Wiring Question

[Stu Fyfe]

Can anyone help us? We have a 65 watt running light at the top of a mast. The total length of the wire will be 65 feet. What size wire should we use and what's the proper color for the wiring? Thanks in advance. We're equiping a 42 ft Atkin ketch for a cruise from Cape Cod to Lunenburg, NS.

[Tom Hunter]

You could probably get away with 16 guage but I use 12 for my running lights. It costs a bit more but does not break as easy.

I would take a look at the other wiring in the boat and use the same color scheme. Nothing is more annoying than rewiring a boat that uses multiple colors for the same function. You can't tell which wire does what and you have to manually trace everything. Don't ask me how I know this.:mad:

[paladin]

Assuming a standard 25 watt fixture and 12 volt system, a pair of #12 awg wires would be sufficient. Red wire will normally be used for the plus or positive side, and black used for the negative line and ground. Lamps burn out at the top and the bulbs need changing....it is a simple matter to wire a diode or two (60 PIV, 10 amp diodes, available at Radio shack) and run the wires at the bottom to a double pole, double throw switch....then if the lamp burns out, flip the switch in the opposite direction and use the same wire pair to activate a second lamp..(or just reverse the wires at the bottom).....I can draw it up and e-mail it if you desire....

[Figment]

I was under the impression that ABYC wants yellow for 12v ground, to avoid potential for confusion with 120v elements.

[paladin]

If you check with the major wire manufacturers for color coded primary wire you will find colors Black, Green and Red.....
I haven't read the AYBC recommendations in the last 20 years...so I cannot comment. However, I do have the charts for wire runs and current losses based on 3% and 10% losses to 85 feet.
Checking with Defender industries catalog under Marine wire manufactured by ANCOR, there is no yellow wire listed.
Most marine wire ends up being covered with paint....

[Stu Fyfe]

Thank you, gentlemen.

[Figment]

Must be an old catalog.
100' yellow 12ga at Defender (http://www.defender.com/product.jsp?path=-1|328|49758|316475|579423&id=578998)

(I'm not trying to be a smart alec)

[paladin]

It's a 2006 catalog....and I also checked with two other resources, and came up with the same information. When I was doing wiring diagrams I never specified wire color, the marine electricians took care of it. I make tables as to current/voltage demands, breakers etc. Also, I have never drawn a boat with anything other than a 12 volt electrical system...one exception was a 12 volt to 24 vold dc-dc converter for some electronics that the client wanted to use with some nav gear. I stopped drawing boats seriously a bunch of years ago, and the last time I used an AYBC handbook I noticed some serious errors. I went to their offices with some notes and pointed them out and was politely told that their recommendations were from "experts". I left with the remark that I hoped their experts didn't kill someone.....The problem involved a specific sending unit to be installed in a fuel tank...using the aluminum tank itself as a dc current return.

[StevenBauer]

Anchor has a wire size calculator online. Look under Technical Info:

www.ancorproducts.com

Steven

[StevenBauer]

There's a color chart there, also.

[The Bigfella]

Isn't 65 watts a lot for a running light?

[paladin]

For a 42 foot boat (30-65 feet) the masthead light will draw about 25 watts...roughly 2 amps. Using the charts that I have with losses at 60 feet the closest would be 2 amps for #12 wire....then you have the wire run to the breaker box, through several connections. It is common to allow some loss for each soldered or crimped connection, as the join will cause a small amount of lumped resistance..You could use #14 wire, it would be lighter, cheaper, more flexible....and with slight built in questions. The next size up will allow less loss and a more consistant voltage level at the top under load.

[Bill Griffin]

If you already have the wire and it's not the ABYC color you can use some bits of heat shrink to color code it, and can also write the circuit # to ID it later. Just don't paint it.

[HR]

Hey Stu,

Not to drift the thread or anything, but if you're coming to Lunenburg you're welcome to pop by for a visit and use our mooring. We're in Stonehurst, which is the point of land that separates Lunenburg Bay from Mahone Bay (lat 44 22.21 lon 064 13 27). When are you making the trip?

Howard

[Gary E]

WHat color wire ??? to the ONE light at the top of the mast???

WHO CARES ??? What possible difference could it make??

as for what wire... screw the people that think they know more and better than you do and use lamp cord, it's plenty good enough for 120 volts.. ougt to do just fine with 12... you do use a fuse? right??

ok... flame away... but prove your point, not just cuz some council sez so.


Ohh by the way... do you have lightning protection on that boat??

[Stu Fyfe]

Howard,
Steve Bauer mentioned you up there. Thanks for the invite. I'll contact you as the July 24th departure date nears. Lee Scarborough, the boat owner and Atlantic Challenge president, just bought some land up there and he has a dock and mooring. So I assume he'll be keeping Peagsus there. I'll get back to you soon.
Stu

[Stu Fyfe]

Gary,
Although you're probably right, the owner wants to follow code as much as possible. I always felt it was easier to trace wire at the panel if you had different colors. As far as lightning protection, I don't think he does have it. I'll mention it. The boat has done two trans-Atlantics and was extensively cruised for eight years. It's been doing coastal duty for the past ten years, so we're refitting as needed, ie. wiring, self steering vane, lifelines, thruhulls, zincs, engine, rigging, etc....

