Users Guide

Table Of Contents
Switch Feature Overview 85
Table 2-6. Class-based Power Management
In four-pair mode, for classes 0-4, twice the power listed in Table 2-6 above is
delivered. Classes 5 and 6 may be two, three, or four-pair power. Classes 7 and
8 are four-pair power. For information about the available system power, see
the Hardware Overview chapter.
Power Management in Guard Band
All Dell EMC Networking PoE-capable switches support a dynamic guard
band, which means that the guard band used varies depending upon the
following factors:
Power management mode
Class of the device being powered up.
Prior to a device being powered up, the switch calculates the following:
threshold power
guard band
(current power consumption + computed
power draw of the new device)
If this value is less than zero (which means powering up the new PD device
will put the total power draw into the guard band or above the switch power
capacity), then the switch does not power up the new device. A device being
Class Usage AF/AT Device (Watts) BT Device (Watts) PD Type
0 Default 15.4 4 1 802.3af
1 Optional 4 4 1 802.3af
2 Optional 7 7 1 802.3af
3 Optional 15.4 15.4 1 802.3af
4 802.3at
or
802.3bt
30 30 2 802.3at
5 802.3bt NA 45 3 802.3bt
6 802.3bt NA 60 3 802.3bt
7 802.3bt NA 90 4 802.3bt
8 802.3bt NA 90 4 802.3bt