July 2003

A MESSAGE FROM THE ELECTRICITY SAFETY REGULATORabout it and bought the matter to theattention of the Electrical Safety Unit.Things were soon resolved very nicely.A couple of chastened interstatechappies were in looking for licencesvery smartly and some of the work wentto local contractors.

Some serious questions were also askedof their customers about engagingunlicensed persons.

To me a couple of good things came inof all this. The local lads were willing todo something proactive about an issueaffecting their industry. No whining andbelly aching that somebody (theGovernment, anybody but me) ought todo something about this sort of thingfrom these guys.

I was very pleased to hear a couple ofrecent stories regarding the activities ofelectrical contractors from interstate.

Both stories tell a tale familiar to us allin the Territory, but this time the endingwas a little different.

It seems a couple of interstatecontractors thought they’d slip intotown unnoticed and do a bit of work.No need to worry about the localblokes.

It appears they came unstuck when theydid a ring-around to try to get a localcontractor to sign a ‘Certificate of

Compliance’ for them. Bit cheeky Iwould have thought, snip the work

out from under the noses of localcontractors and then want one

of them to cover for them.

Seems a couple of thelocal lads had similar

feelings whenthey heard

They were straight on the blower. Bothdisplayed an encouraging amount ofintegrity in dealing with the matter andI appreciate their willingness to step upto the plate.

The other nice aspect is that theElectrical Safety Unit (and the LicensingBoard) was able to do a ‘service’ forindustry when called upon. It gave us thechance to partly answer the question“what do you do for our licence fees?”.

In closing, I hope you all enjoy the newformat for the Conduit.'

Darrol SachsManager, Electrical Safety

Page 2 The Conduit - July 2003

FROM THE CHIEF ELECTRICAL SAFETY OFFICERApril 2003 marks three years since the adoption of the Electricity Reform Act,modernlegislation that supports the fundamental elements of performance-based legislation.

Contrary to the views of some commentators the sky hasn’t fallen in, nor have weseen any apocalyptic change to industry.

The three years in review have provided some significant milestones. Contractorsas a whole are to be congratulated on accepting their commercial responsibilities.

Industry can be confident that their testing and certification today is a lot moreconsistent than in the past. This in the main is due tothe tangible requirements outlined in the Act that, whenfollowed, ensure compliant and safe outcomes.

In recent months some Electrical Safety staffchoose alternative career options and new staffhave enthusiastically taken up the challenge.

Pat Nolan, who has many years contracting experiencein the NT, has taken up the position of Senior ElectricalSafety Officer in the Darwin office and Valda Ioane hastaken up the position of Coordinator of the Auditprogram.

Both Valda and Pat are professional in all aspects oftheir work and we welcome them into the ElectricalSafety Unit.

Tim HallenChief Electrical Safety Officer

POWER PROJECTSRecognising the importance ofskil ls maintenance for itsworkforce, Katherine electricalcontractor Power Projects NTPty Ltd has developed a testpanel suitable for all aspects ofinstallation testing.

The test panel allows workersto practice their installationtesting and inspection techniquesas well as their fault-finding skills.The panel isn’t limited to use byelectricians. Line workers canalso use the panel to practisetheir polarity testing andconnection techniques.

Above: Power Projects NT Pty Ltd supervisor Mick Ainsleyand ‘Macca’ with the Test Panel during construction.

The Conduit - July 2003 Page 3

The last six months has seen the final stages of the NationalCompetition Policy (NCP) Review of the Electrical Workers &Contractors Act with an Amendment Bill being introduced tothe Legislative Assembly.

At the Council of Australian Government’s (COAG) meetingof April 1995, Heads of Government signed three agreementsestablishing the National Competition Policy. They arecommonly referred to as the NCP agreements. Under theNCP agreements, all States and Territories were required todevelop timetables for reviewing all existing legislation, conductreviews in accordance with the timetable and, whereappropriate, amend or repeal legislation that restrictscompetition. The Electrical Workers and Contractors Act wasidentified as requiring NCP review and a review of the Actwas completed on behalf of the NT Government in October2000 by Canberra-based firm Centre for InternationalEconomics.

The Review team made several recommendations that werelater endorsed by the NT Government. These were briefly asfollows:

• Licensing should be retained but should be flexible enoughto accommodate alternative means of signalling a person’scompetence to perform set tasks.

