Re: Current carrying capacity of CAT5?

[Martin Howell <martin.howell@xxxxxxxxxxxx>]

Thanks to all that replied.  I searched for info as well on power over
ethernet, nd the official standard for this is either 12.95 W or 15.4W
at 48 volts, which equates to between 270 and 350mA. But then a D Link
power supply box that I found says its output power is 2.5A at 5V and
its input power is 400mA at 48V.  For those that don't know and may be
interested, POE is sent on pairs 5/6 and/or 7/8, and relies on the
powered target device telling the sender that it is able to accept power
(how does it do this if it needs the power to operate in the first place?).

I think I'm safe with my measly 500mA, but I'll fuse it anyway - no
point in preventing a water leak while simultaneously setting fire to
the house..  Thanks again, all

Martin

ian.bird@xxxxxxx wrote:

>I have a memory from a while back when this came up and it was about
300ma
>per pair (one plus, the other minus) depending on distance. I use CAT5
for
>my watering valves which draw 230ma at 12v and I have set it up so only
one
>can come on at any time. Keith Doxey was the guru answering the
questions
>then.
>
>Ian
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>---------+---------------------------->
>                    Ake Hedman
>                    <akhe@xxxxxxx
>                    om>
>
>                    03/01/2005 07:41
>                    Please respond to
>                    ukha_d
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> 
>-----------------------------------------------------------------------------------------------------------------------------
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>         To:       ukha_d@xxxxxxx
>         cc:       (bcc: Ian Bird/CV/Novartis)
>         Subject:  Re: [ukha_d] Current carrying capacity of CAT5?
> 
>-----------------------------------------------------------------------------------------------------------------------------
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>Martin Howell wrote:
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>>Just completed my pair of water leak detectors for under the
washing
>>machine and dishwasher, loads of coloured LEDs, ooh er missus.  I
plan
>>to feed them with power via the CAT5 cabling, which will also carry
a
>>copy of the status LEDs back to the central indicator panel. 
Anyone
>>know what current can be safely poked down the CAT5 cabling?  The
major
>>current is drawn by the water shut off valves, which are rated at
12
>>volts and 3 watts, by my rusty maths thats 0.25 amps each, and the
>>washing machine has a pair of valves, so 0.5 amps.  Are my lovely
>>coloured lights going to be invisible through a cloud of acrid
smoke?
>>
>>Martin
>>
>>
>>
>>
>500 mA should be fine.
>
>/Ake
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>Yahoo! Groups Links
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