RE: Current carrying capacity of CAT5?

["Keith Doxey" <ukha@xxxxxxxxxxx>]

One important thing to bear in mind is that the melting point of the
insulation is far lower than that of the wire itself.

Once the insulation on the conductors melts the conductors will short
circuit and there will no longer be a heating effect over the length of the
cable carrying ?mA but the heating effect will be limited to the portion
between the short and the power supply and the cable will now be carrying
whatever current the PSU is capable of supplying.

Correct fusing is VITAL to protect from fire in the event of this
happening.
Also bear in mind that the insulation on the conductors is very thin and
can
split if the cable is crushed leading to short circuits as well.

If you are bunching pairs you also have the risk of a single conductor
breaking which would not stop things working but would mean the remaining
conductor(s) would be carrying a heavier current.

Keith

> -----Original Message-----
> From: Martin Howell [mailto:martin.howell@xxxxxxx]
> Sent: 06 January 2005 17:48
> To: ukha_d@xxxxxxx
> Subject: Re: [ukha_d] Current carrying capacity of CAT5?
>
>
>
> Am I reading the table correctly?  If the CAT5 wire is 24AWG copper,
the
> 'fusing current' - presumably the point where the wire melts  - is
> 29amps?  I guess the more important rating is that where the wire gets
> hot enough that the insulation and everything around it catches fire?
>
> Martin
>
> Ake Hedman wrote:
>
> >Found a good table on the upper limits on different cables FI.
> >
> >Fusing Current of Wire in Amperes (approximate)
> >http://www.speff.com/
> >
> >Regards
> >/Ake
> >
> >
> >
>
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