• The objectives of the requirements for ‘additionalexperience’ for contractors should be clearly articulatedby the Board, and it should be demonstrated thatexperience is the best way of satisfying those objectives, ifthey are to be retained.

• The ‘fit and proper person’ test should be amended toovercome concerns relating to its arbitrariness and clarifythe criteria against which the ‘fit and proper’ status will beassessed.

• PAWA’s exemption from licensing should be removed,however approved competency-based assessments shouldbe recognised as a substitute for licensing in certainsituations.

• A more general review of the Act is needed.

The Licensing Board and the Department of Infrastructure,Planning and Environment have long been in support of theadoption of uniform requirements for licensing, including thoserelating to trade classification, grading and qualifications, asagreed by all Australian and New Zealand licensingjurisdictions. Accordingly, drafting instructions for theAmendment Bill was structured to address NCP Reviewrecommendations within a framework that is consistent withnational uniformity agreements.

What is all this likely to mean to you?The Amendment Bill proposes that workers’ licences will beissued in the trade classification of ‘Electrician’ with a gradingof:

• Unrestricted (replacing A Grade Mechanic);

• Supervised (replacing B Grade Mechanic); or

• Restricted (continuing as existing).

Electrical Fitter licences will be converted to a Restrictedgrading, and Linesman and Cable Jointer, while continuing asrecognised trades, will be exempt from licensing requirement(it is understood a national industry ‘Register’ is beingdeveloped interstate for these practitioners). Trained technicalworkers in the telecommunications and aviation industrieswill also be exempted.

Applicants for a contractor’s licence will no longer need towait to gain the additional ‘two years experience’ but willneed to demonstrate competence and the arbitrary ‘fit andproper person’ test will be replaced by established criteriaagainst which a person’s suitability can be assessed.

Lastly, the exemption to licensing status afforded to the Powerand Water Corporation will be repealed and PowerWaterwill need to employ licensed persons as appropriate (this isalready generally the case anyway).

These changes will satisfy NCP recommendations andgenerally bring the Northern Territory into line with nationallicensing requirements, enhancing the portability of Territoryworkers and simplifying applications for licences betweenStates, Territories and New Zealand. Queensland and SouthAustralia will remain the only two States at present retainingLinesman/Cable Jointer licences.

The Amendment Bill proposes that current licences will remainvalid and licences will be issued in the new format as theycome up for renewal, so there will be no need for anyone todo anything out of the ordinary.

The general review is scheduled to be conducted inconjunction with the review of the Building Act and will provideeveryone with an opportunity to table for consideration anyparticular areas of concern they may have with licensingrequirements. So watch for advertisements seekingexpressions of interest and have your say, either individually,or through industry representative groups, such as CEPU andNECA.

CHANGES TO LICENSING LEGISLATION

Page 4 The Conduit - July 2003

NEWS FROM THE CENTREspoke on the changes to the Building Act.Peter Donovan then spoke on skillsmaintenance and courses available,licensing and the role of the TCA. About20 contractors attended the morning.

In the last edition I mentioned that it isup to every electrical worker andcontractor to ensure that their licencesare current. It is also up to electricalworkers and contractor to ensure theirwork is compliant. I have investigatedsome non-compliant work recently,which indicated those concerned eitherdon’t know their work or don’t careabout what they do. When you sign aCOC you are stating that the work hasbeen carried out in accordance withAustralian Standards, has been tested,inspected and satisfies the requirementsof the Electricity Reform Act. If we receivea copy of a COC that has been signedand is not compliant, the electricalworker and contractor concerned willbe the subject of an investigation – I amsure that this is something none of youwould like to go through.

FAREWELL TO JOHN ‘PEN’ PENGILLYJohn Pengilly, known to most here inAlice as ‘Pen’, left the Department inFebruary to take up a position with

Water Resources at Power and Water.

Pen started work as an electricalinspector in 1997 with the Power andWater Authority. In 1998 he went toKatherine for one month to assist withinspections and the restoration of supplyfollowing the Katherine floods. He sawthis as a rewarding experience and wascommended for his efforts.

Pen has been involved with a fewchanges over the years. Probably themost significant was when the electricalinspectors were shifted from the Powerand Water Authority to the Departmentof Industries and Business, and relocatedto the Peter Sitzler Building. At the sametime, we became known as ElectricalSafety.

