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2 Supply voltage
The Web-Thermometer can also be operated either using PoE
or from an external power supply.
1
Connecting an external supply voltage and a PoE infra-
structure at the same time is not permitted.
The current draw can be found in the technical appendix.
2.1 PoE-supply
In PoE environments (Power-over-Ethernet, IEEE802.3af) power
is provided by the network infrastructure. The device supports
both phantom power using data pairs 1/2 and 3/6 as well as
power feed using the unused wire pairs 4/5 and 7/8.
The Web-Thermometer is a device in PoE Power Class 1 (power
consumption 0.44 to 3.84W).
2.2 External supply
As an alternative to PoE power supply the device can also be
powered by an external power supply connected to the screw
terminals on the underside of the housing. A half-wave rectifier
makes the input reverse polarity protected. AC or DC power
may be used, whereby the following limit values must be
observed:
•
AC: 18Veff (- 10%) - 30Veff (+10%)
•
DC: 12V (-10%) - 48V (+10%)
When powering with DC voltage polarity must be observed: