The Spaghetti Monster

The space under the Sb sidedeck in the pilothouse provided an ideal location for the electrical system.On the far left side sit the 2 Sea Frost refr. compressors. The shorepower cable arrives from the right. The house battery box sits beneath the sole adjacent to the installation, meaning very short cable runs and easy maintenance. The cabinet running athwartship to the left will be the nav station desk. I built a heavy face frame, with the center section built to accommodate the distribution panel door I had previously built. I made an enclosure from 1/2” ply. It is vital that the electrical distribution center be protected as much as practicable from water ingress. Dudley Dix’ tale of being knocked down off of South Africa in a storm and having bilge water run up the hull side and short the panel has been taken to heart in this installation.

Also in the picture is shown the isolation transformer, a Charles IsoG2, 3.6kva.



The load wires are all connected to Blue Sea 30A terminal strips. Rather than attempting to run the load wires directly to the breakers, the terminal strips allow for a neat organization of the wires. Jumper strips allow several load wires, lights for example, to be grouped into single circuits. The AC circuits are at the top, completely separate from the DC. The DC negative  and AC green ground (PE) connect together at one point only to the ship’s structure, above the enclosure, as per ABYC regs.

Also shown on the right side of the enclosure are the 600A main DC + bus bars, for sorting out the battery power. I am making use of the new Blue Sea MRBF terminal fuses to protect these high amp battery cables.

With the panels mounted in the door it was time to figure out how to best organize the circuit wires  from breakers to terminal strips, as well as the larger gage supply cables. Fortunately we opted not to put the battery switches in the panel, as those 2/0 cables would be a bear to  install so that the door would  still hinge.

I decided that the smart route was to pre-wire the breakers with pigtails of the appropriate gage (16, 12, or 10), of sufficient length and then bundle these together to lead to the terminal strips. It was an easy matter to use the continuity function on the multimeter to identify which wire was which after the panels were re-installed. The only hard part of this was sitting cross-legged in front of the enclosure for the hours it took to connect and label everything. It was very satisfying to take that huge pile of spaghetti wires and systematically connect them to the proper circuit breaker. Labeling , diagramming and a wire list are the absolute keys to doing this job without frustration.


In the photo below is seen the blue Victron Multiplus 12/3000/150 inverter charger. Most of the AC circuits will normally be supplied by the inverter, with the exception of the air con, water heater and water maker pressure pump. This unit is probably overkill for us, but the extra charge capacity will come in handy for charging our large house bank from the 9kw generator.


Note that there are 2 source selection breakers on the AC panel, top.The reason for this is that with a 240v generator there is the potential of uneven bearing wear and winding overheating if only one side of the rotor winding is being used.(This is my understanding of, and solution to, this problem). I have split the AC loads into 2 groups. L1-N feeds AC-1, which is the inverter/charger loads. L2-N feeds AC-2 which is the air con,water heater and watermaker pump. Thus, when charging the batteries, we will want to run loads from AC-2 to balance the generator. There’s plenty of capacity, and I can live with a bit of cooling down (or warming, as the Flagship Marine unit also has a resistance heating element). Perhaps the unbalance scenario wouldn’t be a problem, but this solution will work. Also, it is important to connect the neutrals correctly so that they are being derived at the correct source, which I think I have done. It’s nice to have a comprehensive understanding of the electrical system so that if problems do arise I will be prepared to correct them.