Pen stayed long enough to see one morechange and that was our relocation tothe department of Infrastructure,Planning and Environment. As it turnedout, our first day in the new office wasPen’s last. I would like to thank him forstaying to assist us with the move.

In closing I would like to take thisopportunity to wish Pen all the best inhis new vocation. I am sure he will makeit a success.

Richard DrummondSenior Electrical Safety Officer

This edition of The Conduit sees ElectricalSafety relocated from the Departmentof Employment, Education and Trainingto the Department of Infrastructure,Planning and Environment. We are nowpart of the Planning and BuildingDivision, which incorporates theconstruction industry trades of Building,Plumbing and Electrical. In Alice Springs,we are now located at level 1 Alice Plaza,Todd Mall.

This year I have kept communicationgoing by sending e-mails, faxes andletters to all Alice Springs, Tennant Creekand Yulara contractors. Our new contactdetails, skills maintenance, licensing andindustry-related courses are a few of thetopics covered in the information sentout, which I hope has been beneficial toyou all.

I have received good feedback fromcontractors with questions relating tothe mail-outs. It’s pleasing to see thatthe communication has been two-wayand I would encourage any contractorswho have questions or informationrelating to the electrical industry tocontact me and I will try to assist.Besides - it may be something I caninclude in my mail-outs.

In March I visited Tennant Creek to carryout a desktop audit, complianceinspections and meet with contractors.As a courtesy, I made contact with allcontractors prior to my visit to organiseappointments where required. Allseemed to appreciate the visit as it gavethem the opportunity to discuss anyissues they had and me the opportunityto pass on information to them.

While I was in Tennant I also attended aforum on the changes to the Building Act.The forum related mainly to the buildingindustry; however, mention was made ofwhere the Electrical Safety Unit fits inwith the building department. Copies ofthe draft are available in our office.

On Friday 14 March Peter Donovanfrom the TCA organised a breakfast atLawrence and Hanson Wholesalers.Fabio Finocchiaro from Infrastructure,Planning and Environment in Darwin

The Conduit - July 2003 Page 5

ROBIN’S RAMBLESlip Base Lighting ColumnsQuoting for a contract to install street lighting?

Does the contract include the use of slip base lightingcolumns?

If it does you must be mindful of the fact that slipbase lighting columns require the fitting of tear-awayconnectors. This is a system of cable clamp blocksand Utilux Connectors, which are designed todisconnect power to the lighting column should itbe hit by a motor vehicle.

Electrical Safety has discovered a number of instancesin both Darwin and Katherine where tear-awayconnectors were not installed on slip base lightingcolumns.

External InfluencesInstalling electrical equipment in areassusceptible to environmental influences?

Clause 1.8.6 External Influences states:

“All parts of an electrical installation shall be designed tobe adequately protected against damage that mightreasonably be expected from environmental and otherexternal influences”.

Electrical Safety has recently found a number ofinstallations where electrical equipment has beeninstalled in locations for which it was not rated. Thishas resulted in leakage in excess of 200 Volts ACposing a risk of electric shock. In one instance aworker received a shock off a standard profile lightswitch.

When installing fixtures, fittings and accessories,contractors and their workers need to be mindfulof the environment in which such items are beinginstalled and ensure the items are rated for theirintended locations.

Robin SmithElectrical Safety Officer

FAQsBy Peter Donovan, from NECA (NT)

In light of recent enquires and to address some of the confusionsurrounding the installation of RCDs, here are three FrequentlyAsked Questions (FAQs) in a series of eight from AustralianStandards addressing RCDs. Australian Standards has a newdedicated website to deal with FAQs (www.wiringrules.com.au)which can be used to gain interpretation on clauses you mayhave doubts about.

FAQ 011/2001: AS/NZS 3000:2000 – CLAUSE 2.5.2

2.5.2 PROTECTION AGAINST EARTH LEAKAGECURRENT – Selection of devices

Question 011/2001 What is the current rating of an RCDprotecting a number of socket-outlet circuits in a domesticelectrical installation?Answer: The current rating is the maximum demand calculatedin accordance with Table C1, Item B(ii) depending on the totalnumber of socket-outlets protected but no smaller than therating of the largest circuit protective device.Example: A single RCD is used to protect three circuits ofsocket-outlets, one of which is protected by a 20 A circuit-breaker and the other two protected by 16 A circuit-breakers.Each circuit supplies 10 single socket-outlets.Solution: Total number of socket-outlets is 10 x 3 = 30.Maximum demand of the 30 socket-outlets = 10 + 5 = 15 A.The rating of the largest circuit-breaker is greater than themaximum demand, therefore the rating of the RCD must benot less than 20 A.

