Is AC feeder bus ok to use?

[Frankly]

Have not seen AFCI breakers used on a boat, but you are correct about mixing neutrals but difficult to arrange in most applications.


Orca what you show should work. There is no reason to drag the circuit neutrals and grounds onto the breaker panel if you can find a fixed back panel to mount them on. Makes a cleaner wiring situation.

A lot of AC circuits but should never run out.

Don't forget a galvanic isolator in the shore power ground.


Frankly

[NPCampbell]

The only non-common sense thing that I have read about ELCI circuits is that you need to keep your inverter fed neutral and ground busses separated from your shore power fed neutral and ground busses. It may trip the ELCI breakers if they are shared.

[BAD ORCA]

Originally Posted by NPCampbell

Are you just daisy chaining the hots but home running the neutrals? I don't know if AFCI is used on a boat or marinas but if you end up sharing neutrals between circuits it can trip AFCI breakers.

The neutrals im not 100% sure yet. I probably will end up connecting them to the neutral bus on the panel but use terminal blocks between the end of the load neutral and the neutral bus on the panel just to make it easier and neater wiring. im not sure if thats still considered a home run?

im working with pretty limited and tight space so this may dictate how i end up doing some of the wiring.

[BAD ORCA]

Originally Posted by Frankly

Have not seen AFCI breakers used on a boat, but you are correct about mixing neutrals but difficult to arrange in most applications.


Orca what you show should work. There is no reason to drag the circuit neutrals and grounds onto the breaker panel if you can find a fixed back panel to mount them on. Makes a cleaner wiring situation.

A lot of AC circuits but should never run out.

Don't forget a galvanic isolator in the shore power ground.


Frankly

ok cool thanks. thats what im probably going to have to do. there is no good area directly behind the panel for bus bars and terminal strips so i may have to mount them all to a piece of plexi or plywood and mount it a couple feet away. from there i will run whatever wires i have to up to the back of the panel. they didnt put the distro panel in a very good place on my boat. unfortunately i will have to make due though until later in the year when i can move it to the nav desk.

[Wotname]

Originally Posted by NPCampbell

The only non-common sense thing that I have read about ELCI circuits is that you need to keep your inverter fed neutral and ground busses separated from your shore power fed neutral and ground busses. It may trip the ELCI breakers if they are shared.

AFAIK you should only have one set of neutral busses. It can be connected to the shore power feed OR to the inverter feed but never both together.

But I might be wrong

[BAD ORCA]

Originally Posted by NPCampbell

The only non-common sense thing that I have read about ELCI circuits is that you need to keep your inverter fed neutral and ground busses separated from your shore power fed neutral and ground busses. It may trip the ELCI breakers if they are shared.

interesting. i'll file that away in the back of the mind until the time comes to install an inverter. this will be my first ELCI install so im going to take my time and install one circuit at a time and test it before adding another.

[NPCampbell]

Originally Posted by Wotname

AFAIK you should only have one set of neutral busses. It can be connected to the shore power feed OR to the inverter feed but never both together.

But I might be wrong

What you say is correct if something is physically disconnecting your inverters neutral from the shared bus. Is that actually done though? If you can run both the inverter and shore power at the same time then I believe you need separate neutral busses.

This is my understanding (electricians feel free to correct me as all my knowledge is pure theory from an EE background with absolutely zero practical experience):

1. You always want the current on the hot legs to equal that of the neutral legs or protection breakers will trip.
2. Neutral and ground should only be tied together at the source of the power so that all the "returning" current takes the neutral instead of some of it returning via ground.
3. An inverter behaves as a power source so ground and neutral are tied together internally in the inverter.
4. If shore power shares a neutral bus with the inverter, part of the shore power neutral current may take the path to ground that is available in the inverter via the shared neutral bus, tripping the protection circuits on the shore power breakers.

Therefore, if you are using shore power to charge you batteries and run your A/C but your inverter is driving your outlets then you have the potential to trip ELCI breakers if they share neutrals.

This exposes the error in the statement that "electricity takes the path of least resistance". Electricity will take every path available to it unless one of those paths is at absolutely 0 resistance.