JAjun wrote

With the power of 12,7W the EAP245 will fit the range of 802.3af.

No, it won't. 802.3af assumes that due to line loss only 12,95 W out of 15,4 W is available for the powered device. Since there should be a reserve capacity, the specs of needing 802.3at are most likely correct. In practice this means that an EAP245 could probably also work with a 802.3af-compliant power source on short cable distances, but if the EAP is under heavy load the PoE source could be insufficient to keep the EAP running, thus leading to sporadic power outages.