Gus (augie47) is correct.
250.142(B) Load Side Equipment states " Except as permitted in
250.30(A)(1)and
250.32(B) a grounded conductor
shall not be used for grounding non-current-carrying metal parts of equipment...........
Exception # 1....existing installations under section 250.140
While the NEC may not often spell out or directly state that
a 4 wire must be run for an appliance, you have to look at what has not been stated or implied. Logic dictates that if you can't use a grounded conductor to ground an appliance then you must use an equipment grounding conductor. By the same token, if an appliance requires a neutral you can't use the equipment grounding conductor in place of the neutral.
There have been many
opinions stated here as to whether or not 4 wire circuits are required for appliances. You have to bear in mind that while we all believe "A man's home is his castle" that doesn't mean that you can wire your house to your liking. At some point in time you'll sell that house and then it will become someone elses castle and one that has not been wired to code. The NEC provides a means to insure that houses built are wired to current code specs.
Another thing that was mentioned in this thread is whether or not a receptacle is required. If an appliance is
fixed in place like a dishwasher or double wall oven a receptacle is not required but a breaker lock-out is. If an appliance is movable like a range/oven then a local disconnect means is required. Personally speaking, I'd rather use a cord/plug/receptacle configuration behind the range than an A/C disconnect.