DC vs AC which is better on boats

Discussion in 'Electrical Systems' started by seadreamer6, Nov 6, 2012.

  1. michael pierzga
    Joined: Dec 2008
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    Location: spain

    michael pierzga Senior Member

    24v windlass for small craft ? sure you can

    faster chain pickup and more power for the same size winch.

    The production runs of ac equipment are huge...millions of units, by many different manufactures. Dc equipment is specialized for the marine market so limited production, high price and less choice.
  2. Frosty

    Frosty Previous Member

    Yes I know but for 40 foot unnecessary.

    Now you have to supply 24 volt --why do that?

    Ive ran 12 volt windlass on 24V its fine and could really work hard.
  3. sdowney717
    Joined: Nov 2010
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    Location: Newport News VA

    sdowney717 Senior Member

    Of course tinned is nice to use and also expensive.

    Multistrand copper is all that is required. My boat built in 1970 37 foot sedan cruiser had both multi stranded and solid copper house wire in the AC system.

    About 5 years ago I pulled out all the solid copper house wire. Looking at it it was in fine enough shape that I reused some of it in my house! I had found that it is the ends where the solid wire attaches that tends to break, not anywhere in the middle. The main issue I think is safety ground, cause if it breaks you have lost the safety ground.

    The boat had been built that way including the wires used to connect to the shore power connections using 10 gauge solid core romex.

    The main issue I think is safety ground, cause if it breaks you have lost the safety ground. A GFCI functions in a way that ground is not even needed, and all outlets should be GFCI protection.

    The multistrand wire I replaced most of it with was 12 gauge extension cord wire, like you will find as a heavy duty 20 amp extension cord. I tinned all the ends with solder and have had zero trouble with any of it. For the wire runs from 30 amp shore connectors to panels and breaker disconnects I used 8 gauge multi strand romex with all ends tinned. You can buy 8/3 wire and then you have multistrand grounds.

    Another requirement is that where wires attach that means of attachment should not bear down directly on the wire. That helps prevent a screw from scoring into a wire weakening the end. Breakers have clamps and so do the connections in the QO box, at least on mine they do. Even the ground and white wires need protection and mine had little clips that did this. You can of course use a copper nut bolt to join wires, but not supposed to use plastic wire nuts.
    You can buy special plastic wire nuts made for wet locations.

    I suppose you could crimp and solder on a solid piece of copper tube or use a bare wire copper tinned splice on the ground and white wire ends and then it wont be bearing directly on the wire ends.

    My boat being a sedan cruiser, all the wire is well protected from rain and bilge.
    I have had zero trouble with it before I improved the wiring and zero trouble with it now.
  4. VertexMarine
    Joined: Sep 2013
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    Location: Western Washington

    VertexMarine New Member

    I work for a company that manufactures marine grade wire and cable. In the industry, if you call your wire "marine grade" or "boat wire" then it should be tinned - every tiny strand individually tinned.

    Some of the more intricate "shipboard control cables" don't necessarily need to be tinned. But regular, primary wire of all sizes should be tinned if it will used for a marine application.
  5. Ike
    Joined: Apr 2006
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    Location: Washington

    Ike Senior Member

    My 1972 Sea Ray 190 has almost all of it's original stranded wire. None of it is tinned. I have conducted tests on it and it is just fine. In the few cases where there was a problem such as high resistance, frayed insulation or broken wires I have replaced it with tinned wire. But correctly installed wire lasts pretty much forever if it hasn't been submerged or wicked up water. The real problem is the connectors. They corrode and need to be cleaned and replaced occasionally. Fuse blocks too need to be cleaned regularly and replaced if they get corroded. Electrical components, especially ones with moving parts like motors, wear out and have to be replaced from time to time.

    Yes tinned is better but it is not required by regulation, or by ABYC standards. Marine wire is.

    PS: I served on a Coast Guard ship built in 1936. Some of the cables in that ship were the original. They decommissioned it in 1982. A lot of the cables they tore out of that ship were installed in 1936.

  6. VertexMarine
    Joined: Sep 2013
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    Location: Western Washington

    VertexMarine New Member

    I pretty much agree. I was expressing somewhat of an opinion in saying that if it's called "marine grade" or "boat wire" then it should be tinned.

    With regard to the connectors, I soooo agree. When I was brokering yachts and when things didn't work (there are ALWAYS things that don't work) at survey, I bet 80% of the time, it was nothing but a poor/neglected connection. They're quite vulnerable to the elements for obvious reasons.
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