Fixed Wire Testing requires the isolation of the electrical supply at various times during the inspection. This will cause disruption to the people in a building and for this reason is something that requires careful planning.
A full survey of an installation prior to the commencement of any inspection and testing programme will enable discussions between the client and the contractor and will help to ensure that any disruption will be kept to a minimum.
In practice it is often advisable to arrange for inspection and testing to take place outside of normal working hours, either overnight or at weekends. This will allow more or less free access to the installation without concern for the productivity or the Health & Safety of the users in the building.
There may still be concerns regarding IT Systems, Servers, Telephony Systems and Building Management Systems which will not react well to sudden power downs. These issues are best dealt with by careful planning of the timing of testing in critical areas and working in conjunction with IT Departments and any other interested parties.
Many contractors will not charge a premium for working out of hours because this generally enables them to inspect and test an installation more quickly and efficiently without the need to 'work around' the users of the building.