Monday, February 18, 2013

I am Mortified, Stupified, She is ELECTRIFIED!

Figure 19 - Mast Grounding and Keel Bolt
Well, the winter is wearing on and you can only stay in the basement for only so long.  After working some 35 pieces of teak and miscellaneous woods and by no means done, I was yearning to turn my attention to some else and so I fired up the portable heater on the boat and took on a another project:  This time it was the grounding wire from the mast.  It was  grounded to the front keel bolt.  It was not in good shape and partially broken at the connector. Let's talk about the grounding of this sloop.

[ABYC Recommendations, Marine Advisor, Spring 2001). Being the Constant Marie is a sailboat with an aluminum mast we have the starting point of a well-grounded lightning rod. This will provide a zone of protection for a radius around its base equal to the height of the lightning rod. Due to some vessels overall length, it may be necessary to install another lightning rod to encompass any areas that do not fall within the zone of protection. Don't forget that the mast itself must be physically bonded or connected through to the common ground - one of the keel bolts or if a encapsulated keel, to the grounding plate, in order to provide optimum protection.  In this case, to the Constance Marie's keel bolt.  The apex of the rod should be a minimum of six inches above any masthead device. The end should be sharpened to a point. The base of the mast or the mast step if metal, should be connected to a keel bolt on externally ballasted vessels. The preferred wire gauge is No. 6 or even better, #4AWG stranded copper. In no case should such a connection be made to a vessel with internal ballast. The result could be a hole blown through the bottom of the hull. Boats with internal ballast should have a copper ground plate of at least one square foot in size installed externally on the hull bottom. The grounding wire should then be connected to the ground plate. All wire conductors should be kept as straight as possible. All large metal objects above and below decks should also be electrically tied into the lightning ground conductor. This is a precaution against side flashes. Large metal objects include shrouds, chainplates, toe rails, sail tracks, winches, steering wheels, and bow and stern pulpits. These items can be tied into the ground conductor wire by a minimum #8AWG stranded copper gauge wire, or connected directly to the hull ground terminus.  And that's exactly what I did.

Figure 19
Front of electrical panel
You might remember earlier that the electrical panel was disconnected from all the AC / DC wires in the first days after the Constance Marie was pulled. 

Figure 20
Back of electrical panel
This is the original electrical panel designed for 1980. Hmmm, what was going on in 1980?
Yearly Inflation Rate 13.58%
Dow Jones Industrial Average 963       
Interest Rates Federal Reserve   21.5%
  Average Cost of new house $68,700   

Median Price Existing Home $62,200
Average Income per year $19,500.00
Average Monthly Rent
 Cost of a gallon of Gas $1.19
Average cost new car $7,200.00

Back to reality.  I was looking at an electrical panel that had the alternating current (AC) designed on the same panel as the direct current (DC). Of course the AC is like the power in your house and the DC is like the power provided by the battery in your car.  Things change over time and codes now require that AC and DC be on separate panels but the Constance Marie is a 30+ years old and I chose to keep things functionally normal.  I would focus on the DC conductivity and fix the AC later.  Remember, we moor the Constance Marie and not slip her at a dock as a matter of routine.  I bought some 5 amp, 10 amp and 15 amp circuit breakers to replace the old ones in the panel.

When I purchased the Constance Marie I discovered that I did not have an owners manual for 1980.  I found one for 1979 and could barely read the wiring diagrams, so I created one myself from physically eye-balling things and the little I could get from the documentation.
I did the same for the AC which was alot more simple.  Remember you can click on the picture to enlarge it.
Figure 21 - DC schematic of the Constance Marie
I checked all the wiring on the boat as best as I could and I was surprised to find twisted pair and not solid core.  I spent the next several weeks putting in new galley and berth stainless steel lights, new running lights, fixing the mast ground and putting in three ground fault interrupter (GFI) sockets in the galley, navigation and head areas.