Installing AC power (shore power)

[Mark.Wilme]

Tim prompted me the question in another post about what else do I need to do while I have access to my engine compartment, well it's not that space per-se but it got me thinking.

We keep the boat in a slip but we don't have shore power. There are times during the week when I am at work that the boat gets used like a camper, but we can't do that forever on battery power without running the engine at the dock or taking a regular old battery charger and a 30ft extension cable and charging the batteries. I have done both and am not fond of either.

Suffice to say I want to install shore power and I think it is straightforward, but because I think that I am now sure it is not.

My needs are simple, I was thinking of :

1. Marinco 30A shore power inlet mounted high on the boat in a semi protected place using normal mounting procedures (3M 4200) where I have access behind for the wiring.

2. That wire (tinned 14ga marine wire) runs to a blue sea AC distribution panel such as this



Truth is I think I would prefer one with a master breaker and then 2 switched circuits, one for the battery charger and one for the 2 or 3 110v outlets that I think I need. But I can't find this in Blue Seas inventory.

3. Run 14ga tinned marine wire to the three outlets I need, wired in series, with at least the first if not all 3 being GFCI. Outlets and wiring to be high and AC wiring to be kept outside of the bilge. Being careful throughout to mark my AC runs differently to my DC runs and if possible keep them physically separate.

4. Second feed from AC Distribution panel to Xantrex 10TB charger charging both my starting and my house batteries through my main battery switch (next). The 10TB will smart charge a 2 battery bank which will be useful for the future but right now both batteries today are identical group 27 batteries (850 CA, Res Cap 170) wired the old fashioned way through a One/Both/Two/Off switch. I know the shortcomings of this but am pretty damned religous about never leaving it in the both position except when charging or if needed for starting (which has never happened).



All of the above seems straightforward. Running the wires, crimping the connections, shrink seal to protect them etc etc. But because it does seem so simple I am thinking I should go out and buy Calders book on sailboat electrics and see what I am missing.

Note my AC demands are not high. mostly battery charging, maybe recharge my laptop, maybe an occassional hairdryer, occassionally, maybe other small loads. I don't forsee any TV's, microwaves, washing machines etc.

M

[Tim]

A basic system like the one you suggest is just about as easy as you think. I have a few suggestions:

1. Plan for future needs. To that end, I would suggest going with 12/3 cable rather than 14. It's overkill for a few outlets, but by using the larger wire you ensure that you will never overload the wiring even if you plug several appliances in at once. It costs very little more at this point to install the larger wire. It should go without saying that the wiring should be marine-grade tinned copper multistrand.

2. A 30-amp system with several outlets will easily handle TVs, microwaves, etc., if you for some odd reason decided you wanted these on your boat.

3. If you install a GFI outlet in the first location and then wire the others downstream, you can have GFI protection on every outlet by only purchasing one specific outlet. Each GFI outlet comes with instructions on how to properly wire it for this purpose. I think all your outlets should have GFI protection, and this is an easy way to do it.

4. You should have a switched circuit panel for more than one circuit. You may, unfortunately, need to go with more panel than you want to get this, or you may be able to find the panel of your dreams online.

5. You should make efforts to keep the AC wiring separate and distinct. You should use the commonly available AC boat cable, which contains a green, black, and white conductor. Green is ground; white neutral; and black is hot. (Note: this is why it's often suggested to use yellow wire for the DC negative side on boats containing AC power, so that a black hot AC wire could never be mistaken for an innocuous DC ground wire.)

6. Use sound wiring practices to install your wires. Keep them far away from water (always), protect all ends with quality connectors and adhesive-lined heat shrink. Never use household-type wiring. Secure the wires frequently (every 12") with non-corrosive clamps, hangers, or what have you. Protect the wires from chafe wherever it may occur.

7. Be sure to wire your main receptacle (and all receptacles and circuits) properly to avoid reverse polarity. If you can find a master AC panel that contains a reverse polarity indicator light, that will help protect you should the marina's wiring be incorrect.

8. Calder's book is always a good, if over-exhaustive, reference. You probably don't strictly need it for your proposed job, but it doesn't hurt to have it in the inventory anyway.

[dasein668]

Calder's book is always a good, if over-exhaustive, reference. You probably don't strictly need it for your proposed job, but it doesn't hurt to have it in the inventory anyway.

It's worth the 50 bucks. While it often seems over-exhaustive, most of the time if I look for an answer to a question elsewhere, I find that I need to go to Calder anyway to find it, or at least for clarification. It's the most-often-reached-for reference book on Dasein.

[Jedediah]

Looking around McMasterCarr one day I discovered a surface mount GFCI device (part # 72155K73) that I'm intending to install with the circuit breaker so that I know all the boats 120VAC wiring will have GFI. It seems like a logical solution, although I haven't tried it yet, and is blackboxing the entire boat as a single piece of equipment which I think should work... Note, I'm limited to a 20A supply so that part number works for me, they also have a 30A version.

[FloatingMoneyPit]

Check out Paneltronics. I bought their 120V, 3 circuit w/ double throw mains panel for a reasonable price at Defender.

And yes, the main switch throws both hot and neutral lines, even though there's only one breaker knob. That kind of threw me when comparing to the Blue Seas panels which have connected double knobs.

http://www.defender.com/product.jsp?pat ... 3&id=51318

[Ceasar Choppy]

I would recommend upsizing your AC wire to at least 12 AWG. Don't know how long your runs are, but for AC wiring, I believe 12 AWG is minimum recommended.