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AS/NZS 3760:2001
Australian/New Zealand Standard™
In-service safety inspection and testingof electrical equipment
AS/NZS 3760
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AS/NZS 3760:2001
This Joint Australian/New Zealand Standard was prepared by Joint TechnicalCommittee EL-036, In-service Testing of Electrical Equipment. It was approved onbehalf of the Council of Standards Australia on 21 May 2001 and on behalf of theCouncil of Standards New Zealand on 4 May 2001. It was published on22 May 2001.
The following interests are represented on Committee EL-036:Australian Chamber of Commerce and IndustryAustralian Electrical and Electronic Manufacturers AssociationBuilding Service Contractors of New ZealandDepartment of Fair Trading, AustraliaDepartment of Mines and Energy QueenslandElectrical Apparatus Service Association, New ZealandElectrical Contractors Association of AustraliaElectrical Contractors Association of New ZealandElectrical Workers Registration Board, New ZealandHousing Industry Association, AustraliaJohn March Pty, AustraliaMinistry of Economic Development, New ZealandOccupational Safety and Health Department, New ZealandOffice of the Chief Electrical Inspector, VictoriaPDL Holdings Ltd, New ZealandWorkCover New South Wales
Keeping Standards up-to-dateStandards are living documents which reflect progress in science, technology andsystems. To maintain their currency, all Standards are periodically reviewed, andnew editions are published. Between editions, amendments may be issued.Standards may also be withdrawn. It is important that readers assure themselvesthey are using a current Standard, which should include any amendments whichmay have been published since the Standard was purchased.Detailed information about joint Australian/New Zealand Standards can be found byvisiting the Standards Australia web site at www.standards.com.au or StandardsNew Zealand web site at www.standards.co.nz and looking up the relevant Standardin the on-line catalogue.Alternatively, both organizations publish an annual printed Catalogue with fulldetails of all current Standards. For more frequent listings or notification ofrevisions, amendments and withdrawals, Standards Australia and Standards NewZealand offer a number of update options. For information about these services,users should contact their respective national Standards organization.We also welcome suggestions for improvement in our Standards, and especiallyencourage readers to notify us immediately of any apparent inaccuracies orambiguities. Please address your comments to the Chief Executive of eitherStandards Australia International or Standards New Zealand at the address shownon the back cover.
This Standard was issued in draft form for comment as DR00900.
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AS/NZS 3760:2001
Australian/New Zealand Standard™
In-service safety inspection andtesting of electrical equipment
Edition 1 AS 3760:1990
Edition 2 AS/NZS 3760:1996
Edition 3 AS/NZS 3760:2000
Edition 4 AS/NZS 3760:2001
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©Standards Australia/Standards New Zealand
All rights are reserved. No part of this work may be reproduced or copied in any form or byany means, electronic or mechanical, including photocopying, without the written permissionof the publisher.
Jointly published by Standards Australia International Ltd, GPO Box 5420, Sydney, NSW 2001and Standards New Zealand, Private Bag 2439, Wellington 6020.
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PREFACE
This Standard was prepared by the Joint Standards Australia/Standards New Zealand CommitteeEL/36, In-service Testing of Electrical Equipment, to supersede AS/NZS 3760:2000.
The in-service safety inspection and testing requirements in this Standard do not cover testing fordesign and approval of equipment (which is covered separately in the AS/NZS 3100, AS 3300/NZS 6200 and AS/NZS 3350 series of Standards).
Changes to AS/NZS 3760:2000 include the following:
(a) Change to the “Scope” to clarify requirements for flexible cords on fixed equipment and tocover fixed RCDs.
(b) Revision of the “Foreword” and “ Inspection and testing” to clarify that equipment does notrequire dismantling.
(c) Additions and changes to Table 2 to clarify cord requirements in office environments, addrequirements in residential type areas, and add requirements for fixed RCDs.
(d) Numerous minor text changes.
The terms ‘normative’ and ‘ informative’ have been used in this Standard to define the application ofthe appendix to which they apply. A ‘normative’ appendix is an integral part of a Standard and subjectto the same level of compliance as if it were in the body of the Standard, whereas an ‘ informative’appendix is provided for information and guidance, and may indicate good practice. Non-compliancewith an informative appendix will not be seen as non-compliance with the Standard.
