FAQ Electrical

1. Who is responsible?
2. What types of appliances can be tested? 
3. How often should electrical equipment be tested?
4. How do I assess the risk of damaged equipment?
5. What does Inspection & Testing involve?
6. Who should do the testing?
7. Who should have PAT Testing training?
8. What is included in a visual Visual Inspection?
9. How do I replace appliance flexes? 
10. Which plug fuse rating should be used?
11. What are the Portable Appliance Test specifications?
12. What should be on the PAT testing labels?
13. What are the landlord legal requirements?
14. What is an RCD?
15. How do I ensure safe working practice?
16. What are the effects of an electric shock?

The Provision and Use of Work Equipment Regulations 1998 (PUWER) requires, every employer to ensure that work equipment is suitable for the purpose for which it is provided, only used in the place and under the provisions for which it is provided. It also requires every employer to ensure work equipment be efficiently maintained and kept fit and suitable for its intended purpose. It must not be allowed to deteriorate in function or performance to such a leval that it puts people at risk. This means that regular, routine and planned maintenance regimes must be considered if hazardous problems can arise.

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 sar 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.”

Portable Appliance Equipment

There are many European standards and guidance notes regarding portable appliances and equipment, though they do not establish a common and specific definition of such equipment. Even so, there does seem to be a consensus of opinion that such equipment is either hand held whilst being connected to the supply, or is intended to be moved whilst connected to the supply, or is capable of being moved without undue difficulty whilst connected to the supply.

It is usual for this equipment to be connected to the supply via a plug and socket, however this is not a requirement for electrical equipment to be deemed portable or transportable. It is common to define a portable appliance by saying that it is ‘anything with a plug top on the end of it’. This is a mistake as it may mean that there are some appliances in the system that are never tested.

The National Association of Professional Inspectors and Testers (napit) define a portable appliance as ‘any electrical item which can or is intended, to be moved whilst connected to an electrical supply.’

The IEE Code of Practice gives guidance on the various equipment types:

Portable appliance

An appliance of less than 18kg in mass that is intended to be moved whilst in operation or an appliance which can easily be moved from one place to another, e.g. vacuum cleaner, toaster, food mixer, etc.

Movable equipment (transportable)

This equipment is either:

18 kg or less in mass and not fixed, e.g. electric fire.
or
Equipment with wheels, castors or other means to facilitate movement by the operator as required to perform its intended use, e.g. air conditioning unit

Hand Held equipment or appliances

This is portable equipment intended to be held in the hand during normal use, e.g. hair dryer

Stationary equipment or appliances

This equipment has a mass exceeding 18kg and is not provided with a carrying handle, e.g. refrigerator

Fixed Equipment/appliances

This equipment or an appliance which is fastened to a support or otherwise secured in a specific location, e.g. bathroom heater

Appliances/equipment for building in

This equipment id intended to be installed in a prepared recess such as a cupboard or similar. In general, equipment for building in does not have exposure on all sides because one or more of the sides, additional protection against electrical shock is provided by the surroundings, e.g. built in electric cooker

Information technology equipment

Information technology equipment includes electrical business equipment such as computers and mains powered telecommunications equipment, and other equipment for general business use, such as mail processing machines, VDU’s photo-copiers

Assessing the frequency of testing

The Health & Safety Executive offers no absolute rules on the frequency of the testing and inspection of portable appliances. The Memorandum of Guidance on the Electricity at Work Regulations suggests that ‘regular inspection of equipment is an essential part of any preventative maintenance program’, but no attempt is made to specify the intervals of time implied by the word ‘regular’. The reason for this omission is obvious; different situations require different measures in order to meet the requirement that the danger is prevented. The factors which effect the frequency of testing must be assessed by the duty holder who thereby makes the judgement.

