I am (re-)designing the electrical wiring of a yacht. The design includes several isolation switches (details see below). Basically there is one switch for each source of power (battery, PV panel, etc.) and another switch which separates all consumers from all all power sources.
Is there any official regulation which specifies which of them must be designated the "main switch"?
I intended to make the switch before the consumers the "main switch" as this way all consumers (except for the Cerbo GX) are cut-off and cannot draw any power while the PV panels still charge the battery. However, I was told that the main switch which must be switched off when leaving the yacht must be the battery isolation switch. Is that so?
More details
On the producer side there are three PV arrays (backboard, steerboard, aft) each with its own Smart MPPT and a Phoenix for on-shore power. Together with the battery everything runs into a distribution box which I call the "charger distribution box". Besides MCBs for each producer and the battery, this distribution box also contains a series of isolation switches which allow me to individually separate each producer from the others. Mostly, this allows me to perform future maintance work on each of these components without shutting down the entire system. On top, this distribution box also includes a 3A MCB to feed the Cerbo GX.
From the "ingress distribution box" one wire runs to another distribution box which I call the "main DC distribution box". That one contains another isolation switch at the entry plus MCBs for each branch circuit feeding all the different DC consumers (i.e. navigation lighs, radio, pantry appliances, outlets, etc.). My idea was that the isolation switch in that distribution box should serve as the "main switch".
An aquaintened harbor master told me that the main switch (i.e. the switch one has to be set to "off" when one leaves the boat) has to be the battery switch. However, he couldn't refer me to any official regulation.
I hoped that it would suffice to cut-off all consumers, except the Cerbo GX, of course, when I leave the boat. The Cerbo must keep running to control the charging process, of course. I wonder how I am supposed to charge the batteries while I spend a day onshore.
