Hi Kevin,

I work in the telecom industry, where we always isolate AC equipment from DC equipment ensuring that each has the required earth path.

I need to locate a regulation in BS7671 or elsewhere that indicates if a distance is required between the two separate systems as there is obviously a different earth potential between the two systems and a person touching the AC equipment and the DC equipment at the same time could in theory receive that difference in potential as an electric shock.

Regards

Mark

Hi Mark,

I am posting a copy of ABYC E-11, which is the marine electrical boat wiring standard for the industry.

On boats, it is required to connect the AC Ground to the DC ground to give a low resistance path to ground in the event of an AC fault to a DC device. Without this connection, the AC path to ground would be through the water which creates an extreme hazard.

Hope this helps,

Kevin

Hi Kevin,

First of all, thank you for all of the time and effort that you put into your website. The boat wiring information that you share is invaluable.

So tell me Mr. Marine Electrical, do my ambitions exceed my abilities?

My wife and I have a small sailboat that we’ve enjoyed for many years. It’s a perfect size for the two of us and can’t imagine anything that would make the boat more fun…with one exception. We find that we are very jealous of our marina neighbors who have shore power. Whether they are using a television, a drink mixer, a vacuum, a toaster, or even a simple battery charger, we start down the “if only” path.

How tough a project is it to add AC power to an older boat? I’m reasonably comfortable with simple household wiring jobs, but have been told that marine AC can be an incredibly complicated and – if not done correctly – incredibly dangerous.

Any suggestions?

Thanks.

Matt

Hi Matt,

No project is too big, not project is too small when “Mr. Marine Electrical” is on the scene!

Seriously, there is a great new product from our partners at EzAcDc that will fit your needs. They have a complete marine shore power system that follows their snap-together philosophy of simplifying boat wiring jobs.

Installation of the new marine shore power system is easy.

The panel is pre-wired and comes with a remote outlet with 10′ of boat cable that simply plugs into a “snap together” plug on the back. The kit is also pre-wired with 10′ of Marine grade boat cable that runs from the boat AC panel to the included shore power inlet.

Best of all, any complex electrical connections are already made inside the powdercoated aluminum box.

All outlets are GFCI protected. And, for additional safety, the AC panel has a dual pole breaker to protect the boater if the dock outlet is wired backwards.

The panel also includes a power “on” indicator light and a reverse polarity light. It also comes with the AC to DC grounding wire that is required by the US Coast Guard. This wire runs from the back of the panel to your DC negative buss, engine ground, or battery negative and provides an additional safety path to ground if you have an AC fault on your boat. Even though required, this wire is redundant on this well-designed system since the GFCI also protects everything.

Additionally, there is a single outlet on the back of the shore power panel to allow a built in AC device to be connected. This is ideal for a battery charger or refrigerator that comes with a standard 15 A household plug. Simply plug it into the back of the panel before installing.

It comes with the industry standard 30 amp Marinco inlet. You can choose between the standard square plastic inlet or upgrade to the stainless steel version. Both will connect to an 30 amp marine cordset or adaptor.

Please let me know how your project turns out. I always like pictures.

Kevin

Hello,

I have recently bought an early 80s 22 ft Chrysler sailboat. The electrcal system is bascalliy non-existent.

I am starting from scratch and want to add a DC system that is capable of accepting shore power. Initially I am only interested in adding basic navigation and communication system and some lighting. However, I do want the system to be expandable and capable of accepting shore power or a portable generator.

I have no idea what I need to start with. Can you please provide some suggestions?

Will

Hi Will,

Our partners at EzAcDc have a great system solution for you.

You can combine their Fully Wired Marine Switch Panel with one of their Deluxe Boat Wiring Harnesses to make a complete system for all of the items you have listed.

The switch panel will control navigation/anchor lights, courtesy lights, and 2 accessories. It includes a voltmeter so you can monitor your battery condition. The boat wiring harness has wires for split red/green forward navigation lights and a single white stern light. It also provides wires for a courtesy light. The additional switches can be connected to other devices such as VHF radios and GPSs.

For the future, connecting marine shore power is not too difficult as long as you as focus on safety. For small systems, you always want to use GFCI protection and the DC ground is connected to the AC ground. Always look at the worst case and make sure a breaker will trip before somebody gets a shock.

The two biggest problems with portable generators are carbon monoxide generation and AC grounding. The best way to connect a portable generator to a small boat is through the shore power connection with a long cordset (keeps CO away from sleeping area). When making your electrical connection, make sure the AC neutral is connected to the AC ground on the generator.

Please let me know if you have any questions,

Kevin

Kevin,

Thanks for the fast reply and I think both the products you reccomend will work great for my boat. But I am still unsure about the shore power connections and the battery charger I would need?

Will

Hi Will,

Besides a battery charger, what other AC devices do you plan on adding to your boat?

Kevin

Kevin,

Whatever cord I would need to connect the battery charger to shore power, a bilge pump (or maybe two due to my boat’s design) and a stereo and a fan.

Will

Hi Will,

I would seriously consider using a battery charger like the Guest 2608A combined with a Connect Charge Inlet as your shore power system. The charger has a standard extension cord plug on the end that snaps into the back of the connect charge inlet. The connect charge inlet mounts through the deck of your boat. You can plug a conventional extension cord into this inlet.

The rest of the devices on your boat can be DC and run off of the battery.

This approach will save you several hundred dollars on your shore power system while achieving the same results.

One of the next EzAcDc items will be marine shore power systems for a small boat. It will include an AC cabin panel, a 30 amp shore power inlet, multiple outlets and cabling. It will also provide a means of connecting a battery charger and a refrigerator. This kit will be on the market for around $300.

Please let me know if you are interested in this type of kit and we can work a discounted deal in exchange for installation photos.

Thanks,

Kevin

Dear Kevin,

I am currently beginning my first boat wiring project, a total rewire of a small Owens cruiser from the late ’60s.

Here’s my problem:

The old wiring runs behind the original paneling and headliner. I could try dismantling everything to remove and replace the wires, but am concerned about damaging any of the woodwork. It’s old. It’s gorgeous. It would be a bitch to replace.

I don’t mind leaving the old wiring in place and just running a new harness, but that still leaves the problem of installing the new wires without causing any damage.

Any ideas?

RP

Dear Ron,

Your problem was common with boat restoration projects – until the introduction of Harness in a Can.

Harness in a Can lets you spray pro-quality boat wiring into even the most hard to reach areas. Simply point, spray, and apply power. What could be easier?

And, it’s not just easy, it’s ABYC approved! Harness in a Can sprays out a harness with correct wire color and sizing – and with all of the connections that you need to get the job done fast.

If you order now, you will also receive a cap snaffler – absolutely free. Cap snafflers snaffle caps off any size jug, bottle or jar…and they really really work.

Call now to order. The toll free number is 877-277-3665. Operators are standing by. That’s 877-APR-FOOL.

Kevin.