hey dude, welcome to KC forums!
this map is a favourite of mine because of the AC to C switching forces you to keep an eye on already cleared areas
btw it's not random it happens when the amount of creeper or anti creeper goes past 2147M in a cell, it will then switch to the other state, so in this map you need to vacuum up the AC and "park it elsewhere" or prevent the fields from compressing it by shielding the areas it's being forced to.
hope that helps a bit.
take it easy dude