Periodic Electrical Installation Inspection – What to Inspect? 

By on

This is the second post in a series of two on periodic electrical inspections. In the first post, I discussed how often inspections should be carried out. If you missed that post, you may want to read it now:

Periodic Electrical Installation Inspection
– How Often?

As with how often, when looking at what to inspect there are two considerations – 1) inspection of systems, which businesses themselves have decided are critical to their operation and 2) the minimum systems which need to be inspected according to regulations.

The aim of any inspection is to ensure that the equipment is still maintaining the safety of persons, protecting equipment and property, providing the correct level of business continuity and has not been damaged or subject to defects.

Regulations such as the IEE Wiring Regulations in the UK and the National Electric code in the US give guidance on the level and detail of the inspection. Regulations tend to deal predominately with the safety of persons and property. Depending on the nature of the installation, it may be prudent for the owner to go beyond regulation by carrying out additional inspections to ensure business continuity.

Inspections will consist of visual investigations, supplemented by testing (for example checking the disconnection of times of protective relays).

  • In the UK, IEE Guidance Note 3, Inspection & Testing, lists items which should be considered for inclusion in any inspection and testing routine:
    • Inspection – joints, conductors , switchgear, fire barriers, extra low voltage systems, basic protection, protective devices, enclosures, marking and labelling
    • Testing – protective/bonding/ring-circuit conductor continuity, insulations resistance, polarity, earth electrode resistance, earth fault loop impedance and functional tests (RCD, circuit breakers)

In determining the extent of inspection and testing, considerable care needs to be taken to ensure everything is covered. On large installations, inspection and testing may cover a sample of the system – with subsequent inspections covering different portions of the system.

Inspections and testing will be carried out around live equipment and only suitably qualified personnel should be doing this work. Records and test results should be kept to verify that periodic inspections have been carried. Inspection and testing records can also be compared across time to evaluate changes in systems and aid in planning maintenance.



Steven McFadyen's avatar Steven McFadyen

Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author

myElectrical Engineering

comments powered by Disqus



DC Component of Asymmetrical Faults

The image (reproduced from IEC 60909) shows a typical fault in an ac system.  From the illustration it can seen that there is an initial dc component ...

Smarter Electrical Distribution

The other day I came across an article in Technology Review on the development of a smart transformer. A professor at North Carolina State University is...

Motor Insulation

Insulation on a motor prevents interconnection of windings and the winding to earth.  When looking at motors, it is important to understand how the insulation...

Restricted Earth Fault Protection

The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...

110 or 230 Volts

I've been considering a blog on the 110 or 230 Volt issue for a while.  While browsing the Internet I came across a great summary by Borat over at  engineering...

Always Use PPE

A lot of our members work in countries where PPE (personal protective equipment) is regulated or they work for companies/organizations which take employee...

A mechanical engineering paper, some history and memories

I was digging in my bookshelf and came across the 80th Anniversary Association of Mine Resident Engineers, Papers and Discussions Commemorative Edition...

Microsoft OneNote

A couple of months ago I came Microsoft's OneNote and downloaded the 60 day free trail. Since then I have been using it regularly and now have a full license...

Wiki Depreciation

We have had the Wiki with us for a long time now, but at last I have decided to say bye bye – more details on why below.

LED Replacement Light Bulb

The inventor of the first visible light-emitting diode makes history again this year as it begins to show customers a 40-watt replacement GE Energy Smart...

Have some knowledge to share

If you have some expert knowledge or experience, why not consider sharing this with our community.  

By writing an electrical note, you will be educating our users and at the same time promoting your expertise within the engineering community.

To get started and understand our policy, you can read our How to Write an Electrical Note