Seaward Instruments

Portable Appliance TestingA Practical Guide

PortableApplianceTestingA Practical Guide

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Contents2. Legislation 02

3. Who has responsibility? 03

4. Competence, Training and Experience 03

5. Types of Equipment 04

6. Classes of Equipment Construction 07

7. The Inspection Process 07

8. Combined Inspection andTesting Procedure 09

9. Electrical Tests 13

10. Frequency of inspection and testing based on risk assessment 18

11. Record Keeping 20

Appendix 23

Seaward:making yourlife easier andmore efficientWorld-Leading Electrical TestEquipment from Seaward

At Seaward Group, we have over 70 years in thedesign and manufacture of innovative electricalsafety test equipment. Today, our first-class rangeof products serves a wide variety of testing andprecision measurement applications.

For the last 30 years we’ve moved ourdevelopments on. Our portable appliance testersare the benchmark for the portable appliancetesting (PAT) market and are regarded as numberone by the industry. Our PAT testing equipmenthas always been designed with the needs of ourcustomers in mind. Safety in the workplace is ofparamount importance and our testers providethe quick and effective key to electrical equipmentpreventative maintenance programmes. That’swhy each Seaward PAT tester is backed by ahuge range of accessories, printers, assetmanagement software and technical support.Peace of mind is guaranteed for our customersbecause they know that help and advice is onlya phone call away.

2. Legislation

Although reference is made to legislation, thisguide should not be considered to be legaladvice. The reader should refer to the specificlegislation and seek legal advice wherenecessary, which may vary from time to time.

Health and Safety at Work Act 1974 (HSW 1974)places a duty of care on both the employer andemployee to ensure the safety of all persons usingthe work premises.

Management of Health and Safety at WorkRegulations 1999 state that every employer shallmake suitable assessment of the risks to health andsafety of his employees to which they are exposedwhilst at work and the risk to the health and safety ofpersons not in his employment arising of or inconnection with the conduct by him of hisundertaking.

The Management of Health and Safety at WorkRegulations 1999 also state that:

a. Every employer shall make a suitable andsufficient assessment of the risks to the healthand safety of his employees to which they areexposed whilst they are at work.

b. Where the employer employs five or moreemployees, he shall record the significantfindings of the assessment.

Electricity at Work Regulations 1989 apply toevery type of electrical equipment and state: “As maybe necessary to prevent danger, all systems shall bemaintained so as to prevent, so far as is reasonablypracticable, such danger.” (Regulation 4(2))

Provision and Use of Work EquipmentRegulations 1998 places general duties onemployers and lists minimum requirements for workequipment to deal with selected hazards whateverthe industry.

The Regulations implement an EU Directive aimed atthe protection of workers and the “general duties” willrequire the need to:

a. Make sure that equipment is suitable for theuse for which it is provided.

b. Take into account the working conditions andhazards in the workplace.

c. Ensure equipment is used only for theoperations for which, and under conditions forwhich, it is suitable.

d. Ensure that equipment is maintained in anefficient state, in efficient working order and ingood repair.

e. Provide equipment that conforms to EUproduct safety directives

f. Plus certain other general duties and specificrequirements etc.

Housing Act 2004 (England and Wales)introduced a new method for assessing risk inresidential properties, called the Housing Health andSafety Rating System, to provide a safe and healthyenvironment for any potential occupiers or visitors.This includes portable electrical equipment and thecondition of associated leads and plugs should betaken into account if they are provided as part of arented dwelling. Portable appliance testing is onemethod of ensuring that electrical equipment is safefor continued use.

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Housing (Scotland) Act 2006 defines the statutoryrequirements that have to be met by a privatelandlord and includes the electrical installation andelectrical appliances. The landlord must ensure thatthe property meets the requirements at the start ofthe tenancy and at all times during the tenancy wherethe landlord is made aware of possible defects.

3. Who has responsibility?

Users of Electrical EquipmentUsers of electrical equipment have a responsibility toensure that equipment they use has no obviousvisual damage or defects. The employer has aresponsibility to provide and maintain a safe plant forevery employee to use (HSW Act 1974 Sect 2(a)).This requirement is endorsed by the (EAWR 1989)Regs 4(1) and 4(2) with specific reference to electricalequipment. The (EAWR 1989) Reg 3(1) also placesthe same duties upon the self-employed.

AdministratorsThe IET Code of Practice gives advice to personsmanaging maintenance schemes. Administrators ormanagers of premises are required to understandand apply the legislation and assess the risks inrespect of electrical equipment and appliances withintheir charge. Administrators have a legal responsibilityto ensure that the electrical equipment in their chargeis safe.

Test OperativeThe person performing the inspections and tests onan item of equipment should be competent to carryout the inspections and tests, assess the results andthe conditions in which the item is being used andstate whether the item is safe for continued use.Training and experience will both be necessary.

4. Competence, Training and Experience

The UserUsers may require training in identification of defectsthat can occur in electrical equipment. Users shouldbe aware that:

a. Equipment that is faulty or suspected of beingfaulty should not be used.

b. Equipment that is faulty should be labelled andremoved from service immediately.

c. The administrator or manager should benotified.

The Duty HolderThe duty holder, normally a manager or supervisor, isrequired to know their legal responsibilities as laiddown in the Electricity at Work Regulations 1989 andhave a legal responsibility to ensure that equipmentin their charge is safe.

Duty holders may require training to allow them carryout risk assessments, maintain records ofinspections, tests and repairs of equipment andmanage the inspections and tests at appropriateintervals. Duty holders are required to interpret therecorded results and take appropriate actions or toprovide relevant information and reports to a moresenior person within the organisation. Competenceto interpret records and results is achieved byappropriate training and experience.

The Test OperativeIn the context of safety testing, the term “competence”refers to a person’s ability to perform the task withoutdanger to themselves or others and to make a validjudgement based on the results, as to whether the unit

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under test is safe to use and is likely to remain safe atleast until the next scheduled test date.

