The previous owner of my vintage Irwin installed a metal breaker box with two 20 amp home type breakers. One breaker is powering my battery charger and the other is for the four outlets on board. I am going to rewire the shore power for several reasons, first the PO used basic solid wire Romex. I have purchased marine wire. The PO installed non GFI outlets (already replaced these). I want separate galley, salon, charger and spare circuit protection. Looking at available panels is there any reason to be concerned about a Main Breaker for the distribution panel? I have a 30 amp shore power breaker on the dock, I see no reason for a Main breaker on board since I am protected at the dock. What do you think?
Shore Power Distribution Panel
- Thread starter Peppercorn
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Look at the Blue Sea Systems Product Line. They make an excellent (I installed one on my boat) Check Ebay. It is an 8 position panel with the top two tied together for main power at 30 amps and reverse polarty. The remaining 6 are all 15 amp circuits. Use a minimum of 14 gauge stranded tin top coat marine grade wire. 12 gauge wire would be better. Remove all existing wire that the PO installed and start from go. Marinco makes excellent power input fittings. I bought my wire on Ebay. Tape or solder the new ABA wire to the existing wire and pull it through.
Yes you should have a marine main breaker on the boat with reverse polarity indication. Even better are the newer ELCI breakers, like a GFCI only for the whole boat and they trip at 30mA of leakage as opposed to 5 mA.
With a standard Blue Seas panel an ELCI could be added at a later date if you have enough slots. ELCI's take up three slots and a standard marine world series main breaker takes up three slots. Marine main breakers are designed to open both the hot and neutral wires not just the hot.
The panel should be within 10' of wire run from the shore power inlet or an additional main breaker should be installed.
Don't forget the green grounding wire gets grounded to the boats DC grounding system and back on shore.
While you are not "required" to comply to ABYC standards re-wiring your boat to the standard helps shift a lot of liability should your wiring practices burn down a marina.
The update to ABYC E-11 requires an RCD (Residual Current Device) / ELCI (Equipment Leakage Circuit Interrupter). This requirement however is BRAND NEW and was only mandated for ABYC compliant builders as of 7/31/2010. It was supposed to go into effect on 2009 but the market could not supply the product fast enough.
11.4.10 Equipment Leakage Circuit Interrupter (ELCI) - A residual current device which detects equipment ground fault leakage current and disconnects all ungrounded (110 V & 240V) and grounded (110 V neutral) current carrying conductors from the supply source at a preset trip threshold.
A GFCI interrupts current at a 5mA level and an ELCI at a 30 mA level. In an AC system that is working as it should the amount of current flowing through the neutral and hot wires is supposed to be equal. If it is not this denotes "leakage" or a ground fault. This leakage is often due to wire jacketing that has been breached but can also happen internally in inverters, battery chargers due to corrosion or failure etc. etc..
If the hot AC wire is leaking and you also have a faulty AC green ground wire, happens a LOT more than you'd think, then the AC current tries to find it's way to ground and can energize just about anything it can leading to dangerous shock hazards on-board, on the doc and in the water near the vessel.
An ELCI or GFCI monitors the balance of electricity in the wires and if it sees a 5 mA (GFCI) or 30 mA (ELCI) difference or imbalance it opens and breaks the circuit. This is much safer than tripping on just 30A of AC current.
ELCI's protect the entire vessel and should be within 10' of the shore power inlet. Keep in mind this is 10 feet of wire not as the crow flies. If your shore power inlet is within 10 feet of wire then an ELCI can serve as your main AC breaker in the panel.
The Blue Seas 3106 toggle ELCI is intended to retrofit and replace the standard world series double pole breaker. It is an easy retrofit and but it does take up an additional slot in the panel over the double pole breaker, three slots vs. two.
GFCI's protect individual branch circuits at 5 mA. GFCI's should be used in the galley, head, machinery spaces or in a weather deck location.
So the easiest and cheapest way to a safe system:
Shore power inlet, to an AC panel with 30A double pole or ELCI breaker & a few branch circuit breakers. Then off to your outlets, using GFCI where necessary, or to your battery charger using proper grounding. Does not have to break the bank to be safe but will certainly cost more than $40.00...
The Blue Seas 8099 panel is a decent choice and comes with a standard 30A double pole. The new panels with ELCI built in are costly, about $280.00 for the Blue Seas 1192 ELCI W/4 branch breakers but the new ELCI breakers are over $130.00 anyway.
While installing an ELCI is an excellent idea, with the Blue Seas 8099 you could always add the 3106 ELCI toggle breaker at a later date and still have three branch circuit breakers.
99.6% of the boats out there at this point, made that up but probably very close to true, do not have ELCI's as you could not even get one last summer, I tried. My boat will have one this spring even though I rarely if ever go to a dock..
A properly wired double pole breaker within 10' WIRE feet from the shore power inlet is still okay provided it's wired correctly and your AC ground (green wire) is connected to the DC ground buss on the boat.
So yes install an AC panel with a marine main breaker or an ELCI breaker and properly attach your green AC ground wire to the DC ground. Your branch circuits will be fed off the branch circuit breakers which with 15A outlets & 14 GA wire would be 15A breakers.
P.S. If you're going to leave your boat plugged in a galvanic isolator is a very good idea...
Absolutely terrific feedback. I completely agree with scraping everything the PO(s) did. Since it was noted on my survey my insurance company will appreciate doing things right and I intend correcting anything that can cause a loss of sleep. 
Thanks for the great replies.
Thanks for the great replies.
Here is the installation I did for a small subpanel on the boat that might work for you,
http://tinyurl.com/4zxnon4 . Chuck
http://tinyurl.com/4zxnon4 . Chuck
Chuckbear, not only was the article you suggested spot on target with my project but the rest of your adventure is nothing short of spectacular. So much information in one spot is priceless. Thanks and that is the exact panel I am planning to install, now I just need to decide on a location.
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