Wiring things together

[Spoonman]

Yes, I realize I'm probably overthinking, but I'm a computer programmer by trade and in my world most problems are caused but 'under-thinking' so I'd rather spend a lot more time thinking about the problem, getting answers, and then solving it once the right way.

I now have several gauges of wire, some red and some yellow, and I have most of my plan for wiring navigation lights, interior lights, and interior fans. What I'm wondering about is splicing wires.

It doesn't seem like a good idea to run one set of wires from the electrical panel and back for each individual light. Wiring them in parallel makes the most sense. The current wiring has one positive 12g and one negative 12g wire running from the electrical panel near the companionway to the forward-most light. All of the lights in between have 14g wires spliced into the 12g. It appears that some insulation was removed at key places along the 12g wires so that the ends of the wires going to lights could be wrapped around the exposed 12g wire, soldered, and then shrink-wrapped.

In my reading I have seen some explanation of soldering this type of connection but I have also seen 3-way terminal connectors. What do people really use in the field these days?

The wrap and solder approach seems kind of old-school to me while the 3-way doesn't seem to have a good way to shrink-wrap the ring which would leave exposed metal in the middle of the wire. I have also seen a step-down butt connector used. In this configuration I would cut the 12g, put 12g on the small side and put both the continuation of the 12g and the beginning of the 14g that goes to the light in the big end. Or maybe there's another way.

I'm open to some real-world suggestions about splicing into the 'main line' 12g wires so that I can hook up my lights. I'm also open to a completely different plan if modeling my new wiring after the old wiring is a bad idea.

Spoon

[Maine Sail]

Most professionals will use a terminal strip for that application with crimped ring terminals or at a minimum captive safety spades.

Soldering only is strongly frowned upon by the ABYC for wire terminations and best avoided if you are not, proficient at soldering and also are not mechanically crimping the terminals. Coat the t-strip with noalox or nooxid and you'll be fine.

I am not a big fan of the three way crimp devices as the rivet they rotate around has a tendency of getting loose over time and creating a resistance point.

[Spoonman]

... and had suggested that I go that route in another thread. It is interesting how varied opinions are on any given topic.

The biggest reasons for rewiring this boat (1972 Creekmore 48) is that I think I'm dealing with the original wiring, some of the wire is copper (not tinned copper), some of the wire has no writing on it so I don't really know what it is, the splices are all soldered and wrapped, and all of the wires are bundled together ('all' meaning AC, DC, data cable that go up the mast, and even the stereo speaker wires). Most importantly I'm rewiring so that I can learn how to do it and so that I'll know exactly how it's done.

My understanding of things is mostly theoretical with little practical experience but I'm trying not to let that slow me down. I do plan to get professional help on the AC but it still appears to be surprisingly simple to wire: black, white, green - don't get them confused.

Spoon

[donradclife]

Buy and read Nigel Calder's Boatowner's Mechanical and Electrical Manual: How to Maintain, Repair, and Improve Your Boat's Essential Systems.

One of the reasons for running individual ground wires to each fixture is to eliminate connections, which are the most common failure points.

[Spoonman]

the 12-volt Bible and Don Casey's book Sailboat Electrics Simplified. Since these are some of the most oft recommended books I have them and have read quite a bit. As a result, I find that the generalities are the same across all 3 books yet the details vary and in few cases do I find 2 of the three authors in agreement on the details.

As a result, I have many questions.

So, I'm not sure what you mean when you say "One of the reasons for running individual ground wires to each fixture is to eliminate connections, which are the most common failures points."

My options appear to be 3:
1) run a positive and a ground from the electrical panel to each individual fixture (seems like overkill and a waste of wire)
2) run a positive and ground from the electrical panel to a terminal block or fuse block amidships and then run individual positive and grounds to each individual fixture from the terminal block. (This approach feels like the best answer, but I don't really know)
3) wire the boat the way it is currently wired: one positive and a ground to the foreward-most fixture and back with each individual fixture along the way tapping into the positive and negative wires (this approach seems to add a lot of connections and requires a lot of soldering).

Nigel Calder doesn't describe how he would wire a set of 5 lights placed at various points throughout the cabin. Don Casey says to wire them in parallel but doesn't describe how he would do it other than to say that 3-way butt connectors are used for tapping into a circuit and that step-down butt connectors can be used to connect two wires to one. Miner Brotherton (12-volt Bible) describes soldering in detail but does not describe how he would wire 5 lights in parallel.

So far it appears that there are two people who've read my posts who like the terminal block idea and one who doesn't.

Anyone else want to weigh in on the proper way to wire these lights?

Spoon

[mitiempo]

I use terminal blocks. It is the neatest way to run branch wires to various fixtures. I don't like the 3 way crimp method.

