Secondary of a transformer has a 400A switch fused at 225A and feeds a panel in another room. The panel showed up with a 400A main breaker by mistake. At this point the main breaker only serves as a disconnect. Are there any code issues with not changing the main to 225A? Just identify in the panel that the breaker is disconnect only?
Michael, this "sub-panel" actually needs no main breaker. So I wouldn't do anything if not questioned. If it became a major problem, why not remove the breaker and install lugs?