FAQ 012/2001: AS/NZS 3000:2000 – CLAUSE 2.5.3

2.5.3 PROTECTION AGAINST EARTH LEAKAGECURRENT – Where required

Question 012/2001 What classification should be appliedto a combined heater/fan/light unit when applying the protectionagainst earth leakage current requirements of Clause 2.5.3?Answer: As such an appliance normally contains a relativelyhigh current heater, the unit is to be treated as an appliance forthe purposes of maximum demand. However, if the unit providesthe light source in a room in a domestic electrical installation,the circuit will require a residual current device (RCD) inaccordance with Clause 2.5.3.1(b).

FAQ 013/2001: AS/NZS 3000:2000 – CLAUSE 2.5.3.3

2.5.3.3 PROTECTION AGAINST EARTH LEAKAGECURRENT – Where required – Other electricalinstallations

Question 013/2001 May a socket-outlet type RCD beused to comply with the requirements of Clause 2.5.3.3?Answer: Yes

Page 6 The Conduit - July 2003

Audit adviceWhile Electrical Safety is charged withmonitoring and regulating the electricalactivities of licensed contractors, it alsohas a stated prime objective to:

Provide an education process toenable electrical contractors toproduce safe electrical installationswithin the Northern Territory.

The Electrical Safety Unit (ESU) has ateam ready to assist electricalcontractors to establish processes tocomply with each of the Acts andRegulations relevant in the NorthernTerritory. Contractors do not need towait until ‘Audit Time’ to request guidancein setting up various policies andprocedures including registers. Contacteither the ESU, or one of the ElectricalSafety Officers (ESOs) to arrange ameeting.

The 2003 Audit CycleThe 2003 cycle of auditing all NTelectrical contracting activities has nowbegun. Any business that has performedelectrical work in the Northern Territorysince July 2001 is required to undertakethe audit process. ESOs will systematicallycontact electrical contractors to confirmdatabase details and to arrange sendingout Audit Packages. The business canchoose to complete the requireddocuments by themselves (a reflectiveaudit), or alternatively request ESOs toassist them (a desktop audit).

In the event that the business has notperformed electrical work in theNorthern Territory since July 2001, theelectrical contractor is required tocomplete a declaration form attesting tothis.

The Audit PackageThe Audit Package has been revised andnow comprises:

• Compliance Measurement Handbook2003 v1 that includes ComplianceMeasurement Templates and Registers

• Compliance Measurement Question-naire v2.

The Handbook provides a step by stepguide to the process. It has beendeveloped with a view to assistingelectrical contractors not only to ensureregulatory compliance resulting in safetyto the user of the electrical installation,but also to assist them to establishprocesses and policies to supportcompliance with the Electricity Reform Act.

Believe it or not, once the policies andprocedures are established, the auditprocess becomes streamlined and can bedone with relative ease. For example, youneed the following registers that shouldbe updated on a regular basis:

• Register of Certificate of ComplianceBooks maintained by the Business

• Register of Instrument Tests

• Register of Employee Licence Details

You also need to maintain copies of (andamendments to) Australian Standards,manuals, rules and statutes relevant toyour line of work and/or speciality.

Audit Choices?When it comes to Audits, you do havesome choices:

When

If you would like to have the audit donesooner rather than later, you can contactElectrical Safety and request an early auditbe done.

There are time limits to respond to anaudit – these are identified in documentssent to you. If you need an extension oftime – request it. Northern Territory lawdrives the audit process and this meansthat penalties may apply if an electricalcontractor ignores a formal request toprovide information. On the other hand,a formal request from an electrical

contractor for a reasonable extension oftime to complete the audit will almostcertainly be approved.

Who

It is not necessary for a proprietor or anelectrical worker to complete thisdocument, however it should be a personwithin the organisation who has anintimate knowledge of the business’policy and procedure and is a dulyauthorised agent of the business. Theperson should also have a workingknowledge of the Electricity Reform Act,Electricity Reform (Safety and Technical)Regulations and the Electrical Workers andContractors Act.

