Standards and Basic Equipment

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Standards and Basic Equipment

• Date 30 October 2008

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Schedule
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Introduction
Load Estimation
Terminology
Basic Equipment
Codes and Standards
Power Distribution Final Circuit
Standby Generator and Power Supplies
Protection Cable Wiring
Earthing
Design of Electricity Distribution
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• Example 1 Load Assessment
• Example 2 Load Assessment Practice
• Addition Information Drawings
• 1. Electrical Equipment
• 2. Terminology
• 3. Code Standard

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Example 1 Load Assessment

• A restaurant has the following electrical
  installations
• 10 nos. of 40W Fluorescent Light
• 3 nos. of 1.5 HP air conditioners (Power
  consumption 980 W/unit
• 2 nos. of 6 kW electric heater
• 2 set of 30A ring-circuit socket outlets
• A) Calculate the current demand of the above
  electrical installations (single phase supply)
• B) Calculate the maximum demand with diversity
  factor of the above electrical installations (3
  phase supply)

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Example 1a
Total Connected Load
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Example 1b
Maximum Demand
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Example 2 Load Assessment (Practice)
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(No Transcript)
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Addition Information Drawings

• Schematic Diagram
• Layout Drawings
• Design Drawings
• Working Drawings
• Combined Services Drawings

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1. Electrical Equipment
A) Transformer
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A1) One Transformer and 11kV Switchgear in High
Rise Building
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A2) Three Transformers and 11kV Switchgear in
High Rise Building
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A3) Minimum Requirements for the Customers
Switchroom Adjacent to Substation for
Multi-transformer Installation
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E) MCCB
D) Fuses Combination Unit (Switch Fuse)
B) Switch Board
C) ACB
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1. Electrical Equipment

• B) Factory-built-assembly (Switchboard)

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Typical forms of separation by barriers of
partition
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1. Electrical Equipment

• C) Air Circuit Breakers (ACB)

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1. Electrical Equipment

• D) Fuse Combination Units and Switch-disconnection
  s

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1. Electrical Equipment

• E) Moulded Case Circuit Breakers (MCCB)

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I) KWH Meter
H) MCB
F) Busbar Riser
G) MCB Distribution Board
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1. Electrical Equipment

• F) Busbar Risers

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1. Electrical Equipment

• G) MCB Distribution Boards

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1. Electrical Equipment

• H) Miniature Circuit Breakers (MCB) - 1

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1. Electrical Equipment

• H) Miniature Circuit Breakers (MCB) - 2

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1. Electrical Equipment

• I) KWH meter

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L) Lighting Switch M) Lampholder N) Socket
Outlet O) Connection Unit
K) RCCB
J) Consumer Unit
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1. Electrical Equipment

• J) Consumer Unit

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1. Electrical Equipment

• K) Residual Current Circuit Breakers (RCCB)

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1. Electrical Equipment

• L) Lighting Switches

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1. Electrical Equipment

• M) Lampholders

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1. Electrical Equipment

• N) Socket outlets

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1. Electrical Equipment

• O) Connection Unit

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1. Electrical Equipment

• P) PVC Cable - 1

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1. Electrical Equipment

• P) PVC Cable - 2

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2. Useful Terminology - 1

• Live Part
• A conductor or conductive part intended to be
  energized in normal use, including a neutral
  conductor.
• Electrical Installation
• An assembly of associated electrical equipment
  supplied from a common origin to fulfill a
  specific purpose and having certain coordinated
  characteristics.

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2. Useful Terminology - 2

• Electrical Equipment
• Any item for such purposes as generation,
  conversion, transmission, distribution or
  utilization of electrical energy, such as
  machines, transformers, protective devices,
  wiring materials, measuring instruments,
  accessories, appliances and luminaries.
• Fixed Appliance
• An appliance which is fastened to a support or
  otherwise secured at a specific location in
  normal use.

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2. Useful Terminology - 3

• Portable Appliance
• An appliance which is or can easily be moved from
  one place to another when in normal use and while
  connected to the supply.
• Earthing
• The act of connecting the exposed conductive
  parts of an installation to an earth electrode.

