Which document is BS 7671:2018+A2:2022 most commonly known as in the UK electrical industry?
Scope Object Fundamental Principles
Question · Easy
BS 7671 is divided into how many numbered Parts?
Question · Medium
Which Part of BS 7671 contains the requirements for inspection and testing?
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In BS 7671, what does the term 'live part' mean?
What is the BS 7671 definition of an 'exposed-conductive-part'?
Which of the following is an example of an extraneous-conductive-part?
What is the standard nominal supply voltage for a single-phase 230 V installation in the UK, as used in BS 7671?
Under the fundamental principles in Part 1 / Chapter 13, what must be considered for every installation before work begins?
BS 7671 generally applies to circuits supplied at nominal voltages up to and including which value AC?
In BS 7671 voltage band terminology, into which band does Extra-Low Voltage (ELV) fall?
Which colour identifies the line conductor of a single-phase AC circuit under BS 7671 harmonised cable colours?
In a three-phase installation using harmonised colours, what are the line conductor colours for L1, L2 and L3?
Which earthing system has the supply neutral and earth combined in a single conductor for part of the network and separated at the origin of the installation?
Assessment General Characteristics
In which earthing system is the means of earthing for the installation provided by an earth electrode at the consumer's premises, independent of the supply neutral?
The first letter in an earthing system designation such as TN-S indicates what?
What does 'Ze' represent when assessing the characteristics of a supply?
Which Part of BS 7671 deals with the assessment of general characteristics such as maximum demand, supply arrangements and external influences?
External influences in BS 7671 are classified using a code. In the code AD4, what does the first letter 'A' denote?
Question · Hard
When determining maximum demand for a domestic installation, what allowance is applied to reflect that not all loads operate at full current simultaneously?
The protective measure 'Automatic Disconnection of Supply' (ADS) is described in which Chapter of BS 7671?
Protection For Safety
Under ADS, what is the maximum disconnection time for a 230 V final circuit not exceeding 32 A in a TN system?
In a TN system, what is the maximum disconnection time for a distribution circuit and circuits over 32 A?
Which of the following is a measure providing BASIC protection against electric shock?
Additional protection by a 30 mA RCD is required for which of the following in most installations under Amendment 2?
What is the rated residual operating current (IΔn) of an RCD used to provide additional protection against electric shock?
Where a 30 mA RCD provides additional protection, what is the maximum operating time at a residual current of IΔn for a general-purpose (BS EN 61008/61009) RCD?
Cables concealed in a wall or partition at a depth of less than 50 mm and not in a permitted zone must additionally be protected by what, where the installation is not under the supervision of skilled persons?
The maximum earth fault loop impedance (Zs) values for circuit-breakers in Table 41.3 are based on disconnection within what time for a final circuit?
A measured Zs taken at ambient temperature must be corrected before comparing with the tabulated maximum Zs. A common rule of thumb is to multiply the tabulated value by what factor (or compare against 80% of it)?
Protective measure SELV requires which of the following?
What is the key difference between SELV and PELV systems?
Chapter 42 deals with protection against thermal effects. Which device or feature was made a requirement by Amendment 2 to protect against fire caused by series and parallel arcing?
Protection against overcurrent (Chapter 43) covers which two types of overcurrent?
For overload protection, the coordination condition requires the design current (Ib), the protective device rating (In) and the cable's current-carrying capacity (Iz) to satisfy which relationship?
A Type B circuit-breaker to BS EN 60898 will operate in the instantaneous (magnetic) region at a current of approximately how many times its rated current (In)?
What does the breaking capacity (Icn or Icu) of a protective device represent?
Which chapter of BS 7671 was substantially updated to require surge protection devices (SPDs) to be considered for protection against transient overvoltages?
Fault protection by protective earthing and automatic disconnection relies on a low-impedance path so that a fault current causes the protective device to operate. Which connection ensures exposed-conductive-parts are tied to the main earthing terminal?
Class II equipment provides protection against electric shock by what means?
In a TT system, fault protection is normally achieved by which device because the earth-fault loop impedance is typically too high for an overcurrent device to disconnect in time?
Which Part of BS 7671 covers the selection and erection of equipment, including wiring systems, isolation and switching, and earthing arrangements?
Selection Erection Equipment
An IP rating such as IP44 describes the degree of protection of an enclosure. What does the FIRST numeral indicate?
What is the maximum permitted voltage drop, as a percentage of the nominal supply voltage, for a lighting circuit in an installation supplied directly from a public low-voltage network (Appendix 4 / Appendix 12 guidance)?
When a wiring system is grouped with other circuits, the current-carrying capacity must be adjusted using which type of factor from Appendix 4?
Chapter 53 requires a means of isolation. What is the defining feature of an 'isolator' (disconnector)?
For a PME (TN-C-S) supply with a 25 mm² supply neutral, what is the minimum copper cross-sectional area of the main protective bonding conductor, per Table 54.8?
Where the cross-sectional area of the line conductors is 16 mm², and the cpc is of the same material, what is the minimum CSA of the circuit protective conductor using the simple selection method in Table 54.7?
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