It will be appreciated that the test person will requirecertain knowledge and information to enable suchvalid prospective judgements to be made. In additionthe test person will require both the knowledge andthe information necessary to make judgementsregarding the testing process and its safety and theskill and ability to put such judgements into practice,this producing a safe system of work. Training andexperience will both be necessary.

It is suggested that the following criteria areconsidered:

a. An adequate knowledge and practicalexperience of electricity and its hazards.

b. A clear understanding of precautions requiredto avoid danger.

c. The ability to recognise at all times whether it issafe for work to continue.

d. The ability to identify equipment and appliancetypes to determine the test procedures andfrequency of inspection and testing.

e. Adequate understanding of the operatingprinciples of both the test equipment and theunit under test.

f. The ability to create test records and takeresponsibility for the work.

g. Adequate knowledge of the required safetystandards.

h. Adequate knowledge of possible hazards at a“strange” site.

The tester’s skill and ability should encompass:

a. Adequate experience of relevant electricalwork.

b. Adequate experience of appliance testing andthe test equipment.

c. Adequate training where (b) cannot beotherwise satisfied.

d. Experience in the interpretation of results.e. Practical “technical” experience of the type of

equipment being tested.

Suitable sources of information may include:

a. Employer’s safety manuals or instructions.b. Equipment manufacturer’s handbooks.c. British Standards (see Appendix).d. Health and Safety Executive (HSE) Guidance

Notes (see Appendix).e. IET Code of Practice for In-Service Inspection

and Testing of Electrical Equipment.

Managers and Supervisors responsible for testingpersonnel should adjust their degree of supervision totake into account any inadequacy of the test person.The (EAWR 1989) Reg. 3 places a duty on the selfemployed to assess their own competence andsubsequently to work within their limitations.

5. Types of Equipment

The IET Code of Practice applies to equipmentsupplied at voltages up to and including 1000V ACor 1500V DC between conductors or 600V AC or900V DC. between conductors and earth includingsingle, two and three-phase equipment supplied at400V, 230V and 110V and at extra-low voltageincluding SELV (Separated Extra-Low Voltage).Several types of electrical equipment are defined inthe IET Code of Practice.

Portable Equipment

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

Hand Held Equipment or Appliances

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

The risk of damage which may cause the safety ofhand held equipment to be compromised can behigh. Also, the use of some hand held equipmentcarries a high risk due to the very nature of its use i.e.the user is in direct contact with the equipment.

Moveable Equipment (Transportable)

This equipment is either:

18kg or less in mass and not fixed, e.g electricfire or:Equipment with wheels, castors or othermeans to facilitate movement by the operatoras required to perform its intended use e.g. airconditioning unit

Such equipment may be considered “transportable”rather than portable, but will still be connected to itssupply where applicable by a flexible cable and plug.The risk of damage which may cause the safety oftransportable equipment to be compromised can behigh. Also, the use of some transportable equipmentcarries a high risk due to the very nature of its use(e.g. a high pressure steam/water cleaner) and insuch circumstances transportable equipment canpresent a greater hazard than most portableequipment, therefore the requirement to periodicallytest must also apply to transportable equipment.

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Stationary Equipment or Appliances

This equipment has a mass exceeding 18kg and isnot provided with a carrying handle e.g. refrigerator,washing machine

Fixed Equipment/Appliances

This equipment or an appliance which is fastened toa support or otherwise secured in a specific locatione.g. bathroom heater, towel rail. Fixed equipment canalso be movable or portable equipment, whenconnected to the fixed installation via a fusedconnection unit (FCU), for security purposes. Thispractice is common in areas used by the generalpublic, e.g. hotels, changing rooms etc. Equipmenttypes connected in this way are numerous e.g.kettles, lamps, hair dryers etc

Appliances or Equipment for Building In

This equipment is intended to be installed in aprepared recess such as a cupboard e.g. a built-incooker.

Information Technology Equipment

This equipment includes electrical businessequipment such as computers, mains poweredtelecommunications equipment and otherequipment for general business use e.g. printers,photocopiers, typewriters etc.

Extension Leads and RCD ExtensionLeadsExtension leads are used where an item of equipmentrequires connection to a mains supply but a convenientoutlet is not available. An RCD extension lead is anextension lead that is fitted with a residual current device.

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Multi-way Adaptors and RCD AdaptorsMulti-way adaptors are used where sufficient mainsoutlets are not available. RCD adaptors are used toprovide protection for users of portable equipment,particularly when used outdoors.

6. Classes of Equipment Construction

Before an item of equipment can be tested theconstruction class must be determined in order toidentify the appropriate tests. The equipment to betested will normally be constructed in one of threebasic classes, designated Class I, II or III.Constructional methods are summarised below, fulldetails can be found in BS2754.

Class I equipment is constructed such thatprotection against electric shock does not rely onbasic insulation alone. In addition to basic insulationaround live internal parts, exposed conductive partsare connected to the protective conductor in thefixed wiring of the electrical installation. Class Iequipment relies upon a connection to the protectiveconductor to prevent exposed conductive partsbecoming live in the event of a failure in the basicinsulation.

Class II equipment is constructed such thatprotection against electric shock does not rely onbasic insulation alone. In addition to basic insulationaround live internal parts, supplementary insulationis provided, there being no provision for connectionof exposed conductive parts to the protectiveconductor. Such equipment is often described as“double insulated” and should carry the symbol .

Class III equipment is equipment in which protectionagainst electric shock relies on a supply from a

separated extra-low voltage source (SELV). In a SELVsupply the voltage is less than 50V rms and noexposed conductive parts are connected to theprotective conductor.