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CONTENTSPage
FOREWORD .................................................................................................................................. 4
SECTION 1 SCOPE AND GENERAL1.1 SCOPE ......................................................................................................................... 61.2 APPLICATION ............................................................................................................ 61.3 REFERENCED DOCUMENTS .................................................................................. 71.4 DEFINITIONS ............................................................................................................. 8
SECTION 2 INSPECTIONS AND TESTS2.1 FREQUENCY OF INSPECTION AND TESTS ....................................................... 122.2 PERSONNEL ............................................................................................................. 122.3 INSPECTION AND TESTING ................................................................................. 122.4 ACTION RESULTING FROM INSPECTION AND TESTING .............................. 152.5 DOCUMENTATION ................................................................................................. 15
APPENDICESA TEST OF EARTHING CONTINUITY ..................................................................... 18B INSULATION RESISTANCE AND LEAKAGE CURRENT TESTING ................ 20C INSULATION RESISTANCE TESTING OF PORTABLE ISOLATION
TRANSFORMERS .................................................................................................... 23D TEST FOR OPERATING TIME OF RCDs (RESIDUAL CURRENT
DEVICES) ................................................................................................................. 26
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FOREWORD
In-service testing is necessary for the safety of persons using the equipment and for the proper dischargeof the obligations of employers and employees, as listed in legislation covering occupational healthand safety matters. This Standard specifies in-service safety inspection and testing protocols andcriteria that satisfy these obligations and provides a cost effective approach to safety withoutjeopardizing personnel safety or involving excessive equipment downtime.
The following requirements are necessary for the safety of persons using electrical equipment:
(a) Equipment needs to be designed and manufactured to appropriate safety standards.
(b) Equipment, without being dismantled, needs to be subjected to routine inspection and testingto detect obvious damage, wear or other conditions which might render it unsafe.
(c) Equipment identified as faulty needs to be withdrawn from service and referred for repair ordisposal by expert personnel.
(d) Appropriate equipment needs to be used for each particular application.
(e) In specific cases, e.g. for use in confined spaces, equipment also needs to be used in accordancewith an appropriate set of rules linking the type of work with the class of equipment andenvironmental safety facilities.
This Standard refers only to the matters in Items (b) and (c).
The following information provides some insight and background to the inspection and electricaltesting requirements specified in this Standard and relevant regulatory codes.
PRINCIPLES OF CONSTRUCTION OF ELECTRICAL EQUIPMENT
Exposed metal parts of equipment operating from supply voltage must be prevented from becominglive in the event of insulation failure or the bypassing of insulation during the normal use of theequipment (e.g. through the ingress of conducting liquids or other conducting materials).
This protection may be provided by either one or both of the following:
(a) Provision of basic insulation between the exposed metal parts and the live parts, and earthingthe exposed metal parts. Equipment in which some or all of the exposed metal parts requireprotective earthing, are basic insulated items which are also referred to as Class I equipment.
(b) Provision of double or reinforced insulation between the external metal parts and the liveparts. Equipment in which none of the external metal parts require protective earthing, due tothe provision of double or reinforced insulation, are double insulated items, also referred to asClass II equipment. This equipment is marked with the symbol or with the words ‘DOUBLEINSULATED’ .
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PROTECTIVE EARTHING
The resistance to earth from protectively earthed parts in Class I equipment must be low enough topermit adequate fault current to flow to earth, thereby ensuring that the overcurrent protection devicein the final sub-circuit (i.e. fixed wiring) opens quickly in the event of insulation failure.
The protective earthing conductor also ensures that any leakage current from the live parts withinClass I equipment flows to earth via a low resistance path.
INSULATION RESISTANCE
Insulation resistance testing is intended to ensure the integrity of the insulation between live mainsparts and exposed or external metal parts.
Accordingly, equipment must have its insulation resistance measured prior to commissioning, and atregular intervals during its service life to ensure that no degradation has occurred since manufacture,during transport or over its service life.
TEST EQUIPMENT
The equipment required to carry out the tests detailed in this Standard should be subjected to routinecalibration to ensure its accuracy is maintained.
DOCUMENTATION
Records of maintenance, including tests, should be kept throughout the working life of the equipment.Such records are a useful management tool for reviewing the frequency of inspection and test, andensuring that inspection and testing has been carried out.
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STANDARDS AUSTRALIA/STANDARDS NEW ZEALAND
Australian/New Zealand Standard
In-service safety inspection and testingof electrical equipment
S E C T I O N 1 S C O P E A N D G E N E R A L
1.1 SCOPE
This Standard specifies procedures for the safety inspection and testing of electrical equipment; lowvoltage single phase and polyphase, which is to be entered into service for the first time, or which isalready in-service, has been serviced, or is available for hire or resale (see Note 1).
Electrical equipment includes: (see Notes 2 and 3)
(a) Portable, hand held and stationary appliances, designed for connection to the low voltagesupply by a flexible cord (see Note 4).
(b) Cord Extension Sets and Electrical Portable Outlet Devices (EPODs - power boards)
(c) Flexible cords connected to fixed equipment in certain environments (see Note 2).
(d) Portable isolation transformers.
(e) RCDs - Portable type (PRCD), socket outlet type and fixed switchboard type.
NOTES:
1 New equipment, being placed into service, requires written evidence of compliance to the relevantstandard, or to this standard.
2 Fixed equipment is not normally considered to represent a hazard unless the flexible cord is subjectto flexing in normal use or the whole equipment is open to abuse or is in a hostile environment, e.g.window mounted type room air conditioners are not considered to represent a hazard.
