Electrical System - Main Switchboard

I had to redo the complete wiring from scratch. The placement of the original switchboard was totally idiotic, in the passageway – it is where water falls from outside, and where you will sooner or later step on, breaking the switches. I relocated it to the port side above the settee. This location is not ideal, either, in a wipe-out (listing 90 degrees to the port side) and if there is some water in the boat (even 20 liters will be enough), the whole switchboard and especially the inverter will be soaked in water. But there is no alternative safe location on Catalina…

Overall View of the Switchboard.

The main battery (100 Ah) is installed under the step of companionway. A large piece of marine plywood was glued with epoxy to the hull. To prevent the battery from moving, stainless steel angles were screwed into the plywood and into this recess the battery was installed. Using only battery retentions belts is not enough to guarantee that it would not move in extreme conditions!

Battery holder.

Fron the battery, I have two hot lines, both fused with in-line fuses. One line is the main line for all the 12 V circuits with a 25 A fuse, and the other line, with a fuse of 40 A, is the line which goes to an inverter through a cut-off switch. Both of these fuses are inside the battery box. This can be dangerous, because in theory a spark when a fuse goes off could ignite hydrogen fumes, but I was more worried about running unfused lines which sooner or later may make a short circuit due to chafing. There are also two ground lines, one for the 12 V Circuit and the other for the inverter.

Rotary switch -the entry point to the Switchboard.

The main rotary switch has three position. Off - as shown on the photo disconects everything. To the left, connects everything, to the right, disconnects everything except for the main bilge pump. The idea was to be able to leave the pump on, but everything else off. In the end I never used this feature. Also, the switch is not a waterproof special switch, but a simple high-current switch. So far it worked fine, but it should defintively be changed to a more water-proof version later. The battery charge (both from the outboard engine and from the solar panel) by-pass the switch (if the solar panel is connected, the internal circuit is energized despite the fact that the main rotary switch is disconnected). This was a mistake and also should be modified.

Part of the Switchboard. "AUX. 1"- is the autopilot switch. "AUX LIGHTS" is the red night light inside, and Dome lights are standard cabin illumination.
Another part of the Switchboard. "INSTRUMENTS" is for GPS Chartplotter, "AUX. 2" is for the secondary bildge pump.

The 12 V circuit is more or less standard: I have navigation lights (on top of the mast), anchor lights, cabin lights (white/red), autopilot, horn (yes, I installed electrical horn from a car), VHF radio, GPS Plotter, and second bilge pump. There is a separate circuit for the main bilge pump with the floater switch. When navigation lights are on, the compass light is also on.

 

 

All of the wiring goes through rigid conduits (red ducts).

All of the wires go through conduits. When installing them, I selected them so as to have some extra room for future expansions, but it turned out that it was still too tight! Also, I was not able to purchase marine grade wire when making the installation, so that sooner or later I will have to redo the wiring.