Malahini electrical

Designs for inboard or outboard power

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Malahini electrical

Postby Hercdrvr » Mon Mar 27, 2017 8:52 pm

Been installing the electrical system. Took a couple pillows with me under the bow to get comfortable. I put some extra effort into making it a nice and tidy electrical system.
-Bilge Blower
-2 Bilge Pumps
-Nav lights
-Interior lights
-Inverter 150watt

Used all marine grade 14G wire from fuse box to components and 10G from battery to fuse box. It's overkill on wire size for the small load, better safe than start a fire and My banana fingers prefer to work with bigger wire anyway.
Mounting battery under the bow to bring the CG forward. A concern is the 16ft starter cables. I figured starter will draw maybe 250 amps so Wire charts says 1G wire is needed for a 16ft run.

As always, jump in and critique my work so I don't blow myself up.

Matt B
2 bilge pumps
Power supply wires are temporary

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Re: Malahini electrical

Postby mrintense » Tue Mar 28, 2017 3:15 am

It's a bit hard to tell the orientation of the circuit box in the last photo, but assuming it's oriented so the wires come in at the sides, you might want to add drip loops on those wires rather than have them angle down towards the connections.
a.k.a. Clipper

Crafting a classically styled Vera Cruise named "Some Other Time"

Clipper's Vera Cruise Build

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Re: Malahini electrical

Postby gdcarpenter » Tue Mar 28, 2017 3:55 am

I think you are okay with 10 gauge for the starter. On my ZIP the battery is forward where keel meets breast hook feeding a Mark35A which I guesstimated to draw about 35 Amps. I also tested the long cable cranking an in line 6 Merc and all was well. I can't imagine you will ever draw anywhere near your anticipated 250 Amps with your starter, an automotive V8 draws less. It's also a temporary draw as you generally should not crank continuously in any event.

I did add terminals at the transom to connect the engine leads to the main power cable. I also put a 90 amp breaker on the engine feed cable as insurances as my cables run below the floor boards. You do know you will need a similarly sized cable for the ground side of the engine starter cable.

You might consider a larger gauge from battery to fuse panel as all your circuits are fed by that one lead. Granted, with the few electrical items you have, and that they most likely will not all be on at once, you might be okay. Given the length of some of your runs, especially bilge pumps that can draw around 5 Amos apiece, 14 gauge is likely not overkill. Looking good.
This is my first, last and only boat build.

Posts: 529
Joined: Mon May 11, 2015 12:52 pm
Location: McKinney TX

Re: Malahini electrical

Postby Hercdrvr » Tue Mar 28, 2017 5:59 am

Carl, the fuse panel is vertical and yes, drip loops would have been a nice touch. I'll play around with it and see if I can make some startigic low points prior to the fuse block.

My reference to a 250 amp draw is a high side guess and only a short spike on initial engagement of starter. Minimum battery requirement for my engine is 380cca. I used this chart to size my battery to engine cables. ... -Table.pdf

Matt B

Posts: 529
Joined: Mon May 11, 2015 12:52 pm
Location: McKinney TX

Re: Malahini electrical

Postby Hercdrvr » Tue Mar 28, 2017 6:12 am

Being a former 727 flight engineer I had to give my electrical busses names. So I have
1. Essential Bus (starter)
2. Battery Direct Bus (everything else)
3. Emergency DC Bus (set of jumper cables) ... UOIWm-tBfM:

This is all a joke of course

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