Topic: Wiring the Mast & Lightning Protection

I'm about to re-wire the mast on my Contessa.  The existing wiring harness had a hot wire going to each light (anchor, steaming, spreader, etc.) and then used the aluminum mast as the return conductor.  Is this the standard way to wire a mast?  It seems like it might dramatically increase the risk of severe damage to the entire electrical system if you were to receive a lightning strike on the mast.  Wouldn't it offer a much reduced risk of electrical system damage if a positive and negative conductor was run up the mast for each light and the mast was not used as a conductor?  Thanks in advance for anyone who weighs in on this topic!!!  Cheers,  Brian

Re: Wiring the Mast & Lightning Protection

I've not seen a setup like yours. What grounds your mast? If that ground ever becomes corroded and looses continuity, as it will, then nothing works. I would not install such a system and would recommend a proper negative wire to each device with soldered and heat-shrinked connections inside the mast. I would also recommend using tinned copper wire to reduce corrosion.
John

.                               ,,,,,
                               (o o)
------------------oOO---(_)---OOo------------------

3 (edited by mhall 2013-04-04 08:10:59)

Re: Wiring the Mast & Lightning Protection

Using the mast as a connector was done on a few US boats back in the 1960s and proven to be unacceptable as John states.   Wire size (AWG) is a major issue that depends on the amperage carried, the acceptable voltage drop, and the "round-trip" length of the wire.  Acceptable voltage drop for lighting is around 10%.  In rewiring my anchor light & steaming (masthead) light, I used 14ga tinned marine-grade wire for a round-trip of 60ft (anchor light).  I could have used 12ga but had a reel of 14 hanging around.
Merrill

Re: Wiring the Mast & Lightning Protection

You should have a send and return for each circuit up the mast.  I have spreader lights, a steaming light, an anchor light, and a windex light (very low amps).   Only the anchor and windex lamp share a common ground.  Assuming you will have the minimum added to this mix of a TRI light.

12 gauge is about right for the job, due to the lengths back to the panel.  14 can do in a pinch -- but remember that the inefficiency of the smaller gauge will cost amps. 

Plan your circuits ahead, and map it out.  Runs are always longer than you think!

"Lolly Jo" #230
C. Paul Carter
Montreal, QC

Re: Wiring the Mast & Lightning Protection

Paul,

You're right on using 12ga.  I got my sizes  mixed up.  I actually used 12ga on all lighting aboard and still have around 100' left.  With LED bulbs for the anchor & masthead lights, 14 would have made it.  Yesterday was filled with senior moments.

Re: Wiring the Mast & Lightning Protection

I was going to have a circuit for each spreader light (4 conductors) as well as an OGM tri color anchor strobe (3 conductors).  (I don't have a dedicated steaming light........I'm using the anchor light for that)
Does anyone know what electrical fitting I would use that would mount just forward of mast on deck?

Re: Wiring the Mast & Lightning Protection

I would recommend an LED anchor light for the top of the mast because a regular bulb can drain your battery overnight.

You can get very good British combined anchor/nav lights that switch from a white light to a tri-colour with the flip of a switch for $120 or so.

Re: Wiring the Mast & Lightning Protection

Brian,

Just for clarification...when you're using your anchor light as a steaming light, I'm assuming that your tri-color light is switched off and you're using your deck-level port and starboard nav lights.  Is this correct?

Merrill

Re: Wiring the Mast & Lightning Protection

Can't use an anchor light as a steaming light cos you'll confuse everbody. They won't know whether you are anchored or ... steaming.  (Why do we still say steaming?)

The tricolor at the top of the mast or nav lights on deck are good with a steaming light, but should be turned off when you anchor.

