303 #2 - Supply Systems & Earthing Arrangements Quiz

Which of the following is a three-phase voltage in the UK?

• 230V

• 110V

• 400V

• 500V

What does TN-S stand for in an earthing system?

• Transformer-Neutral Separated

• Terra-Neutral Split

• Terra-Neutral Separate

• Twin-Neutral System

In a TT system, what provides the earth connection?

• The supply authority

• A rod or electrode installed by the contractor

• The neutral conductor

• The metallic sheath of the cable

Which supply system shares the neutral and earth conductor?

• TN-S

• TT

• TN-C-S

• IT

What does the 'C' in TN-C-S represent?

• Copper

• Combined

• Current

• Circuit

What type of installation is most likely to use a TT system?

• Large retail park

• Rural property with no reliable earth from the DNO

• Urban office block

• Warehouse with substation

Which of the following is an advantage of a TN-S system?

• Cheapest install cost

• No need for main bonding

• Reduced interference and separate earth conductor

• Works without earth

The earth and neutral conductors in a TN-C-S system are shared up to:

• The socket outlet

• The consumer unit

• The light fitting

• The transformer

What colour is typically used for protective conductors?

• Red

• Blue

• Green/yellow

• Black

Which regulation section of BS7671 deals with earthing arrangements?

• Chapter 42

• Chapter 43

• Chapter 54

• Appendix 2