Note: Not all double insulated equipment bearsthe mark, however, if the mark is applied theequipment must be double insulated. For thepurposes of electrical safety testing, if a piece ofequipment does not bear the it should betreated as Class I.

7. The Inspection Process

User CheckUser checks are performed before equipment isplugged in and switched on. The check involves avisual inspection of the mains plug, mains flex andthe appliance for obvious signs of damage ordegradation. An assessment should also be madeof the suitability of the environment and the purposefor which the equipment is to be used. User checksare an important safety precaution as the user of theequipment is most familiar with its operation. Userchecks do not need to be recorded unless a problemis discovered, in which case the equipment shouldbe labelled to show it is not to be used and removedfrom service as soon as possible. The administratoror manager should be notified.

Formal Visual InspectionIn practise, many equipment defects can be foundduring a formal visual inspection. Many potentialhazards arise due to the way in which a piece ofequipment is used or abused. For example, portable equipment may be prone to being droppedor a piece of movable equipment with a long,

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trailing mains flex may be damaged as theequipment is moved around. Potential hazards suchas enclosure damage, damage to the mains flex,signs of overheating, incorrectly fitted mains plugs,incorrect fuses etc. can be identified by a thoroughvisual examination.

A formal visual inspection carried out by a competentperson will make the greatest contribution tominimising risk and eliminating potential safetyhazards. Advice on the frequency of formal visualinspections is given in Table G (see page 19).

A formal visual inspection should include aninspection of the following:

1. Manufacturer’s instructionsa. The equipment should be installed and

used in accordance with themanufacturer’s instructions.

b. The correct voltage, frequency and currentrequirements should be verified.

c. Requirements for ventilation or heatdissipation should be met.

2. Environmenta. Suitability of the equipment for the

environment or purpose for which it isbeing used e.g. risk of mechanicaldamage, exposure to weather,temperature, fluids, corrosives, flammablematerials.

3. Switching of equipmenta. The inspector should determine whether

there are suitable means of disconnectingthe equipment from the mains supplyunder normal use, to carry outmaintenance and in the event of anemergency (if applicable to the equipment).

4. User feedbacka. Where possible the user of the equipment

should be consulted as to whether thereare any known problems or faults. The usermay be aware of intermittent problems thatmay not be apparent during the inspection.

5. The equipment enclosure/casinga. Physical damage such as cracks or chemical

corrosion. Particular attention should be paidto areas around switches, fuses, protectivecovers and mains couplers where damagemay result in live parts becoming exposed.

b. Signs of overheating.c. Signs of ingress of fluids or foreign bodies.

6. Mains plugsa. Correct fit in the mains outlet – not loose

and can be removed without difficulty.b. Cracks or damage.c. Signs of overheating.d. Properly tightened off terminal screws.e. Correct wiring.f. Mains flex is properly secured by the cable

grip.g. Correct fuse rating and type.

7. Mains cablesa. Damage, cuts or fraying. Extension leads

should be checked along the entire length.b. Joints or connections which are unsafe e.g.

taped joints.c. Appropriate length.d. Correct rating for the equipment.

8. RCD protected adaptors or extension leadsa. Correct operation of the RCD should

be confirmed.

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Operator accessible fuses on the outside of theequipment should be checked for correct type andrating. If the equipment manufacturer has specified aparticular rating for the plug fuse, this should also bechecked. If the manufacturer has not specified a fuserating for the plug the maximum current carryingcapacity is detailed in Table H (see page 22) relatedto the cross-sectional area of the cable conductors.Ensure that properly manufactured cartridge fusesare used and that fuses have not been replaced witha metal bar, wrapped in metallic foil or similar non-standard method.

Note: The requirements of a formal visualinspection will vary according to the equipmentbeing inspected and the environment in which itis used. The ‘prompts’ built into SeawardPortable Appliance Testers are intended toprovide guidance and should not be taken as acomprehensive list of items to be checkedduring a formal visual inspection.

8. Combined Inspection andTesting Procedure

Safety ConsiderationsInspection and testing should only be carried out bya person who is competent to perform the inspectionand testing and interpret the results obtained.

Preliminary InspectionBefore inspection and testing is carried out the testoperative should obtain a copy of any previous testrecords if they are available. This will allow anassessment to be made of any degradation of theequipment under test.

Before attempting to carry out any electrical safetytests, the following preliminary inspection should becarried out:

a. Ensure that the equipment can bedisconnected from the mains supply and otherpower sources. If permission is received,disconnect the equipment from the supply.

b. Disconnect the equipment from all otherequipment, communication links and telecomlines.

c. Where the equipment under test has theprovision to supply mains power to otheraccessories (for example a monitor poweredfrom PC base station) the mains connectioncan remain in place during the tests.

d. Ensure that equipment is not in contact withextraneous metalwork such as parts of officefurniture.

e. Thoroughly inspect the equipment under testfor damage, as described in Formal VisualInspection.

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f. Inspect the mains plug as described in FormalVisual Inspection.

g. Inspect the mains cable as described in FormalVisual Inspection.

h. Assess the suitably of the equipment for theenvironment.

i. Where possible, consult the user as to whetherthere are any known problems with theequipment.

Note: Special care should be taken whereequipment is powered from an uninterruptiblepower supply (UPS) or has internal batterybackup.

In-Service TestsThe IET “Code of Practice for In-Service Inspectionand Testing of Electrical Equipment” recommends asystem of periodic inspection and testing, with up-to-date records, as a means of demonstratingcompliance with the Electricity at Work Regulations1989. Most companies and organisations that wishto comply with the requirements of the Electricity atWork Regulations 1989 will carry out in-service testsat intervals determined by risk assessment.

The order in which the tests are performed isimportant to the safety of the test operative. Thetesting sequence of Seaward portable appliancetesters is designed to contribute towards a safesystem of work. The sequence should always be:

1. Earth continuity test2. Insulation resistance test3. Protective conductor/touch current test or

alternative/substitute leakage test4. Functional check

An insulation test should always be carried out beforeattempting any tests which involve applying mainspower to the equipment under test as it may detecta dangerous insulation failure.

