I have a system where the current output exceeds what I am allowed to add to the 200A bus in the main panel, so I will be installing using taps. My AC output conductors run through a 60A fused disconnect, then to a gutter where I will make my taps. I was told by an engineer that the conductors from the load side of the fused disconnect to the gutter need to be run in RMC. Is RMC the only option I have here? I've been searching the code with no luck. Can someone clarify this for me?