Sequence of Test in Electrical Inspection and Testing

The tests to be carried out, where relevant, during the initial verification of new installations are listed in BS 7671 as follows:

  • A Continuity of protective conductors including main and supplementary equipotential bonding, Reg. 612.2.1 
  • B Continuity of ring final circuit conductors, Reg. 612.2.2
  • C Insulation resistance, Reg. 612.3
  • D Protection by SELV, PELV or electrical separation, Reg. 612.4
  • -Protection by SELV, Reg. 612.4.1
  • -Protection by PELV, Reg. 612.4.2
  • -Protection by electrical separation, Reg. 612.4.3
  • E Basic protection by a barrier or enclosure provided during erection, Reg. 612.4.4 
  • F Insulation resistance/impedance of floors and walls, Reg. 612.5 
  • G Polarity, Reg. 612.6 
  • H Earth electrode resistance, Reg. 612.7 
  • I Protection by automatic disconnection of the supply, Reg. 612.8 
  • J   Earth fault loop impedance, Reg. 612.9 
  • K   Additional protection, Reg. 612.10 
  • L  Prospective fault current, Reg. 612.11 
  • M Check of phase sequence, Reg. 612.12 
  • N   Functional testing, Reg.612.13 
  • O   Verification of voltage drop, Reg. 612.14 

Reg. 612.1   requires that tests A to G, where relevant, must be carried out in that order before the installation is energised.
The resistance of any earth electrodes, test H, must he measured before the installation is energised, Reg. 612.1.