The recommendations given by the IET Code ofPractice for In-Service Testing of Electrical Equipmentare as follows:

Class I AppliancesEarth continuity test Insulation resistance test or protectiveconductor current test or alternative/substituteleakageFunctional checks

Class II AppliancesInsulation resistance test or touch current testor alternative/substitute leakage testFunctional checks

Fixed Equipment or Appliances

Fixed equipment or appliances are more difficult toinspect and test due to their connection to the fixedwiring of an installation. This does not mean that onlyvisual inspections are required for these types of

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equipment and they should be subjected to a fullcombined inspection and test at intervals determinedby risk assessment.

Testing fixed equipment or appliances must be carriedout by a competent person, in accordance with thespecific tests for particular class of equipment. Theperson carrying out the inspection and testing:

must be competent to carry out safe isolationprocedures,must be competent to carry out this morecomplex arrangement of work,must ensure safe systems of work areobserved at all times,must ensure all inspections and tests, arerelevant to the class of equipment.

Where the frequencies of any combined inspectionand testing for permanently fixed equipment,determined by risk assessment, are similar to thosefor the fixed installation, inspection and testing canbe undertaken during periodic inspection and testingof the fixed installation. Where equipment could besubjected to higher use or have a greater risk ofdamage, additional formal inspections may berequired.

Appliance Cable SetsA 3-core appliance cable should be tested as a ClassI appliance and the following tests should be made:

Earth continuityInsulation resistanceWiring polarity check

A 2-core appliance cable should be tested as a ClassII appliance and the following tests should be made:

Insulation resistanceWiring polarity check

Note: Seaward portable appliance testers areequipped with appliance cable tests thatautomatically perform all of the recommendedtests, including wiring polarity.

Extension leads, multi-way adaptorsand RCD adaptorsExtension leads and multi-way adaptors are testedas a Class I appliance and the following tests shouldbe performed:

Earth continuityInsulation resistanceWiring polarity check

When the extension lead or multi-way adaptor isfitted with an RCD, the RCD must have a ratedresidual operating current (the current at which theRCD is designed to operate) not exceeding 30mA.

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Testing After RepairThe IET Code of Practice recommends thatequipment that has been repaired should beinspected and tested either in accordance with themanufacturer’s production tests or in-service tests.The decision is based upon the type of equipmentand the nature of the repair.

Class I AppliancesEarth continuity testInsulation resistance testDielectric strength testProtective conductor current testFunctional checks

Class II AppliancesInsulation resistance testDielectric strength testTouch current testFunctional checks

Testing after repair is performed to ensure that therepair has not compromised the electrical safety ofthe electrical equipment and this is reflected by therecommended electrical tests. For example, the earthcontinuity test will demonstrate that all protective earthconnections have been replaced when the applianceis reassembled. Similarly, the dielectric strength testis a useful means of ensuring that all insulatingmaterials has been correctly reassembled and thatthe insulation on live conductors has not beendamaged during reassembly, for example, whenwires are trapped or damaged by fixing screws.

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The IET Code of Practice for In-Service Inspectionand Testing of Electrical Equipment also recommendsthat the operation of the RCD should be checkedusing an RCD test instrument to determine that thetrip time is within the limits specified in Table A below:

RCD Type Maximum tripping time at ratedcurrent

Maximum tripping time at 5x ratedcurrent

Portable devices to BS 7071 RCD trip time ≤ 200ms RCD trip time ≤ 40ms

BS EN 61008BS EN 61009 RCD trip time ≤ 300ms RCD trip time ≤ 40ms

TABLE A

Note: Many Seaward portable appliance testers are equipped with an RCD trip time test for testingthe operation of RCDs in accordance with the recommendations of the IET Code of Practice for In-Service Testing of Electrical Equipment.

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Testing Hire EquipmentThe IET Code of Practice does not coverinspection and testing of equipment or appliancesthat are used for commercial gain hire purposes.Equipment hire companies should refer to the HireAssociation of Europe (HAE) and Event HireAssociation (EHA) document, HAEEST2012:‘Guidance on Electrical Safety Testing in the HireIndustry’, which gives guidance on in-serviceinspection and testing for hire equipment prior toits release to customers/clients.

The HAE/EHA Code of Practice recommends thatcombined inspection and testing should compriseof some or all of the following:

Visual InspectionEarth continuity testInsulation resistance or protectiveconductor/touch current testDielectric strength testLoad (Run) TestPolarity checkFunctional checks

9. Electrical Tests

Earth ContinuityThis test is performed on Class I equipment or mainscables and is used to verify the integrity of theconnection between the protective conductor and allexposed metal parts intended to be connected tothe protective conductor.

The IET Code of Practice for In-service Inspectionand Testing of Electrical Equipment recommendseither of the following:

A continuity measurement with a short circuittest current within the range 20mA to 200mA.

orA continuity measurement with a test currentnot less than 1.5 times the rating of the fuseand no greater than 25A for a period ofbetween 5 and 20 seconds.

Note: Some appliances, for example ITequipment, may have accessible metal partswhich are connected to earth for functional orshielding purposes only. If the high current testoption above is used, the test current will flowthrough sensitive components or wiring notintended to provide a protective earthconnection. Inappropriate use of a high testcurrent may damage the equipment under test.If in doubt, a low test current should be used.

When testing equipment with a mains cable, thecontinuity test is made between all accessibleearthed metal parts of the equipment and theearth pin of the plug. When testing equipmentwithout a mains cable, the continuity test is madebetween the earth pin of the mains input socketand all exposed metal parts. The resistancemeasurement should be observed while flexingthe cable and an inspection of the flexible cableterminations at the equipment and the plug or flexoutlet should be made. Variations in measuredresistance should be investigated.

