Generators are two massive ANMCs are unique in that they do not attack Aya Brea but are a threat because they are powering a barrier that is keeping Aya from entering the lowest recesses of the Shelter known as Neo Ark. They are known as dynamos in the introduction of Neo Ark meaning that they are capable of generating power indefinitely. Both fights are virtually identical and the control panel that is regulating them must be controlled to kill the Generator otherwise they just regenerate.
This is the first Generator encountered. This is not a threat and is encountered in the lower of the two floors of the generator complex. This, along with its "brother" is not a threat but are protected by Watchers which can prove to be a pain.