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Extension Lead Test

P

Phil Allison

Jan 1, 1970
0
** 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
 
B

Baron

Jan 1, 1970
0
Phil Allison Inscribed thus:
** 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

25 to 30 amps. :)
 
S

Swanny

Jan 1, 1970
0
Phil said:
** 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

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

Metro

Jan 1, 1970
0
Phil Allison said:
** 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
I don't know the answer.You must remember thought that the 75c cable rating
is the highest temperature of the environment that a cable of that rating
can be used. Could you explain what the rating of your cable has to do with
your project. Presumably you didn't have any protection for your cable
otherwise it would have tripped.

Metro
 
P

Phil Allison

Jan 1, 1970
0
"Baron"
Phil Allison Inscribed thus:

25 to 30 amps. :)


** 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
 
D

David

Jan 1, 1970
0
"Baron"


** 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.

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
 
P

Phil Allison

Jan 1, 1970
0
"David the Psychotic Autistic Pedant"

Fact is Phil has no idea.


** 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
 
M

Metro

Jan 1, 1970
0
David said:
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
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.
 
D

David

Jan 1, 1970
0
"Phil the Psychotic"



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


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.
 
B

Baron

Jan 1, 1970
0
Phil Allison Inscribed thus:
"Baron"


** 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.

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

Phil Allison

Jan 1, 1970
0
"David Eather"
Phil said:
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 ...


** 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
 
M

Metro

Jan 1, 1970
0
Phil Allison said:
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.


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.
 
P

Phil Allison

Jan 1, 1970
0
"Metro the Masturbator "


** Get back to perusing your fat chick porn sites.

You vile, know nothing, fuckwit TROLL !!





....... Phil
 
P

Phil Allison

Jan 1, 1970
0
"David Eather"
Phil said:
Yes, anyone *can* - but mostly they don't,


** 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 .......


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


** 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.

But, you might be surprised that if you were their employee, many larger
companies would not thank you for your diligence.


** 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
 
A

Amigo

Jan 1, 1970
0
David said:
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
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.
 
D

David

Jan 1, 1970
0
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.


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
 
J

John Tserkezis

Jan 1, 1970
0
** You think Chinese copper has more ohms than others ??

You bet your arse it does. (see my other thread on this)

Of course, they use less copper, and just blatantly lie about it on
the label.
 
J

John Tserkezis

Jan 1, 1970
0
Phil said:
** 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.
Indeed.

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.

And this crap will STILL be imported regardless. Kinda like saying you
don't like that particular droplet of ocean water, and the tide is
coming in. Are YOU going to stop it?

Worst still, no-one was likely to find out because these power cords
are supplied for low power gear that will never heat the cable above spec.
Till of course they take that particular power cable and plug it into
something that DOES take 10A, all the while wondering why they're left
with a smouldering mess.
 
J

John Tserkezis

Jan 1, 1970
0
kreed said:
With everything having moulded plugs now, once you cut it, you have to
replace the plug.
I think that the current test is a better idea, especially if you have
a lot of them to test.

It's all bullshit.

We did our own cable testing in-house at my last job, and I assure you,
the cable tester did not in the least care about current (or perhaps)
resistance testing. And as long as it got an OK from the tester box, we
signed the label, and the auditors were happy as pie.

We tested it with the chinese bullshit IEC power cables, and all of
them passed with flying colours. All they do is check to see each wire
goes to where it's supposed to, and there isn't high voltage leakage
between them.

Passed with flying colours and I routinely threw them out because I
could not, and would not trust them.

The supplier doesn't care. The most you'll do is legally *make* them
supply real cables and throw out the fake ones.
Per unit product price jumps by $10, and your supplier of $15 chinese
hard drive cases now charges $25 for the same thing.

And you're still paying $15 because you're now shopping from his next
door neighbour who still hasn't been nabbed yet, especially since your
first supplier has since gone out of business, and you're sourcing real
leads cheaper in quantity from elsewhere anyway.



*THAT* is reality, and how does this help *anyone*?.
 
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