The measured resistance should not exceed thevalues given in Table B on the following page.

Note: Nominal values for resistance of theprotective conductor of the supply cable aregiven in Table G (see page 22)

Where possible, it is advisable to test equipmenttogether with its supply cable. If the mains cable isnot detachable, no practical alternative exists.

Care should be taken to ensure that test connectionsto the equipment under test make clean metal-to-metal contact otherwise contact resistance mayintroduce significant errors.

It is possible for Class I equipment to have conductivemetal parts which are not accessible to the operator,accessible metal parts with protection against electricshock being provided by double or reinforcedinsulation or to have ‘unearthed’ metal parts whichare in casual or fortuitous contact with earthed metal.In this case no earth continuity test is specified.

Insulation ResistanceInsulation resistance is measured by applying a testvoltage of 500V DC and measuring the resistance.

When testing a Class I appliance the voltage isapplied between both live conductors (phase andneutral) and the protective conductor (earth).When testing a Class II appliance, the test voltageis applied between both live conductors (phaseand neutral) and a test probe. The test probeshould be applied to any exposed metal parts orany suspect parts of the enclosure whereconductive material may have accumulated.Multiple tests may be required.

Modern portable appliance testers produce a testvoltage which is current limited. The voltage is notdangerous but could be uncomfortable.Appliances should not be touched during aninsulation test.

This test may not be suitable for certain types ofappliance. In the case of equipment fitted withmains filters, voltage limiting devices or surge

Class of Construction Minimum Insulation Resistance

Class I heating and cooking equipment With a rating to 3kW 0.3Mohm

All other Class I equipment 1.0Mohm

Class II equipment 2.0Mohm

Class III equipment 0.25Mohm

TABLE C Minimum Acceptable Insulation Resistance Values

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TABLE B

Appliances with a supply cable (0.1 + R) ohm

Appliances without a supply cable 0.1 ohm

3 core appliance mains cables (0.1 + R) ohm

Extension leads, multi-way adaptors and RCD adaptors (0.1 + R) ohm

Note: R is the resistance of the protective conductor of the supply cable

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protection it may not be possible to obtain asatisfactory insulation resistance measurementwith a 500V DC test voltage. IT equipment whichdoes not comply with BS EN 60950 may bedamaged by the 500V DC test voltage.

An alternative/substitute leakage, an insulationresistance test at a reduced test voltage such as250V DC or a protective conductor/touchcurrent measurement may be more appropriate.

This test should be performed with theequipment switch ON. Some electronicequipment may contain mains filter circuitsconnected between live/neutral and earth.Such devices could cause the insulationresistance to be less than specified. Themanufacturer/supplier must be consulted inthese cases as to the acceptable value ofinsulation resistance.

Insulation Resistance for Heating andCooking AppliancesFor equipment such as portable cookers theinsulation resistance when cold can be very low.Switching on the appliance for a period of timedrives out any absorbed moisture, enabling morerealistic resistances to be obtained.

Alternative or Substitute LeakageMeasurementAlternative or substitute leakage is measuredusing a technique similar to that used whenmeasuring insulation resistance. A test voltage isapplied between both live conductors (phase andneutral) and the protective conductor (earth)during a Class I test, or, a test probe connected tothe equipment enclosure during a Class II test.The resultant current is measured and then scaled

to indicate the current that would flow at thenominal supply voltage.

The test voltage is 50Hz AC and normally in therange of 40V to 250V. The test voltage is currentlimited and so there is no hazard to the testoperative. As the test voltage has the samenominal frequency as the mains supply theleakage paths are similar to those found when theequipment is in operation. Similarly, because thetest voltage is not greater than the nominal supplyvoltage of the equipment under testmeasurements are not affected by transientsuppressors, MOVs or other voltage limitingdevices.

Portable appliance testers automatically make thenecessary connection between the live andneutral conductors and apply the correct scalefactor to the measured current. The equipmentunder test must be switched ON during the test.

Dielectric Strength TestThis test is also known as the “high voltageleakage test”, “high pot test” or “flash test” and isa ‘type approval test’ or ‘production test’.

Standard Basic Insulation SupplementaryInsulation

ReinforcedInsulation

EN 60335 Safety of Household Electrical Appliances 1000V 2500V 2500V

EN 60065 Audio, Video and Similar Electronic Apparatus– Safety Requirements 1500V 2500V 2500V

EN 60950 Safety of Information Technology Equipment,Including Electrical Business Equipment 1500V 1500V 3000V

Table D Dielectric Strength Test Voltages

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Test voltages of 1500V AC and 3000V AC areavailable on selected Seaward testers that includethis test.

The 1500V AC is applied at the mains plug of theappliance under test, between the protective earthconductor and the live/neutral conductorsconnected together. The 3000 V AC test is appliedbetween the live/neutral conductors connectedtogether at the mains plug and a high voltage testprobe applied to the enclosure of the applianceunder test. No other connection is necessary.

EN 60335 “Safety of household and similar electricalappliances” allows a high voltage leakage current of0.75mA/kW with an overall maximum of 5mA. AsSeaward testers are intended to test equipment witha maximum power consumption of approximately3kVA the pass level defaults to 3mA. Equipment toBS2769 “Hand held electric motor operated tools”requires a ‘flash’ test voltage of 1.5kV and themaximum permitted leakage is 0.75mA. The testshould be conducted with the unit under testswitched ON.

Table D defines the test voltages for a range ofappliances.

Warning:During flash testing, close proximity tothe high level of charge present could causedamage to certain types of electronic equipmentwhich incorporates semi-conductor devices.The advice of the equipment manufacturershould always be sought before testing whensuch conditions are suspected.

