If you have installed your WAX650S access point (AP) and recognize that the limited power is on, the likelihood is that it's requiring 802.3bt (max 60W) of PoE in order to ensure full power mode.
If the WAX650S is using IEEE 802.3af PoE or IEEE 802.3at PoE Plus, the limited power mode will be preferred because the WAX650S, technically, requires 31 Watts to ensure the full power mode that enhances throughput.
The LED lights could also indicate that it's in limited power mode:
What could happen if force power mode?
If the WAX650S is forcing the full power mode, the AP will use the PoE power that it needs, which means that it will utilize max throughput no matter if it has the PoE needed for it or not.
Note! If the 802.11at is not enough for WAX650S, the WAX650S could begin to restart itself.
You will find the user guide for WAX650S here: