Maintaining portable electrical equipment

Maintaining portable electrical equipment

Do you have control over or use portable electrical equipment in the workplace?

This guidance is for managers, electricians, technicians and users and gives sensible advice on maintaining portable electrical equipment to prevent danger. It covers equipment that is connected to the fixed mains supply or a locally generated supply.

It outlines a recommended maintenance plan based on a straightforward, inexpensive system of user checks, formal visual inspection and testing.

HSG107 (Third edition) Published 2013

HSE Books Page 1 of 24

© Crown copyright 2013

First published 1994 Second edition 2004 Third edition 2013

ISBN 978 0 7176 6606 5

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This guidance is issued by the Health and Safety Executive. Following the guidance is not compulsory, unless specifically stated, and you are free to take other action. But if you do follow the guidance you will normally be doing enough to comply with the law. Health and safety inspectors seek to secure compliance with the law and may refer to this guidance.

Contents

Introduction 4

Explanation of terms used 6

Hazard 6

Risk 6

Portable 6

Earthed equipment (Class I) 6

Double insulated equipment (Class II) 6

Reasonably practicable 7

What does the law require? 8

Controlling the risk 9

Portable equipment and cables 9

Next steps 10

Maintenance 12

User checks 12

Formal visual inspection 13

Combined inspection and test (PAT) 15

Maintenance, test records and labelling 15

Frequency of examinations 16

Repair and replacement 19

Appendix 1 Legal requirements 20

Appendix 2 Summary 22

References and further reading 23

Further information 24

Introduction

1 This guidance is for those who have control over or use portable electrical equipment, such as managers, electricians, technicians and users. It gives sensible advice on maintaining portable electrical equipment to prevent danger. In this document the term ‘portable’ is used to mean portable, movable or transportable.

2 The scope of this guidance is limited to Class I and Class II equipment (see paragraphs 13 and 14).

3 Portable electrical equipment could cause an electric shock or burn, or fire due to damage, wear or misuse. This guidance covers most electrical portable equipment used in all environments, eg electric drills, extension leads, office equipment, portable grinders, pressure water cleaners, floor cleaners, electric kettles and similar equipment used in all environments. Major items of plant, such as vehicles, cranes and generators, are beyond the scope of this guidance, as are electromedical equipment, electrostatic spraying equipment, and equipment used below ground in mines, for which there are special requirements.

4 Business equipment (such as computers, printers, photocopiers etc) does not present the same level of risk as other equipment (such as electric drills) providing the leads and plugs are protected from mechanical damage or stress. Movement, and therefore damage through being moved, is less likely to occur, and the equipment is often double insulated and used in a dry, clean environment with non-conducting floors. Guidance for low-risk environments is contained in INDG236.1

5 This guidance covers portable equipment that is connected to the fixed mains supply or to a locally generated supply, for example a local diesel generator. The safety of portable electrical equipment depends on the continued integrity of the earthing, and correct connections of the fixed electrical installation (this includes the wiring, fuse box/consumer unit, and switches up to and including the socket supplying the equipment). You should also correctly select, use and maintain the fixed installation; although this is outside the scope of this guidance it is covered in Inspection and testing Guidance Note 3 from the Institution of Engineering and Technology (IET).2

6 The maintenance plan described in this guidance is based on a straightforward, inexpensive system of user checks, formal visual inspection and testing. User checks and formal visual inspections can be carried out by a competent employee. In this context ‘competent’ means having suitable training, skills and knowledge for the task to prevent injury to themselves or others. This guidance also makes it clear when testing is needed. When testing is necessary, a greater degree of competence will be required. The plan is explained in more detail in paragraphs 34–49. People in control are, however, free to take other action or use alternative control measures that achieve the same standard of safety.

7 Portable electrical equipment should only be used in accordance with the manufacturer’s instructions, for its intended purpose, and in the environment it was designed and constructed for.

8 The IET’s Code of Practice for In-service Inspection and Testing of Electrical Equipment is aimed at practitioners contracted to carry out portable appliance testing, students undertaking the appropriate qualifications and/or examinations, facility managers etc. It gives advice and makes recommendations on what may be considered to be ‘pass’ or ‘fail’ conditions. It also gives guidance both for those with management responsibility for electrical maintenance but who may have little technical knowledge, and for those who actually carry out the inspections and tests.

Explanation of terms used

Hazard

9 A simple definition of a hazard is anything that can cause harm if things go wrong (eg a fault on equipment).

Risk

10 A simple definition of risk is the chance (large or small) of harm actually being done when things go wrong (eg risk of electric shock from faulty equipment).

