question

matthias-nagel avatar image
matthias-nagel asked

Battery switch vs. yacht main switch: Must they be the same?

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.

wiringswitchyacht
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
cardy01 avatar image
cardy01 answered ·

Hello

The relevant European Standard is EN13297:2022 which is referenced from the Recreational Craft Directive.

That says that a battery disconnect switch shall be installed in the positive conductor of a DC system (from memory all the Victron schematics I have seen have disconnect switches for every battery bank) which is I think what you describe.

It then says there are exceptions: one of which is "charging devices intended to be used when the craft is unattended" and cites solar panels as an example, these need protection by fuse or breaker as close "as practical" to the battery terminal.

Your Harbour Master may be quoting you his own harbour regulations ..... I leave you to draw your own conclusions.

1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

matthias-nagel avatar image matthias-nagel commented ·
The relevant European Standard is EN13297:2022.

Thanks. I‘ll order a copy.

It then says there are exceptions: one of which is "charging devices intended to be used when the craft is unattended" and cites solar panels as an example, these need protection by fuse or breaker

This exception comes close to what I expected and makes a lot more sense.

Your Harbour Master may be quoting you his own harbour regulations .

No, he wasn't quoting anything. I asked him for the source of that information and he told me that this was "common knowledge" and it had always been that way and that he has been in that job for decades. So the typical urban legends based on dangerous, half knowledge and individual conclusions.

0 Likes 0 ·

Related Resources

Additional resources still need to be added for this topic

Victron Wiring Unlimited PDF

Victron Wiring Unlimited Online