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2. Useful Terminology - 4

• Protective Conductor
• A conductor used for some measure of protection
  against electric shock and intended for
  connecting together any of the following parts
• Exposed conductive parts,
• Extraneous conductive parts,
• Main earthing terminal,
• Earth electrodes
• The earth point of the source

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2. Useful Terminology - 5

• Equipotential Bonding
• Electrical connection maintaining various exposed
  conductive pats and extraneous conductive parts
  at substantially the same potential
• Exposed Conductive Part
• A conductive part of equipment which can be
  touched and which is not a live part but which
  may become live under fault conditions

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2. Useful Terminology - 6

• Extraneous Conductive Part
• A conductive part liable to introduce a
  potential, generally earth potential, and not
  forming part of the electrical installation.
• Circuit Protective Conductor (CPC)
• A protective conductor connecting exposed
  conductive parts of equipment to the main
  earthing terminal.

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2. Useful Terminology - 7

• Earthing Conductor
• A protective conductor connecting a main eathing
  terminal of an installation to an earth electrode
  or to other means of earthing.
• Direct Contact
• Contact of persons or livestock with live parts
  which may result in electric shock.

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2. Useful Terminology - 8

• Indirect Contact
• Contact of persons or livestock with exposed
  conductive parts made live by a fault and which
  may result in electric shock.
• Skilled Person
• A person with technical knowledge or sufficient
  experience to enable him to avoid danger which
  electricity ay create.

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2. Useful Terminology - 9

• Instructed Person
• A person adequately advised or supervised by
  skilled persons to enable him to avoid dangers
  which electricity may create.
• Low Voltage (L.V.)
• Voltage normally exceeding Extra Low Voltage but
  not exceeding 1000V a.c. or 1500 d.c. between
  conductors, or 600V a.c. or 900V d.c. between
  conductors and earth.

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2. Useful Terminology - 10

• Extra Low Voltage
• Voltage normally not exceeding 50V a.c. or 120
  d.c., whether between conductors or to earth.

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3.1 Statutory Ordinances and Regulations

• Electricity Ordinances and the following
  subsidiary regulations
• Electricity Supply Regulations
• Electricity Supply (Special Areas) Regulations
• Electricity (Wiring) Regulations
• Electricity (Registration) Regulations
• Plugs Adaptors (Safety) Regulations.

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3.2 Relevant Codes and Guides to Statutory
Regulations

• Code of Practice for the Electricity (Wring)
  Regulations.
• Code of Practice for Minimum Fire Services
  Installations and Equipments

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3.3 Non-statutory Regulations/ Standards

• Regulations for Electrical Installation, 15th
  edition and/ or 16th edition.
• Supply Rules.
• British Standards Specifications Codes of
  Practice or other equivalent national standards
  and publications.

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3.4 Electricity Ordinance Part 1

• The electricity Ordinance (Ordinance No. 16 of
  1990) was assented by Hong Kong Governor on 22
  March 1990 and came into operation on 2 November
  1990.
• With the enactment of the Electricity Ordinance,
  only Registered Electrical Workers (REW) are
  allowed to undertake electrical work from 1 June
  1992 onwards. An owner of a fixed installation
  shall obtained a certificate prepares and signed
  by a Registered Electrical Contractor/Worker
  certifying that the installation complies with
  the Ordinance.

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3.4 Electricity Ordinance Part 2

• The Electricity (Registration) Regulations was
  made under Section 59 of the Electricity
  Ordinance 1990. There are 5 grades of Electrical
  Workers. They are

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3.4 Electricity Ordinance Part 3
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3.4 Electricity Ordinance Part 4

• The Code of Practice for the Electricity
  (Wiring) Regulations, hereinafter called the
  Code, was published in June 1992. The content of
  the Code is mainly based upon the IEE Wiring
  Regulations which gives technical guidelines on
  how the statutory requirements of the Electricity
  (Wiring) Regulations can be met, There are total
  26 codes, including two for future use, and 10
  appendices. Installations to be complete and
  connected to electricity supplied before 1.6.1994
  which comply with Supply Rules and the relevant
  requirements of the 15th and/or 16th editions of
  the IEE Wiring Regulations are deemed to have met
  the requirements of the Electricity (Wiring)
  Regulations.

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3.4 Electricity Ordinance Part 5

• The Code applies to all low or high voltage fixed
  installations in buildings and premises including
  domestic and commercial buildings, factories and
  industrial undertakings, except fixed
  installations in mobile units such as aircrafts,
  motor vehicles, ships and those exempted by the
  Director of Electrical Mechanical Services.

