City & Guilds News

2381 Requirements for Electrical Installations BS 7671: June 2001

1           Scope, Object and Fundamental Principles for Safety
           ( 4 Questions - 8% of Mark )

1.1        Identify examples of installations in the scope of BS 7671 and particular requirements               for specific installations and locations.
1.2        Identify those installations that are excluded from BS 7671.

1.4        State the requirements for installations in premises licensed under the statutory control             of an authoritative body.
1.5        State the requirements regarding the fundamental principles relating to protection for                safety, design, selection, erection and verification of electrical installation.

2          Definitions
           ( 2 Questions - 4% of Mark )

2.1       Use Part 2 of BS 7671.

3          Assessment of General Characteristics
            ( 8 Questions - 16% of Mark )
3.1        Identify those external influences that determine the selection of equipment and                       installation methods/techniques.
3.2        State the need to consider compatibility and maintainability in the selection of                           equipment.
3.3        State the need to divide an installation into suitable circuit arrangements.
3.4        Determine the number and types of live conductors for installation circuits.
3.5        State the source (eg standby, external) and characteristics necessary for a supply.

4          Protection for Safety
           ( 13 Questions - 20% of Mark )

4.1        Identify the differences between direct and indirect contact.
4.2        State means of protection against electrical shock
a           direct contact
b           indirect contact
c           both direct and indirect contact,
             (excluding IT)
4.3        Describe how the requirements for shock protection are affected by a         value of the                           external loop Impedance (Ze)
b          compliance with Zs = R, +R2 +Ze
c           compliance with tables 41 A, 41B1, 41B2, 41D.
4.4        Describe means of protection against fire, burns and harmful thermal effects.
4.5        Identify the difference between overcurrent and fault current
4.6        Describe methods of overcurrent and fault current protection and the need for
            co­-ordination with conductors and equipment.
4.7        State the difference between, and the requirements for
a           isolation
b         switching off for mechanical maintenance
c           emergency switching.
4.8        State the requirements for protection against
a           overvoltage
b         undervoltage.
4.9        Identify precautions where particular risks of danger of fire exists.

5         Selection and Erection of Equipment
          ( 15 Questions - 25% of Mark )

5.1        Identify the need for compliance with British Standards, or harmonised European                                          Standards and Codes of Practice.
5.2        State the effects that operational conditions and external influences have on the choice               of installation methods, materials and equipment.
5.3        State the effect of each of the following on the selection and erection of wiring systems
a         types of wiring system
b         external influences
c          current carrying capacity of conductors
d         cross-sectional area of conductors
e         voltage drop
f          electrical connections
g         minimising the spread of fire
h         proximity of other services
i          maintainability.
5.4      Use the following to determine conductor size, and select appropriate cable from                        Appendix 4
a         design current
b         over current protection
c         cable route
d         correction factors
e         volt drop limitations
f           diversity.
5.5        State identification requirements for live and protective conductors.
5.6        Describe the need for, and the, siting and wording requirements of warning notices and             labels.
5.7        Identify types of devices offering protection against overcurrent.
5.8        Describe earthing arrangements to facilitate earthed equipotential bonding and                                automatic disconnection of supply (EEBAD).
5.9        State the recognised types of earth electrode and their applications.
5.10      Determine, and select types and sizes of protective conductor for
a           main equipotential bonding conductors
b         supplementary bonding conductors
c          circuit protective conductors
d         earthing conductors.
5.11      Describe the protection offered by a
a           residual current device (red)
b         residual current plus overcurrent breaker (rcbo).
5.12      Describe the dangers in the use of equipment outside the equipotential zone.
5.13      State how electric shock protection is provided by
a           red protected socket outlets/circuits
b          the installation of an red in a TT system.
5.14      State that switchgear must be chosen with regard to the prospective fault current at the             point of installation.
5.15      State that cables are subject to electro-mechanical and electro-magnetic stress in                     addition to thermal damage under fault conditions.
5.16      Apply, BS7671 to the installation of transformers, rotating machines, accessories and                current using equipment.
5.17      State the requirements for supplies for safety services.
5.18      State requirements for generating sets.

6          Special Installations
           ( 7 Questions - 10% of Mark )

6.1        State the requirements for safety measures in a location containing bath shower.
6.2        State the special precautions that must be applied regarding swimming pools and                                paddling pools, and for protection against electric shock in hot air saunas.
6.3        Identify the requirements relevant to temporary installations within construction sites.
6.4        Identify the requirements relevant to installations within agricultural and horticultural                  premises and locations where livestock may be housed.
6.5        Identify the requirements for electrical installations in caravans, motor caravans and                   caravan parks.
6.6        Identify the requirements for installations comprising highway power supplies, street                    furniture and street located equipment.
6.7        Identify the requirements relevant to the installation of equipment having High                           Protective Currents.

7          Inspection and Testing
           ( 8 Questions - 12% of Mark )
7.1        Identify the items to be checked during the inspection.
7.2        State the need for diagrams, charts or tables to be available prior to the verification                  process.
7.3        Identify testing procedures.
7.4        State minimum values of insulation resistance.
7.5        State the requirements for inspection and testing of alterations and/or additions to an                 existing installation.
a           Electrical Installation Certificate
b         Minor Works Certificate
c           Periodic Inspection Certificate.
7.7        Identify the requirement for periodic testing.

8          Use of Appendices
           ( 3 Questions - 5% of Mark )

8.1       Apply relevant information/data within Appendices
a          British Standards to which reference is made in the Regulations
b         Statutory regulations and associated Memoranda
c         Time/Current characteristics of overcurrent protective devices
d         Current-carrying capacity and voltage drop for cables and flexible cords
e         Classification of external influences
f           Electrical Installation Certificate, Minor Works Certificate and Periodic