In the questionnaire there are noquestions of a technical nature, howevermost questions relate to the NorthernTerritory’s legislation regarding safety andnotification. Parts 3 and 4 relate toAustralian Standards.

The electrical contractor can choose todo a reflective audit him/herself, or anESO can do a desktop audit with you, or,using a combination of the two, you canreceive guidance by an ESO in the processof doing a reflective audit. The choice isyours.

Peter Donovan, Trade ContractorsManager of the Territory ConstructionAssociation is available to assist theelectrical contracting community. He maybe contacted on mobile 0421 991 787,ph 8922 9666, or e-mail onmbant@ozemail.com.au

What

Although answering the questions in thequestionnaire is compulsory, they aremultiple-choice questions. It’s up to youto choose the correct answers!

It’s the choice of the electrical contractoras to which Certificates of Compliance(COC) will be identified for audit (5 fromeach book). Electrical work covered bythe submitted COC’s will be inspected.

To ensure the integrity of informationsupplied, Electrical Safety will collate allindustry returns of reflective audits andthen will formally audit every tenth returnreceived.

NOTES FROM INSIDE

The Conduit - July 2003 Page 7

It’s also the choice of the ElectricalContractor whether to proceed with anaudit or to make a declaration that thebusiness has not performed electricalwork in the Northern Territory since July2001.

It’s as simple as that!You have two choices

Declaration or Audit

Where

If the electrical contractor chooses todo a desktop audit, it will be conductedat mutually convenient time and placeduring a face to face interview with theESO tasked to the audit.

If the electrical contractor chooses todo a reflective audit, they will completethe Questionnaire, update the Registersand then post or fax legible photocopiesof relevant documents to the ESU.

Electrical contractors in Alice Springs,Yulara and Tennant Creek will be auditedby ESO’s from the ESU in Alice Springs.All other audits will be done through theDarwin ESU.

If your organisation has branches acrossthe Northern Territory covered by oneElectrical Contractor’s Licence theresponses must reflect the policies andprocedures actively practised in eachbranch.

Valda IoaneElectrical Safety Project Officer

ADRIAN’S ADVICE

Correctly filling in Certificates of ComplianceElectrical installations in the NT are on occasion still being certified by Certificatesof Compliance which are not correctly filled out.

Electrical installation work carried out in the Northern Territory is required bylegislation to be certified by a licensed Northern Territory electrical contractor.

Section 69 (c) of the Electricity Reform Act asks for requirements of the Regulationsas to notification (filling in a Certificate of Compliance) to be complied with.

Regulation 5 Electricity Reform (Safety and Technical) Regulations advises theCertificate of Compliance must be filled in by the licensed electrical workertesting and examining the electrical installation before the installation is madeavailable for energisation.

What are the benefits of the electrical contractor ensuring a Certificate ofCompliance is correctly filled out?

Well, importantly, the contractor’s customers are able to meet their specificduty of care using the Certificate of Compliance.

A correctly completed certificate means the customer is protected against beingin breach of their responsibilities outlined in Section 68 of the Act.

It also means your business has identified in full the extent of the work undertaken,limiting your businesses liability by not including the work of others.

If the Certificate of Compliance is not signed, not dated, or you leave off theaddress or person to whom you issued the certificate, ask yourself if theCertificate of Compliance is valid. The answer is, of course, that it’s not.

Please take care when certifying – your attention to detail supports your customerand your business.

For any further information on legislative requirements for your business callthe Electrical Safety Unit on 8924 7477.

Adrian HiggsElectrical Safety Officer

Page 8 The Conduit - July 2003

LATE MAIL FROM PATFOOD FOR THOUGHT

Equipotential Bonding andProtective Earthing

ConductorsIn an electrical installation there are threedistinct sets of conductors in the MEN earthingsystem. They are the Main Earth, ProtectiveEarth and Equipotential Bonding Conductors.

The main earthing conductor is self-explanatory.

Definitions from AS/NZS3000:2000

Clause 1.4.61 Main earthing conductor

A conductor connecting the main earthingterminal/connection or bar to the earthelectrode.

Simple enough. But what about the protectiveearth and equipotential bonding conductors?

Definition.

Clause 1.4.49 Equipotential bonding

Special electrical connection intended to bring exposed conductive parts or extraneous conductiveparts to the same or approximately the same potential, but not intended to carry current in normalservice.

Definition.