Portable

11 There is no legal definition of portable equipment. However, in this guidance it means equipment that is intended to be connected to a generator or a fixed installation by means of a flexible cable and either a plug and socket or a spur box, or similar means. This includes equipment that is either hand-held or hand-operated while connected to the supply, intended to be moved while connected to the supply, or likely to be moved while connected to the supply.

12 Extension leads, plugs and sockets, and cord sets that supply portable equipment are classified as portable equipment because they operate in the same environment and are subject to the same use as the equipment they serve. Portable equipment also includes appliances which have been fixed for security purpose such as those in public areas of hotels and changing rooms, eg kettles, hairdryers, hand dryers, lamps etc. The electrical supply to the equipment is assumed to be at a voltage that can give a fatal electrical shock, ie more than 50 V ac or 120 V dc.

Earthed equipment (Class I)

13 This equipment relies on the metallic (exposed conducting) parts of the equipment being effectively earthed. If this earth connection is lost there is a possibility of the exterior of the equipment becoming live, with a potentially fatal result. Anyone touching live metal will be in contact with electricity.

Double insulated equipment (Class II)

14 This equipment (which includes double insulated equipment marked ) is constructed with high-integrity insulation and does not have nor need an earth connection to maintain safety. If you cannot see this symbol, you should assume that the electrical equipment is a Class I appliance.

Reasonably practicable

15 This means balancing the level of risk against the measures needed to control the real risk in terms of money, time or trouble. However, you do not need to take action if it would be grossly disproportionate to the level of risk.

What does the law require?

16 The legal requirements relating specifically to the use and maintenance of electrical equipment are contained in the Electricity at Work Regulations 1989. These Regulations apply to all work activities involving electrical equipment. They place duties on employers, the self-employed and employees (subsequently referred to as ‘dutyholders’). These duties are intended to control risks arising from the use of electricity.

17 The Regulations require that electrical systems and equipment must be maintained, so far as reasonably practicable, to prevent danger. This requirement covers all items of electrical equipment including fixed or portable equipment.

18 The Regulations do not specify what needs to be done, by whom or how frequently (for example, they do not make it a legal requirement to test all portable electrical appliances every year). This allows the dutyholder to select precautions appropriate to the risk rather than having precautions imposed that may not be relevant to a particular work activity. Note that even if a contractor is used to carry out maintenance procedures, the dutyholder still has overall responsibility for complying with the law. For more information see HSE publication HSR25 Memorandum of guidance on the Electricity at Work Regulations 1989.4

19 There are also legal duties on manufacturers and suppliers covering the initial integrity (safety) of new work equipment. There are general duties covering the use and maintenance of work equipment, designed to ensure that it remains in a safe condition. For more information see Appendix 1.

Controlling the risk

20 Failure to maintain equipment is a major cause of electrical accidents involving portable equipment. The likelihood of accidents occurring and their severity will vary depending on the type of electrical equipment, the way in which it is used and the environment it is used in.

21 Control of risks arising from the use of portable electrical equipment should be based on a risk assessment. A risk assessment is about identifying hazards and taking sensible and proportionate measures to control the risks in the workplace. Risks can be managed and controlled by setting up an appropriate maintenance plan including the measures referred to in paragraphs 34–49.

22 Factors to consider when making the risk assessment include:

■■ type of equipment – the vast majority of which will be either earthed equipment or double insulated equipment; ■■ whether it is hand-held or not. Equipment that is held by hand or handled when switched on will present a greater degree of risk because, if it does develop a dangerous fault, the person holding it will almost certainly receive an electric shock; ■■ manufacturer’s recommendations; ■■ initial integrity and soundness of the equipment; ■■ age of the equipment; ■■ working environment in which the equipment is used (eg wet or dusty) or likelihood of mechanical damage; ■■ frequency of use and duty cycle of the equipment; ■■ foreseeable misuse of the equipment; ■■ effects of any modifications or repairs to the equipment; ■■ analysis of previous records of maintenance, formal visual inspection and combined inspection and testing (see paragraph 52).

Portable equipment and cables

23 Portable equipment and the electrical connections to it (eg the plug and flexible cable and its terminations) are likely to be subjected to, and more vulnerable to, physical damage and wear or harsh treatment in use than equipment which forms part of the fixed installation. The fixed installation is usually provided with a significant degree of protection against damage by the fabric of the building or fixed enclosure. However, floor boxes containing socket outlets can easily trap and damage cables if not properly used. It is important to remember that the same legal requirement to maintain systems applies to the fixed installation and all electrical equipment connected to it.

24 The risk of receiving an electric shock will be greater when the user of portable electrical equipment is standing on a surface that is a good electrical conductor (such

as a wet floor, the ground outside, a concrete floor or on scaffolding) than if they are standing on a wooden floor or dry carpet and not in contact with earthed metalwork.