3 Specialised electronic equipment, e.g. portable computers, may sustain damage if not tested inaccordance with the manufacturer’s instructions. Accordingly advice should be sought from themanufacturer or agent before proceeding with in-service tests.
4 Inspection and test includes the flexible cord connected to equipment.
1.2 APPLICATION
This Standard is intended for use by those persons involved in the testing, maintenance, repair anduse of electrical equipment in environments listed in column (a) of Table 2, which also includes somespecific equipment types. While Clause 2.3 of this Standard specifies the method of inspection and
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testing, the following companion Standards covering special environments are to be referred to forthe intervals of testing:
AS 3001 Electrical installations – Movable premises (including caravans) and their siteinstallations
AS 3002 Electrical installations – Shows and carnivals
AS/NZS 3003 Electrical installations – Patient treatment areas of hospitals and medical and dentalpractices
AS 3004 Electrical installations – Marinas and pleasure craft at low voltage
AS/NZS 3012 Electrical installations – Construction and demolition sites
AS/NZS 4249 Electrical safety practices – Film, video and television sites
1.3 REFERENCED DOCUMENTS
The following documents are referred to in this Standard:
AS1939 Degrees of protection provided by enclosures for electrical equipment
(IP Code)
3001 Electrical installations – Movable premises (including caravans) and their siteinstallations
3002 Electrical installations – Shows and carnivals
3004 Electrical installations – Marinas and pleasure craft at low voltage
3190 Approval and test specification –Residual current devices (current-operatedearth-leakage devices)
AS/NZS3003 Electrical installations – Patient treatment areas of hospitals and medical and
dental practices
3012 Electrical installations – Construction and demolition sites
3100 Approval and test specification – General requirements for electricalequipment
3199 Approval and test specification for cord extension sets
3551 Technical management programs for medical devices
4249 Electrical safety practices – Film, video and television sites
ISO9000 Quality management and quality assurance Standards
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The following documents provide supplementary information.
AS/NZS3000 Electrical installations (known as the Australian/New Zealand Wiring Rules)
3017 Electrical installations – Testing guidelines
3175 Approval and test specification – Residual current-operated circuit-breakerswithout integral overcurrent protection for household and similar uses (RCCBs)
3350.1 Safety of household and similar electrical appliances Part 1: Generalrequirements
1.4 DEFINITIONS
For the purpose of this Standard, the definitions below apply.
1.4.1 Class I equipment (basic insulated, protectively earthed equipment)
Equipment in which protection against electric shock does not rely on basic insulation only, butwhich includes an additional safety precaution, in that conductive accessible parts are connected tothe protective earthing conductor in the fixed wiring of the installation in such a way that thoseaccessible parts cannot become live in the event of a failure of the basic insulation.
NOTES:1 Class I equipment may have parts with double insulation or parts operating at safety extra-low
voltage.2 Equipment intended for use with a flexible cord or cable includes a protective earthing conductor as
part of the flexible cord or cable.
1.4.2 Class II equipment (double insulated equipment)
Equipment in which protection against electric shock does not rely on basic insulation only, but inwhich additional safety precautions such as double insulation or reinforced insulation are provided,there being no provision for protective earthing or reliance upon installation conditions.
This equipment is generally manufactured with a non-conductive (insulated) enclosure, and is markedeither with the words ‘DOUBLE INSULATED’ or with the symbol to allow easy identification.
NOTE: Class II equipment may also be manufactured with metal enclosures which are double insulatedfrom live parts.
1.4.3 Competent person
A person, who the person in charge of the premises ensures has acquired through training, qualification,experience or a combination of these, the knowledge and skill enabling that person to perform thetask required correctly.
1.4.4 Cord extension set (extension lead)
An assembly of a plug intended for connection to a mains outlet socket, a sheathed flexible cord anda cord extension socket.
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1.4.5 Electric portable outlet device (EPOD) (power board)
A device, other than a cord extension set, having a single plug intended for connection to a mainsoutlet socket, a sheathed flexible cord and an assembly of one or more outlet sockets.
It may incorporate a reeling or coiling arrangement.
1.4.6 Exposed metal
(a) A conductive part of electrical equipment which:
(i) Can be touched with the jointed test finger as specified in AS 1939; and
(ii) Is not a live part but can become live if basic insulation fails.
Exposed metal parts are required to be connected to a protective earth.
(b) The term exposed metal does not apply to the following:
(i) Live parts.
(ii) Parts separated from live parts by double insulation or reinforced insulation, or by othermetal parts themselves earthed or having double insulation or reinforced insulation.
(iii) Metal nameplates, screw-heads, covers or plates, and their means of fixing, which cannotbecome live in the event of failure of insulation of live parts, or, be exposed to arcingcontact with live parts.
NOTE: ‘Failure of insulation’ in this context is taken to include accidental bridging of an insulatinggap by metal or partially conducting material such as carbon dust or moisture, as well as electricalbreakdown.
