Ensuring the safety of electrical installations

No health and safety manager responsible for maintaining the safety of electrical installations can ignore the requirements of the 17th Edition wiring regulations, explains Jim Wallace of Seaward.

BS 7671 (The IEE Wiring Regulations) are the national standard to which all domestic and industrial wiring must conform.

The 17th Edition contains substantial changes to align with European harmonisation documents and came into force on 1 July 2008.

The introduction of the 17th Edition does not automatically mean that installations complying with previous editions are unsafe or need to be upgraded, but the new standard will apply to all new electrical installations and alterations.

In health and safety terms, compliance with BS7671:2008 is regarded as an acceptable means of demonstrating compliance with the Electricity At Work Regulations 1989.

Although there continues to be seven parts to the regulations, in a different order than previously, the updated version has been completely restructured and adopts the IEC numbering system.

Many of the chapters have been completely rewritten and many of the changes are technically complex.

Under 'protection against electric shock', for example, the terms direct contact and indirect contact have been replaced with basic protection (against touching live parts) and fault protection (from conductive parts that have become live due to an earth fault).

There are more stringent electromagnetic compatibility (EMC) requirements and harmonisation of bathrooms.

A section has been added on luminaires and lighting installations for interior and exterior lighting installations, including highway power supplies and street furniture.

In addition, seven new special locations have been introduced to address the risk associated with certain environments or facilities including marinas, exhibition areas, solar-powered systems, mobile units and temporary installations such as amusement parks and fairground booths.

There are also important changes to terminology and definitions with the 17th Edition incorporating 90 additional definitions alongside the original 170 in the 16th Edition.

Among the changes to the scope and fundamental principles of the regulations is the inclusion of four new regulations for the protection of persons and livestock against voltage disturbances and electromagnetic influences.

There is also a specific requirement for appropriate documentation for all installations.

Of particular interest to the health and safety manager, Regulation 134.2.1 requires that inspection and testing must be carried out by a 'competent person' to verify that standards have been met.

Importantly, a 'competent person' is defined as someone 'who possesses sufficient technical knowledge and experience for the nature of the electrical work undertaken and is able at all times to prevent danger, and where appropriate, injury to themselves and others'.

In practice, this means that inspection and testing should only be taken by experienced engineers that are qualified to the City and Guilds 2392 - 10 course 'Fundamental Testing, Inspection and Initial Verification'.

This course is now recognised as the qualification for competent persons carrying out initial inspection and testing of electrical installations.

For periodic inspection and testing, competent persons should successfully complete the C and G 2392 - 20 'Inspection, Testing and Certification of Electrical Installations' course in addition to the 2392 - 10 course.

Once the initial verification of the installation has been completed, which includes both inspection and testing, the regulations call for the issuing of an Electrical Installation Certificate, together with a schedule of test results and a schedule of inspections.

The certificate includes space for three signatures - the person responsible for the design, the person responsible for the construction and the person carrying out the inspection and test of the installation.

It should be emphasised that the signature for the inspection and test section is the person who actually carries out the inspection and test and not someone else who may be in authority.

In some cases, all three sections may require signature by the same person and this is perfectly acceptable.

However, the Electrical Installation Certificate should not be signed until any defects identified by the person responsible for inspection and test have been corrected.

An Electrical Installation Certificate (or a Minor Electrical Installation Works Certificate), stating the extent of the works covered, shall be issued once the inspector is satisfied that the works comply with the regulations.

Any defects found in related parts of the installation, not affecting the safety of the alteration or addition should be reported in writing to the person ordering the work.

If existing defects affect the new work then these defects need to be corrected before an Electrical Installation Certificate can be issued and before the new work can be put into service.

An example of this is where bonding or equipotential bonding is inadequate or omitted, as this would seriously affect the safety of the whole installation, including the new work.

The Electrical Installation Certificate should not be used for periodic inspections.

The 17th Edition regulations stipulate that the designer of the installation is responsible for specifying the interval to the first periodic inspection and test.

There is also the positive recommendation (Regulation 135.1) that every electrical installation is subject to periodic inspection and testing by a competent person (in accordance with Chapter 62).

For example, the IEE Guidance Note for periodic fixed installation test frequencies advise a maximum period of five years between inspections and testing for commercial offices, shops and hospitals - reducing to three years for industrial facilities, leisure complexes and theatres.

For some special installations, such as swimming pools, petrol stations and caravan parks, the maximum period between inspections and testing is one year.

This represents a substantial difference from the previous edition, which presumed that a programme of risk assessments, records and preventative maintenance could be adopted in place of periodic testing.

The Periodic Inspection Report form is only to be used for the inspection of an existing installation and should include both inspection and test results.

Again the extent and limitations of the report needs to be stated and recommendations of defects and their remedies should be made.

The report includes a numbering system for this purpose, as follows: 1 - Requires Urgent Attention; 2 - Requires Improvements; 3 - Requires Further Investigation; and 4 - Does Not Comply With BS 7671:2008 (although this does not necessarily imply that the electrical installation is unsafe).

Several associations and trade bodies allow the issuing of a Minor Works Certificate.

A minor works is defined as 'work which does not include the provision of a new circuit'.

Testing is still essential and a number of tests are specifically identified as essential to confirm safety.

Also included on the form is space to allow the inspector to comment on the existing installation.

In a practical sense, for most electrical contractors involved in installation testing, the most frustrating part of the job is the recording of test data onto test certificates.

Invariably, current working practices involve the printing out or copying of a certificate for all premises to be tested at the beginning of the working day.

As circuit testing is undertaken on site the electrician will then usually record details of the inspection with written information on the 'dummy' certificate.

At the end of the day, back in the office, the manually recorded results will then be transferred to an 'original' certificate for the customer.

Because of the cumbersome and time-consuming nature of this process, a number of other alternative test and recording systems have been introduced.

The most common is the use of a PDA onto which a copy of the certificate has been pre-loaded.

As wiring results are made, the data is stored on the PDA and then transferred to a desktop application, for the output of test certificates.

Smart phone and portable laptop applications work in the same way by transferring data gathered in the field, via an intermediary device, back to the host computer where the master certificates are held.

In all of these existing approaches there are clear inefficiencies of working time and the associated risk of human error associated with the manual recording or transfer of test data.

There are also cost and ergonomic considerations - such as whether a contractor should need to purchase and carry a tester and a PDA, or how an electrician successfully holds and operates the tester, test leads and a PDA while recording the results at the same time.

In addition, with these established test and certification processes it is difficult and time consuming to perform verification of data while on site and there is reduced traceability of results - particularly with handwritten records.

Overall, existing installation test and certification systems can therefore be inefficient and are not cost effective - an important consideration when the electrician is expected to carry out dozens of tests, often in tight time scales to meet productivity targets.

To address the issues a new test concept has been introduced in the shape of the Powerplus 1557.

This tester incorporates an electronic copy of the inspection and test certificate enabling measured circuit values to be automatically placed in the correct fields of the onboard documentation.

Once all inspection and test data has been collected, the software scans the certificate and warns the user if any fields appear to be incomplete or invalid.

The certificate assistant also holds many of the commonly used tabulated values, such as earth loop impedance tables, avoiding the need to take bulky reference material onsite.

When inspection and testing is complete, the certificate held inside the tester can be transferred to the accompanying PC software for completion, printing or supply in electronic format to customers in line with the 17th Edition wiring regulations.

This in turn provides improved operating efficiencies, greater security and protection of intellectual property - all significant concerns for the health and safety manager seeking compliance with the 17th Edition wiring regulations.

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