Playing horde round about the wave 40 mark you should get all 4 power taps available to spawn, spawn each of them like you would in King of the hill, by standing in the circles. To do this faster do this on beginner, just so you won't die so quick. And AFTER the wave has started get 4 players in your team to stand by them then press and hold X until you claim the fabricator power, should pop a minute after. EASY!
Quick edit. You cannot do this without 4 people in your team. One power tap per player. It won’t work if one person collects power from multiple power taps.
This can now be done with all players (including Jack)
Can also be done on Horde Frenzy a lot earlier as there are only 12 waves