(iv) Parts within an enclosure, the cover of which requires the use of a tool for its removal.
NOTE: A key is not considered to be a tool except where special circumstances prevail, e.g. theuse of the key is restricted to technical service personnel having an appropriate level ofelectrotechnical training.
(v) Parts within equipment, the configuration and mass of which are such that the parts arenot accessible during normal use and movement of the equipment.
NOTE: Non-metallic material which is conductive to a degree which may contribute to a hazardouscondition arising shall be deemed to be exposed metal, subject to the above provisions.
1.4.7 Fixed equipment
Equipment which is fastened to a support or otherwise secured in a specific location.
NOTE: Adhesives are not recognized as a means of fastening fixed equipment to a support unlessspecifically allowed in an individual Approval and Test Specification or other Standard.
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1.4.8 Flexible supply cord
A flexible cable or cord, for supply purposes, which has one end connected to a plug with pinsdesigned to engage with a socket outlet, and the other end either –
(a) connected to terminals within the equipment; or
(b) fitted with a connector designed to engage with an appliance inlet fitted to the equipment.
1.4.9 Insulation
One or a combination of the following:
(a) Basic insulation
The insulation applied to live parts to provide basic protection against electric shock.
NOTES:1 Basic insulation does not necessarily include insulation used exclusively for functional purposes.2 Basic insulation was previously known as single insulation.
(b) Supplementary insulation
An independent insulation, applied in addition to the basic insulation, to ensure protectionagainst electric shock in the event of a failure of the basic insulation.
(c) Double insulation
Insulation comprising both basic insulation and supplementary insulation.
(d) Reinforced insulation
A single insulation system applied to live parts, which provides a degree of protection againstelectric shock equivalent to double insulation, under conditions specified in this Standard.
NOTES:1 The term ‘ insulation system’ does not imply that the insulation must be one homogenous piece. It
may comprise several layers which cannot be tested singly as supplementary or basic insulation.2 Appendix D in AS/NZS 3100 provides information on the safety principles of the design and testing
of electrical equipment including insulation-encased and metal-encased class II construction.
1.4.10 May
Indicates the existence of an option.
1.4.11 Residual current device (RCD)
A mechanical switching device designed to make, carry and break currents under normal serviceconditions and to cause the opening of the contacts when the residual current attains a given valueunder specified conditions.
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RCDs are classified in AS 3190 according to their rated residual current as follows:
(a) Type I : ≤ 10 mA
(b) Type II : > 10 mA ≤ 30 mA
1.4.12 Voltage
Differences of potential, normally existing between conductors and between conductors and earth asfollows:
(a) Extra-low voltage – not exceeding 50 V a.c. or 120 V ripple free d.c.
(b) Low voltage – exceeding extra-low voltage, but not exceeding 1000 V a.c. or 1500 V d.c.
(c) High voltage – exceeding low voltage.
1.4.13 Shall
Indicates a statement is mandatory.
1.4.14 Should
Indicates a statement is preferred as indicating good practice, but is not mandatory.
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S E C T I O N 2 I N S P E C T I O N S A N D T E S T S
2.1 FREQUENCY OF INSPECTION AND TESTS
Equipment shall be inspected and tested –
(a) prior to initial introduction to service. Where the equipment is new the supplier shall bedeemed responsible for the initial electrical safety of the new equipment;
(b) before return to service after a repair or servicing, which could have affected the electricalsafety;
(c) prior to each hire (for hire equipment, inspection only) and additionally tested at not greaterthan monthly intervals; and
(d) at intervals not exceeding those specified in Table 2.
NOTE: Regulatory authorities, other Standards, workplace safety requirements or manufacturers’instructions may specify shorter intervals appropriate to particular industries or specific types ofequipment.
2.2 PERSONNEL
The inspection and testing tasks specified in this Standard should be carried out by a competentperson as defined in 1.4.
2.3 INSPECTION AND TESTING
2.3.1 General
Inspection and testing shall be carried out at the intervals specified in Table 2.
All equipment shall be visually inspected and physically checked in accordance with Clause 2.3.2.
In addition testing shall be carried out to Clause 2.3.3.
2.3.2 Inspection
The following equipment checks shall be made by visual and physical inspection on all equipment:
(a) Check for obvious damage or defects in the accessories, connectors, plugs or extension outletsockets.
NOTE: For low voltage portable equipment and cord extension sets fitted with AS/NZS 3112 type (flatpin) plugs and extension sockets, the use of clear backed or integrally moulded (non rewireable) plugs,and cord extension sockets is recommended. Clear backed plugs and sockets facilitate the easy inspectionof the effectiveness of the sheath grip.
(b) Check that flexible cords are effectively anchored to equipment, plugs and cord extensionsockets.
NOTE: This inspection, including flexing and straining at points of entry and clamping points, may becarried out in conjunction with the continuity test to Clause 2.3.3.1. This may detect broken strands orloose connections.
