The inspection of any electrical installation should almost always be carried out with the supply disconnected. 

Inspectors have been known to remove accessories  and consumer unit covers whilst the supply is energised. Such dangerous practice can lead to unnecessary risk of electric shock and is considered unacceptable.

The inspection of an electrical installation should always be carried out in a safe manner. Indeed, Regulation 611.1 of BS 7671 requires that inspection precedes testing and is normally to be done with that part of the installation under inspection disconnected from the supply.

Regulation 14 of the Electricity at Work Regulations requires that '…no person shall be engaged in any work activity on or so near any live conductor (other than one suitably covered with insulating material so as to prevent danger) that danger may arise unless':

a)   it is unreasonable in all circumstances for it to be dead; and

b)   it is reasonable in all circumstances for him/her to be at work on, or near it, while it is live; and

c)   suitable precautions (including where necessary the provision of suitable protective equipment) are taken to prevent injury.

Because anything other than a superficial external inspection will require covers and accessories to be removed, an inspector should not work on or near exposed live parts of a circuit that could reasonably be isolated from the supply and made dead. Isolation of a circuit(s) must therefore precede inspection.

The recommended safe isolation procedure to be followed is that published in the Electrical Safety Council’s Best Practice Guide 2, which is accessible and free to download at www.esc.org.uk