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Brent

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Just came home from the local chandlery with cat eye lights nav lights to mount on the CS. No more stealth night sailing. Can someone remind me what size wire to use for a 12v circuit with a run of about 18 feet drawing 0.8 watts?

I am planning a flush mounted stern light also, plus a mast head light on the mizzen. Havent figured out how to get wires up to the mast head light in a way that can easily be dis/connected for easy mast handling. So clever solutions for that are sought also.

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I recommend 14/2 gauge Ancor marine grade stranded.

.8W=12V nominal X .067A, right?

Not much of a load, but the larger gauge will effectively have no drop. You could use 16 gauge too. Do not use solid wire.

On my 24 foot sailboat, I have a red/green light on the bow, a white stern light, a mast under sail light, a mast head anchor light, and a deck lamp off the mast too. I run 16 gauge on the branches and 12 gauge from the batteries to the jboxes. On power hungry runs, like the 12v outlets or the autopilot, I run 10 gauge. Always use stranded. I will sometimes use non marine grade wire since I am not building or planning on any off shore cruisers, but when in doubt and can get it, I use the marine grade. Don't use any wire with paper in its insulation. I like Beldon and Alpha products. THHN single stranded in conduit or just bundled and tucked works well too. I started using that in the Navy and on many special machine projects in some terrible environments. Seal up the connections to minimize water wicking into the wire. I could go on for hours about wire, having spent a career as a controls engineer/designer. What I hate is the "marine tax" you get with anything having "marine" in the name. There are many just as good or better options if you spend time studying the standards from which the "marine" product derives.

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Great info guys, Thanks.

My local boat supply places only carry single conductor wire, and it is pricey. I am thinking that two conductor will make for a cleaner installation. So far I have only found 100 foot spools online; about 60 feet more than I will probably need. Haven't ordered anything yet, thot I would look around a little more.

I was planning soldered connections where ever possible. I suppose these should be covered with something more sophisticated than electrical tape...

Probably will go with one of those portable jump start type batteries.

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Brent- as an individual you can solder if you want to. As a professional builder I can't . Soldered connections aren't "code" Code requires crimped, using marine grade wire. The soldered connections are felt to be more brittle and subject to vibrational damage.

Just for your information :)

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I think there is something in the latest Practical Sailor about crimp vs. solder. According to that and per Charlie, crimping is better, provided it is done correctly, but it often is not. If a good crimp cannot be made then solder it. Personally, I only use solder when I must, and then anchor the wire to minimize mechanical movement.

Charlie, what code are you referring to?

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I know the CG has Codes applicable in this area, though I find it odd that soldering is unacceptable, being they do it all the time in the automotive industry.

Only thing I can think of (correct me here) is that marine grade wire is copper coated with a 'tin or solder' type of product (right??). So, when you solder, you break down this protective coating within???

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Don't think the NEC/NFPA covers it.

Nope , these folks have NO jurisdiction in these matters. Just trust me on this , as I have worked as Fire Marshal (no mis-spelling, this is correct)in charge of such. It is the Coast Guard and 'their' code which which applies, or another 'maritime' code. .

:)

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I believe you. Now to find the codes. Being an engineer for so many years, and engineers live and die by the specifications and codes, I want to look any applicable codes over. My guess is that there are standards adapted by the commercial boat building companies, maybe an umbrella group of them to standardize specifications. I will search the CG codes issues online, then call the local CG if needed. If you discover a link, would you share it with us? I will do like wise. I like codes. They are the result of lots of experience and disasters. This helps keep from making old mistakes over and over.

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Wow! What a wealth of information. I obviously dont know much about wiring boats, but apparently know some people who do! I really appreciate all the comments. As a result my boat will get wiring that is better than I would of come up with on my own.

Brad, Defender has everything I need to get the job done. Thanks for the link.

Jake, Charlie, Greg I am looking forward to what you come up with in the way of codes. Like Greg said, these codes are written on the hard experience of others. Not a bad place to start for sure.

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The "code" that you are referring to is the ABYC (American Boat and Yacht Council). It is a the basis for the safety standards for most of the world many countries adopted it in whole, such as Australia and I think Canada and in the EU, the ISO standards were plagiarized from it! We became members 20 years ago. Their standards are very sensible and are adopted after working with the USCG. NFPA, ASTM, UL, USGregs, among other organizations, and of course members of the industry etc...They are constantly updating and revising as new materials and techniques are introduced. The book of standards is large and heavy and you get updates several times a year.