Clause 1.4.72 Protective earthing conductor.

A conductor, except a main earthing conductor, connecting any portion of the earthing system to theportion of the electrical installation or electrical equipment required to be earthed, or to any otherportion of the earthing system.

Still simple enough, you say. OK, ask yourself this question.

Question: Is the earthing conductor fixed to the metal frame of the main switchboard a protectiveearthing or equipotential bonding conductor?

Make sure you get it right because if you don’t, your installation will be non-compliant and thereforeunsafe. Because in this instance size DOES matter.

(Check on page 10 for the answer.)

Pat NolanSenior Electrical Safety Officer

Newsflash. Amendment 3 for AS/NZS 3000:2000 was released on 23 July 2003, and isnow in effect. Obtain your copy today from the Territory Construction Association oronline at www.standards.com.au.

The Conduit - July 2003 Page 9

The requirement for applicants applyingfor renewal of electrical workers’licences to evidence skills maintenanceis proceeding well. However a coupleof points to remember are:

1. Be sure to lodge a renewal applicationbefore the licence expires even ifevidence of maintaining skills is notimmediately available, as an expiredlicence cannot be renewed, resulting inthe need for a totally new application.

2. The skills that are required to beevidenced are those needed to carry outbasic electrical installation work,including the testing of that work, so thatit is left in a safe and compliant conditionin accordance with AS3000 Wiring Rules.

Working in some aspects of theelectrical industry may require skills orknowledge that are more advanced orspecialised than the basic level of skill.However, an electrical mechanic’s licenceentitles the holder to perform electricalinstallation work at the basic level at anytime of the holder’s choosing and it istherefore imperative that the necessaryskills and familiarity with currentstandards are maintained and evidenced.This generally involves the areas of cable/material selection, installation, earthingand testing, all to AS 3000 & AS 3008.1.1.

There are many ways of presenting thisevidence and they are contained in aseparate information sheet availablefrom the Board’s office. For those who

are not carrying out the type of workdescribed in the foregoing, there are alsovarious methods available, includingrefresher courses. Information regardingthese is also contained in theinformation sheet.

Disciplinary ActionsSince the last edition of the conduit theBoard has received 12 complaintsregarding alleged unlicensed or non-compliant work.

Three currently have Show Causehearings under way, five (all from onecompany) had decisions deferredpending future audits being carried out.Two were issued warnings/advice, whileone was found unproven and one is stillunder investigation.

Training of apprenticesRecently several cases have come to theBoard’s attention that raise concernsregarding adequate on-the-job training

being provided to apprentices. Whenyou employ an apprentice it is yourresponsibility as the employer orsupervisor to ensure a broad variety ofwork is carried out by the apprenticeto the extent that competency isachieved in all tasks. You should workwith the Registered TrainingOrganisation (Technical College) toensure all required areas of on the jobtraining are addressed and competencyachieved to ensure a licence outcome.

Centralian College in Alice Springsreports that the first nine SystemsElectrician apprentices trained under thenew training package sat their finalmodule (505A) in March.Congratulations to those who weresuccessful.

John Toohey, Executive Officer and PennyDeSouza, Licensing Officer

Electrical Workers and ContractorsLicensing Board

ELECTRICAL LICENSINGSkills Maintenance for Electrical Workers

Page 10 The Conduit - July 2003

STEPS TO COMMENCE AN AUDITUnless the Electrical Safety Unit has received a request fromyou to initiate an audit, then the first step will be:

1. An Electrical Safety Officer will contact you to check time/date, contact details, and ask whether electrical work hasbeen performed under your contractor’s licence since July2001.

2. If not, a declaration will be sent to you to complete.

3. If affirmative, you will be asked whether you wish toproceed with a reflective audit or a desktop audit.

4. If you choose a desktop audit, a date, time and place willbe agreed upon to conduct the audit.

5. If you choose to do a reflective audit, the Audit Packageand a letter will be sent establishing the date of the audit,thereby commencing the process.

MUNRO’SMEMORANDUM

It was brought to my attention recently thatunder the Building Act Building Code ofAustralia Volume 2 Part 3.12, as in force from01/01/03, concerning Energy EfficiencyMeasures, new houses with dark colouredroofing material are required to have thermalinsulation installed in the ceiling space.

