12V Negative - Shared or Per-Circuit?

[dohenyboy]

Calder has it right when he suggests sub-panels. It is so much easier to wire and to trace problems.



Why can't things remain where i carelessly left them?

[Terra Nova]

Use separate individual grounds run to a common ground bus, not numerous ground buses.

[a64pilot]

Originally Posted by dohenyboy

Calder has it right when he suggests sub-panels. It is so much easier to wire and to trace problems.

That I think is ideal, but possibly not warrantied on smaller, simpler boats.
But there seem to be far more electrical items now on a boat compared to say 30 yrs ago though, I think a lot of us are running out of panel space, I like home run circuits, I dis-like sneak circuits, but home runs require a lot of breakers, hence the sub panel.

[hellosailor]

Running a dedicated ground to each device can prevent some esoteric problems like ground loops, but that's normally not a concern on a small boat. Lots of extra wires, extra costs, extra weight, all NEEDLESS, really.


You might consider a compromise if you are worried about efficiency an reliability. Run a separate ground wire for each subsystem, i.e. one to a common point for the instruments (which are usually near each other), one to the helm, on up each side of the boat for the port/starboard cabin lights, perhaps on for the mast lights....


Failure of the ground bus isn't, or should be, a major concern if your wiring is at all competent. Striping the wires, also not a concern if you are using an automatic wire stripper, which can spread back the insulation without cutting the wire, make a splice and cover much neater and stronger and quicker afterwards. Or a vampire tap of any kind. A hot wax glue gun can be used to secure those splices to the hull, so they are protected from movement and chafe as well.


If you want to run duplex all over...bear in mind, you won't be able to use ABYC color coding, or any other kind, for your wiring. Duplex will invariably be red and black, or red and yellow, and all look the same. Either way, generous use of a Brother P-Touch can help you keep them sorted out for future reference.

[Terra Nova]

Originally Posted by hellosailor

...Lots of extra wires, extra costs, extra weight, all NEEDLESS, really...

Where do you come up with this stuff?

[hellosailor]

Do me a favor, tn, go to the user controls in the forum, add me to your ignore list, and make us both happier. 'bye.

[Terra Nova]

Your previous post qualified you for wiring advice ignore.

[lateral]

Originally Posted by Terra Nova

Use separate individual grounds run to a common ground bus, not numerous ground buses.

Agreed!

What turned out most convenient for me was running duplex color coded but wth single stud common ground pts at strategic places so as to make use of heavier guage return to grounded bus at switch board.
Only one actual ground point, but several "nodes", to avoid loops.

[Frankly]

Sub panels with a common feed and return make a lot of sense (electrically and economically). Usually all circuits are not drawing at the same time so the voltage drop is less. I build small panels with a little black box (from our dearly departed Radio Shack), three or four breakers and a ground bus no big effort.

My little 32 ft IP has 4 in addition to the original rather generous IP panel. Bow equipment, steering pedestal electronics, navigation station, and the 30 amp engine feed.

Commercial buildings have been wired that way for years.

Frankly