Basic Electrical System Info?

MQMurphy · Post by **MQMurphy** » Sun Dec 04, 2005 5:57 pm

Need a reference source for basic info on boat wiring. I have a project boat (1967 24' f'glass sloop built in Nova Scotia) that needs a little of everything and a lot of some things. My previous boat owning/sailing experience was with a wooden Thistle I owned 25 years ago. There's a panel with 6 switches labeled "DC24V" - does this mean I've got to have 2 12V batteries connected, or is this a max rating for the switches?
Thanks.[/b]

Post by **Tim** » Sun Dec 04, 2005 7:58 pm

24 volt electrical systems are common in some areas. Perhaps that's what your boat has...or perhaps it's just a panel that someone found and installed in the boat. If you have 12 volt batteries connected in series, rather than parallel, then you have a 24 volt system, as your panel suggests.

MQMurphy · Post by **MQMurphy** » Sun Dec 04, 2005 9:07 pm

Thanks, Tim. Actually, I don't know what sort of system the boat had. There were a couple of 12 volt batteries sitting in the boat, but not hooked up. I'd really like to see something that will tell me what gauge wire should be run from the battery location to the panel and what gauge from the panel to the various devices (lights, bilge pumps, etc.) Also, I'm assuming that the battery location should be in the lazarette - correct? There are two platform kind of things in that compartment and I assume that one would be for a fuel tank (the outboard installs in a well there) and one would be for the battery. Have I mentioned my cluelessness? Maybe that is the absolute wrong location for the battery ( . . . ies?), but I don't see any other indications of previous installations. Some previous owner had done a few 'interesting' things to the boat. Some of them probably due to impatience or expedience - I'm not pointing any fingers, I know there'll come a time when I'll take a shortcut - things having to do with hardware and fasteners. I'd like to run all new wires, so if there is a sort of basic primer on elec systems I'd be interested. Thanks.

Jason K · Post by **Jason K** » Sun Dec 04, 2005 9:21 pm

While I have somewhat mixed feelings about Don Casey's books, they are, if nothing else, simple. One of which deals with electronics:

http://www.amazon.com/gp/product/007036 ... s&v=glance

I haven't picked this one up, but it is well reviewed by Amazon readers. They are pretty cheap books and it may be a good place to start.

MQMurphy · Post by **MQMurphy** » Sun Dec 04, 2005 9:38 pm

Thanks, Jason. I'll put in an order for that one. What do you like and not like about Don Casey's books. I am totally unfamiliar with him - let me give you a little bit of a picture - does every new sailboat guy or gal read Slocum's "Sailing Alone Around the World"? I'm reading it online. Trying to immerse myself, and there just isn't enough daylight here in NJ these days to stick to the boat jobs.

Peter · Post by **Peter** » Sun Dec 04, 2005 10:02 pm

Mike:
My re-reading of Slocum's book rekindled my love of sailing after a 35 absence. If you like that one, he wrote another that's one of my favorites: "The Voyage of the Liberdade".

Don Casey also wrote a book called "This Old Boat". It's sort of a compendium of all his smaller books. My only complaint about it is the quality of the sketches ... his smaller books are better illustrated.

Jason K · Post by **Jason K** » Mon Dec 05, 2005 12:30 am

Don Casey is certainly very knowledgeable and I think he has done a real service with his elemental and well organized books. That said, he has a tendency to oversimplify and I don't agree with some of the methods he proposes. Another thing that bothers me is that he'll spend a great deal of time covering a subject that has what I consider limited relevance, while hardly acknowledging topics I feel need more attention. An example is This Old Boat - while an excellent book, he devotes many, many pages to canvas work and far fewer to, say, applying primers and topcoats.

Does every new sailboat guy or gal read Slocum's "Sailing Alone Around the World"?

Yes! It's a good sign that you're on the right track.

I really enjoy reading and rereading Around the World Alone, though it makes my girlfriend nervous that I'll sail off without her. :) I think I've read most of the popular sailing books out there; I can't get enough. Perversely, the more dangerous the voyage and the harder it is on the yachtsmen, the more I want to get out on the water. Is that true for anybody else?

Post by **Tim** » Mon Dec 05, 2005 7:56 am

Don Casey's books are good beginner's primers, and serve a good purpose--just like the Dick and Jane stories might have been good primers at the onset of your reading career. But while the information remains valid, often we outgrow the simplicity contained therein.

At the other extreme is Nigel Calder, who tends to be impossibly detailed and complex, and always several steps ahead of the reader's experience level, whatever it might happen to be.

Here are a few books on electrical that you might want to check out. At one time or another, I found useful information in each of them, though I haven't referred to any of them in some time.

Sailboat Electrics Simplified, By Don Casey

Boatowner's Mechanical and Electrical Manual, by Nigel Calder

Boatowner's Illustrated Handbook of Wiring, by Charlie Wing

Wiring 12 Volts for Ample Power, by David Smead and Ruth Ishihara

Living on 12 Volts with Ample Power, by David Smead and Ruth Ishihara

MQMurphy · Post by **MQMurphy** » Mon Dec 05, 2005 8:07 am

Thanks for that list, Tim. I'll start at the simple end :)

Post by **Tim** » Mon Dec 05, 2005 8:13 am

MQMurphy wrote:Some previous owner had done a few 'interesting' things to the boat. Some of them probably due to impatience or expedience - I'm not pointing any fingers, I know there'll come a time when I'll take a shortcut - things having to do with hardware and fasteners. I'd like to run all new wires, so if there is a sort of basic primer on elec systems I'd be interested. Thanks.

Once a boat's electrical system becomes a couple decades old, with all the "improvements" added over the years by a string of unskilled (usually) owners, it is most certainly easier--and very wise--to rip it all out and start fresh.

Not only does this help ensure a safe, quality system that works as intended, but it gives the installer (you) a firsthand, deep knowledge of the wiring setup, which is extremely valuable going forward.

It's not inexpensive to rewire an entire boat--even simple boats can tend to get complicated these days--but it is always worth the cost and effort. There are myriad shortcuts, none of which I condone. Use quality materials and do the job to a high standard, and it will always pay off.

I find new wiring to be great fun, and installing electrical systems is one of my favorite jobs now. I love the potential for organization, neatness, and so forth. Conversely, I have about zero tolerance for older, hodgepodge systems, and cannot recommend spending too much time fussing with a decrepit old system when that time would be better spent installing a whole new system.

BTW, you'll probably find that my suggestions are rarely, if ever, the "cheapest" way out. My answers seldom take cost into account, though bugetary constraints are part of all jobs. We each must make choices based on the money available for a given job, but remember that cut corners have a nasty way of rearing their ugly heads at the worst possible time. Everyone makes mistakes borne from inexperience or a lack of specific knowledge, but if you know you're doing something the wrong way, it's best to step back and reconsider...and then do what you know is right.