The IET Code of Practice does not recommend theuse of the dielectric test as an in-service test but doesstate that it may be appropriate after a repair inaccordance with the manufacturer’s production orin-service tests, depending on the equipment andthe nature of the repair.

The Hire Association Europe (HAE) and Event HireAssociation (EHA) Guidance on Electrical Safety Testing in the Hire Industry includesrecommendations and guidance on the use ofdielectric strength testing.

Preload CheckSeaward portable appliance testers automaticallyperform a pre-check before tests which involvesapplying mains power to the equipment undertest. This is included to protect the test personfrom potential hazards produced by a very lowimpedance or short circuit being present between

Class of Construction Maximum Permissible Current

Portable or hand-held Class I equipment 0.75mA

Class I Heating appliances 0.75mA or 0.75mA per kW, whichever is greater, with amaximum of 5mA

Other Class I equipment 3.5mA

Class II equipment 0.25mA

Class III equipment 0.5mA

Table E Protective Conductor/Touch Current Limits

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LIVE and NEUTRAL. The test should beconducted with the equipment switched ON.

Load TestA load test is not a ‘required’ safety test, howeverit can provide useful information regarding theoperation of the equipment under test. Theportable appliance tester will apply the supplyvoltage to the equipment under test and measurethe power consumption in kVA or load current inamperes.

The test is included since a higher power thanexpected from the specification may indicatereduced functional efficiency. A significant changefrom a previously recorded figure may provide anearly warning of bearing failure in an electricalmachine or shorted turns within a transformer, bothconditions indicating the need for maintenance.Abnormally low power could be the indication of anopen circuit, ruptured fuse or other form of fault.

Protective Conductor/Touch CurrentMeasurementThe protective conductor/touch current is measuredfrom live parts to protective earth for Class Iequipment, or from live parts to accessible metal

parts of the enclosure on Class II equipment undernormal operating conditions. This test is analternative to the insulation test where the insulationtest is inappropriate. This test will provide evidence ofpossible deterioration of certain components underload and may indicate that the method of connectionof the equipment to the supply is inappropriate.

Table E defines the limits for protective conductor ortouch current.

Note: Should the equipment contain a mainsinterference suppression capacitor or filter,some residual leakage will be measured; thiswill not necessarily indicate a fault condition.

Warning: Special care should be takenduring tests where the equipment under testis energised. Portable tools and rotatingmachines etc. should be rendered safebefore the complete test sequence begins.All such machines should therefore bephysically secure and have their cutting,grinding, drilling bits etc. removed wherepossible; where guards are provided theyshould be in place.

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10. Frequency of inspection basedon risk assessment

Guidance on the frequency of testing and/orinspection is provided in the IET Code of Practiceand in HSE Guidance Notes such as ‘MaintainingPortable Electrical Equipment in Low-riskEnvironments’. The duty holder should determinethe appropriate interval between inspection andtesting based on robust risk assessment.

Risk AssessmentAny risk based assessments are the responsibility ofthe duty holder however a duty holder may enlist theservices of a competent person to assist in thisprocess. Risk assessments should be reviewedregularly to ensure that any control measures areeffective and that there are no changes which mayalter the level of risk. If there are any significantchanges, the risk assessment should be updated.

When assessing risk, the following factors should beconsidered:

1. The environment2. The users 3. The equipment class of construction4. The equipment type 5. The frequency of use6. Type of installation methods7. Previous records

Guidance on the initial frequency of suggestedinspection and test periods is given in the IET Codeof Practice for In-Service Inspection and Testing ofElectrical Equipment, and can also be found in theHSE publications HSG107 Maintaining Portable

Electrical Equipment and INDG236 MaintainingPortable Electric Equipment in Low-RiskEnvironments.

The table overleaf appears in the HSE GuidanceNote HSG107 ‘Maintaining Portable ElectricalEquipment’ and provides suggested initialmaintenance intervals.

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Type of business User checks Formal visual inspection Combined inspection and test

Equipment hire N/A Before issue/after return Before issue

Battery operated equipment(less than 40 V) No No No

Extra low voltage (lessthan 50 V ac), telephoneequipment, low-voltage desklights

No No No

110Vequipment Yes. weekly Yes, monthly Yes, before first use on site

then 3-monthly

230V equipment Yes, daily/every shift Yes, weekly Yes, before first use on site then monthly

Fixed RCDs Yes, daily/every shift Yes, weeklyYes, before first use on sitethen 3-monthly (portable RCDs monthly)

Equipmentsite offices Yes, monthly Yes, 6 monthly Yes, before first use on site

then yearly

Heavy industrial/high riskof equipment damage (notconstruction)

Yes, daily Yes, weekly Yes, 6-12 months

Light industrial Yes Yes, before initial use then 6-monthly Yes, 6-12 months

Office information technologyrarely moved, eg desktopcomputers, photocopiers, fax machines

No Yes, 2-4 year No if double insulated, otherwise up to 5 years

Double insulated (Class II)equipment moved occasionally(not hand-held), eg fans, tablelamps

No 2-4 years No

Hand-held, double insulated(Class II) equipment, eg somefloor cleaners, some kitchenequipment

Yes Yes, 6 months - 1 year No

Earthed (Class I) equipment,eg electric kettles, some floorcleaners

Yes Yes, 6 months - 1 year Yes, 1-2 years

Cables, leads and plugsconnected to Class Iequipment, extensionleads and battery chargingequipment

YesYes, 6 months - 4 years depending on type of equipment it is connected to

Yes, 1 - 5 years depending on the equipment it is connected to

Note: Cables, leads and plugs connected to Class II equipment should be maintained as part ofthat equipment. Cables leads and plugs not dedicated to an item of equipment should bemaintained as individual items as appropriate. Over time, when you look at the results of userchecks, formal visual inspections and portable appliance tests you will notice trends. These maytell you that you need to look at or test electrical equipment more or less often, depending on thenumber of problems being found. If electrical equipment is grouped together for testing at thesame time, you should use the shortest testing interval in the group rather than the longest.Alternatively, it may be appropriate to group your electrical equipment by testing interval. The IETCode of Practice has a similar table but with the information presented in a slightly different manner.In some instances with more detail and specifics, however, the two sets of information areconsidered to be consistent with each other.

