Do they have main disconnects? If not, how do you figure out the total amperage?
Most of the condos I have seen out here have the main out by the meter (much like apartment complexes). They are usually consolidated together so the meter reader doesn’t have to walk all over creation to check the meters. Try checking there.
The feeder for that panel is required to have an OCPD protecting it. As Thomas menitoned they’re typically located adjacent to the metering equipment.
Are these panels essentially acting like subpanels? Should the grounds and neutrals be floating in these types?
The typical situation I see is a row of meters in a common area, each with a disconnect.
Then a subpanel inside each apartment or condo.
Thus, it’s a subpanel, a true subpanel. The main is somewhere else.
See NEC 250.32 and related for rules about bonding neutral and ground.
You can prove this is a subpanel by adding up the amps of all the breakers, and noticing that number is far above any any reasonable current. There must be another breaker.
The same would apply in a service panel
The panel shown is a “sub-panel”. The neutrals are isolated from the enclosure and there is a separate EGC bus that is bonded to the enclosure just as it should be.
Yes, upstream usually at metering equipment.
Unknown ampacity when Unknown ampacity. Limitations: Ampacity.