Power Nodes are strategic neutral buildings found in skirmish maps that are able to be captured by any player participating in the match. Power Nodes may be captured by any valid unit by right clicking on the node and having the unit spend the necessary time to turn the node to your (team's) control.
To turn a Power Node to your (team's) control, a unit must spend 20 seconds in melee range of the node after having been ordered to capture by right clicking the node. If the node is already under enemy control, it will take 15 additional seconds to decapture the node from the enemy before it can begin being transferred to your (team's) control.
If a node is not fully captured (unit did not spend the full 20 seconds), the capture process will not be reversed instantly but will deteriorate quickly, until a squad moves to finish the process or until the node's capture process is completely back to the neutral position.
If a node is in the process of being captured by an opposing player (or team), it cannot be captured by you(r team) until the capturing enemy squad is destroyed or ordered to do anything other than capture the node. If one of your (team's) squads begins the capture process, the node will instantly revert to full neutral position, and the 20 second capture process will begin.