It is unclear. Most AHJs do require working space in front of the condenser disconnect. The strange thing is the same guys don't seem to care about the air handler, that might be in a closet or up in the attic where is no way you can push Jim Pauley's mythical refrigerator box up to the disconnect (a rough idea of what working space looks like that he uses in his road show).
If we are talking resi, clearance issues on new construction arise when 'who is there first'. When the EC is doing trim out for finals, he mounts the discos at the location. The CUs are dropped after, and sometimes the disco is behind them, or the tall units block the disco.
When the AC line set is in & charged, guess who has to move what??
Replacement CUs usually are OK. Best comment I can add is each job has to be treated individually.
The world is not even perfect at my house We put in a mini split and I wanted the condenser set near the existing one but about 3' away so I would maintain my 30" in front of the grouped disconnects with a little wiggle room to spare. I even put the pad in with the center that far away. The <expletive deleted> installer put it near the close edge of the pad!!! I ended up with about 28" as far as we could push it without running another line set. Fortunately the inspector left his yard stick in the truck.
Putting A/C condensers (water heaters etc) above the FEMA flood plane has been standard here for years if the finished floor of the home is FEMA compliant. You see blocked up platforms under the condenser or water heaters in garages that are below the FEMA level.
If the house is grandfathered below FEMA, they usually ignore the water heater and AC.
Is that an indication of where FEMA says the flood plane is? We see that at the beach where they have to build piling houses. These days the FF is about 14 feet off the sand and that is up hill from the water. They are usually 10'-12' higher than the road out front.
In one of the towns I inspect, the town gave people permission to raise their houses as long as it was the height that was governed by FEMA. The heights were different in several parts of town. Needless to say, the closer you were to the river, the higher the flood plane was. They will even allow you to build a new house in the flood plane, but there is no basement and no walls on the first floor. The water has to be allowed to flow in, under, and around the house. So all of your utility services enter in on the 2nd floor.
The water and sewer comes up out of the ground and is wrapped around with all sorts of protection from cold, inside of a hollow column.