10 (edited by stefan_d 2013-04-12 16:48:50)

Re: Wiring the Mast & Lightning Protection

as far as Canadian collison regulations go:

a powerboat under 12m (or a sailboat, whilst "steaming...") can display sidelights and one all-around white light - this can be at the top of the mast, or a combination of stern light and partial white light forward (usually referred to as steaming light **edit: and installed usually one-half to  two-thirds way up a sailboat mast)

while sailing (vessel length 7-20m) - sidelights and stern light, or tricolour (**edit: at top of mast, or masthead)

so for simplicity's sake, one can get away with sidelights, one stern light, and a one 360 deg white light at top of the mast and cover off all scenarios. 

for the extra effort of two more circuits, it's not a bad idea to add a combination steaming/deck light installed on the leading edge of the mast, (**around 2/3 the way up)  you can turn on the "friday night lights" and makes it far easier to anchor and work on deck in the dark without having to hold a flashlight.......

on another sidenote about wiring sizes, don't forget that runs are cumulative, this doesn't always work in a bad way....  you can effectively lessen voltage drop by running larger wire where it's easy (inside the boat, ie 12ga panel to mast step) and then dropping down where its not quite so fun to work or not required (14ga, mast step to LED anchor light) instead of running 14 for the round trip, and being borderline on the run.   buy (marine) wire from a wholesaler, by the roll, and you'll never again worry about cheaping out on an extra 6$ worth of wire and again ending with borderline runs

delcity is a great supplier, and you can buy listed wire (almo) and all sorts of other cabling, goodies, and tools from them.  last i bought was about half the price of the ancor stuff...

Re: Wiring the Mast & Lightning Protection

We got some semantics here that need clarification.  First, the tri-color light is mounted at the mast "top".  The common steaming light is also called the "masthead light".  It is mounted on the head of the mast which is the forward surface of the mast.  The term "head", referring to the crappier, comes from the old days when the facilities were in the bow (head) section where the bow wave would keep everything clean except in the case where plum duff was served. "Steaming" (power vessel underway) is not an anachronism since most of the world's vessels are powered by steam.  Another term is cutlass bearing vs. cutless bearing – I assume that this will be covered later.

Re: Wiring the Mast & Lightning Protection

If you are cruising, I would suggest an automatic electric eye switch for the anchor light. It was common for me to go away from the boat in the afternoon with full intent on getting back to the boat before dark and then before you know it, its 10pm and you are still sitting on someones boat or restaurant. On one occasion I went to a beach party with only my prescription sunglasses. On heading home in the dark, I ended up motoring around the crowded anchorage. I could not make out my boat with the dark glasses on and I could see any boat with the glasses off.

Re: Wiring the Mast & Lightning Protection

Hello Merrill,

Yes, that is correct.  I will use the 360 degree white light at the top of the mast (also the anchor light) for the stern light/steaming light in combination with a red/green nav light on the bow when motoring and the tri-color nav light at the top of the mast (same fixture -- OGM with strobe) only when sailing.  This is perfectly legal and explained clearly in the federal regulations pamphlet put out by the coast guard on boat lighting.  The reason I am doing this is because I want to avoid a white stern light on the transom that is putting out light that will reflect off of the Monitor windvane, etc, and blinding/annoying me. 

In regards to what Seeadler said about a photodiode to make the anchor light turn on and off automatically.........I bought this feature as well on my OGM tri-color/anchor/strobe light fixture.  The strobe is another feature that I realized was going to be extremely valuable due to its awesome ability to make you seen by other boats in poor visibility conditions when you heave to and go get some sleep, etc. (like Larry Pardey talks about in his book about cruising the orient).

Thanks everyone for your great comments!   B

My complete re-fit is on schedule and I'll be launching the boat in St. Louis MO in November for the "big trip."

Re: Wiring the Mast & Lightning Protection

Also meant to say that the not only is the strobe extremely valuable for safety, it also used very low power consumption!

B

15 (edited by bertinol 2013-04-19 06:21:10)

Re: Wiring the Mast & Lightning Protection

I use a VMG Marine combo anchor/tri-light at the top of my mast. It uses low-wattage LED bulbs that switch from 360 degree white to tri-colour with a flick of a switch. It's also a lot cheaper than many. The importer lives in Collingwood.

Re: Wiring the Mast & Lightning Protection

Hi Brian,

Your system is in full compliance with 72 COLREGS 23(c) and 25.  The only place where you could be in trouble is along the remote northern areas of the Maine coast where the tri-color has been proven to be a moose attractant.  Good luck.

Merrill

Re: Wiring the Mast & Lightning Protection

Someone may be interested to know that the conduit inside the mast of an 1985 era boat is in 2 sections, and these sections seem to move fairly easily. Handy to know if running a new wire through, without the aid of pre-existing wire.