How to ensure electrical equipment is safe

Rod Taylor, managing director of Seaward Electronic Ltd, looks at the safety of electric tools and equipment used in the industrial workplace.

Although there are legal duties on manufacturers and suppliers covering the integrity of new plant, tools and equipment, where electrical safety in the workplace is concerned, responsibility stops firmly with the employer.

HSE statistics show that in the five years between 1996/7 and 2000/1, 71 people were killed and 2804 people were inured at work in accidents involving electricity.

Earlier figures show that serious electrical related fires caused over GBP320million of damage between 1990 and 1995 - in one year alone 2000 fires were said to be caused by faulty leads to appliances.

It has been estimated that around a quarter of reportable electrical accidents involve portable tools and electrical equipment.

Records indicate that a large number of injuries - and, on occasion, even deaths - are due to electric shock from misused or faulty electrical equipment and most could have been avoided if proper electrical checking procedures had been applied.

The Legal Position: The Health and Safety At Work Act 1974 puts a duty of care upon both employer and employee to ensure the safety of all persons using the work premises.

The Provision and Use of Work Equipment Regulations 1998 (PUWER) requires employers to ensure that work equipment is so constructed, adapted and maintained to be suitable for the task for which it is provided.

However, the particular legal requirements relating to the use and maintenance of electrical equipment in the workplace are contained in the Electricity at Work Regulations 1989 (EAWR).

Regulation 4(2) of the EAWR requires that all electrical systems are maintained so as to prevent danger.

The word 'system' includes any electrical items in the workplace when they are connected to a recognised power source - essentially covering anything with a plug.

As a result, the safety requirement covers all items of electrical equipment including fixed, portable and transportable equipment.

This would typically comprise power tools, industrial electrical appliances, IT equipment, vending machines and similar equipment.

Given this scenario, providers of electrical equipment must maintain and manage their electrical tools and appliances in order to prevent an accident.

The majority of equipment defects can be found during visual inspection prior to electrical safety testing.

For example, a detailed examination by a competent person is likely to eliminate hazards caused by cable or plug damage or other obvious signs that the equipment's condition could create faults or a danger to users.

However, to identify all potentially dangerous faults, visual inspection needs to be linked with a programme of testing capable of revealing any electrical faults such as earth continuity, insulation integrity, correct polarity, unacceptable earth leakage and other potential problems.

Pass or Fail: A wide range of specialist test instruments verify the safety of electrical appliances in keeping with the requirements of different working environments; realistic precautions for one type or size or organisation might be totally inappropriate for a larger or different type of business.

For example, simple to use, low cost 'checking' instruments which provide unambiguous pass or fail indications for certain elementary electrical tests are likely to be suitable for low risk areas and/or use by inexperienced personnel.

These instruments are more appropriate for checking electrical safety after repair or service and are also more restricted in terms of the range of appliances or tools that can be tested.

Technology developments have led to the growing introduction and use of 'intelligent' products.

The use of microprocessor controlled testing technology has made instruments more user friendly, enabling engineers to undertake faster testing, often using automatic test sequencing and giving results which can indicate progressive deterioration in a particular electrical tool over time.

As a result, there are now safety testers available with quick start up, an ability to test 110 and 240V equipment from the same power source, with integral test codes for automatic test sequences, an ability to test earth bond and leakage when multiple earth paths exist and dedicated testers which are specific for particular types of equipment - specialist power tools, IT, lighting or medical equipment testers, for example.

In the industrial environment, earth leakage measurements are particularly important for motorised equipment or where heating elements are incorporated in the equipment.

This is because earth leakage can rise significantly over time perhaps leading to the equipment becoming unsafe.

Even though flash testing is not required for in-service testing as defined by the IEE 'Code of Practice for In- service Inspection and Testing of Electrical Equipment', a case can still be made for limited use of flash testing with some appliances, including, for example, Class II power tools.

Test Frequency: Frequency of testing is another factor that requires some consideration based on the type of equipment, typical usage and the environment in which it is expected to operate.

Clearly tools, appliances and equipment used in an engineering workshop or factory environment will need much more frequent inspection and testing than some office-based appliances.

The HSE note 'Maintaining Portable and Transportable Electrical Equipment' provides some broad based suggestions on inspection and testing intervals by type of business.

The IEE 'Code of Practice for In-Service Inspection and Testing of Electrical Equipment' also gives some fairly detailed test specifications for different types of electrical equipment in different workplaces.

Ultimately, however, circumstances may vary and it is here that training or advice offered by test equipment manufacturers or service companies can assist greatly in helping employers determine the correct course of action for their own electrical safety needs.

Record Keeping In any proceedings for an offence in contravention of the EAWR, the most effective method is for the dutyholder to prove that 'all due diligence' had been exercised and that measures had been taken to prevent accidents.

As a result, the facility to record test results for subsequent demonstration that testing had been carried out is another area where considerable technological progress has been made in recent years.

Sophisticated safety testing software packages have been developed to enable the user to set up a detailed database of all tests undertaken on tools and appliances.

The most advanced programmes can also be used to produce bar codes for different appliances with details of serial numbers and test codes for automatic testing routines.

The use of computerised safety testing programmes also enables data to be transferred directly from the instrument to a PC-stored database allowing an automatic update of test records, the generation of test reports and advance testing schedules.

Electricity is a powerful but potentially dangerous energy source.

Companies of all sizes now recognise the benefits of regular inspection, test and maintenance programmes as part of effective safety management policies.

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