Electrical Installation

One of the benefits of having an outboard with a 12 V charging system is being able to have a 12 V supply on board to power up equipment such as a VHF radio, a Chart Plotter, and Navigation lights.

Boat instrumentation - summer 2014

The initial system will be extended over the winter of 2014 / 2015 to power up NASA wind instrumentation and a Speed / log repeater. 

Battery Box

The system that I installed is pretty simple. The outboard charges a 12 Volt car battery which is contained in a proprietary batter box. The battery Box has a battery condition indicator (LED type) and a master cut off switch. 

Battery Condition Indicator and Master Switch

From the battery a supply feeds the VHF Radio, Chart plotter and lights via a small fused switch panel set into the top of the instrument "Pod". An additional inline fuse was fitted as double protection for the radio. The switch panel is "marine grade" and is totally waterproof (I hope !)

Switch Panel

One of the biggest challenges was running the cables required for power to the navigation lights and the aerial cable for the VHF as both of these need to be run to the top of the mast.

Hardwood insert in mast covering cable rebate

Because Tra Bhui is rigged with a Lug Sail configuration, any wires or conduit fixed to the outside of the mast would not only look unsightly, but would be potentially damaged by the Sliding Parrel (the metal collar which has a hook and which is used to attach the yard arm to the mast). 

The solution was to cut a rebate for the cables into the mast which would be sealed with a hardwood inset. This would provide a secure cable route without compromising the overall performance of the mast. This will have to be modified to accommodate the cable for the wind instrumentation. Details of the modification to the mast can be found under the post titled “Refurbishment of the Mast and Spars”. A marine quality cable connector was fitted to the front thwart to allow the mast power cable to be disconnected before the mast is lowered.

Conduit to protect electrical cables

To protect the power cables, 18 mm plastic conduit was installed where required and rubber grommets have been inserted into any holes cut through the fiberglass panels to prevent chaffing.

Marine Grade cable

Marine grade electrical cable which has tinned conductors was used for all the wiring, with all joints being soldered and protected by self annealing electrical tape on top of heat shrink sleeves