In arriving at a judgement as to the frequency of testing, a duty holder is likely to assess the following factors:-

• 1. The environment – equipment installed in a benign environment will suffer less damage than equipment in an arduous environment
• 2. Users – if the users report damage as and when it becomes evident, hazards will be avoided. Conversely, if equipment is likely to receive unreported abuse, more frequent inspection and testing is required
• 3. The equipment construction – the safety of a Class 1 appliance is dependant upon a connection with earth of the electrical installation. If the flexible cable is damaged the connection with earth can be lost. Safety of Class 2 equipment is not dependent upon the fixed electrical installation
• 4. The equipment type – appliances which are hand held are more likely to be damaged than fixed appliances. If they are Class 1 the risk of danger is increased, as the safety is dependant upon the continuity of the protective conductor from the plug to the appliance.

Estimate of Risk Level

This is a simple calculation to give an estimate of the level of risk of items of electrical equipment.

Start with a BASE RISK of 0 POINTS then add:

• •2 points if the item is used in a wet or corrosive environment OR uses water or a corrosive substance in its operation. (e.g. Kettle)
• •2 points if it has a flexible supply cord that is subject to flexing OR that is subject to harsh treatment.
• •1 point if it has a heating element OR 240V electric motor.

If the sum is 2 points or more it is GROUP A, High Risk

If the sum is 1 point it is GROUP B, Medium Risk

If the sum is 0 points it is GROUP C, Low Risk

In-Service Testing

The IEE Code of Practice recognises four test situations.

• 1. Type Testing to an appropriate standard
• 2. Production testing
• 3. In-Service testing
• 4. Testing after repair

This document is limited in covering topics concerned with In Service Testing only.

This is the testing carried out as a routine to determine whether the equipment is in a satisfactory condition.

In-Service testing will involve the following:

• (a) Preliminary inspection
• (b) Earth continuity tests (for Class 1 equipment)
• (c) Insulation testing (Which may sometimes be substituted by earth leakage measurement)
• (d) Functional checks.

Electrical testing should be performed by a person who is competent in the safe use of the test equipment and who knows how to interpret the test results obtained. This person must be capable of inspecting the equipment and, where necessary, dismantling it to check the cable connections.

If equipment is permanently connected to the fixed installation, e.g. by a flex outlet or other accessory, the accessory will need to be detached from its box or enclosure so that the connections can be inspected. Such work should only be carried out by a competent person.

Who should carry out the Inspection and Testing?

The Electricity at Work regulations states that:

“No person shall be engaged in any work activity where technical knowledge or experience is necessary to prevent danger, or where appropriate, injury, unless he possesses such knowledge or experience, or is under such degree of supervision as may be appropriate having regard to the nature of the work”

The IEE Code of Practice states, those carrying out the inspection and testing must be competent to undertake the inspection and, where appropriate, testing of electrical equipment and appliances having due regard of their own safety and that of others. What should be considered is that the ‘danger’ to be prevented, includes not just the dangers which may arise during the testing procedure to the tester and others, but also the dangers which may arise at a later date as a result of using equipment which has not been effectively tested.

The tester must have an understanding of the modes of electrical, mechanical or thermal damage to electrical equipment and appliances and their flexes which may be encountered in any environment.

Training must include the identification of equipment and appliance types to determine the test procedures and frequency of inspection and testing. Persons testing must be familiar with the test instruments used and in particular their limitations and restrictions so as to achieve repeatable results without damaging the equipment or the appliance.

PAT Testing Training

All people involved in the PAT testing process need to be trained and competent to do so.

The Test Operative

The person undertaking the testing must be competent to inspect & test an electrical appliance in order to determine if it is safe to use based on the inspection and test results. Training will be required and must cover the following areas:

• Identification of equipment types
• Appropriate test procedures
• Frequency of inspection & testing
• Visual inspection
• Correct use of test instruments
• Record keeping

The Inspector

In most cases this will be the person doing the testing. This is the person responsible for formal visual inspections of the equipment. Training will be required in order to correctly visually inspect the equipment including checking the cable and the plug, including the internal wiring.

The Administrator / Duty Holder

Administrators have a legal responsibility to ensure that all electrical equipment in their charge is safe. Training may be required in order to understand their responsibilities. Training should include:

• Understanding of the IEE Code of Practice.
• Record keeping of the inspection and testing and repairs.
• Appropriate intervals for re-inspecting and re-testing.
• Interpret recorded test results and take appropriate action.

The person repairing Faulty Equipment.

The person responsible for repairing any faulty equipment must be trained and competent to do so. Equipment must be re-tested following the repair and record kept of the repair.

The User

Users of the equipment should be able to check for obvious faults before switching on and using it. They must also know what to do if they find a fault. Training may be required.

Training and Qualifications

No specific qualifications are required to under take the PAT testing, rather that they must be competent to do so. However a City & Guilds 2377 – Inspection and Testing of Electrical Equipment, qualification is available. The City & Guilds 2377 course has been designed jointly by the IEE and City & Guilds.

Competent Person

A competent person is defined as – ‘A person possessing sufficient technical knowledge or experience to be capable of ensuring that injury is prevented.’

Visual Inspection

Formal visual inspections should only be carried out by persons competent to do so. The results of the inspection must be documented.

The following must be considered when carrying out the inspection

Suitability of the equipment/environment

The equipment should be assesed for its suitability for the environment or the nature of the work being undertaken. When the work environment is harsh or hazardous particular care needs to be taken when selecting the equiopment and assessing the frequency of inspection and testing.

Good Housekeeping

A check should be made to ensure the equipment is installed and is being operated in accordance with the manufacturers instructions. Notwithstanding the manufacturers instuctions, the following are examples of items which should be checked:

• (a) Cables located so as to avoid damage
• (b) Means of disconnection/isolation readily accessible
• (c) Adequate equipment ventilation
• (d) Cups, plants and work material correctly placed to avoid spillage
• (e) Equipment positioned to avoid strain on cord
• (f) Equipment is being operated with the covers in place and any doors are closed
• (g) Indiscriminate use of multi-way adaptors and trailing sockets is avoided
• (h) No unprotected cables run under carpets

Disconnection of equipment

The means of isolation from the electricity supply must be readily accessible to the user, i.e. in normal circumstances it must be possible to reach the plug and socket without to much difficulty.

The condition of the equipment

Prior to the commencement of the users should be asked if they are aware of any faults and if the equipment works correctly. The following items need to be inspected:

• (a) The flexible cable
• (b) The socket outlet, if known
• (c) The appliance
• (d) The plug head

Some of the following checks may not be possible for equipment fitted with a non-rewirable plug

• (i) Check detachable power cords to Class 1 equipment incorporates a CPC
• (ii) Identify signs of overheating
• (iii) Internal inspection; cord security, polarity, connections
• (iv) If non-rewirable plug; cord security, burning odours
• (v) Correct size fuse fitted, BS marked, ASTA marked
• (vi) Security of plug cover
• (vii) Check the flexible cable connections and anchorage at the equipment, if practical

Replacement of appliance flexes

For flexes to be protected by the fuse in a BS1363 plug there is no limit to their length, providing their cross-sectional areas are below:

3A 0.5mm2
13A 1.25mm2

Other considerations such as voltage drop may limit flex lengths. Smaller csa’s than those given are acceptable if flex lengths are restricted. However, for replacement purposes the above simplified guidance is appropriate.

The maximum lengths recommended for extension leads are not applicable to appliance flexes or cord sets.

Fuse Ratings

For the convenience of users, appliance manufacturers have standardised on two plug fuse ratings- 3A & 13A and adopted appropriate flex sizes. For appliances up to 700W a 3A fuse is used, for those over 700W a 13A fuse is used.

A variety of fuse ratings (1A, 2A, 3A, 5A, 7A, 10A 13A common ratings in bold) are available.

The fuse in the plug is not fitted to protect the appliance, although in practice it often does this. Appliances are generally designed to European standards for use throughout Europe. In most countries the plug is unfused. If an appliance needs a fuse to comply with the standard it must be fitted within the appliance. The fuse in the plug protects against faults in the flex and can allow the use of a reduced csa flexible cable. This is advantageous for such appliances as electric blankets, soldering irons and Christmas tree lights, where the flexibility of a small flexible cable is desirable.

With some loads it is normal to use a slightly higher rated fuse than the normal operating current. For example on 500 W halogen floodlights it is normal to use a 5 A fuse even though a 3 A would carry the normal operating current. This is because halogen lights draw a significant surge of current at switch on as their cold resistance is far lower than their resistance at operating temperature.

