The Electrical Project

The Electrical Project


So... electrics.  I used to fear the electrical side of things, as this has always been one side of Naval Architecture I have been weak on.  The installations for Contradanza left me bewildered and confused.  Recently I have started to tackle this job, and have started doing my sums and working out how the system will go together.  The following thoughts and design work will inform the actual installations and preparation work that goes in the boat at this stage.


Requirements list

I have a few specific requirements from the electrical set up.  Firstly and foremost, it has to be as self sufficient and as self replenishing as possible.  Therefore Solar panels feature heavily, along with the option of charging from the outboard, and maybe even a wind turbine.  Having done the calcs around a 50aH battery is indicated, but I will be istalling closer to 100aH for the sake of a little extra redundancy and to accomodate any future modifications to the system.  I will be replacing approx. 10aH per day under normal cruising conditions, which a 40 watt panel should manage in 7 - 10 hrs.  Supplementary will be the charging available from the outboard, and a small shore power setup for running onboard appliances and charger for the battery.  This should ensure ample charging and battery capacity even if I go over budget on occasion.  An inverter may be added over time too.

The lighting will be all LED to keep demands low.  12v halogen lighting is incredibly power hungry, and has no place on such a small boat.  Using well priced budget LED sets from means I can have task lighting throught the boat, even in the lockers for much less current draw than even 1 Halogen lamp!  There will be LED Navigation lighting, compass lighting and so on.  Instruments will be basic, and consist initially of the following:

  • NASA BM-1 Battery monitor
  • ICOM M411 Marine DSC VHF
  • Garmin Handheld Marine GPS (exact unit to be determined, but will need NMEA output for a laptop and the VHF)
  • A depth/log instrument, probably NASA

This may be supplemented eventually with some kind of chartplotter/fishfinder combo.

There will be two electrical bilge pumps in the cabin, a stereo, several 12v sockets and that ought to round out the initial electrical installations onboard Contradanza.

I will be developing and manufacturing my own switch panel in carbon fibre, just because I can and it will look amazing :-)

A battery switch will be available to isolate the system.  Cabling will be 1 size above what is recommended to ensure cable losses are kept to a minimum.  Equipment positioning will be considered such that cable runs are kept to a minimum.  All crimp terminals shall be of the heat shrink variety and cabling to be of marine quality - tinned.  A Dymo label printer is to be aquired and all wire ends clearly labelled for ease of future fault finding and maintennance.  Cable runs to be neat, tidy and suitably fixed to position with adhesive cable tie pads.  No electrical installations are to occur where there may be risk of petrol vapour.  Consideration to be given to ease of maintenance of the switch panel and therefore panel quick disconnects are to be considered for the panel mounting.  Fuses are to be of the blade variety to ensure availability.


Electrical Load Balance Calculation

Electrical load balance discussion,

Link to calc sheet


Switch Panel Design

Switch Panel Design Discussion,

Link to Drawing


Wiring Diagram

Wiring discussion

Link to Drawing


Suppliers & Equipment

Last Updated (Tuesday, 27 September 2011 14:48)