Initial Verification Inspection Testing Procedures

by Steve on July 1, 2011

Electrical Inspection and Testing is a vital part of maintaining the safety of an electrical installation. This article offers an overview of the sequence of electrical testing procedures as given in Guidance Notes 3 for new work initial verification to comply with BS7671.

Important.  This article is an overview of the requirements for electrical testing and inspection. BS 7671 and the Guidance Notes are definitive and should always be consulted to verify information obtained from this website.

Safety Concerns

Electrical testing involves an element of risk and the IEE Regulations include the requirements for Health and Safety regarding Competent Persons and Safe Isolation. Anyone carrying out inspection and testing has a duty to ensure the safety of themselves and others.

Competent Persons

The definition of a Competent Person can be found in Part 2 of BS7671 and would be reasonably need to meet all of the following requirements:

  • Possess enough experience and technical knowledge to avoid danger to themselves and others by following Safe Isolation and Testing Procedures
  • Be skilled and familiar with the testing procedures and safe operation of appropriate test instruments
  • Have a knowledge of the current requirements of BS7671 relevant to the type of installation for inspection and testing
  • Be in possession of enough information about the installation to enable them to carry out the work safely. This would include being able to re-instate the installation in a completely safe and serviceable state after the inspection and testing is completed.

Safe Working

Regulation 611 requires that testing and inspection procedures should normally be carried out with the relevant circuits or that part of the installation disconnected from the supply.  Any work must be carried out with regard to the Electricity at Work Regulations LINK which clearly refers to any work activity near ‘live’ conductors.

Initial Verification Testing Procedures for New Installations

Guidance Notes 3 states that new installation tests or Initial Verification should be carried out in the following sequence where relevant:

  1. Continuity of protective conductors, including main and supplementary bonding
  2. Continuity of ring final circuit conductors
  3. Insulation resistance
  4. Protection by SELV, PELV or by electrical separation
  5. Protection by barriers or enclosures provided during erection
  6. Insulation Resistance of non-conducting floors and walls
  7. Polarity
  8. Earth Electrode resistance
  9. Protection by Automatic Disconnection of the Supply (ADS)
  10. Earth Fault Loop Impedance
  11. Additional Protection
  12. Prospective Fault Current
  13. Phase Sequence
  14. Functional Testing
  15. Voltage Drop

Periodics and Electrical Installation Condition Reports

The testing procedures for Periodic Inspections or Condition Reports (EICRs) may not be the same as for initial verification. This may be due to circumstances beyond the control of the inspector where parts of an installation are not accessible or are unable to be safely isolated.  Find an overview of tests at: Periodic Inspection Testing Procedures.

Reference and Guidance

Guidance Note 3 is an indispensable reference source for anyone carrying out the inspection and testing of electrical installations.  It covers all aspects of the required  electrical testing procedures in detail such as Test Methods 1 (R1+R2)  and 2 (R2) which are alternative ways of testing the continuity of protective conductors including main and supplementary equipotential bonding.


If you need to get trained up and qualified for electrical inspection and testing here are the related C&G courses.

C&G 2392 – Fundamental Inspection & Testing- 4 day course

C&G 2391-10 – Advanced Inspection & Testing- 4 day course

C&G 2391-20 – Design & Verification

C&G 2399-01, C&G 2399-11 and C&G 2399-12
Installing & Testing Domestic Photovoltaic (PV) Systems Certificate.
This is for electricians wishing to self-certify solar PV installations through the NIC’s MCS Installer Scheme. 4 day course

Be sure to check out your local colleges and training centres for more info and exact pricing of their specific City & Guilds electrical inspection and testing training courses.


{ 1 comment… read it below or add one }

Benn Lloyd June 3, 2015 at 08:43

I am very inspired by this post. It has told me a lot about initial verification.

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