Test Specifications

Earth Continuity – Soft Test

All modern PAT testers are able to perform a low current earth continuity test, this is usually referred to as a ‘soft test’. The test current can be within the range of 20mA to 200mA, but 100mA or 200mA is typical. Confusingly the equipment manufacturers use differing terminology for this test, it may also be referred to as ‘Earth Screen Test’, ‘Screen Bond Test’ or ‘Continuity Test’. This test is used for IT equipment where the primary purpose of the earth connection is for screening purposes and a high current earth continuity test may damage the equipment. The 3rd Edition of the IEE Code of Practice has now states that this test can be carried out on all class 1 equipment not just IT equipment, this has led to a range of mainly battery operated testers being introduced that do not carry out a high current earth continuity test. Some older testers may not have a soft test function and therefore are not suitable for testing IT equipment.

Earth Continuity – Hard Test

The high current earth continuity test (hard test) is carried out at a current of not less than 1.5 times the rating current of the appliance, and no greater than 25 amps. The purpose of this high current test is to ensure any potentially corroded earth wires are suitably stressed, especially so on appliances that are susceptible to corrosion such as fridges, washing machines, kettles, dryers etc. Some battery powered testers do not have a high current earth continuity test.

Insulation Test (500V & 250V)

The insulation resistance test is normally measured by applying a test voltage of 500 Vdc, however the 500 V test may not always be suitable for testing IT equipment or other equipment containing electronic components. An alternative test may be an earth leakage test, touch current test, substitute leakage test or the insulation resistance test at a reduced voltage, usually 250 Vdc.

Earth Leakage Test (230V & 110V)

The earth leakage test also known as the protective conductor current test, is an additional or complementary test to the insulation test. This test is used where the insulation test gives suspect results or can not be used. A typical application is for testing equipment that contains a heating element, such as a kettle, where the properties of the element may give a misleading insulation reading. Some testers can only carry out this test on 230V, others can also test 110V equipment.

Substitute Earth Leakage Test

The substitute leakage test is similar to the leakage test but is carried out at a lower voltage, this is useful for testing equipment that you do not want to power up for short periods of time, i.e. a computer. However this test does have limitations because appliances with electronic switches, relays or other active circuitry, will not be tested beyond the switch.

Touch Current

The touch current test is used as an alternative to the leakage test for class 2 equipment.

Load Test (230V & 110V)

The load test is usually performed at the same time as the earth leakage test to measure the power and/or the current the appliance is consuming. An abnormal power consumption may indicate potential faults with an appliance. As with the earth leakage test, some testers can only carry out this test on 230V, others can also test 110V equipment.

Flash Test

The flash test, also known as dielectric strength testing or hi-pot testing, is not normally carried out as part of the standard in-service inspection and testing and is usually only carried out by the appliance manufacturer.

RCD Test

The IEE Code of Practice recommends that in addition to the basic functional test, the trip time of portable RCDs should be tested. Some PAT testers now incorporate this function.

PAT Testing Labels

All equipment that has been tested and inspected must be clearly identifiable. This usually achieved by labelling the equipment with a PAT Testing label.

The label/sticker must contain the following

• Unique identification code to enable equipment to be indefinable
• The status of the equipment following the testing ie. PASS or FAIL
• The date the equipment was tested together with the re-test period or the re-test date

The above information on the label is designed to enable the equipment to be easily identifiable even if several similar items exist within the same premises and also indicate to a non-technical user if the equipment is due for re-testing or should not be used.

Additional information contained on the label may include fuse rating, engineers initials, company name or logo.

Many modern PAT testers are able to read bar-coded labels and this is particularly suitable for the identification code. Barcodes should ideally contain both the barcode and the numerical number underneath.

Labels or stickers can vary in design but should be of suitable quality that they can readily stick to a variety of surfaces. They should also be durable and hard wearing to such an extent that they are capable of withstanding the period between testing without deterioration. The label should be positioned in a prominent position where it can be clearly seen.

