Exploring more of the odd Redstone behaviour of some RotaryCraft machines.
The problem appears to be that some Redstone wires/conduits won't connect to them when they should. For instance, place a ProjectRed red alloy wire or an EnderIO redstone conduit next to a CVT or an ECU and they won't connect. They still react in some way to the Redstone signal in the adjacent block but they'll do unexpected things. For instance, the ECU won't shut off the engine on top of it completely (according to the animation it's still running and if it's a gas turbine you'll still get damaged standing behind it) but it will cease to use up fuel or generate power.
This can be circumvented by using a way to transport the signal that outputs directly into the machine without the need to connect. Options are Project Red integrated circuits (you must place them directly next to the machine) or Engineer's Toolbox modular sockets with redstone output or redstone logic modules.
But I think it's a bug nonetheless. I don't know which mod would be responsible, but redstone-transporting wires and conduits should connect to machines affected by redstone signals.