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ground wire in mast

Jul 6, 2020
8
Mariano Mallozzi Pearson 27 Lancaster PA
rebuilding my mast I have a mast headlight as well as lights on my spreaders is there any counter indication to using a single ground wire?
 
Jan 19, 2010
9,999
Hunter 26 Charleston
If the mast itself is grounded the light itself can be grounded to the bolt that attaches the light to the mast. Sort of how they do it on trailer lights.
 
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Jan 11, 2014
7,826
Sabre 362 113 Fair Haven, NY
If the mast itself is grounded the light itself can be grounded to the bolt that attaches the light to the mast. Sort of how they do it on trailer lights.
This would put the mast in the boat's DC electrical circuit, which isn't a good idea. In addition to the mast, the shrouds, the bonding system would also be placed into the DC system. The bonding system connects various metal bits in the boat to equalize the electrical potential between them to reduce galvanic reactions. This could accelerate the degradation of the various metals.

As @Stu Jackson said, it is acceptable to have one DC negative wire service 2 or more devices, provided the wire is sufficiently large enough to handle the current of both devices. On mast lighting the wiring should be at least 16 ga so that the wire is strong enough to support itself when hanging from the masthead. 16 ga is more than large enough to handle the load from a couple of LED lights.

Some fixtures, like Tricolor/Anchor lights and Steaming/Deck lights are wired with 3 conductor cable.
 
Jul 6, 2020
8
Mariano Mallozzi Pearson 27 Lancaster PA
I do have 16 gauge tinned wire that I'm using in the mast is it necessary to use tinned wire throughout the boat?
 
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Jan 11, 2014
7,826
Sabre 362 113 Fair Haven, NY
It is best to pay a little extra and use marine grade tinned wire for two basic reasons. The tinning helps to limit corrosion. Unless you correctly crimp and seal the ends of the wire, water and moisture can intrude and cause the wire strands to corrode.

Second, although nominally the same, marine wire is a little larger than SAE (automotive wire). Marine wire also has finer strands making it more flexible and less resistant to work hardening from vibration and movement and subsequently breaking.

For mast wiring, I like to use duplex or triplex wires. These have 2 or 3 separate marine grade wires in a common jacket. The jacket provides some mechanical support, there are fewer wires slapping around in the mast, the wiring is more organized, and only one wire has to be fished up the mast instead of 2 or 3.

With boats there is a great temptation to use products from the automotive, RV, or household world. In some places this is perfectly acceptable, in other places these are a poor choice. When it comes to fuel, electricity, or holes beneath the waterline, the only good choices are marine grade products. Electricity, fuel burning outside the motor, and failed through hull fittings are some of the most common causes of boat disasters.
 
Oct 24, 2010
2,399
Hunter 30 Everett, WA
I also agree with Dlochner. I would only add that but using the mast ground, you invite the same issues That plague trailer lights. By that I mean poor ground connections due to corrosion at multiple points of contact. I always run separate grounds even in a trailer so that when a little bit of corrosion gets in a connection on the trailer it doesn't stop the lights from functioning properly.
 

RoyS

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Jun 3, 2012
1,205
Hunter 33 Steamboat Wharf, Hull, MA
Regarding a common ground wire; It is difficult to daisy chain the ground wire connections and retain reliability. I consider the mast unaccessible for repairs. If possible, suggest you run separate 16 GA cables for each device.
 
Jul 6, 2020
8
Mariano Mallozzi Pearson 27 Lancaster PA
the mass does have an interior conduit which I've been able to run the wire for the wind vain
 
Jan 19, 2010
9,999
Hunter 26 Charleston
I also agree with Dlochner. I would only add that but using the mast ground, you invite the same issues That plague trailer lights. By that I mean poor ground connections due to corrosion at multiple points of contact. I always run separate grounds even in a trailer so that when a little bit of corrosion gets in a connection on the trailer it doesn't stop the lights from functioning properly.
I never put that together until I read this post. :banghead: I must have rewired my trailer at least 50 times over the years.
 

LloydB

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Jan 15, 2006
541
Macgregor 22 Silverton
A separate set of conductors for each device function at the top of the mast will give you the best serviceability. Multi conductor cables are usually easier to pull through a conduit than many separate cable pairs and usually each conductor has a different color which makes it easier to connect up to the correct device and for future troubleshooting. You will be glad you went full boat with marine grade if you have to pay a technician to come in and find a ground fault or RF trouble. That said I still get ticked off when I find that I have to wait until after sunset in order to figure out the trailer lights or when the blue light comes on.
 
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DArcy

.
Feb 11, 2017
1,249
Islander Freeport 36 Ottawa
I do have 16 gauge tinned wire that I'm using in the mast is it necessary to use tinned wire throughout the boat?
I'd use marine, tinned wire when rewiring a boat. Tinned wire is more corrosion resistant and you get consistent jacket material. Considering the challenges associated with running the wire and properly crimping connections, the little extra cost of the marine grade wire isn't much.
 
Jan 25, 2011
2,223
S2 11.0A Anacortes, WA
If you have a problem with the gnd wire, all functions using that gnd wire will not work. I prefer separate wires in a jacket
 
Oct 22, 2014
16,087
CAL 35 Cruiser moored EVERETT WA
I must have rewired my trailer at least 50 times over the years.
WOW... Did not take me that many times.

It dawned on me one of the (damn again fixit) times that I needed to stop thinking of the boat trailer as a land trailer and start thinking of it like a boat. That is when the lightbulb lit. Scraping and cleaning the ground wire connections could all be resolved if I ran ground wires from the lights to the plug fitting. Problem solved..
 
Jul 6, 2020
8
Mariano Mallozzi Pearson 27 Lancaster PA
what kind of wire connectors are you using to connect the mask to the boat
 
Jan 11, 2014
7,826
Sabre 362 113 Fair Haven, NY
what kind of wire connectors are you using to connect the mask to the boat
Use insulated heat shrink adhesive connectors. Best to heat them with a heat gun, lighters and flames can get too hot. Also use a proper crimper.

Here's an example. You might say you don't need that many, if you stay in boating you will eventually use them all. And when you came the cost to Anchor terminals, you'll see these are a bargain.

 
Jul 6, 2020
8
Mariano Mallozzi Pearson 27 Lancaster PA
looking to see what kind of connectors you actually use to connect the mast wiring to The boat wiring do you something that can be taken apart like on a trailer hitch