Budgeting PoE Power
The PoE switch component in a 4-port device can output a total of 64 W of power to the connected
devices, and on an 8-port device can output a total of 128 W. Each PoE port is capable of outputting 16 W to
standard PoE devices, and 30 W to PoE+ devices. This typically means that a 4-port device can support up
to 4 standard PoE devices or up to 2 PoE+ devices, and an 8-port device can support 8 standard PoE
devices or up to 4 PoE+ devices.
Advanced users can manually adjust the PoE power budget for each port to consistently accommodate the
cameras needed.
If you choose to manually adjust the PoE budget at each port, be aware that you must also account for
potential power loss in the cable. Unless the amount of power loss in the cable is known, use the following
estimates:
l
If the device uses less than or equal to (<=) 16 W — expect 2.5 W of power loss.
l
If the device uses more than (>) 16 W — expect 4.5 W of power loss.
To calculate the recommended power budget for each port, use the following equation:
Power budget =
<Camera power consumption>
+
<Expected cable power loss>
Example
: Connect the following 4 cameras to a 4-port device:
2 x HD dome cameras
( 9 W + 2.5 W) x 2 = 23 W
1 x HD PTZ camera
25.5 W + 4.5 W = 30 W
1 x HD micro dome
4 W + 2.5 W = 6.5 W
Total
= 59.5 W
The total power consumption of the 4 cameras is within the PoE switch component limits.
Note:
If you miscalculate the required power for a PoE port, the connected camera may be shut
down if total power output exceeds 64 W.
Budgeting PoE Power
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