Extension Lead Test - Page 3

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Re: Extension Lead Test



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 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



Re: Extension Lead Test


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Today I was working with a colleague doing a network cable
installation in a local club.
While there, I noticed an black coloured extension cable of
approximately 15 metre, with moulded ends (ie: not home made) that
was clearly marked 0.75 mm sq on the cable.

If not for recent discussions on this forum, I wouldn't have even paid
attention to it.

It stood out because the writing on the black cable was in white. It
was connected to an urn.  I would guess this would easily be a 10a
load.
The urn wasn't on so I don't know how hot it would get. I informed the
person in charge that the cord was illegal and should be destroyed and
replaced.
He claims that they bought a quantity of extension cords of various
lengths along with  "disco" type lighting (spotlights, lasers, chasers
etc) from a "reputable  (and PA) equipment supplier on the Gold Coast
and there was nothing wrong with the cord, it worked fine".
There were heaps of them used in their "nightclub" area for all the
disco lights, and also for plasma screens etc.

They couldn't get them anywhere else in black colour and "other
colours glow under the UV disco lights".
Told him that by all means keep them, if you want to risk a fire, and
to be responsible for the consequences.

Re: Extension Lead Test



"kreed"

While there, I noticed an black coloured extension cable of
approximately 15 metre, with moulded ends (ie: not home made) that
was clearly marked 0.75 mm sq on the cable.

It stood out because the writing on the black cable was in white. It
was connected to an urn.  I would guess this would easily be a 10a
load.

The urn wasn't on so I don't know how hot it would get. I informed the
person in charge that the cord was illegal and should be destroyed and
replaced.

** Where did you get that idea from ???

The 1 sq mm conductor, 10 amp rated extension cable I tested reached its max
safe operating temp of 75C with 24 amps passing through it.

A simple calculation shows that a 0.75 sq mm version would dissipate the
same heat per metre if the current were 21 amps. ( 21 squared / 24 squared
= 0.76 )

So there is a big safety margin above nominal for both cables and the
difference in current handling is fairly small.

Most IEC leads use 0.75 sq mm and so do many extension leads.


.....   Phil




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