303 #9 – Installation Methods

What appendix of BS7671 covers current-carrying capacities and correction factors?

• Appendix 1

• Appendix 3

• Appendix 4

• Appendix 6

What does the installation method influence when designing a circuit?

• Type of RCD used

• Cable colour

• Current-carrying capacity

• Consumer unit size

What is meant by grouping factor?

• A regulation about group work

• A number used to multiply cable prices

• A correction factor when cables are run close together

• A minimum R1+R2 value

Which factor affects a cable installed in insulation?

• Ambient temperature

• Protective conductor size

• Derating due to heat retention

• Volt drop regulation

Which value is used when calculating volt drop?

• Ze

• mV/A/m

• Ib

• Insulation resistance

What is the volt drop limit for a final circuit supplying lighting (230V)?

• 10%

• 3%

• 5%

• 0.4%

If the run of a circuit is 30m, carrying 20A, and the volt drop per amp/metre is 11mV, what is the total volt drop?

• 3.3V

• 11V

• 6.6V

• 2.2V

What is the purpose of calculating correction factors like Ca, Cg, and Ci?

• To test resistance

• To confirm aesthetics

• To ensure cable safety in real installation conditions

• To match conduit size

Which of these is NOT a recognised installation method code in BS7671?

• 100

• A1

• C3

• B2

What tool is most commonly used to locate correction factors in design?

• Voltage drop calculator

• GN1

• BS7671 Appendix 4

• Building Regs Part P