I have a question, You have an new in ground pool and a new pool cabana. Instead of running a 100 amp sub panel feeder to the cabana, they run it to the pool filter panel. Then they run a 60 amp feeder into the pool cabana. The Cabana has a sub panel with 7 breakers. The main breaker for the cabana is just outside in the pool filter panel. Does the cabana need a main breaker?
Most separate building services would say yes unless there is just 1 branch circuit. There is a main 2 pole 60 amp but instead of it being in the cabana, it is just outside in the pool filter panel.
How far is the disconnect from the point of entry to the cabana?
The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors.
The pool panel is just outside the back of the pool cabana. There is a storage area under the cabana where the sub panel for the cabana is located. A breaker lock would also service the purpose, however if you read the code, you are "Suppose" to have a main inside a separate building. This is another spot in the code, where you actually have to see the install in order to make the right call.
For the record, I think that most EC's would have run the feeder to the cabana, then out to the pool panel, not the other way around.
OK, lets change up the situation a little bit. If the panel in the cabana has under 6 breakers, the main can be outside. OK, However what if the cabana has more than 6 circuit breakers? Would you need a main now? (6 operating handle rule?)
The NEC has looked at this differently over the years. Originally there was the 6 handle rule, then they started talking about "lighting and appliance panelboards" and imposed a 2 breaker rule on them. In 2008 they removed that and we are back to 6 handles in most situations. You still need a main breaker (protected by an overcurrent protective device having a rating not greater than that of the panelboard) but 408.36 says it can be anywhere in the supply like the start of the feeder in the originating building. At least that is how I read it