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(c) Check for damage to flexible cords –
(i) the inner cores of flexible supply cords are not exposed or twisted;
(ii) the external sheaths are not cut, abraded, twisted, or damaged to such an extent that theinsulation of the inner cores is visible; and
(iii) unprotected conductors or insulation tape are not in evidence.
NOTE: Running the supply cord through the hand will often detect internal damage.
(d) For portable outlet devices, check that the warning indicating the maximum load to be connectedto the device is intact and legible.
(e) Check that any controls are in good working order i.e. they are secure, aligned and appropriatelyidentified.
(f) Check that covers, guards and the like are secured in the manner intended by the manufactureror supplier.
(g) Check that safety facilities and devices are in good working order.
(h) Check that ventilation inlets and exhausts are unobstructed.
2.3.3 Testing
2.3.3.1 Earthing continuity
All Class I equipment –
(a) with exposed metal: must have the continuity of the protective earthing conductor from theplug earth pin or supply earth point to the exposed metal checked at intervals as specified inTable 2. The resistance shall not exceed 1 ohm.
(b) without exposed metal: such as cord extension sets, EPODs and PRCDs must have checkedthe continuity of the protective earth conductor from the earth pin of the connector plug to theearth socket/contact of the outlet(s). The resistance shall not exceed 1 ohm.
NOTE: This test is to be carried out during inspection to Clause 2.3.2(b).
2.3.3.2 Insulation test
When tested at 500 V d.c. (or, for equipment containing an MOV, at 250 V d.c.), in accordance withAppendix B, at the intervals not greater than those specified in Table 2, the insulation resistancebetween components of equipment shall be as specified below. Alternatively a leakage current testmay be performed at rated voltage with values not exceeding those stated below –
(a) not less than 1 MΩ from live parts to exposed metal parts of class I equipment or alternativelynot greater than 5 mA leakage current in the protective earth conductor;
(b) not less than 1 MΩ between live supply conductors and external metal parts in Class IIequipment, or alternatively not greater than 1 mA leakage current to any external metal;
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(c) not less than 1 MΩ between live supply conductors and the earthing conductor in cord extensionsets, portable outlet devices or portable RCDs; and
(d) not less than 0.01 MΩ between live supply conductors and exposed metal parts on appliancescontaining mineral insulated metal sheathed heating elements. This requirement is not applicableif the equipment is double insulated and has no exposed metal parts.
NOTES:
1 When equipment containing MOV surge protection or EMI Suppression is tested, the voltage appliedbetween live parts and earth may be 250 V d.c. This is intended to avoid triggering the MOV or EMISuppression and the equipment failing the test.
2 A live part is a conductor or conductive part intended to be energised in normal use, including theneutral conductor. The protective earth conductor is not a live part.
3 Where equipment contains, by design, resistors installed between live conductors and earth, valuesof insulation resistance not less than the effective value of the resistors are acceptable provided themanufacturer can prove that the resistors are part of the design.
4 The insulation resistance of RCDs with functional earth (FE) connections shall be not less than0.1 MΩ. Alternatively, portable RCDs which require the supply to be closed, and units with an FEconnection may be tested for leakage current with a maximum value allowed being 2.5 mA. (Afunctional earth is a connection with earth to ensure the correct normal operation of the RCD).
2.3.3.3 Testing of portable isolation transformers
When tested in accordance with Appendix C, at intervals not greater than those specified in Table 2,the insulation resistance between components of portable isolation transformers specified below shallbe not less than 1 MΩ between the following:
(a) Live supply conductors and earthed exposed metal parts of the Class I transformer or enclosingcase.
(b) Live supply conductors and external metal parts of Class II transformers or enclosing case.
(c) Live supply conductors and the connections from the transformer output (secondary) winding.
(d) Connections from the transformer output (secondary) winding and earthed exposed metal parts.
2.3.3.4 Test for operation of RCDs
When tested in accordance with Appendix D at intervals not exceeding those specified in Table 2 themaximum tripping time for RCDs shall not exceed the values shown in Table 1.
NOTES:
1 The test for operating time using a.c. for Type A RCDs (a.c. and d.c. pulse sensitive) is acceptable asd.c. calibration is linked to a.c. calibration and verified by type test.
2 Portable RCDs which are permanently wired to terminals in equipment may be tested by push buttononly, observing the operating time, which should be without undue delay. In case of doubt, use anexternal timer circuit, capable of detecting the test current start and finish, to measure disconnecttime of not more than 150 mS for a 30 mA unit, and 40 mS for a 10 mA unit. (The test button currentis assumed to be 200% x rated residual current).
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TABLE 1MAXIMUM TRIPPING TIMES
RCD Type A.C. RMS test current Maximum tripping timemA mS
Type I 10 40
Type II 30 300
2.4 ACTION RESULTING FROM INSPECTION AND TESTING
2.4.1 Non-compliant equipment
Where in-service inspection or testing identifies equipment which fails to comply with the criteriagiven in this Standard, the equipment shall be –
(a) withdrawn from service immediately, have a label attached to it warning against further use;and
(b) sent for repair, disposal or destruction by an authorized repair agent or service personnel.