While the standards are voluntary in this country, the insurance industry has adopted the ABYC as their standard, so if a boat does not meet the ABYC it may not be able to get insurance. We have been surveying boats for 20 years to this standard.

It is probably not worth the money for an individual amateur small boat builder to join the ABYC as it is quite expensive and most of the standards are outside the scope of the needs of the home builder. If you are building a cruising boat you SHOULD join for at least one year and get the book of standards. However the ABYC does offer an electrical section only made for the professional marine electrician, individual builder, or boat owner who wants to do his own work.

I will synopsize part of what the standard concerning solder says:

8.15.15: / 9.17.12.8...joining...must be able to withstand a tensile force equal to the value shown in .... then in 8.15.19: Solder shall not be the sole means of mechanical connection in any circuit....

The main problem with solder is that it creates a rigid point and in a boat that is not a good thing. I've seen vibration do a lot of negative things to both electrical and plumbing systems on a boat.

Just to quickly touch on some of the other issues that were raised - yes there is a marine wire. No it is not just expensive house wiring, it is really different and much better. It is tin coated and has heavier waterproof insulation and yet maintains flexibility. Yes there are standards for the color coding on a boat and no they are not the same as for a house. RV etc... I think marine wiring is worth every cent and would never use anything else. While here, let me just make a comment or two based on my years of observation about boat wiring. DO NOT ever use wire nuts. Keep your AC and DC sides wired correctly and separate. Never use the incorrect outlets for AC/DC. Electrical parts, even marine are relatively cheap in the scheme of things - a fire which destroys your boat is NOT.

For those who would like to have the ABYC electrical guides for AC and/or DC, you can contact the ABYC at: www.abycinc.org

We could go on and on on this subject, but won't bore everyone to sleep!

Those that are interested can get the standards and if it doesn't apply, you can wake up now! :roll:

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Pretty much what I figured. This is how the boiler codes were arrived at in the US. Once the insurance companies required following a certain standard, everyone else eventually followed.

I will get the ABYC electrical code. Last time I looked it over was 10 years or so (I think). There were many manufacturers of wire which met the code then, but did not bother to apply a "marine" label or go through the cost of doing so due to the very limited market. Same wire as the marine grade. Tinned wire, multi-stranded, number of strands, twist per foot, capacitance, inductance, etc.....same stuff, just not graded as marine. Most insurance companies have a clause somewhere in their requirements that say in essence that it must meet a given specification. What forces so many to comply with the "marine" grade sticker is the threat of law suits. Same sort of thing has destroyed several industries in this country in the last 20 or 30 years. If I were a commercial boat builder I would do exactly as you do...use marine grade wire. That gives you the best protection from law suit, if not necessarily the best products to use.

Greg.

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OK, I just joined ABYC and ordered the standards CD. Should be some fun digging through it.....yeah, only something an engineer would like :lol:

Since I do occasional boat repairs for people around here, I need to have this. That's what I am going to tell my wife anyway. She won't believe me, but......

Thanks, Graham (and Charlie)! :)

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  • 2 weeks later...

OOPS! :oops: :oops: I must eat crow on this one; NFPA No 302 "Fire Protection Stands for Motorcraft".

Learn somethin' new everyday! Now the UFC doesn't have jurisdiction! :) But that is going away here and we are adopting the IFC! :)

More confusion...in actuallity, the NEC is really a section out of NFPA, that has generaly been adopted as the 'standard'. NFPA 70 is 'electrical' (UFC 85) which in turn became the NEC. Then depending upon where you live, there are local amendments, just to make life interesting. :D Now if we throw UL in there........ :roll: :roll:

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It is worse than you think. All the standards in the USA reference each other in a merry go round sort of way. When a standard says one thing then references a different standard saying something else and so on it becomes a real mess that only a pay off to an inspector solves. NEC is a part of NFPA, which references IEEE which references ISA which references UL which references NEC, etc. Another ringer is the "local" codes, which starts another ring around the rosy. :roll:

This is based on over 30 years as a controls engineer working on projects.

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Then you know the pain this becomes! They do all reference each other, then you have to watch which edition or printing or???

Then, which code has the higher authority in a conflict (this is also a fun one to run through)! Wow, we could go on and on with this, huh? ;) ;)

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