Title: Standards and Basic Equipment
1Standards and Basic Equipment
2Schedule
3Introduction
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
4- Example 1 Load Assessment
- Example 2 Load Assessment Practice
- Addition Information Drawings
- 1. Electrical Equipment
- 2. Terminology
- 3. Code Standard
5Example 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)
6Example 1a
Total Connected Load
7Example 1b
Maximum Demand
8Example 2 Load Assessment (Practice)
9(No Transcript)
10Addition Information Drawings
- Schematic Diagram
- Layout Drawings
- Design Drawings
- Working Drawings
- Combined Services Drawings
111. Electrical Equipment
A) Transformer
12A1) One Transformer and 11kV Switchgear in High
Rise Building
13A2) Three Transformers and 11kV Switchgear in
High Rise Building
14A3) Minimum Requirements for the Customers
Switchroom Adjacent to Substation for
Multi-transformer Installation
15E) MCCB
D) Fuses Combination Unit (Switch Fuse)
B) Switch Board
C) ACB
161. Electrical Equipment
- B) Factory-built-assembly (Switchboard)
17Typical forms of separation by barriers of
partition
181. Electrical Equipment
- C) Air Circuit Breakers (ACB)
191. Electrical Equipment
- D) Fuse Combination Units and Switch-disconnection
s
201. Electrical Equipment
- E) Moulded Case Circuit Breakers (MCCB)
21I) KWH Meter
H) MCB
F) Busbar Riser
G) MCB Distribution Board
221. Electrical Equipment
231. Electrical Equipment
- G) MCB Distribution Boards
241. Electrical Equipment
- H) Miniature Circuit Breakers (MCB) - 1
251. Electrical Equipment
- H) Miniature Circuit Breakers (MCB) - 2
261. Electrical Equipment
27L) Lighting Switch M) Lampholder N) Socket
Outlet O) Connection Unit
K) RCCB
J) Consumer Unit
281. Electrical Equipment
291. Electrical Equipment
- K) Residual Current Circuit Breakers (RCCB)
301. Electrical Equipment
311. Electrical Equipment
321. Electrical Equipment
331. Electrical Equipment
341. Electrical Equipment
351. Electrical Equipment
362. 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.
372. 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.
382. 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.
392. 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
402. 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
412. 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.
422. 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.
432. 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.
442. 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.
452. Useful Terminology - 10
- Extra Low Voltage
- Voltage normally not exceeding 50V a.c. or 120
d.c., whether between conductors or to earth.
463.1 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.
473.2 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
483.3 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.
493.4 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.
503.4 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
513.4 Electricity Ordinance Part 3
523.4 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.
533.4 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.
543.4 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.
553.4 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.
563.4 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.
573.5 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.
583.5 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.
593.5 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.
603.5 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.
613.5 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.
623.5 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
633.6 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.
643.6 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.
653.7 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.
663.7 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.
673.7 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.
683.8 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.
693.8 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)
703.8 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.
713.8 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.
723.8 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.
73Q A
74The End