25 The most vulnerable item of any portable equipment is often the cable (sometimes called cord, lead or flex) that supplies the equipment. Most portable equipment is supplied by a flexible cable, which is made up of thin, flexible wires covered in insulation and then enclosed in an overall sheath. The cable may deteriorate due to ageing or environmental effects, abuse or misuse, fail because of repeated flexing, or suffer mechanical damage. The most obvious examples of mechanical damage are being struck or penetrated by objects.

26 Repeated or excessive flexing of the cable will eventually cause the conductor to fracture and the sheath to crack. Damage usually occurs first at the cord grip or gland where the cable enters the equipment or its plug. The damage is usually apparent at the user check (see paragraphs 38–39) and should be reported. The cable should be replaced before a dangerous fault develops, such as exposure of conductors, or possibly arcing between broken conductor ends.

27 Some portable equipment (such as floor polishers, hedge trimmers, saws and soldering irons) is capable of causing damage to the sheath, or even to the insulation of its own flexible cable. The cable should be secured in such a way that it does not come into contact with parts that are moving or hot. The users of such equipment should always be alert to avoid such damage. If damage does occur they should stop using the equipment and report it to their manager.

28 An example of a high-risk activity is the use of a pressure water cleaner, powered by a 230 V electrical supply, with the cable trailing on the ground where it can be damaged by vehicles and other equipment, and where water is present. Damage to the cable or other parts is likely to expose the operator or others to the risk of electric shock.

29 Similar risks result when electrical equipment such as drills or portable grinders are used in a harsh and sometimes wet environment such as at a construction site. There is a high probability of mechanical damage and in some circumstances the metal casing of equipment can become live.

30 Sometimes ‘unauthorised’ equipment is brought to work by employees (eg electric heaters, kettles, coffee percolators, electric fans). Use of such equipment should be controlled and it may need to be included in the maintenance plan (particularly the formal visual inspection described in paragraphs 40–46) if its use is allowed. Equipment that fails a user check (paragraphs 38–39), a formal visual inspection (paragraphs 40–46) or, where relevant, a combined inspection and test (paragraphs 47–50) should not be used until it is repaired by a competent person.

31 Lower risks result from floor cleaners or kettles that are generally used in a more benign environment, eg offices and hotels. But such equipment can still be subject to intensive use and wear. This can eventually lead to faults that can also result in a shock, burns or, more rarely, a fire.

Next steps

32 Having identified the hazards, the next stage of the risk assessment is to consider what action is needed to manage the risks responsibly. Generally everything reasonably practicable must be done to protect people from harm.

33 The Management of Health and Safety at Work Regulations 1999 require that a record is made of the significant findings of the risk assessment and what is already in place to control the risks. Any record produced should be simple and focused on controls. If there are fewer than five employees it does not need to be written down. But it is useful to do this so it can be reviewed at a later date, for example if something changes. If there are five or more employees, the risk assessment must by law be written down.

Maintenance

34 Although a good initial level of safety can be achieved by correct selection and use of equipment and its connectors and cables, lasting safety can only be attained by ongoing and effective maintenance.

35 An electrical accident can lead to a potentially fatal electric shock, or fire affecting the whole premises. The maintenance plan should therefore be designed to be proactive, ie planned to prevent incidents arising, rather than reactive, where action is taken following an incident or accident. The action taken should be appropriate to the risk, eg the frequency of inspections and any necessary testing will depend on the type of equipment in use, how it is used, how often, and where it is being used. Maintenance will need to be carried out more frequently where the risk is high, eg on construction sites, and less frequently where the risk is lower, eg in offices.

36 Effective maintenance of portable electric equipment can be achieved by a combination of:

■■ checks by the user; ■■ formal visual inspections by a competent person; ■■ where necessary a combined inspection and test, also known as a portable appliance test (PAT), by an electrically competent person.

The aim of these checks is to determine whether the equipment is fully serviceable or whether remedial action is necessary to make sure it is safe to use.

37 Managers should follow up these procedures by monitoring the effectiveness of the system and taking action where faults are found, particularly when faults are frequent.

User checks

38 The person using the equipment should be encouraged to look at it before use and check for signs that it may not be in sound condition, for example:

■■ damage (apart from light scuffing) to the supply cable, including fraying or cuts; ■■ damage to the plug or connector, eg the casing is cracking or the pins are bent; ■■ inadequate joints, including taped joints in the cable; ■■ the outer sheath of the cable is not effectively secured where it enters the plug or the equipment. Evidence would be if the coloured insulation of the internal cable cores were showing; ■■ the equipment has been subjected to conditions for which it is not suitable, eg it is wet or excessively contaminated; ■■ damage to the external casing of the equipment;

■■ loose parts or screws; ■■ evidence of overheating (burn marks or discolouration).

39 These checks also apply to extension leads, plugs and sockets. A user