ACU build time is no 60,000, compared to the energy cost of 5,000,000. Basically, when a T1 engineer is ordered to assist a damaged acu, it will repair it for -416 energy per second.
To help alleviate this problem, we should increase ACU build time 100x, to 6,000,000. That way, T1 engineers will only use 4 energy to repair it.