WIRE TYPE AND POWER DISTANCE
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The distance capability of wire is dependant on its ability to deliver DC power, and separately, to deliver high-frequency
data signals.
The graph below shows maximum power delivery when using a 56V power supply. If you are locally powering your
camera (or other remote device), then this graph does not apply. The graph on the next page shows the maximum data
delivery rate.
A Distance Calculator can be found at www.nvt.com.
PoE devices require a minimum of 43V to operate. With a 56V supply, we have up to 13V of allowable voltage drop on
the wire.
The voltage will dip in proportion to the remote (camera) load. The graph below shows what PoE power distances are
supported for various loads and wire types.
●
Start with the camera wattage at the left. Sometimes IP cameras are listed as to their PoE Class rather than wattage.
●
Now read over to the right until you find your kind of wire. Then look up (feet) or down (meters) to find your
maximum distance.
●
If your wire is not among the examples, simply measure its total resistance and find the value on the right side of the
graph. The maximum supported wattage is on the left.
Network Video Technologies
(+1) 650.462.8100 • +44 (0) 208 977-6614
nvt.com • [email protected]
Figure 3 - Power Distance
