Best way to run electrical wiring through my trawler 28 build

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MageDK
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Best way to run electrical wiring through my trawler 28 build

Post by MageDK »

I’ve read a few different approaches here. Some people swear by just running the cable through the boat. Some say run it through some type of conduit. I’ve read some people say conduits just hold moisture and can degrade the wiring even faster.

Does anyone have any recomendaciones?



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OrangeQuest
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Re: Best way to run electrical wiring through my trawler 28 build

Post by OrangeQuest »

You have to take into consideration on where the wiring will run. Under a sole, then you would need conduit to make it easy to route and if you ever need to make wiring repairs. If you don't need the wiring to run under the sole, then you can run it through ribs/frames and secure the wiring between frames/ribs per the AYBC standards. You also want to use marine grade wiring to reduce corrosion. Water can "wick" down any unsealed opening in the wire and start corroding over time, in conduit or not. Once it happens, the whole length of wire needs replacing.

In a marine environment, moisture will find weak spots whether it is down a pipe or under a deck/gunnel. Good wiring practices when building the wiring connects and routing it takes time during the build but pays off when you don't have to fight corroded wiring a few months of operation.
"that it isn't just an ordinary sort of boat. Sometimes it's a Boat, and sometimes it's more of an Accident. It all depends." "Depends on what?" "On whether I'm on the top of it or underneath it."
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fallguy1000
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Re: Best way to run electrical wiring through my trawler 28 build

Post by fallguy1000 »

Conduit allows connections every 4'.

Bare wires must be connected every 18" to the boat.

The basic rule of thumb in wiring is shorter runs are always best. Why? Longer runs require thicker wires. Thicker wires are very expensive, harder to work with...

Minimum gauge wire for a boat after device
Pigtails is 16.
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TomW1
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Re: Best way to run electrical wiring through my trawler 28 build

Post by TomW1 »

MageDK here is a all the information you need to determine what wire size you need for everything on your TW28. https://www.bluesea.com/resources/1437 When you measure a circuit length it is both to and back to the power source or negative ground bar. Hope this helps you. Like fallguy says the shorter the better but that is not always possible.

Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

MageDK
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Re: Best way to run electrical wiring through my trawler 28 build

Post by MageDK »

Thanks for all the info, but it's not really the wire guage or length of the runs that concern me. I'm a pretty fair hand when it comes to electronics. I've never done electronics on a boat before so I was worrying more about the marine environment specifics. Are there any special tricks to keeping the wires from corroding faster than they do on land? Any special type of conduit materials or wire connectors?

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OrangeQuest
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Re: Best way to run electrical wiring through my trawler 28 build

Post by OrangeQuest »

Are there any special tricks to keeping the wires from corroding faster than they do on land? Any special type of conduit materials or wire connectors?
Good crimping tools, don't over strip the wire ends, use heat shrink terminals that also have the glue inside them to seal the bare wire to the insulation of the wire. The marine grade wires are all tinned and the crimp will help seal the ends at the terminals and helps prevent the moisture from wicking down the wire. Use a good terminal sealer/anti corrosion spray at all terminals and if possible, add a dip in the wires before the terminal to keep moisture from following the wires to the terminals. Where there is a wire gauge size difference, like a small gauge wire for a radio to a larger gauge wire, use terminal blocks (buss bars) instead of butt connectors. Avoid having buss bars and terminal blocks in areas where moisture can collect like the bilge or near a scupper.

Keep in mind that voltage drop in DC circuits are more critical when it comes to marine application. I think the standard for bilge pumps, VHF radios and such, is 5% drop and all other circuits is 10%, so wire gauge is important.
"that it isn't just an ordinary sort of boat. Sometimes it's a Boat, and sometimes it's more of an Accident. It all depends." "Depends on what?" "On whether I'm on the top of it or underneath it."
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fallguy1000
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Re: Best way to run electrical wiring through my trawler 28 build

Post by fallguy1000 »

Some people use dielectric grease inside their crimps, but it is a mistake.

Just use all tinned wire, all tinned fittings, a ratcheting high quality crimper, heat shrink all connections.
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TomW1
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Re: Best way to run electrical wiring through my trawler 28 build

Post by TomW1 »

OrangeQuest the drops allowed are 3% not 5% for critical items and 10% for all others. See my post above. Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

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Re: Best way to run electrical wiring through my trawler 28 build

Post by cape man »

Are you building this boat or just quizzing us on how? Running wires is a LONG way down the road for a TW28 build! :lol: :lol:
The world always seems brighter when you've just made something that wasn't there before - Neil Gaiman

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OrangeQuest
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Re: Best way to run electrical wiring through my trawler 28 build

Post by OrangeQuest »

TomW1 wrote: Sat Aug 06, 2022 3:39 am OrangeQuest the drops allowed are 3% not 5% for critical items and 10% for all others. See my post above. Tom
It's been a few years since I calculated, ordered and ran my wiring...I couldn't remember the critical number. I used Bluesea's app to do it and rounded up the amps to my electric loads. Once I flip the hull back over I will need to order some electrical supplies to complete my build.
"that it isn't just an ordinary sort of boat. Sometimes it's a Boat, and sometimes it's more of an Accident. It all depends." "Depends on what?" "On whether I'm on the top of it or underneath it."
A. A. Milne

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