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3.4 Electricity Ordinance Part 6

• All electrical installation works including new
  installation, repair, alteration or addition made
  to an existing installation shall be carried out
  by a Registered Electrical Worker and certified
  that the wiring installation is completed to the
  relevant design and is in compliance with the
  Electricity (Wiring) Regulations. The REW should
  not sign certificate for tests and inspections
  (Form WR1) unless he has carried out or witnessed
  the tests and inspections, and is satisfied with
  the results. Normally the date of certification
  should not be later than two weeks after the date
  of the tests and inspections.

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3.4 Electricity Ordinance Part 7

• After the electrical works are completed, the
  Registered Electrical Work (REW) and the
  Registered Electrical Contractor should sign Work
  Completion Certificate (Form WR1) and issue it to
  the Owner. The REC should ensure that a copy of
  proper record including a simple line diagram
  with symbols and test results is made available
  to the owner of the electrical installation upon
  completion of work. It is also the responsibility
  of the REC to keep proper records on all
  electrical works carried out by him and his
  employees for 5 years.

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3.4 Electricity Ordinance Part 8

• The Performance Monitoring Point System (PMPS)
  was introduced and administrated by the
  Electrical and Mechanical Services Department of
  Hong Kong Government for monitoring the
  performance of REWs to ensure that the electrical
  work undertaken by them is in compliance with the
  undertaken by them is in compliance with the
  Electricity Ordinance, in particular to the
  Electricity (Wiring) Regulations. The system was
  effective on 1 January 1994. Details of defect
  items for use in the PMPS would be discussed in
  Chapter 10.

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3.5 IEE Regulations Development 1

• A) Development
• The 1st Edition published at 1882, the 15th
  Edition issued at 1981 but enforced by local
  power companies on 1.1.1985. The 15th Edition had
  a substantial change taking into account of the
  Harmonization Documents of European Committee for
  Electrotechnical Strandardization CENELEC) and
  was arranged according to the new plan for IEC
  Publication 364 Electrical Installation of
  Buildings. The 15th Edition was prepared by IEE
  Wiring Regulations Committee which was fully
  representative of all appropriate interests
  including contractors, manufactures, users,
  government departments, inspection authorities,
  etc. The 15th Edition contains 6 Parts and 17
  Appendices. From 1981 there are 5 amendments to
  the 15th issued by the Institution of Electrical
  Engineers, they are
• January 1983 Amendments
• May 1984 Amendments
• January 1985 Amendments
• January 1986 Amendments
• June 1987 Amendments.

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3.5 IEE Regulations Development 2

• The 16th Edition was issued on 10 may 1991. It
  superseded the 15th Edition from 1.1.1993. There
  are 7 Parts and 6 Appendices. A new Part 6
  concerning special installations and locations is
  added in this edition which includes the areas of
  swimming pools, highway power supplier, sauna
  heater, etc. However, some useful Appendices
  shown in 15th edition are removed but they will
  be published under separate covers IEE Guidance
  Notes for reference.

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3.5 IEE Regulations Development 3

• The 16th Edition gas incorporated the latest
  revisions and changes of CENELEC Harmonization
  Documents and most Parts have been rewritten for
  clarity. On 2 October 1992 the IEE Wiring
  Regulations were converted into British Standard
  BS76711992. A primary reason for the conversion
  of the contractors to comply with the EC
  utilities and public contracts directives, which
  required a national standard to be quoted for
  wiring installations in large contracts.

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3.5 IEE Regulations Purposes/ Objective 1

• B) Purposes/Objectives
• The Regulations is designed to protect persons,
  property and livestock against hazards arising
  from an electrical installation. It deals with
  electrical installation with emphasis on the
  safety of the user including the protection
  against electric shock, fire, burns, injury from
  mechanical movement of electrical equipment. It
  also provides general outline of the basis of
  good installation works, including planning and
  execution. Overall, the IEE regulations
  constitutes a valuable guide to safe construction
  and installation.

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3.5 IEE Regulations Purposes/ Objective 2

• The Regulations is usually classified as a
  non-statutory regulation. Although not legally
  enforceable, it is frequently quoted as the
  example of recommended practice and should be
  entirely referred to in an contract.