[Gary E]

Ahh... he's got $$$.... yeah, follow the code.. :)
everyone including the insurance co will be happy

But now since you've run a wire way up there, it will make a good path for ligntening...
UNLESS you make a BETTER and SAFER path...

[Figment]

WHat color wire ??? to the ONE light at the top of the mast???

WHO CARES ??? What possible difference could it make??

as for what wire... screw the people that think they know more and better than you do and use lamp cord, it's plenty good enough for 120 volts.. ougt to do just fine with 12... you do use a fuse? right??

ok... flame away... but prove your point, not just cuz some council sez so.

Who cares? Whoever has to work on it NEXT, that's who.

To prove the point about lamp cord, I'd have to show you some of the lamp cord I removed from my boat. I can't do that, because it all went straight into the dumpster. Marine environment and motion of the ocean had done its thing. The insulation was only slightly less brittle than the conductors, which were quite corroded.

Shoddy electrical work causes fires. Period.
Weigh the cost of a fire against the savings of cutting corners.
Nonsense.

[Gary E]

Who cares? Whoever has to work on it NEXT, that's who.

To prove the point about lamp cord, I'd have to show you some of the lamp cord I removed from my boat. I can't do that, because it all went straight into the dumpster. Marine environment and motion of the ocean had done its thing. The insulation was only slightly less brittle than the conductors, which were quite corroded.

Shoddy electrical work causes fires. Period.
Weigh the cost of a fire against the savings of cutting corners.
Nonsense.


Well... ok...
But let me ask you...

How old was that boat when you deemed the wiring should be replaced?
10 yrs?... 20??

Was it wired with decent methods??
Was it water proofed??

How long do you expect ANY wiring to last??

[HR]

Stu,

Small world - Lee's place is on our street, next cove over. Look forward to meeting you.

Howard

[Figment]

The replaced wiring was between 10 and 30 years old.

The methods and materials of the original wiring were of decent (hardly "gold-plated") quality. Subsequent work varied in quality from good with proper connections, to crap lamp cord and wire nuts.

I don't really know how long to expect wiring to last. My point is that the good stuff far outlasts the crap.

[paladin]

to further the conversation....
Use red as the positive, and black as the negative return to follow tradition. There is a place for the green wire, but it is to be used as a "common" ground to tie all metal together to reduce potential differences...not as the current carrying ground. Also, a "lightening ground should not ne a thin wire.....the thin wire will act as a fuse.....
the ground "wire" should be preferably as wide as 10% of the length, normally inpossible in a mast, but the best way is to tie the masthead, if metal, to all the standing rigging, assuming metal standing rigging, and internally tie the chainplates to ground straps internally and then through a thru hull grounding plate.....there's no substitute for square inches....

[ssor]

Hey Chuck, on old lightning protection systems on houses and barns they often use a copper conductor that was formed into a helix as if they had taken thin wall tubing and crimped it to form a three point star shape cross section and then twisted it . In other systems I have seen braided copper cable. So I wonder if there is a good explaination for these choices or did it just seem like a good idea at the time?

[paladin]

Copper tubing in a straight run is fine....helix is a no-no....braid is bad....you want as heavy and straight run to ground as possible, braid twistes and turns and is a relatively small cross section to the current...
It ain't the voltage that gets ya, it's the current....think of a monster hose, the voltage is the pressure, larger hose, lower pressure....but the current is always there so you need to get it to ground as soon as possible without driving around and around a country road hauling a load of highly explosive cargo.....
Without going to great detail, I have a 10 volume set of books, each the size of a good encyclopedia, on getting rid of electrical/electronic pulses, emp radiation and the like, and they barely touch the surface on the subject. At one time I designed shielded structures and EMP housing for all sorta of crap, during the Reagan administration.......and I HATE the subject.....3 years, night/day/weekends/holidays I barely slept, grabbed snacks etc while researching the stuff....and now I am part owner of a company that deals with the subject constantly......and nagged everyday to get more involved and I'm trying to run and hide....I hate peeeeple.....well..some peeeples.....:p

[ssor]

I have always thought that the lightning protection systems on houses worked more on statistical likely hood then on any sound electrical experience. I have seen trees that had the bark stripped off in a six inch wide path from top to bottom. I saw one tree that had taken a hit at the top and half way down the bolt transferred to an adjecent tree and finished the trip. Or maybe it was that it started in the shorter tree and jumped to the taller on the way UP.

[TMny]

SSOR-
I believe the NationalFireProtectionAdministration writes the NationalElectricalCode, and regs/suggestions for lightning grounding.

It is somewhat probabilistic , but it is science-based engineering. I think that within the last 15 years{25??} that the radius of a circle/sphere of protection from an elevated (grounded) point was decreased from , like 50' , to , like 25'.

A few years back i read a piece which categorized lightning bolts by amperes (they keep finding larger incidences). I believe most 'bolts' run from 2000 Amps to 20K Amps. But the outliers can run 200,000 Amps !

In suburban areas with aerial electric utility plant, around 90% of strikes are absorbed by the grid.
Good practice with trees is to protect them with rods , and cables. The exploding steam disrupts the bark and sapwood beneath ....