[Maine Sail]

Originally Posted by Spoonman

Anyone else want to weigh in on the proper way to wire these lights?

Spoon

There are a few "proper" ways to do this and either a direct run or parallel run is okay, series would be a non-preferred method as would soldering the connections without crimping them also. Direct runs for each light are over kill and even high end builders don't do this. It takes up capacity in chases and can de-rate the current carrying capability of the bundled wires in the conduit or chases.

Crimp three ways terminals can be used but are horribly un-reliable in my experience. As a result I have not used one in perhaps 12-15 years. I see plenty of them and they are often a corroded or loose point of resistance.

Step down butts with two wires in one end and one wire out the other are also often used but I personally dislike this method as your wire diameter is rarely if ever the "right" size for the crimp terminal. I also use adhesive lined heat shrink crimp connectors so why waste the money if you can't get a 100% water tight seal. Two wires in one end will not seal with heat shrink.

Terminal blocks allow a lot of variability and are easier trouble shooting. Coated with terminal grease they can last for as long as the heat shrink connector.

I will generally run a main feed for something like the bow cabin lights including v-berth and head. I then pull off each individual light, with it's own wire, from the centrally located terminal strip. This usually keeps the individual runs for each light, from the t-strip, to less than 10 - 12 feet and saves a ton of wire when compared to running all the way back to the panel.

I always prefer the t-strips to be easily accessible and not buried or hidden. Therefore I do not use them at the individual light fixture to feed/daisy chain over to the next one as they would often be buried behind a head liner.

There are many ways to do this. Most reputable pros I know choose terminal strips. If you want to wire you boat safely you may want to join the ABYC, they offer individual memberships at a reasonable cost, and get the standards.

[nickmerc]

Spoon,

I rewired my entire boat (except the mast) two winters ago. I was fortunate in that my supplier for the components was very close by and offered lots of free advice. It was cheaper than joining ABYC for rewiring one boat and I still had access to the standards as well as a professional to answer my questions.

I ran a negative wire of heavier gauge (it will depend on your electrical loads) down each side of my boat with bus bars in key locations. I then ran a positive wire for each group of components to the farthest location and had terminal strips located in easily accessible locations along the way that I could "splice" into. For the terminal strips I put them in plastic boxes with covers to prevent accidental contact. I found some cheap ones at a large electronics supply house that fit my terminal strips perfectly. The boxes keep hands, metal objects, and water from contacting the positive terminals. This is mostly due to old habits from my industrial machine building days.
________
MELROSE COLLECTIVE

[hellosailor]

Spoon, you can also use spade terminals (qd's) without using the 3-way ones. Since a yellow crimp accomodate 10/12 AWG wire, it will also accomodate 2x12AWG wires. So, you can cut the main 12AWG wire that runs all the way forward, strip bith sides of the cut, and crimp them both into one yellow terminal connector. Now you plug in the 14AWG run to the one fixture, mating up to that one connection, but you've got a "3way" connection.

There are also guillotine splices, like a 3M "scotchlok" (?) block, where you slip it over one unbroken wire, insert a tap wire, and squeeze down on the "guillotine" in the middle, which slips down and makes the two contacts. IIRC 3M says they are not to used where there's a lot of vibration since the guillotine can also become a cutter, but they seem popular in the auto shops and that vibrates a lot more than boats do.

There's more than one way to skin a cat, and a lot depends on the individual care you take about making connections, how well they are made, strain relieved, mounted, tied off, all that stuff. Do a robust and clean job, and the odds are it will be a good one, regardless of which process you use.

[peikenberry]

Spoonman, you're not over thinking. This is a subject that requires a lot of thinking. The first think you need to do is do a diagram fo what you want to do. I agree, get a copy of the ABYC (American Boat and Yacht Council (ABYC) - Welcome) standard E-11 and follow it religiously. see New Boatbuilders Home Page - Electrical System Planning. It's aimed at builders but applies to anyone planning wiring on a boat. By the way those different colors are due to the wiring color codes. New Boatbuilders Home Page - Electrical Wiring Color Codes

I don't like spliced wires. I prefer terminal blocks. Most boat fires are electrical in origin and almost all due to high resistance connections that overheat. The more connections the more chance of problems. High resistance connections can be due to loose connections but on boats more frequently to corroded connections.

Soldering is not banned or disallowed. What ABYC says is that solder can not be the sole means of support. A lot of people crimp and solder. I prefer crimp.

Separate those AC wires from those DC wires! It is too easy to get things mixed up. DC and AC panels should either be in separate panels or if in one panel box, clearly separated. ABYC requires that the AC side of a panel box have some sort of shield to keep from accidently contacting the AC circuits while working on the DC.