2.4.2 Compliant equipment
Following in-service inspection and testing, compliant equipment shall be fitted with a durable, non-reusable, non metallic tag.
New equipment, in accordance with Clause 2.1(a), need not be inspected or tested, but shall betagged, and the tag will be marked with the date as per (b) below prior to introduction to service.
The tag, which may be colour coded to identify the period in which the test was performed, shallinclude –
(a) the name of the person or company who performed the tests; and
(b) the test or re-test date.
NOTES:
1 Some Regulatory Authorities or other Standards, such as AS/NZS 3012 and the AS/NZS ISO 9000series, may require other inspection and test records to be kept.
2 AS/NZS 4249 and AS/NZS 3012 provide guidance on one method of colour coding. Alternativemethods are acceptable.
2.5 DOCUMENTATION
Where records of test and inspection are kept, all the following should be recorded:
(a) A register of all equipment.
(b) A record of formal inspection and tests.
(c) A repair register.
(d) A record of all faulty equipment.
NOTE: Regulatory requirements may require documentation to be kept in some cases. Referto Standards AS/NZS 3000, AS 3002, AS/NZS 3003, AS/NZS 3551, AS/NZS 3012 andAS/NZS 4249.
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TABLE 2
TESTING AND INSPECTION INTERVALS FOR ELECTRICAL EQUIPMENT
(CAUTION: This page must be read in conjunction with the Standard as a whole, and particularly Clause 2.1)
Type of environment and/or Interval between inspection and testsequipment
Class of equipment Residual Current Devices (RCDs) Cord extension sets and EPODs
Class I Class II Push-button test by user Operating time RCD tester(protectively earthed) (double insulated)
Portable Fixed Portable Fixed (a) (b) (c) (d) (e) (f) (g) (h)
1 Factories, workshops, places 6 months 12 months Daily, or before 6 12 months 12 6 monthsof work or repair every use, months monthsmanufacturing, assembly, whichever ismaintenance or fabrication the longer
2 Laboratories, health care and 12 months 12 months 3 months, or 6 2 years 2 years 12 monthseducational establishments, tea before every use, monthsrooms and office kitchens whichever is
the longer
3 Office environment: Where 12 months 12 months 3 months 6 2 years 2 years 12 monthsthe equipment or supply flexible monthscord is subject to flexing innormal use OR is open to abuseOR is in a hostile environment
4 Office environment: Where 5 years 5 years 3 months 6 2 years 2 years 5 yearsthe equipment or supply cord is monthsNOT subject to flexing in normaluse AND is NOT open to abuseand is NOT in a hostileenvironment
Licensed to Peter A Corish on 02 Oct 2002. Single user licence only. Storage, distribution or use on network prohibited.
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TABLE 2 (continued)
Type of environment and/or Interval between inspection and testsequipment
Class of equipment Residual Current Devices (RCDs) Cord extension sets and EPODs
Class I Class II Push-button test by user Operating time RCD tester(protectively earthed) (double insulated)
Portable Fixed Portable Fixed (a) (b) (c) (d) (e) (f) (g) (h)
5 Hire equipment (note 3) Inspect before each Inspect before each Prior to each NA Prior to each NA Inspect beforehire. hire. hire. hire. each hire.Test monthly Test monthly Test monthly Test monthly Test monthly
6 Repaired/serviced/second After repair or service which could affect electrical safety, or on re-introduction to servicehand equipment
7 Equipment used for 6 months 12 months 3 months NA 2 years NA 12 monthscommercial cleaning
8 Residential type areas: 2 years 2 years 6 months 6 2 years 2 years 2 yearsResidential institutions, hotels, monthsboarding houses, hospitals, accommodation houses, motels, hostels and the like
NOTES:1 Multiple environments may exist in any location e.g.: An ‘office’ classification and a ‘ laboratory’ classification may exist within a ‘ factory’ establishment.2 Regulatory Authorities, other Standards, workplace safety requirements or manufacturers’ instructions may specify intervals appropriate to particular industries or specific types of equipment.3 RCDs in transportable equipment shall be regarded as portable RCDs.4 The following Standards refer only to the inspection and testing method of Clause 2.3 of this Standard, but not to the intervals of testing in Table 2 above. Refer to the appropriate standard
for specific test intervals:AS 3001 Electrical installations – Movable premises (including caravans) and their installationsAS 3002 Electrical installations – Shows and carnivalsAS/NZS 3003 Electrical installations – Patient treatment areas of hospitals and medical and dental practicesAS 3004 Electrical installations – Marinas and pleasure craft at low voltageAS/NZS 3012 Electrical installations – Construction and demolition sitesAS/NZS 4249 Electrical safety practices – Film, video and television sites
Licensed to Peter A Corish on 02 Oct 2002. Single user licence only. Storage, distribution or use on network prohibited.
