated consumers, specify certification and accreditation procedure, prepare building codes, maintain Central EC fund and undertake promotional activities in co-ordination with center and state level agencies. The role would include development of Energy service companies (ESCOs), transforming the market for energy efficiency and create awareness through measures including clearing house.

• Role of Central and State Governments: • The following role of Central and State Government is

envisaged in the Act • Central - to notify rules and regulations under various

provisions of the Act, provide initial financial assistance to BEE and EC fund, Coordinate with various State Governments for notification, enforcement, penalties and adjudication.

• State - to amend energy conservation building codes to suit the regional and local climatic condition, to designate state level agency to coordinate, regulate and enforce provisions of the Act and constitute a State Energy Conservation Fund for promotion of energy efficiency.

• Enforcement through Self-Regulation: • E.C. Act would require inspection of only two

items. The following procedure of self-regulation is proposed to be adopted for verifying areas that require inspection of only two items that require inspection.

• Penalties and Adjudication: • Penalty for each offence under the Act would be in

monetary terms i.e. Rs.10,000 for each offence and Rs.1,000 for each day for continued non Compliance.

• The initial phase of 5 years would be promotional and creating infrastructure for

• implementation of Act. No penalties would be effective during this phase.

• The power to adjudicate has been vested with state Electricity Regulatory Commission which shall appoint any one of its member to be an adjudicating officer for holding an enquiry in connection with the penalty imposed.

Role and Scope of IS and IEC code• NATIONAL ELECTRICAL CODE 2011 • This Part 1/Section 1 of the Code describes the scope of the

National Electrical Code. • This Part 1/Section 2 of the Code covers definitions of terms. • This Part 1/Section 3 of the Code covers graphical symbols for

diagrams, letter symbols and signs which may be referred to for further details.

• This Part 1/Section 4 of the Code covers guidelines for preparation of diagrams, charts and tables in electrotechnology and for marking of conductors.

• This Part 1/Section 5 of the Code covers units and systems of measurement in electrotechnology.

• This Part 1/Section 6 of the Code covers standard values of ac and dc distribution voltages, preferred values of current ratings and standard system frequency.

• This Part 1/Section 7 of the Code enumerates the fundamental principles of design and execution of electrical installations.

• This Part 1/Section 8 of the Code covers guidelines for assessing the characteristics of buildings and the electrical installation therein.

• This Section 9 of the Code covers the essential design and constructional requirements for electrical wiring installations.

• This Part 1/Section 10 covers guidelines and general requirements associated with circuit calculations, namely, short circuit calculations and voltage drop calculations for cables and flexible cords.

• This Part 1/Section 11 of the Code covers requirements for installation work relating to building services that use electric power.

• This Part 1/Section 12 of the Code covers general criteria for selection of equipment.

• This Part 1/Section 13 of the Code covers general principles of erection of installation and guidelines on initial testing before commissioning.

• This Part 1/Section 14 of the Code covers general requirements associated with earthing in electrical installations. Specific requirements for earthing in individual installations are covered in respective Parts of the Code.

• 1.1 This (Part 1/Section 15) of the Code covers guidelines on the basic electrical aspects of lightning protective systems for buildings and the electrical installation forming part of the system.

• 1.2 Additional guidelines if any, for specific occupancies from the point of lightning protection are covered in respective sections of the Code.

• 1.1 This Part 1/Section 16 covers the protection requirements in low voltage electrical installation of buildings.

• 1.2 This part does not cover the primary protection against lightning which is covered under Part 1/ Section 15.

• This Part 1/Section 18 of the Code covers the aspects to be considered for selection of equipment from energy conservation point of view and guidance on energy audit.

• This Part 1/Section 19 of the Code covers guidelines on safety procedures and practices in electrical work.

• This Part 1/Section 20 gives frequently referrred tables in electrical engineering work.