when you say powered, you mean they don't receive electricity, or they aren't powered automatically?
if they aren't powered automatically, and you're using redstone wire to power them all at once, you should be aware that sometimes, when exiting a game and leaving a powered redstone line on, the redstone signal losing it's effect, and it requires a refresh. if that's the case, refresh it, or switch to levers (by attaching them directly to the macerators them self)
in case i'm wrong and you meant that no electricity pass through the cables, then you should double check your converters output/input directions, and if the MFSU has electricity inside, which is above the minimum requirement output
if you're only powering macerators, you should might as well consider moving back to MFE and skip the MV transformer. just for testing, that is.