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 Return to top of page · Post #: 1 · Written at 6:47:43 AM on 27 August 2011.
Tinradio's Gravatar
 Location: Sydney, NSW
 Member since 22 April 2011
 Member #: 884
 Postcount: 29

Further to Brads mention of this on the Home page. During the week whilst using a heat gun to remove vehicle decals a burst of electricity shot through the extension lead right next to the female plug.Flicked off power & removed from power point.Informs the boss who not surprisingly remarks to give him the lead & he`ll replace the plug! "We need to get the work done quickly" says he.(a typical every day, ten minute response which sadly our multi national company uses) Huh,you fix that,you use it yourself.You are neither licenced nor oh&s conversant.In the interim he dug out a 10 amp cheap lead.So with intrepidation i`m using it ever fearful of what may happen again. cheers


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
Back to Mono

 
 Return to top of page · Post #: 2 · Written at 8:50:46 AM on 27 August 2011.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5628

That's a fairly common scenario.

In the home, anyone is allowed to fix appliances and extension leads. Only fixed wiring is regulated by laws in each state and territory and whilst not uniform, they are fairly similar in scope.

In the workplace there is more consensus on getting trained specialists to carry out all types of maintenance work. I'm unsure if laws exist that prohibit unlicensed people carrying out repairs to appliances though, for example, there'd be plenty of people who fix washing machines for a living that do not have an electrician's licence.

For the sake of reducing liability however, a lot of businesses would get qualified people to do even such basic tasks. I am in charge of eight maintenance staff where I work and trades do not cross paths - meaning that electricians don't repaint walls, plumbers don't construct walls, painters don't lay new sewerage lines and carpenters don't stand at lathes or milling machines. The boys do help each other when it is a big job but the appropriate tradesman or craftsman oversees the high-tech bits of every job.

On a slightly unrelated note, in the past few years in Silicon Chip, a magazine I've enjoyed reading since it was first published in the late 1980's debate has taken place on the touchy subject of the need for electrical licencing.

Some people believe there is little harm in allowing unlicensed people to work on the fixed wiring of their own home, citing that most people who feel confident in doing-so will have a good idea of which wires go where.

Unfortunately this is not always the case and rarely is so. Commonwealth Government statistics show that in recent years 67% of those who are electrocuted each year in Australia were either unlicensed or innocent by-standers. 75% of those electrocuted died in the workplace. The total number of electrocutions each year in Australia varies from year to year but averages at around 35 people.

There's more to consider when running cables than just being able to connect wires in the correct polarity. As dictated by the SAA Wiring Rules:- how long is the cable run, what will the cable be feeding (lights, powerpoints, fixed appliances, etc), how many 'points' will be connected to the wire, what environment will the wire be laid in, what is the minimum-sized conductors allowable by law. Electricians are trained to deal with these issues on a daily basis and it becomes second-nature to them. Unlicensed people are seldom likely to consider most of these things. Because of that I do not support the official view of Silicon Chip that unlicensed people be exempted from the current licensing arrangements. In my time I've seen too many flameouts, incorrect wiring sizes, rough workmanship, incorrect labelling, etc to think that relaxing laws could be justified. This isn't to say all unlicensed people will mess up, just a fair proportion of them and the sole motivation for doing unlicensed work is to save a few bob, when in reality the cost of getting an electrician in is buying the customer a legal and safe installation that should last at least 50 years.

What I just said above can also apply to extension leads. Whilst the plug and socket on an extension lead are always rated at a minimum of 10 amps, the flexible cord itself will not always carry this load. If you are using a palm sander then a $16 orange/yellow job from Bunnings will do the job nicely. If you are using a welder, then it may be wiser to consider a better quality option with Australian-made cable and make sure the lead is fully uncoiled to prevent meltdown.

In all states and territories, flexible cords have to be tested for continuity, polarity and insulation between conductors on a regular basis. A visual inspection of the condition of the lead, plug and socket is carried out at the same time and then the lead must be either tagged if tests are passed or taken out of service if one or more tests fail. Each state has different requirements depending on whether the site is a workshop, kitchen, laundry, office, etc. In workshops and on building sites most jurisdictions require this testing to take place monthly. Employers can be fined heavily if such testing does not get done at the required intervals. Forgetting or 'because we can't afford it' is no excuse and I think 'employer' also means middle managers and immediate supervisors - scary, though if people do the right thing then there's nothing to worry about.


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 3 · Written at 9:43:41 AM on 27 August 2011.
STC830's Gravatar
 Location: NSW
 Member since 10 June 2010
 Member #: 681
 Postcount: 846

More than likely what has happened is that over time repeated flexing of the cord at the female plug has caused the strands of wire inside the cable to break one by one until the wires remaining melted like a fuse.

To minimise the flexing at the plug don't flick the cord to move it and treat it with care generally.


 
 Return to top of page · Post #: 4 · Written at 10:59:36 AM on 27 August 2011.
Larry's Gravatar
 Location: Mildura, VIC
 Member since 5 May 2011
 Member #: 896
 Postcount: 108

Agreed, Always go for Aussie made cables & fittings, Stay away from The Chinese brands, They are often full of flaws


 
 Return to top of page · Post #: 5 · Written at 9:13:48 PM on 27 August 2011.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 3867

Best one I have seen recently was a guy get a tickle from an electric drill. It was Bizzare; There was a continuous loop of bare wire through the insulation?

This just had to have happened in the wire manufacture.

This loop lurked just under the strain reliever and finally worked enough wire out to be touched. When I inspected it I realised it was on Neutral which really should not be that lively.

I tracked down every lead that the thing had been plugged into. Finally getting to a power board that had been rewired and the Neutral & Active transposed.

Should there have been a Residual Current trip, it would have triggered. To my knowledge in Vic. on construction sites there must be RCD's and tagged cables.

I can tag leads legally in Vic.

Do Not depend on RCD's if you are using a Variac (Slide regulator) Below around 160VAC a 30mA RCD will not trip.

Marc


 
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