I don't believe so. For example a water heater might require a 40A circuit but after the incoming terminal block only 20A conductor might be run to each element.
Than can you explain why the NEC (and UL) will not allow supplying that WH with a 100 amp feeder?
Or why HVAC equipment has a maximum breaker size listed on it?
Just because the 'protection' does not mirror 240 and 310.16 does not mean that the breaker does not protect the appliance wiring from bursting into flames before the OCPD opens.
In your water heater example what would you say does protect the conductors from short circuits if not the branch circuit OCPD?
I am not trying to bust your chops, we just see this differently.
Bob.
