Extension Lead Test

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** Hi to all my friends,

following on from the "Appliance lead" thread  -  I was motivated to test a
length of nominal 10 amp extension lead, the kind you buy at a K-Mart store
or similar and marked as using 3 x 1.0 sq mm conductors with a 75C temp
rating.

I used a 300VA toroidal tranny modified with a heavy gauge overwind that
produces 3 volts rms at 30 amp continuous to drive current into a 1.1 metre
length of the above cable, with the blue and brown conductors linked at one
end. A Variac allowed the current to be adjusted from zero upwards to about
50 amps (short term only).

Finally I tied the head of a K type thermocouple lead tightly onto the
outside of the above cable it's mid point.

With the 1.1 metre length of cable lying on the bench, I increased the AC
current in steps until the thermocouple meter read 75C  -   it took half an
hour or so to finally stabilise.

How many amps did it take to reach 75C ??

Take a guess.



....   Phil



Re: Extension Lead Test


Phil Allison Inscribed thus:

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25 to 30 amps.  :-)

--
Best Regards:
                     Baron.

Re: Extension Lead Test


"Baron"
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** Close -  the cable stabilised at 75 C when passing 24 amps.

Temp rise above room ambient was 50 degrees C.

At this temp, the cable itself is still perfectly safe to use but the
possibility remains that the plug and socket may get rather hot if the pins
are not reasonably free of tarnish.

Fact is though that 24 amps will soon trip a 16 amp or even 20 amp breaker
in the AC supply circuit.



....   Phil






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Fact is Phil has no idea. Take a guess at how long a 20A circuit breaker
will take to trip at 24A? For extra credit, how long will a 16A circuit
breaker take to trip at 24A?

At least Phil has acknowledged he was wrong last time when he was
talking about 15A breakers, and has used the correct ratings.

Note that the current rating for flexible cable subject to flexing is
taken for a maximum temperature of 60C (ambient 40C). Where flexible
cords are used as fixed wiring, higher temperature rise is permitted (ie
higher current).

David



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"David the Psychotic Autistic Pedant"


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** So says a grossly autistic, anonymous, lying lunatic pedant.

BTW:

The only good pedant is a DEAD  one.

I do sincerely hope David the Pedant's death is not soon  -

but rather as long and agonising as possible.




.....  Phil




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take to trip at 24A? For extra credit, how long will a 16A circuit breaker take
to trip at 24A?
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about 15A breakers, and has used the correct ratings.
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for a maximum temperature of 60C (ambient 40C). Where flexible cords are used as
fixed wiring, higher temperature rise is permitted (ie higher current).
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Whats up Phil?

Unable to answer a simple question about a circuit breaker?

How long will it take to trip to trip a 20A circuit at 24A? Not a really
difficult question if you have any idea about circuit protection.

How long is "soon"?

You really should have tried to complete Uni. You might have learnt a
little bit about electricity. Fuse and circuit breaker behaviour was
probably covered in third year subject.

Come on Phil, you must have an some idea. Go out an buy one if you must.
Be careful though you don't blow the one fuse supplying power to your
apartment.

David

Hint. Think hours rather than seconds.


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 One wonders why Phil in his project twisted the blue and brown cores
together? He should have bared the ends and held each end between finger and
thumb. He would then easily find out at what amperage the breaker would
trip. 'nough said really.



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I think you are being a pedant, David.

One thing I do believe is that Phil A is pretty competent and knowledgeable
with electronics/electrical and I wouldn't hesitate to ask him to work on
gear of my if he would do so.


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Phil *thinks* he knows everything. Fact is that he does not. When some
one dares to correct him, or point out something Phil does not know, he
becomes very aggressive, and attacks the person, and then repeatedly
posts the same attacks as he has nothing else positive to contribute.
You only have to read this thread to see this.

Fact is that Phil could only manage to complete two years of university
before being kicked out. Fact is that Phil is not even a licensed
electrical contractor (and does keep up with the latest standards). As
evident in previous he thinks "15 amp breakers are usual in the power box".

Phil also *thinks* that 24A will trip a 20A breaker "soon". Because Phil
thinks this, that must be true, and nobody better disagree. Fact is that
a 20A breaker may take 2 hours to trip on 20A. Don't take my word. Look
it up on a circuit breaker manufactures web site, and see the time vs
current tripping curve.

Electricity is something that you really do need to know about, and
being pedantic about it may well save peoples life. Look at the
insulation debacle to see why.


David


Re: Extension Lead Test


Phil Allison Inscribed thus:

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That mirrors my experience !  The contact faces are the weak points...
Phenolic stinks.

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--
Best Regards:
                     Baron.

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A guess, based on the probability that it is a no-name Chinese cable,
about 16A.

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7.5A

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"David Eather"
 Phil Allison wrote:
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**  You think Chinese copper has more ohms than others ??


....   Phil



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No, but I buy a lot of stuff from China. My experience is just because
the manufacturer says it has "whatever" specification there is no
guarantee as to the truth of the mater if the market is competitive or
an extra dollar can be made - examples might be fake pharmaceuticals,
pet food filled with melamine because it improves the result of fixed
nitrogen tests and 200Amp jumper cables with lots of plastic but less
copper than a single 10 amp conductor (not kidding - "Supercheap" got
stuck with thousands of them)

My experience is about 70% of stuff is as spec, 20% is usable but
deficient in some way eg missing features, missing accessory, lower
rating etc, and 10% is just crap. Which means you either have to always
deal with shipping agencies and companies you have found reliable or
always know that your taking a chance of your money disappearing in
return for nothing of value.

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"David Eather"
 Phil Allison wrote:
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** Wot a lot of piffle.

Anyone can check and see if the conductors are really 1 sq mm copper inside
or simply compare the self heating with another known lead connected in
series.

If that lead had really reached 75C with only 7.5 amps  -  I would have
notified the relevant safety authority and all hell would then break loose
with product recalls and the lot.



....   Phil




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You must remember though that the 75c cable rating
is the highest temperature of the environment that a cable of that rating
can be used.  It has nothing to do with the amperage of the conductor. It is
the insulation
that is the rating. It is the job of the breaker or overload to control the
load.



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Yes, anyone *can* - but mostly they don't, that is until someone gets
burnt (no puns intended) or some external force points out in an
undeniable public way that there is already a fly in the ointment.

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I have no doubt that you would (and it is the right thing to do of
course) and there would be recalls.

But, you might be surprised that if you were their employee, many larger
companies would not thank you for your diligence. Finding such a problem
would point out failures in the management and control structures (hence
faults with the top management) and a string of incompetences all down
the management line and now that the problem has been pointed out (ie
they are aware of it) they are liable for damages caused if they don't
take steps to fix the problem.

This is much worse than if there becomes a public problem (like someone
else's home burning down), when they are not liable because the product
was properly certified as complying to Australian standards and it is
not their fault that some overseas dodgy supplier lied and cheated
(hence the various pushes to get supplier certified).

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"David Eather"
 Phil Allison wrote:
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** Only takes  ONE  consumer to notice the  BLOODY OBVIOUS and report it to
the safety authority.

You are deliberately IGNORING  the facts of this * particular *  situation
and fabricating a false argument.

I suspect nothing I say will stop you from continuing to do so.

The bee in your bonnet is indeed a very busy one  .......



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**  Thing is, the makers and suppliers of such extension leads are also well
aware of the  VERY  SERIOUS  repercussions of the blatant and CRIMINAL type
fraud you blithely imagine can easily be happening.

My comment about 'all hell breaking loose' was meant quite literally.


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** True enough  -  but irrelevant to the issue here.

On more than a few occasions and while acting as a concerned outsider  -  I
have felt compelled to inform particular businesses & companies in Australia
that they were making, selling, advertising or publishing things in a way
that was VERY  FAR  outside of what is fair or legally acceptable practice.

For my trouble,  I have received in consequence threatening letters from the
culprit's lawyers, several very hostile phone calls, an attempted smear
campaign against myself and my own small business in one case a direct
threat against my personal safety.

The culprits involved are mostly very well known to readers of this
newsgroup.

You don't need to tell me anything.



....  Phil



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- A0%I
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Regardless of what you may think of Phil,
I fully believe this and would advise others to consider this advice
carefully before any action.

& would add that with QLD state government, they don't just threaten,
they act.
Assuming other states are as bad, be very careful if you start on a
gov department,
especially if they tell you they aren't interested in your complaint
(no matter how legit).

Personally now know 2 people who have tried this, and one paid a very
high price..



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Yes, I remember cases of this type being exposed on this group going
back to at least 2002.
IEC leads.
I still remember a certain dickhead who despite the technical facts,
continued to argue the point.




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Re: Extension Lead Test



"kreed"
"Phil Allison"

Yes, I remember cases of this type being exposed on this group going
back to at least 2002.
IEC leads.
I still remember a certain dickhead who despite the technical facts,
continued to argue the point.


** That poster was called  "Miro".

A blow-in from "aus.photo" and "alt.satellite.tv.australasia".

Wot a lunatic.



....  Phil






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