If you want more interesting looking, get some pole top style medium voltage switch with mechanical operator at ground level and mount it on top of a 30+ foot pole next to their AC unit.Yes there is an upstream OCPD, breaker in a panel. The 508 disconnect is in lieu of the typical unfused disconnect switch or pullout for a residential outdoor unit. Modern style house and I was tasked to source something "more interesting looking"
I bet many dwellings you won't have over 5kA at the AC unit, but there will be some that do.You're good to go then. Just be careful when buying one. Some are only listed at 5kA SCCR, which is basically a minimum value UL allows if untested. In a typical residential application, you will need at least 10kA, unless the switch is series listed with the specific up stream breaker in that panel (whinh might only be possible if it's the same brand).