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3.5 IEE Regulations Purposes/ Objective 3

• The IEE Regulations is intended to be applied to
  general electrical installations at voltage range
  of Extra Low Voltage and Low Voltage buy the
  following types of installations are excluded
• Equipment of motor vehicles, aircraft, ships,
  etc.
• Railway traction and rolling stock equipment
• Lighting protection installations to BS6651
• Lift installations covered by BS5655
• Installations at mines

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3.6 Supply Rules 1

• The Supply Rules was issued by local power
  companies. It covers the general and technical
  terms and conditions upon which the power company
  will supply electricity. In other words, a
  consumer wished to obtain electricity from the
  power company, the installation shall abide by
  the Supply Rules.

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3.6 Supply Rules 2

• The Supply Rules is not intended to take place of
  a detailed specification. The object is to
  establish safety guidelines for a installation
  and maintenance of electrical equipment. In the
  event of conflict between the Supply Rules and
  IEE Regulations, the former shall take
  precedence.

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3.7 International Recognized Standards
Organizations 1

• A) British Standard Institution (BSI)
• An independent non-profit-making association
  incorporated by a Royal Charter in 1929
• The UK national standards making body and
  represents the UK in international standards.
• BSI publishes standards for a wide range of
  products and systems, including electrical
  equipment and components. The Codes of Practice
  are also issued by the BSI indicate standards of
  good practice which take the form of
  recommendations.

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3.7 International Recognized Standards
Organizations 2

• B) The International electrotechnical Commission
  (IEC)
• An international non-governmental organization
  whose members are the national electrotechnical
  committees (like the British Electrotechnical
  Committee representing U.K. in the organization.)
• The organization is responsible for
  standardization in the field of electrical and
  electronic engineering, and publication of IEC
  standards.
• Members exceed 40 countries and represent more
  than 80 of the worlds population.

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3.7 International Recognized Standards
Organizations 3

• C) European Committee for Electrotechnical
  standardization (CENELEC)
• An intermediate (between IEC BSI), regional
  level organization, and the members are mainly
  from European countries.
• The major aim is to remove technical differences
  between the CENELEC members by mutual agreement
  via Harmonization Documents.

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3.8 Certification 1

• Test certificates complete with type-test
  certificates and factory reports/ drawings, where
  applicable, shall be submitted to prove their
  electrical equipment are complied with the
  standards and suitable for use.

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3.8 Certification 2

• Type-test certificates are usually requested to
  be carried out by an Independent Testing
  Authority. Recognized international testing
  organizations are listed below for reference
• Association of Short Circuit Testing (ASTA)
• National Measurement Accreditation Service of UK
  (NAMAS)
• Hong Kong Laboratory Accreditation Scheme
  (HOKLAS)
• N.V. tot Keuring van Electrotechnische Materialen
  (KEMA)
• Association des Station dEssais Francaises
  dAppareillage (ASEFA)
• British Standards Institution (BSI)

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3.8 Certification 3

• Any products comply with BS Specifications may
  register with the trade mark BS (e.g. BS3676
  mark at the back of lighting switch plate) which
  describe a particular product or range of
  products manufactures in term of the required
  dimensions, performance and safety in accordance
  with the British Standard. The presence of the
  BSI Kite Mark on a product is an assurance that
  the product has been produced under a system of
  supervision, control and testing operated during
  manufacture and including periodical inspection
  of the manufacturers work which comply with the
  requirements of the relevant British Standards.

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3.8 Certification 4

• ASTA as the officially recognized UK
  certification authority for electrical
  installation equipment such as fuses, lighting
  switches, miniature circuit breakers (MCB),
  switchboards, etc. ASTA issues certificates for
  such products based on type testing to British
  Standards, IEC Standards and the recognized
  standards of other countries. Manufacturers can
  be licensed to use the ASTA Diamond Mark, which
  demonstrated compliance with a specified British
  Standard and involves both factory and market
  surveillance.

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3.8 Certification 5

• The UK certifying body for electric cables is the
  British Approvals Service for Electric Cables
  (BASEC). When you see the BASEC marks you know
  that the cable has been manufactured and tested
  to British Standards and have BASECs independent
  assurance within the scope of the scheme. The
  BASEC mar is usually applied to the sheath, or
  a core of a cable. The BASEC HAR mark will also
  be given in the case of cables meeting harmonized
  international standards.

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Q A
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The End