Periodic inspection and testing forms part of the routine maintenance programme for any electrical services on a site. Intersafe's Adrian Pendle warns of common mistakes.
8 October 2015 | By Adrian Pendle
Periodic inspection and testing involves testing the electrical services and systems that conduct electricity around a building.
It covers all the fixed wiring in a building and includes items such as main panels, distribution boards, lighting, socket outlets, air conditioning and other hard-wired plant. It also involves performing a sequence of rigorous visual inspections and electrical tests on all systems in a building.
The frequency of such inspection will vary depending on the type of installation. For instance, for educational establishments the maximum period between inspections and testing is five years, whereas for leisure complexes it is three years. You may have heard Periodic inspection and testing also referred to as:
- Fixed wire testing
- Electrical inspection condition report (EICR)
- Fixed installation testing
- Hard wire testing
- Test and inspection
- Fixed testing
- Electrical testing
Electricity at Work Regulations 1989
Employers are responsible for ensuring the health and safety of both their employees and members of the public on site and to ensure that they are not at risk from their work activities. Regulation 3 of the Electricity at Work Regulations 1989 recognises a responsibility that employers and many employees have for electrical systems:
"It shall be the duty of every employer and self-employed person to comply with the provisions of the Regulations in as far as they relate to matters which are within his control."
It shall be the duty of every employee while at work:
(a) to co-operate with his employer so far as is necessary to enable and duty placed on that employer by the provision of the Regulations to be complied with: and
(b) to comply with the provision of these regulations in so far as they relate to matters which are within his control.
When inspection and testing is being carried out there is a requirement for parts of the installation to be isolated for periods of time. It is often advisable to perform testing out of hours so that disruption to the client and staff on site can be kept to a minimum. This type of electrical testing is a legal requirement and so getting it right is crucial. But mistakes can be made. Here are the six most common avoidable ones:
Making sure that cable sizes are correct when carrying out
periodic testing and inspection is crucial. An inspector could assess a cable size incorrectly, which in turn could make the protective device unsuitable. An unsuitable protective device could enable a cable to carry more load than it is capable of. This causes the cable to melt - a common cause of electrical fires.
It is vital that any current-using equipment is disconnected when carrying out an insulation resistance test. If it isn't it could lead to electronic equipment being damaged or destroyed. To minimise the risk, carry out the test at 250 volts first to get an indication if anything is still on the circuit, then complete the full 500V test. It is difficult to isolate all electronic equipment during periodic inspection and testing because of the amount of equipment still in the circuit - lights, heaters and neons. For this reason we mainly focus on the neutral earth IR test which finds any faults most over current devices don't detect except for residual current devices (RCDs).
Relying on previous board schedules
When you look at a circuit board for the first time you assume that the labelling is correct. If a switch is labelled lights you assume that it means lights. But the board schedule might not be right; it may have been incorrectly labelled. Using circuit charts when carrying out periodic inspection and testing is useful as it ensures that your board schedule is correct and up to date. Out-of-date and inaccurate board schedules are not only dangerous to electrical contractors because of the danger in assuming a circuit has been isolated for working on, but also for end users trying to re-energise a trip circuit.
A circuit may have had additions since installation, for instance, extra sockets that have been installed incorrectly. This could mean that alterations to the original circuit might not be as standard or as first installed. When carrying out periodic testing and inspection the first things to look for are alterations, as these could cause faults.
The mains switch
Inspectors can find that the mains switch in a building has not been turned off or operated for a long time, sometimes nearly 10 years! This means that when they come to operate the switch, there may be problems switching it back on again. Mains switches don't just deliver power; their job is to interrupt power as well. The mains switch should be serviced regularly as this can lead to unforeseen problems when it comes to testing.
Inspectors can sometimes find that Tenby clamps have been used on SWA cables. This should absolutely not be the case as the clamp can crush the cable. Tenby clamps should only be used on water and gas pipes.
Adrian Pendle is director at Intersafe