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A P P E N D I X A
T E S T O F E A R T H I N G C O N T I N U I T Y
(Normative)
A1 GENERAL
The test of earthing continuity resistance shall be conducted to Clause 2.3.3.1 during in-service testingof all class I equipment. The test shall be in conjunction with the inspection to Clause 2.3.2 includingflexing and straining at points of entry and clamping points. This may detect broken strands or looseconnections.
A2 INSTRUMENTATION
An equipment tester, or continuity tester of accuracy Class 5 or better.
NOTE: Class 5 denotes an accuracy of 5% full scale deflection.
A3 TEST CONDITIONS
Earthing continuity resistance shall be measured between any exposed metal, including rotating metalparts, and the earth pin of the plug or to the supply earth. The resistance shall not exceed 1 Ω. (SeeNote 3 below.)
For cord extension sets, portable outlet devices, and portable RCDs, the resistance betweenthe earthing connections of the plug and sockets shall be measured. The resistance shall not exceed1 Ω. (Refer to Note 3 below.)
Guidance to the allowable lengths of flexible cord sets is available in AS/NZS 3199.
NOTES:
1 Figure A1 shows one method of testing resistance.
2 For definition of exposed metal refer to Clause 1.4.6.
3 Values measured (with the appliance cord included), are usually found to comply with a value of lessthan 0.5 Ω.
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FIGURE A1 MEASUREMENT OF EARTH CONTINUITY RESISTANCE BETWEENEXPOSED METAL PARTS AND THE EARTH PIN OF THE MAINS PLUG
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A P P E N D I X B
I N S U L A T I O N R E S I S T A N C E A N DL E A K A G E C U R R E N T T E S T I N G
(Normative)
B1 GENERAL
Insulation resistance to Clause 2.3.3.2 (or alternative leakage current test on class I equipment) shallbe measured during in-service testing of all equipment, cord extension sets, portable outlet devices,and portable RCDs. Portable RCDs which require the supply to be closed, and units with an FEconnection, alternatively may be tested for leakage current. The allowable maximum value is 2.5 mA.
B2 INSTRUMENTATION AND METHOD
B2.1 Insulation resistance
An insulation resistance meter is required with the following characteristics:
A measuring circuit isolated from earth.
Nominal measuring voltage is 500 V d.c. (250 V d.c. may be used for equipment containing MOVs).
NOTE: For guidance on the requirements of insulation measuring equipment refer to AS/NZS 3000Clause 6.3.3.3.1 (i.e. maintain terminal voltage within +20% and –10% when measuring a resistanceof 1 megohm.
Accuracy Class 5 or better.
NOTE: Class 5 denotes an accuracy of 5%, full scale deflection.
B2.2 Leakage current
Measurement of the current in class I equipment protective earth conductor can be carried out whilstthe equipment is operating by:
(a) A direct reading meter in the protective earth wire circuit of the test equipment;
(b) A clamp meter in conjunction with special cord set where the protective earth conductor canbe safely separated for measurement.
The meter must be capable of recording 5 mA ±5 %.
B3 TEST CONDITIONS
NOTE: A live part is a conductor or conductive part intended to be energised in normal use, includingthe neutral conductor. The protective earth conductor is not a live part.
B3.1 Class I equipment – Live parts to exposed metal parts (earthed)
Insulation resistance is measured between live supply conductors and exposed metal parts, with themains switch/selector on the equipment in the ‘ON’ position. The resistance shall be not less than1 MΩ. Alternatively the current in the protective earthing conductor with the equipment operatingmay be measured. The measured current is not to exceed 5 mA.
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NOTES:
1 Figure Bl shows testing of insulation resistance of exposed metal parts.
2 Mineral insulated metal sheathed heating appliances can have an initial insulation resistance of lessthan 0.01 MΩ after storage for an extended period. This may be rectified by suitable remedial action.
3 Exposed metal is defined in Clause 1.4.6 and is required to be earthed.
B3.2 Class II equipment – Live parts to external metal parts (not earthed)
Insulation resistance is measured between live supply conductors and external metal parts, with themains switch/selector on the equipment in the ‘ON’ position. The resistance shall be not less than1 MΩ.
NOTE: Figure B2 shows testing of insulation resistance of external metal parts.
B3.3 Conductors in flexible cords
For cord extension sets, portable outlet devices and portable RCDs, the insulation resistance shall bemeasured between live supply conductors and the earthing conductor, with the mains switch/selectorfor the equipment in the ‘ON’ position. The resistance shall be not less than 1 MΩ. When internalcomponents may affect test values obtained, attention is drawn to Note 3 and 4 of Clause 2.3.3.2.
NOTE: Figure B3 shows testing of an EPOD.
