Part P BS 7671 IET Wiring Regulations 1 — Questions and Answers
Question 1: What is the full title of BS 7671?
- Requirements for Electrical Installations (IET Wiring Regulations) (Correct answer)
- British Standard for Safe Electrical Practice
- Institute of Electrical Engineers Code of Practice
- National Wiring Standard for Domestic Properties
Correct answer: Requirements for Electrical Installations (IET Wiring Regulations)
BS 7671 is titled 'Requirements for Electrical Installations' and is published by the IET (Institution of Engineering and Technology), commonly called the IET Wiring Regulations.
Question 2: Which edition of BS 7671 is currently in force in the UK?
- 18th Edition (2018, with amendments) (Correct answer)
- 17th Edition
- 16th Edition
- 19th Edition
Correct answer: 18th Edition (2018, with amendments)
The 18th Edition of BS 7671 came into force in January 2019 (with subsequent amendments); it is the current standard for electrical installations in the UK.
Question 3: What is the purpose of BS 7671?
- To provide requirements to protect persons, property and livestock against hazards from electrical installations (Correct answer)
- To specify electrical product manufacturing standards
- To certify electrical engineers
- To regulate the electricity supply industry
Correct answer: To provide requirements to protect persons, property and livestock against hazards from electrical installations
BS 7671 sets out the requirements for designing, erecting and verifying electrical installations to protect persons, property and livestock from dangers arising from those installations.
Question 4: What is Regulation 110.1 of BS 7671 concerned with?
- The purpose, scope and fundamental principles of the regulations — protecting against shock, fire and burns (Correct answer)
- Cable sizing calculations
- Testing procedures
- Consumer unit specifications
Correct answer: The purpose, scope and fundamental principles of the regulations — protecting against shock, fire and burns
Part 1 of BS 7671 (including Regulation 110.1) sets out the scope, object and fundamental principles of the regulations, stating the purpose of providing protection against electric shock, fire, burns and other hazards.
Question 5: What does 'SELV' stand for in BS 7671?
- Separated Extra-Low Voltage (Correct answer)
- Safety Extra-Low Voltage
- Standard Electrical Low Voltage
- Switched Extra-Low Voltage
Correct answer: Separated Extra-Low Voltage
SELV stands for Separated Extra-Low Voltage — a system operating at low voltage (below 50 V AC or 120 V DC) that is electrically separated from earth and other systems, providing inherent protection against shock.
Question 6: What is the maximum AC voltage that defines 'extra-low voltage' in BS 7671?
- 50 V AC (or 120 V ripple-free DC) (Correct answer)
- 110 V AC
- 25 V AC
- 12 V AC
Correct answer: 50 V AC (or 120 V ripple-free DC)
Extra-low voltage (ELV) is defined in BS 7671 as not exceeding 50 V AC or 120 V ripple-free DC between conductors, or 50 V AC / 120 V DC to earth.
Part P BS 7671 IET Wiring Regulations 1
What is the full title of BS 7671?