The importance of electrical testing verification
Correct electrical testing and verification is required on all projects, large or small.
Electrical safety is part of the building regulations covered under Part P; from this we have statutory regulations. These are the lawful duties placed on individuals and duty holders. Competent electrical contractors will be working to the current electrical non-statutory and statutory regulations to ensure their electricians are fully qualified and installations are to best practice.
Statutory regulations
- Health & safety at work act 1974 electricity at work regulations 1989 HSR 25
- Non- Statutory Regulations
- Guidance notes 1-8 by the IET
- BS 7671-2018+A2-2022 by IET
- BS 7671 On-site Guide by IET
- HSE GS38 – Electrical test equipment for electricians
No matter what electrical works are carried out, you should receive one of three electrical certifications. They are ether an electrical installation certificate, periodic inspection certificate or a minor works certificate.
An electrical installation certificate is for new installations, new circuits or major alterations.
A periodic inspection certificate is on an existing installation. We need this to ensure the installation complies with regulations, on change of occupancy, change of use of the premises, after additions or alterations where there is a significant change or where there is reason to believe that damage may have been caused.
A minor works certificate is when there are new circuits added and there are only minor additions.
The test that should be carried out is as follows.
- Dead testing
- Continuity of Protective Conductors, including main and supplementary bonding
- Continuity of Ring Final Circuit Conductors
- Insulation Resistance
- Site Applied Insulation
- Protection by separation of circuits
- Protection by barriers or enclosures provided during erection
- Insulation of non-conducting floors & walls Polarity
- Live testing Polarity
- Earth Electrode Resistance
- Earth Fault Loop Impedance (Ze & Zs)
- Prospective Fault Current
- Functional Testing (RCD test included)
Once the test sheets are submitted, it is important to get an independent witness to verify the testing results. This is because the results can change, and we want to ensure that the certificate is as accurate as possible.
The temperature can cause the figures to change, and additional parrel paths added to the circuit, incoming main Ze, changing electrical outlets and many more.
L&P Commissioning can check the electrical installation to ensure good practice and compliance to regulations has been achieved.
We will also review the electrical test certification prior to witnessing. We will check testing records to design calculations, cable sizing, breaker sizes & types, number of points and testing recorded results. We will also ask for any recording that stand out to be witnessed to ensure the correct testing procedure and data has been recorded. For larger installations and LV panels, we will ask to see the torque setting on bolts, tug testing of cables and terminations and correct labelling of the circuits.
For more information: https://lpgroup.co.uk/capabilities/commissioning/
Kyri Michael, Senior Commissioning Manager