Electrical, DC Distribution Panels, Part 2: Wiring

The color-coded wires for the three different DC panels
Now that I had figured out where I would locate the three DC distribution panels, I could begin the process of wiring these panels. In this posting I describe how I accomplished this in Oystercatcher, my Ericson 25.
In the first part of this two-part article, I described my rationale for locating these three DC distribution panels above the spice rack in the galley.
In the picture below we see the wires as they appeared at the end of the wiring process. The terminal post that you see on the right side of the picture is for the DC positive leads. There are three, 10 gauge yellow wires, one for each DC panel. Ideally, I would have used red wire for this, but I had an excessive amount of 10 gauge yellow wire on hand (wire that I had in the wiring of negative leads in the main circuit). To remind myself that these yellow wires here for the DC panels were positive wires, I wrapped red tape around the ends of each wire and labeled them as positive. You'll notice a 6 gauge red wire running aft from the post. This wire runs to the main DC breaker, which stands between the main battery bank and the entire DC system.
On account of the limited amount of space within the alcove box behind the three DC panels, I decided to mount the terminal blocks for these panels about eigth feet forward, in that part of the alcove box that was near the bulkhead. I figured this would give me plenty of space to make the necessary connections, and I was right. Why terminal blocks, you may ask? Why not just run the various wires directly to the back of the DC panels? Flexibility. That's my response. Terminal blocks allow you to alter circuits more easily, and they prevent you from having to run single wires half way around the boat. Additionally, they help you keep everything organized and thus intelligible.
Here's how the terminal blocks looked after I had reached the end of the wiring process - three terminal blocks for three DC panels. Notice that I have color coded the wires - gray for the first panel, blue for the second, and orange for the third. I've also labeled the ends of each wire and sealed each label with clear, heat-shrink tubing.
I could not simply screw the terminal blocks into the fiberglass hull. I had to create plywood backers that I could adhere to the hull with epoxy. I started by cutting the backers to the right size and then coating each side twice with neat epoxy to protect them from humidity.
It had been some forty years, but the hull was still waxy from the mold that the Ericson company had used in the manufacturing process in 1975. I used xylene to remove the wax, wearing thick, nitrile gloves and a respirator to protect my skin and lungs.
The hull, freshly cleaned and ready for some epoxy.
I would be installing terminal blocks elsewhere, in other alcove boxes. Below, you see the alcove box in the starboard side of the main salon, forward, near the bulkhead.
Here's the alcove box in the head. It too would receive a terminal block or two.
Similarly, the alcove box above the hanging locker on the port side would receive a terminal block.
The cotton rag that I used to wipe the hull with xylene was covered with yellow, waxy, gunk.
Next, I pulled out the acetone to wipe down the backers that I would glue to the hull with epoxy. Acetone removes impurities and dust and thus permits a better bond.
I spread out plastic here and there in preparation for the glue-up. I also made ready a roll of Gorilla tape. This tape would hold the pieces of wood in place while the epoxy set.
The blocks needed to be centered in the space so that there would be enough room for the wires that would feed into them from above and below.
Therefore, I marked reference lines on the hull with a black, Sharpie brand marker.
With everything ready to go, I mixed up a small batch of neat epoxy and spread it thoroughly over the back of each piece of wood.
Then I used the same brush to wet the appropriate areas of the hull.
I then thickened the neat epoxy with colloidal silica (not pictured), and I spread the thickened epoxy over the backs of the pieces of wood before pressing them into place on the hull.

I ordered the wire, the terminal blocks, and the heat-shrink tubing and terminals from Genuine-Dealz/Best Boat Wire in Brunswick, Georgia. This was a much more affordable approach to things than ordering Ancor brand wire from a big name chandlery. This Genuine-Dealz wire was made in the U.S.A., and it was copper-stranded and tin coated, just like marine wire is supposed to be.
I used 30 amp terminal blocks instead of 20 amp ones, primarily because 30 amp blocks are larger. I find 20 amp blocks difficult to work with, because the screws are tiny.

I did my best to use terminal blocks with more terminals than I needed for my immediate purposes. This would provide me with some flexibility in the event that I wanted to reconfigure things in the future, or add additional lights or other things to a particular circuit.
I did my best to estimate how many materials I needed for this project. I was close, but I still ended up having to order some additional wire, blocks, and heat shrink terminals.
I sat in the cockpit, underneath the tarp, which covered the entire boat, and made 18 total runs that would join the 3 DC panels to the set of three terminal blocks some eight feet away.
Notice that on one end are ring terminals and on the other are quick disconnects. The former were for joining these wires to the terminal blocks, and the later were for joining them to the DC panels.

With these leads in hand, I began to join them to the terminal blocks.
These I joined on the top row of screws on the terminal blocks. To the bottom I had joined the various wires that ran throughout the boat - to lights and other such things.
I suspended these leads with wire hangers from the top of the alcove box. This would allow them to flex and move to some degree and thus would extend their working life.

We've come full circle now to where we began - with pictures that depict the end of this project.

Now I needed to install the three DC panels and wire all the lights and other such things that this DC electrical system would power.
This ends this posting on my wiring of the three, DC distribution panels on Oystercatcher, my Ericson 25.

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