dallmeier SDF5450HD-DN, Commissioning Manual

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20 Rev. 1.0.0 | © 2019 Dallmeier | www.dallmeier.com
SDF5450HD-DN Commissioning
If you operate the device with Power over Ethernet (PoE), observe the following
notes:
NOTICE
Damage to the contacts of the RJ45 connectors by contact erosion when un-
mating the jack-plug connection under PoE load
Un-mating the jack-plug connection while transmitting PoE power causes ero-
sion and pitting by electrical arcs on both the jack and plug contacts (especially
when repeatedly un-mating the jack-plug connection under PoE load).
Electrical arcs are generated, since the electric potential difference (voltage) and
therefore the intensity of the electric field between the contacts rises sharply
when un-mating the jack-plug connection.
The more un-mating cycles are carried out under PoE load, the higher the loss
of contact material due to metal evaporation by electrical arcs, which in turn
accelerates the material erosion process on the contact surfaces.
Damaged contacts with an increased contact resistance may lead to a reduced
data transfer rate, unreliable network connectivity or even total device failure.
➡
Always disable PoE on the relevant port of your PoE switch (or PoE midspan
device) or disconnect the used single-port PoE injector from the power sup-
ply before un-mating the jack-plug connection in order to prevent damage to
the contacts of the RJ45 connectors by contact erosion.