Electrical, AC Receptacle, Galley, Port Side, Part 2: Wiring

The AC receptacle, fully wired and installed
Choosing the place where I would install the AC receptacle and then installing it (at least temporarily) were projects in and of themselves, and it was for these reasons that I devoted the first part of this two-part article to them. In this second part, I discuss the process of wiring this receptacle. I use the word process here not without deliberation. Since I was not simply replacing the existing wire for an existing receptacle or simply replacing an existing receptacle itself, I first had to determine how to route the wires. Then I had to determine how I would join them to this entirely new receptacle in such a confined space. How I did all of this on Oystercatcher, my Ericson 25, is the subject of this posting.
 
You'll recall that it was on the port side of the galley that I had also temporarily installed most of the other major components of the AC and DC electrical systems - the battery switch, the battery monitor, the main DC breaker, the AC distribution panel, the two bilge switches, and the three DC distribution panels.
The most challenging task was trying to determine how to fit all of these components into this space and, at the same time, trying to imagine how the wiring, that would go behind them, would fit into that space behind them.
Compounding these challenges was the space itself behind these components. This was a cockpit locker. The space was small; it was not easy to access; and, despite whatever I might need to do from an electrical standpoint, it still needed to be used for its intended purpose - stowing gear.
In terms of the wiring itself, I needed to figure out how to route the wires from the AC distribution panel on the far left to the AC receptacle on the far right.
A simple, straight shot would not do. For one thing, I had to route the wires through the protective covers, which would require me to make right angles. For another, I had to take into account all the other wires that I would need to route through this area.
Everything also needed to fit behind the protective cover that I was in the process of creating for this space.
Additionally, I had to take into account the wiring that would be passing from the cockpit locker into the lazarette, directly beneath it.
All of this was so complex that it was difficult to know where to begin. I had to start somewhere, and one of the first things I did was to route the wires for the AC receptacles that would be on the starboard side of the boat. These I placed in a gray, plastic conduit to help prevent chafing. At the same time, I routed the 6 AWG (American Wire Gauge) grounding cable for the AC system. This I put inside of a small, black, plastic conduit. In the picture below, you can see this black conduit coming down from the cockpit locker with the gray one.

Note that I am now using the word cable as opposed to the word wire in speaking of the AC system. I'm doing this because many people use the word cable to refer to large wire. 6 AWG wire, or I should say cable, falls into this category. Likewise, many people, including manufacturers, refer to bundled marine wire as "boat cable." The wire that I selected for the AC system was bundled or sheathed in a white, plastic, protective cover.
Up in the cockpit locker I left enough slack in these cables so that I could terminate them and join them to the AC distribution panel. Ideally, I would have left more slack in the cables, but I didn't want to have too much of it left over at the end of the project, especially in a cockpit locker. Pay no attention to the wires on the far left. These were some of the remnants of the old wiring. I had already removed almost all of it. Some of it I left here and there, just to remind me of some of the major routes of the old system.
After I had routed the above mentioned AC cables (in other words, the ones that passed through the lazarette), I thought it would be smart to go ahead and route some of the wires and cables for the DC system before I routed the AC cable that is the subject of this posting - the AC cable that would join the AC distribution panel to the AC receptacle, pictured right in the photograph below. As I said before, I had to take all of these other wires and cables into account. Otherwise, I would never be able to fit all of these pieces of the puzzle together.
When the time at last came for me to route this cable, I began by cutting a hole in the top of the electrical box. In the world of residential construction, the box you see pictured below is known as a "shallow" box. It is intended for tight spaces, and this space in this cockpit locker was, without a doubt, tight. The standard, punch-out hole in this box was not the right shape or size. Therefore, I used my Dremel to cut a rectangular-shaped oval hole that was just the right size for the boat cable that needed to pass through it. After I fed the cable through the box, I carefully stripped the white, protective cover back to reveal the three 10 AWG wires within. One was black, one was white, and the other was green.
Some might say that 10 AWG wire is too big, but not me. After all, I was dedicating this receptacle to the window unit style air conditioner that I would mount in the companionway when the weather was hot and humid. These appliances draw a lot of power, and I wanted to minimize resistance and voltage drop. Besides, I had to buy 10 AWG wire for the shore power inlet. Likewise, I needed to buy 10 AWG wire for the AC receptacle on the starboard side of the galley, which was dedicated to the battery charger, and which would draw 11 amps while charging.
Inside the boat, I joined the green wire, which is the ground wire, to the screw terminal with a forked heat-shrink terminal that I had earlier installed on the end of the wire.
As far as the black wire (hot) and the white wire (neutral) were concerned, I joined these to the receptacle in the style commonly seen in residential wiring jobs. Instead of crimping and heat-shrinking terminals on the ends of the wires, I simply stripped the wires to the proper length, inserted them into the appropriate holes, and tightened down the appropriate screws. Why did I do it this way? Well, from what I could tell, it appeared that there was just no way that I could fit the receptacle into the shallow box if I used heat-shrink terminals on the ends of these wires. Using a heat-shrink terminal on the green wire would work, since the screw terminal for this green wire was more recessessed than the ones for the black and white wires. This seemed like a really bad decision on my part, but I did not see any way around it at the time.
Having joined the three wires to the AC receptacle, I had a buddy stand in the boat and hold the receptacle steady while I slowly worked the cable through the box. The goal, of course, was to fasten the box to the bulkhead where it belonged.
After I had secured the box in its proper place, I began to think about how I might route the cable. Having installed the cable on the top side of the box, I already knew that I needed to route it upward and across rather than downward and across.
To protect the back of the bilge switches, I had installed a modified old work box, pictured below in blue. Over this I had already routed the red positive cable from the back of the main DC breaker. This seemed like a good route for the AC cable as well.
As I routed the AC cable, I left room for the black conduit that I soon afterwards routed downward from the bilge pump switches. The gray conduit that I had earlier routed upward, over the bulkhead was for the yellow negative 10 AWG wires for the DC distribution panels in the galley.
At this point I considered this part of the overall AC wiring project complete. Several weeks later, however, I returned to this circuit to have a second look at the receptacle. Ever since I had installed it, I had been concerned about my decision not to install heat-shrink terminals on the black and white wires. Therefore, I thought it would be a good to return to this receptacle and reevaluate the situation.
My greatest concern, of course, was that these wires would soon corrode in the warm, salty air of Charleston, South Carolina. The space in this shallow work box was indeed very tight, but I thought I might be able to make this receptacle fit with heat-shrink terminals on the black and white wires. The issue with heat-shrinks, as you can see on the green wire below, is that they inhibit the bending of the wire.
My first thought was that I could help matters by cutting off half of the heat-shrink material. After dry-fitting the one pictured below on one of the wires, however, I changed my mind. I wanted these wires to be as protected as possible.
It was not easy crimping these terminals on the wires.
There was no extra wire, so I had to do this work right up next to the bulkhead.
Even more challenging was the heat shrinking of the terminals. I had to set up a temporary shield of plain mahogany to protect the varnish on the finished mahogany panel behind the battery switch. I also had to use needle nose pliers to turn the terminals as I applied the heat. If I had not done this, I would not have shrunk the terminals correctly.
The work area got so hot that the blue electrical box became soft and pliable. After I had finished the job, I took this picture of the box, as seen from the cockpit locker. Notice how the right hand side is slightly concave. Fortunately, the black plastic conduits beside it were unaffected.
The Pass & Seymour brand GFCI that I used was more welcoming than other brands for the use of heat-shrink terminals. Some of them have plastic nubs near the screws which prevent you from inserting a forked terminal underneath the screw. Why not use ring terminals you might ask? Well, the screws are not designed to be removed from the receptacle. Having done some residential wiring, I knew this. Nevertheless, I thought it was worth trying to remove them, so that I could use ring terminals instead of forked terminals, since the former provide better contact than the latter. With a little force I was able to remove the first screw. Not a problem, or so I thought. Immediately afterwards, I reinstalled the screw and attempted to tighten it down. It would not cooperate. The reason? I had stripped the threads. The result? The GFCI was ruined. What did I have to do? Go out and buy another one. The lesson learned? Forked terminals are the way to go on AC receptacles. By the way, in case you're wondering, in my experience in installing the AC receptacles in Oystercatcher, I found that the screws on the receptacles, regardless of the two different brands that I used, were Number 8 in size.
The makers of these receptacles have done a lot to keep people from making dumb mistakes while wiring them. For instance, they have placed yellow tape over the screws on one end to warn people not to install wires on those screws if this GFCI is the only receptacle on the circuit. Likewise, they have labeled the screws according to the wires they are to receive.
After double-checking and then double-checking one more time, I installed the wires in their appropriate locations.
I felt much better now that all three of these wires were protected with heat-shrink terminals.
Fortunately, I had very little trouble fitting the receptacle into the box, even though the heat-shrink terminals made the fit even tighter than it already was.
At last I could install the stainless steel protective plate and call this part of the overall AC wiring project complete.
This ends this posting on how I wired the AC receptacle on the port side of the galley in Oystercatcher, my Ericson 25.

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