Equipment failing the inspection and testing must be put beyond use and clearly labeled with a sticker indicating that it has failed.

Landlord Legal Requirements

Anyone who lets residential accommodation (such as houses, flats and bedsits, holiday homes, caravans and boats) as a business activity is required by law to ensure the equipment they supply as part of the tenancy is safe.

The Electrical Equipment (Safety) Regulations 1994 requires that all mains electrical equipment (cookers, washing machines, kettles, etc), new or second-hand, supplied with the accommodation must be safe. Landlords therefore need to regularly maintain the electrical equipment they supply to ensure it is safe.

The supply of goods occurs at the time of the tenancy contract. It is, therefore, essential that property is checked prior to the tenancy to ensure that all goods supplied are in a safe condition. A record should be made of the goods supplied as part of the tenancy agreement and of checks made on those goods. The record should indicate who carried out the checks and when they did it.

It is strongly advisable to have the equipment checked before the start of each let. It would be good practice to have the equipment checked at regular intervals thereafter. You should obtain and retain test reports detailing the equipment, the tests carried out and the results.

RCD’s

RCDs are often known by other names, eg., earth leakage circuit breakers (ELCB) or safety switches.

An RCD is an electrical safety device specially designed to immediately switch the electricity off when electricity “leaking” to earth is detected at a level harmful to a person using electrical equipment. An RCD offers a high level of personal protection from electric shock. Fuses or overcurrent circuit breakers do not offer the same level of personal protection against faults involving current flow to earth. Circuit breakers and fuses provide equipment and installation protection and operate only in response to an electrical overload or short circuit. Short circuit current flow to earth via an installation’s earthing system causes the circuit breaker to trip, or fuse to blow, disconnecting the electricity from the faulty circuit. However, if the electrical resistance in the earth fault current path is too high to allow a circuit breaker to trip (or fuse to blow), electricity can continue to flow to earth for an extended time. RCDs (with or without an overcurrent device) detect a very much lower level of electricity flowing to earth and immediately switch the electricity off.

RCDs have another important advantage – they reduce the risk of fire by detecting electrical leakage to earth in electrical wiring and accessories. This is particularly significant in older installations.

How They Work

RCDs work on the principle “What goes in must come out”. They operate by continuously comparing the current flow in both the Active (supply) and Neutral (return) conductors of an electrical circuit.
If the current flow becomes sufficiently unbalanced, some of the current in the Active conductor is not returning through the Neutral conductor and is leaking to earth.
RCDs are designed to operate within 10 to 50 milliseconds and to disconnect the electricity supply when they sense harmful leakage, typically 30 milliamps.

The sensitivity and speed of disconnection are such that any earth leakage will be detected and automatically switched off before it can cause injury or damage. Analyses of electrical accidents show the greatest risk of electric shock results from contact between live parts and earth.
Contact with earth occurs through normal body contact with the ground or earthed metal parts. An RCD will significantly reduce the risk of electric shock, however, an RCD will not protect against all instances of electric shock. If a person comes into contact with both the Active and Neutral conductors while handling faulty plugs or appliances causing electric current to flow through the person’s body, this contact will not be detected by the RCD unless there is also a current flow to earth.
On a circuit protected by an RCD, if a fault causes electricity to flow from the Active conductor to earth through a person’s body, the RCD will automatically disconnect the electricity supply, avoiding the risk of a potentially fatal shock.

Examples of equipment recomended to be protected by a RCD

• • Hand held electric power tools, such as drills, saws and similar equipment.
• • Tools such as jack-hammers, electric lawn mowers.
• • Equipment on construction sites.
• • Equipment such as appliances which move while in operation, such as vacuum cleaners and floor polishers.
• • Appliances in wet areas such as kitchens, including kettles, jugs, frying pans, portable urns, food mixers/blenders.
• • Hand held appliances such as hair dryers, curling wands, electric knives etc.
• • Cord extension leads.

Safe work practices – Managing electrical safety in the workplace

Employers must carry out a risk assessment to identify potential workplace electrical hazards and to access the likelihood of injuries from the exposure to these hazards. This will enable appropriate control measures to be implemented.

General precautions – Always ensure that: