INTELLIGENT BRANDS // Cabling
ACCELERATED DEGRADATION
OF BALANCED TWISTED PAIR
PERFORMANCE DUE TO THE USE
OF REMOTE POWERING (POE+)
Excel Networking discusses the effects of repeated and
extended heating of Ethernet cables.
I
t had been observed during testing
carried out in conjunction with De
Montfort University in 2014 that
heating due to remote powering over
twisted pair cables appears to degrade
the cable performance. With power
heading towards 100W, this could be
significant.
In fact we even witnessed failure within
the cable bundles when thermally
insulated and operating at this high
power and hence temperature, this
was presented in the Proceedings of
IWCS 2014. In this present study, we
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INTELLIGENTCIO
assessed the performance degradation
of balanced twisted pair cable by
repeated heating cycles for both
temperatures within the standards
specification and beyond.
It was suspected that repeated heat
cycles would lead to accelerated
ageing of the compounds used for the
dielectric insulating materials around
the conductors, which in turn would
lead to changes in the performance
values of the cables when tested.
Part of these assumptions were based
upon work being carried out by SPIE
the Specialist Plastics Industry group
who are looking to launch similar
research in conjunction with UL
(Underwriters Laboratory) after they
had related concerns regarding the
performance of the cladding materials
used in fibre cables.
The tests in the study thermally
cycle the cable from an ambient of
+20 degrees up to an ambient of
+70 degrees to see if there is any
substantial ‘knee point’ in behaviour.
Also, to assess the performance
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