Is this a commercial Pool?If yes then what state is the pool located in? Different states, different codes.Some methods are: based on water volume, surface area, flow rate. Some have a combination of...
If you mean the maximum occupancy of a room, then several things are considered. The square footage of the room, the room's purpose, and the number of emergency exits that exist are factored in.
Generally, devices designed for use on an AC circuit cannot be supplied from a DC supply. The reason is that whereas DC loads are simple resistances, so current is calculated by volts divided by...