Table F: Suggested Initial Maintenance Intervals Maintaining portable electrical equipment HSG107 (3rd. edition) HSE 2013

Con

stru

ctio

n

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11. Record Keeping

Although there is no legal requirement to keeprecords of inspection and testing, the HSEMemorandum of Guidance on the Electricity at WorkRegulations 1989 advises that records ofmaintenance including tests should be keptthroughout the working life of the equipment.

In any proceedings for an offence consisting of acontravention of the EAWR 1989 Rep 4 (4).5 and 8to 16 inclusive (i.e. those Regulations requiring“absolute” compliance); Regulation 29 states that itshall be a defence for any person to prove that theytook all reasonable steps and exercised all duediligence to avoid the commission of that offence.

The most effective method for the duty holder toprove that he “exercised all due diligence” etc., is toproduce proper records of the measures taken toprevent the accident. Hence full and accuraterecords made at the time of testing becomeessential, and the managed system designed toachieve this must be in place before the accident.

Step By Step ApproachA step-by-step approach would include thefollowing:

a. Conduct a survey to identify all portable andtransportable appliances which exist with theduty holder’s control.

b. Each appliance should be marked with aunique identification code, cross referencingtest results and inspection details.

c. A register of all equipment should then becreated to include the following details:1. Identification number

2. Location in which the equipment is kept3. A description of the appliance4. Serial number5. Periods between tests6. Any other details.

Due to the large number of appliances and thedetails that must be recorded a computer databaseis likely to be the most effective and efficient methodof data collection and storage.

A comprehensive software package, such asSeaward’s PATGuard, will enable the user to set upa detailed database of all items at any particularlocation easily.

By recording the information outlined in (c) aboveworking documents can be produced which are auseful aid to proficiency and safety. For example awork schedule can be generated grouping productsby test date, task sheets can be printed providing theperson conducting the tests with a list of all items duefor testing, together with their location, identificationnumber etc.

Use of Advanced Portable ApplianceTestersWhere advanced portable appliance testers areused, data can be transferred directly from theinstrument to the database providing automaticcreation or update of records.

In such situations reports of untested appliances andthose which failed the tests can be produced andsubmitted to the duty holder for the appropriateaction to be taken, this insures the investigation isthorough and avoids oversight.

Action on Completion of TestsAny equipment found unsafe must immediately beremoved from use, labelled with its fault andtransferred to the repair facility and the appropriateperson informed.

Although there is no requirement in the Electricity at WorkRegulations 1989 to label equipment, the duty holdermay find it useful to label equipment with the informationshown below to indicate that it has been tested:

a. Unique identifier or asset IDb. Current safety status e.g. PASS or FAILc. The date testedd. The identity of the test person

Such information will enable the duty holder tomanage this aspect of the overall safety of the areawith his control. The IET Code of Practice 4th Editionrecommends that the date for re-testing should notbe marked on the label.

A convenient method of labelling equipment mayincorporate a barcode. Seaward have a range ofinstruments which can be used with a barcodereader and collect appliance number and test codeswithout the need for manual data input. A full rangeof labels and data collection accessories are availablefrom Seaward.

Data Transfer Between TestInstrument and PC

Advanced Seaward PAT Testers contain output ports which allow the tester to be connected to a PC running PATGuard software. Selected appliancesfrom various locations can have their test data sentdirectly to the PAT (this is called upload) which afterdisconnection from the PC may then be taken to thelocation where the appliances are to be tested.

Simply by inputting the appliance number, the PATwill search the upload memory in an attempt toidentify that particular appliance. If the appliance isidentified the pre-determined sequence of testswill be suggested to the user. If this is accepted,the instrument will then automatically conduct thetests and record the results.

The advantage of this approach is that it helps avoiduncertainty as to which tests should be conductedon a particular appliance.

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22

Nominalconductorc.s.a.mm2

NominalconductorResistance At20°C mΩ/metre

Length metres Resistance at20°C mΩ

Max currentcarryingcapacityA

Max. diameterof individualwire inconductormm

Approx. No ofwires inconductor

0.75 26

1.01.5 2.02.53.04.05.0

2639526578

104130

6 0.21 24

1 19.5

1.01.52.02.53.04.05.0

19.529.339.048.858.578.097.5

10 0.21 32

1.25 15.6

1.01.52.02.53.04.05.0

15.623.431.239.046.862.478.0

13 0.21 24

1.5 13.3

1.01.52.02.53.04.05.0

13.320.026.633.339.953.266.5

15 0.26 30

2.5 8

1.01.52.02.53.04.05.0

8121620243240

20 0.26 50

Table G Supply Lead ResistanceNominal resistance of appliance supply cable protective conductors (cables to BS6500).

The above table gives figures for the nominal resistance of the protective conductor per metre lengthand for various lengths of cable that may be fitted as supply leads to appliances. Once an earth bondtest has been performed the approximate resistance of the protective conductor can be found anddeducted from the test results to give a more realistic figure for the resistance of the earth bonding ofthe appliance.

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Appendix

HSE Guidance NotesHSG13 Electrical Testing

HSG107 Maintaining Portable Electrical Equipment

HSR18 Administrative guidance on the application of the EC ‘Low Voltage Directive’

HSR25 Memorandum of guidance on the Electricity at Work Regulations 1989

PM29 Electrical hazards from steam/water pressure cleaners

PM32 The safe use of portable electrical apparatus

PM38 Selection and use of portable electric handlamps

GS27 Protection against electric shock

GS37 Flexible leads, plugs and sockets.

