Greg the moment you install the fused disconnect it becomes a feeder.
royta
I do not see anyway out of connecting a grounding electrode.
I would install a small breaker enclosure mounted at the units to serve as the OCP and disconnects
I would verify what the feeder wire size is and see if 50 amps is the max. OCP allowed.
Use the correct conductor rating and round up to the next standard breaker size. This may allow you to go larger than the 50 amp OCP now in place.
If it happens to be 6 Copper 75 C wire you may be able to use a 70 amp breaker.
Look at the ACs tag, if it needed a 50 amp breaker the minimum circuit ampacity is likely to be in the high 20s to low 30s.
How big is the new unit?
Bob