If the thermal insulation is installed in such amanner that it is laying on the surface of theceiling it could impact on the wiring system.Where bulk thermal insulation surroundsand is in contact with unenclosed orenclosed cables they are deemed to becompletely surrounded. Where bulk thermalinsulation is prevented from completelysurrounding unenclosed or enclosed cable,such as where an unenclosed or enclosedcable is clipped to a structural member or islaying on a ceiling, it is deemed to be partiallysurrounded.

The method of installation of cables andthermal insulation in a ceiling space willdetermine the current-carrying capacities ofthe cables as per the tables in AS/NZS3008.1.1:1998. There is an increasedlikelihood of thermal insulation beinginstalled in ceiling spaces because of thisrequirement. Electrical contractors would dowell to keep this requirement in mind whenwiring houses to ensure compliance withstandards.

Fred Munro,Electrical Safety Officer

From page 8: LATE MAIL FROM PATAnswer: Protective earthing conductor.

See fig. 5.3 AS/NZS3000:2000 Page 143.

Have you held an Electrical Contractor’s Licenceat any time since July 2001?

IF YOU ANSWERED YES TO THIS QUESTION,BY LAW YOU MUST DO ONE OF TWO THINGS.

In the event that the business has not performedelectrical work in the Northern Territory since July

2001, you are required to complete a declaration formattesting to this fact.

A declaration needs to be completed and submitted.This will enable Electrical Safety to update records

indicating that an audit isn’t required during this cycle.

ORYou must complete an audit.

IT’S AS SIMPLE AS THAT!

YOU HAVE TWO CHOICES

DECLARATION OR AUDIT

If you need an Audit Declaration form, phone ESU on 8924 7478.

The Conduit - July 2003 Page 11

FROM THE MINESThere have been numerous incidents/accidents relating tocables in cable trays.

Each time the major contributing factor has been theoverloading/overcrowding of the cable tray due to obsoleteinstallation supply cable left in the tray.

The two basic rules for redundant cables in cable trays are:

1. If the cable will or might be re-used in its location:

a) The cable is to be safely disconnected and terminatedwith all cores bonded to earth and enclosed at bothends.

b) Both ends of the cable are to be labelled to indicatethe cable origin and end. Sometimes the previouspurpose and size of the cable can also be recorded.

c) Never leave an unused cable connected to a circuitbreaker or fuse holder.

2. If there is no further use for the cable in its location theentire length of cable is to be removed.

The reasons for the above rules are:

a) If a cable has not been disconnected and insulated as in 1a) above, there are risksof:

– A person making contact with a live conductor with all the implications

– A live conductor arcing and starting a fire.

b) As more cables are added or left in the cable tray, the weight of the cables willput stress on the tray and its supports beyond their design perimeters untilpossible deformation or failure creating an unsafe condition.

c) Redundant cables left in cable trays contribute to the build-up of a thermalinsulation for other operating cables around. This may lead to the cables beingunder-rated for their purpose and unsuitable for the safe performance theywere designed for.

This could also present a fire hazard due to insulation failure, possibly malfunction ofthe equipment supplied and contravene Australian Standard specifications (AS 3008.1Table 23 or 24.)

Michel RuchSenior Electrical Inspector, Mines Division

Department of Business, Industry and Resource Development.

Page 12 The Conduit - July 2003

ELECTRICAL SAFETY UNITDARWIN1st Floor, Energy House

18-20 Cavenagh Street

GPO Box 1680

DARWIN NT 0801

Telephone: 08 8924 7477

Facsimile: 08 8924 7115

ALICE SPRINGSLevel 1, Alice Plaza

Todd Mall, Alice Springs

PO Box 2130

ALICE SPRINGS NT 0870

Telephone: 08 8951 9246

Facsimile: 08 8951 9222

ELECTRICAL WORKERS AND CONTRACTORSLICENSING BOARDGround Floor, Cavenagh House

38 Cavenagh Street

GPO Box 1680

DARWIN NT 0801

Telephone: 08 8981 5435

Facsimile: 08 8999 8967 DO YOU NEED ASSISTANCE?Electrical Safety Officers are available on request to talk to you and conducteducation sessions at your workplace.

Please contact Electrical Safety on 08 8924 7477.

For all audit information and enquiries, please contact:

Valda Ioane

Electrical Safety Project Officer

Telephone – 08 8924 7478

Facsimile – 08 8924 7115

E-mail – valda.ioane@nt.gov.au