Codes of PracticeIET Code of Practice for In-service Inspection and Testing of Electrical Equipment 4th Edition ISBN 978-1-84919-626-0

Hire Association of Europe (HAE) and Event Hire Association (EHA) document, ‘Guidance on Electrical Safety Testing in the Hire Industry’ HAEEST2012

LegislationThe Health and Safety at Work etc. Act 1974 ISBN 0 10 5437743

The Electricity at Work Regulations 1989 (S.I.1989 No 635) ISBN 0 11 096635X

The Plugs and Sockets etc. (Safety) Regulations 1987 (S.I.1987 No.603) ISBN 0 11 076603

Contains public sector information licensed under the Open Government Licence v2.0 -http://www.nationalarchives.gov.uk/doc/open-government-licence/version/2/

A multi-tasking and fully customisable PATwith additional health and safety features and on-board camera for unrivalled record keeping.

Apollo 600 includes a universal riskassessment tool and the ability to store up to 50,000 appliance records, plus 2,000images - providing visual evidence of testenvironments; perfect for advanced record-keeping in organisations with high-volume workplace test and inspection routines.

Apollo 600 – a multi-taskingPAT tester with on-board camera

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PAT testers from Seaward

The winning line up of downloading PATtesters from Seaward

TheApollo Series

A straightforward electrical safety tester with QWERTY keypad for fast data entry and storage of up to 2,000 appliance records.

Ideal for mid-volume testing in compliancewith the IET 4th Edition Code of Practice, the Apollo 400 offers easy and efficient data management with remote data transferand USB downloading.

Apollo 400 – a simple, no-nonsense PAT tester

A powerful PAT tester with a built-inPAT retest calculator and flexible user-configurable sequences for recordingany non-electrical workplace test or inspection.

The ability to customise a number of settings, and a large memory tostore up to 10,000 appliance records,makes the Apollo 500 a versatile anddependable tool for high volume PAT testing.

Apollo 500 – a fast & fullycustomisable, versatile PAT tester

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ToughRugged enclosure can withstand theharshest of environments

Dual voltageTrue dual voltage for testing both 230V &110V appliances, whether the tester ispowered by a 230v or 110v supply

ReliableProven to be extremely reliable, accurateand hardworking

Primetest 250+Handheld, compact and featurepacked to test most workplaceappliances

Accurate and reliable earth continuity testingFeatures Seaward’s unique zap circuit Go to www.seaward.co.uk/zap-circuit formore information

Simple data management Store up to 999 test records and download to a PC with a single key press

Plug and printPrint pass and fail labels to the Test n Tag Proprinter via serial cable with no setup

A comprehensive dual voltage PATwith flash test

Supernova Elite

PAT testers from Seaward

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Handheld unit for testing earth continuity,insulation resistance and substitute leakag

e

with measured test result values

Accurate and reliable earth continuity testing Features Seaward’s unique zap circuit Go to www.seaward.co.uk/zap-circuit for more information

Handheld and battery poweredThis lightweight tester is extremely portable

Long battery lifeConducts up to 5000 tests before battery requires replacing

Primetest 100

Primetest 50Basic Pass/Fail handheld unit for testing earth continuity and insulation resistanceof appliances

Simple to useEasy to use push button operation

Accurate and reliable earth continuity testing Features Seaward’s unique zap circuit. Go to www.seaward.co.uk/zap-circuit for moreinformation

Handheld and battery poweredThis lightweight tester is extremely portable

PATGuard 3 ElitePATGuard 3 Elite is a completesoftware solution for recording,storing, and reporting on test andinspection data downloaded fromyour PAT tester.

Tag records with images as visual evidence and produce professional reports and certificates for total traceabilityand comprehensive record keeping.

Save time by using PATGuard 3 Elite to produce invoices, schedule retests andupload retest data to your tester.

PATGuard 3 Elite is recommended for use with Seaward downloading testers, and isalso compatible with other non-Seawardbranded testers.

PATGuard ElementsPATGuard Elements softwareprovides a fast solution for creatingan electronic record of handwrittentest results, taken from any PAT tester without a memory.

Manually enter test and inspection results tomaintain a formal log of appliance history andcreate a range of professional test reports,including an invoice report.

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Software

For a free trial of PATGuard 3 Elite, visit www.seaward.co.uk/PG3trial

For a free trial of PATGuard Elements,visit www.seaward.co.uk/PGE

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AccessoriesChoosing the right accessories will make the job of PAT testing faster and easier. Our unique range of accessories will help you get the most from your tester. The range includes scanners and Bluetooth enabled printers, a variety of leads and adaptors, pass/fail labels and verification units.

To see the full range of PAT accessories available, visitwww.seaward.co.uk/pataccessories

TrainingWe offer a number of training courses designed to support those in the PAT testing industry, some of which are City & Guilds approved. We also offerproduct training to ensure you get the most out of your Seaward product.

www.seaward.co.uk/training

Online resources & supportAt Seaward we take pride in giving you all of the tools to help make your life easier.We have a host of online resources and technical support features on our websiteincluding, FAQs, interactive videos, helpful how-to guides and an online forum forinstant support and advice.

www.seaward.co.uk/faqs

Service, calibration & repairCalibrationhouse takes care of your test and measurement equipment by providing calibration services (including on-site calibration), service, spares and repairs. Contact us for hassle-free quotations at competitive prices.

www.calibrationhouse.com

Seaward, Bracken Hill, South West Industrial Estate,Peterlee, County Durham, SR8 2SW United Kingdom

Tel: +44 (0) 191 586 3511 Fax: +44 (0) 191 586 0227Email: info@seaward.co.uk Web: www.seaward.co.uk

@SeawardPAT Seaward Group Seaward Group

Rev 4.8

Copyright © 2017 Seaward Electronic Ltd.

RRP £20