FIGURE B1 MEASUREMENT OF INSULATION RESISTANCE BETWEEN LIVE SUPPLYCONDUCTORS AND EXPOSED METAL PARTS OF TYPICAL CLASS I APPLIANCE
e.g. electric soldering iron
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FIGURE B2 MEASUREMENT OF INSULATION RESISTANCE BETWEEN LIVE SUPPLYCONDUCTORS AND EXTERNAL METAL PARTS OF TYPICAL CLASS II APPLIANCE
e.g. an electric drill
FIGURE B3 MEASUREMENT OF INSULATION RESISTANCE BETWEEN LIVE SUPPLYCONDUCTORS AND EARTHING CONDUCTOR OF EPOD
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A P P E N D I X C
I N S U L A T I O N R E S I S T A N C E T E S T I N G O F P O R T A B L EI S O L A T I O N T R A N S F O R M E R S
(Normative)
C1 GENERAL
Insulation resistance is measured on portable isolation transformers to Clause 2.3.3.3.
C2 INSTRUMENTATION
An insulation-resistance meter is required with the following characteristics:
(a) A measuring circuit isolated from earth.
(b) Nominal measuring voltage 500 V d.c.
(c) Accuracy Class 5 or better.
NOTE:
1 Class 5 denotes an accuracy of 5%, full scale deflection.
2 For guidance on the requirements of insulation measuring equipment refer to AS/NZS 3000, i.e.maintain terminal voltage within + 20% and – 10% when measuring a resistance of 1 megaohm.
C3 TEST CONDITIONS
Insulation resistance shall be not less than 1 MΩ and shall be measured between –
(a) live supply conductors and earthed exposed metal parts of a Class I transformer or enclosingcase.NOTE: A method is shown in Figure C1.
(b) live supply conductors and external metal parts of Class II transformers or enclosing case;NOTE: A method is shown in Figure C1.
(c) live supply conductors and the connections from the transformer output (secondary) winding;andNOTE: A method is shown in Figure C2.
(d) the connections from the transformer output (secondary) winding and earthed exposed metalparts.NOTE: A method is shown in Figure C3.
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FIGURE C1 MEASUREMENT OF INSULATION RESISTANCE BETWEEN LIVE SUPPLYCONDUCTORS TO PORTABLE ISOLATION TRANSFORMER AND EXPOSED METAL
PARTS
FIGURE C2 MEASUREMENT OF INSULATION RESISTANCE BETWEEN LIVE SUPPLYCONDUCTORS AND TRANSFORMER OUTPUT (SECONDARY) WINDING
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FIGURE C3 MEASUREMENT OF INSULATION RESISTANCE BETWEEN TRANSFORMER(SECONDARY) WINDING AND EXPOSED METAL PARTS
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A P P E N D I X D
T E S T F O R O P E R A T I N G T I M E O F R C D s( R E S I D U A L C U R R E N T D E V I C E S )
(Normative)
D1 GENERAL
The operating time of RCDs shall be checked to Clause 2.3.3.4 with maximum values to Table 1.
D2 INSTRUMENTATION
An RCD tester to apply rated tripping current ±5% and measure time ±2.5%.
D3 TEST CONDITIONS
A current, equal to the rated tripping current, shall be suddenly applied between active and protectiveearth and the operating time measured.
NOTES:1 Tests are applied by the instrument test button (suddenly applied). In case of doubt the number of
test operations, up to 5, may be required.
2 Some RCDs may have a different result (approximately 10 mS) depending on the point on wave ofthe test current. In case of doubt operating time at both 0o and 180o should be tested.
3 Load leakage and stored energy can affect the result and increase the meter trip time indication. Incase of doubt all load on the circuit should be disconnected.
4 A 240 V test meter, used on 230 V may give a low test current and corresponding longer times.Ensure the correct rating and tolerance of the test instrument.
5 Tests on three phase units are carried out on one phase only. In case of doubt, as the vector of the testcurrent and the load leakage current are important, the load should be disconnected.
6 The test from active to earth involves the complete earth fault loop and the resistance of the earthwire, or current flowing in the earth wire may affect results. In case of doubt a bench test may berequired.
7 Portable RCDs which are permanently wired to terminals in equipment may be tested by push buttononly, observing the operating time, which should be without undue delay. In case of doubt, use anexternal timer circuit, capable of detecting the test current start and finish, to measure disconnecttime of not more than 150 mS for a 30 mA unit and 40 mS for a 10 mA unit. (The test button currentis assumed to be 200% x rated residual current).
The following tests are not required by this Standard:
(a) Calibration sensitivity at slowly rising current;
(b) Non trip threshold (50% rated sensitivity);
(c) d.c. pulse tests for class A. The test for operating time using a.c. for type A RCDs (a.c. and d.c. pulsehalf wave sensitive) is acceptable as d.c. calibration is linked to a.c. calibration and verified by typetest. The test for operating time, ensures that both type AC (sine wave a.c.) and type A have retainedtheir type test calibration.
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