BS 7671 Part 1

Who can carry out an initial verification of an installation? Mark one answer

• A. A member of the public

• B. A skilled competent person

• C. An instructed person

• D. The owner of the installation

Answer explanation

Page 27 - 134.2.1 - You are answering a Part 1 question so look in the Part 1 Contents, page you will see section 134.2 is for 'Initial Verification' a quick browse to, page 27 you will find 134.2.1 'Inspection and testing shall be carried out by one or more skilled persons competent to verify that the requirements of BS 7671 have been met'

What is the maximum d.c. circuit voltage covered by the regulations BS 7671? Mark one answer

• 1000 V a.c.

• 1500 V a.c.

• 1500 V d.c.

• 230 V a.c.

Answer explanation

Page 20 - 110.1.2 (i) - The Part 1 contents, page does not provide any help here, so try the Index, on, page 555 under 'Voltage - Range covered by the Regulations' you are directed to 110.1.2 (i) and (ii)

Which of these methods is not achieving fault protection? Mark one answer

• Increasing the earth fault loop impedance to a high value

• Limiting the duration of a current resulting from a fault, which can pass through a body, to a non-hazardous value

• Limiting the magnitude of a current resulting from a fault, which can pass through a body, to a non-hazardous time period

• Preventing a current resulting from a fault passing through the body of any livestock

Answer explanation

Section 131.2.2 is located in, page 23. And by order of elimination of items that are true, the correct answer will be left.

Increasing the earth fault loop impedance to a high value does not achieve fault protection, as it can lead to lower fault currents and therefore longer disconnection times, increasing risk of electric shock.

What characteristic of the supply must be included in an electrical installation certificate? Mark one answer

• Details of the client

• Particular requirements of the distributor

• The material of the main protective bonding conductors

• The name and signature of the installer

Answer explanation

Page 24 - 132.2 (v)

What is the preferred range of frequencies in BS 7671?

• 25 Hz, 50 Hz, 60Hz

• 50 Hz, 100 Hz, 400 Hz

• 50 Hz, 400 Hz, 1000 Hz

• 50 Hz, 60 Hz, 400 Hz

Answer explanation

Page 20 -110.1.2 (i) the preferred range of frequencies are 50 Hz, 60 Hz and 400 Hz

Conductors shall be identified in accordance with?

• Section 512

• Section 513

• Section 514

• Section 515

Answer explanation

Page 27, section 134.1.3

BS 7671 includes requirements for?

• Electric fences installed on farm-land

• Lift installations in office blocks

• Wiring systems and cables not specifically covered by the standards for appliances

• Wiring systems on military aircraft

Answer explanation

Page 20, section 110.1.2 (iii) BS 7671 outlines standards for electrical installations, including wiring systems and cables not specifically covered by appliance standards, making this the correct choice.

BS 7671 is?

• Non-statutory and cannot be used as evidence to show compliance, in a court-of-law

• Non-statutory but can be used as evidence to claim compliance with a statutory requirement in a court-of-law

• Statutory and can be used as evidence to show compliance, in a court-of-law

• Statutory and cannot be used as evidence to show compliance, in a court-of-law

Answer explanation

Page 20, section 110.1.2 (iii) BS 7671 is non-statutory but can be used as evidence to demonstrate compliance with statutory requirements in court. This means it provides guidance but is not legally binding.

When designing an electrical installation, it is necessary to prevent mutual detrimental influences between the electrical installation and non-electrical installations, what should be taken into account?

• Electromagnetic interference

• The ambient temperature of the installation

• The earth fault loop impedance

• The short circuit current capacity

Answer explanation

Page 26, section 132.11 Electromagnetic interference is crucial to consider as it can adversely affect both electrical and non-electrical installations, leading to performance issues. The other options, while important, do not directly address mutual influences.

Where new materials are invented for use within electrical installations are departures permitted from BS 7671?

• No

• Sometimes when the designer feels he likes the new materials

• With supporting evidence that they are a lower standard than the regulations

• Yes providing the resulting degree of safety of the installation is not less than that obtained by compliance with the regulation

Answer explanation

Page 27, section 133.5

Departures from BS 7671 are not permitted unless the safety of the installation is maintained.