How do I ground my electrical system?

I am in the final stages of a 4 year rebuild of a 27' sailboat. I want to start the electrical system, but the one basic item I can't figure out is how to ground the AC & DC systems. I have no inboard engine, and my keel is a swing type and not accessable.

 

www.uscgboating.org --then regulations --then Boatbuiders Handbook. Then electrical section. Covers everything you can ask a question about. It has wiring diagrams. Have a problem, post back and we will answer it.

 

Thanks, But It's the same problem . All the diagrams and the sailboat section show and talk about bonding through the keel and engine. The electrical books that I have are the same. What do you do if you don't have an engine, and the keel is not accessable?

 

You have a 12 volt battery to power everything? NO motors?

 

Do you have a light at the top of the mast? Do you have anything to carry a lightening strike from the top of the mast to the water below your boat?

 

Do you have a metal or carbon type of fiber mast or rigging? Radio or antenna?

 

Web search- sailboat lightening protection -Read the US Boat site one. The rest are OK. Post back your thoughts. I will post mine.

 

Weather you bond the 12V system is a personal choice , many times a simple boat will show NO electrolisis after years imersed.

THE 120V system can kill you if you do it wrong.

There (US systems) the green wire is a ground that should NEVER be attached to the white neutral wire.

Only if you produce your own electric , genset or inverter , will those two be joined at the power source , ONLY while producing 120v power.

FAST FRED

 

At this time my mast is down. I would like to add lightning protection, but again, all the instructions say to run copper strip to the keel. I can't get to the swing keel to do that. All power (when sailing) is off a twin bank of batteries. I will use a kicker outboard when not sailing. I have 30 amp shore power, but not grounded yet.

Thanks for your input.
Jerry

 

I agree with you completly about the copout by the USCG on electrical 120 vac and lightening wiring. The shore power section has been deleted.

 

Electrical work is really pretty simple, but there are concepts you need to understand, that most folks don't. There are several good books on the subject and I strongly recommend you get one or two of them.

I don't like bonding metal components in a boat, though it is a common practice in the USA, it isn't in most other countries. I like isolated systems, for a number of reasons, that aren't necessary to go into here.

Your AC system will "carry the bond" (ground) through the shore power cord. If you generate 120 VAC on board with a genset you will get the same with the internal 3 wire arrangement running throughout the yacht, though depending on the genset manufacture and the installation, you may or may not have a grounding plate installed on the hull. You're best off following the genset manufacture's instructions or having it professionally installed.

Lightening protection will require a ground plate affixed to the outside of your hull. There are complete, commercially available systems that can be installed or you can do it yourself. Typically this is a large gauge wire, possibly having a mast top rod, connected to a ground plate bolted to an underwater location on the hull.

12 VDC from a battery bank is reasonably basic and doesn't need a "ground". Basic 12 VDC work is as simple as bringing the positive and negative (some folks call this negative post a ground, but it's not) legs of a circuit to the device you want to operate. Typically this is done by supplying the 12 VDC to a fuse or breaker panel (AC is done very similarly, though there is an extra wire to deal with, which is a real "ground"), where it's branched off to the different needs. Some of these needs will require switching, indicator lights, relays, etc. Most devices you may buy (new) will show a simple wiring diagram in the installation instructions.

The easiest way to get a handle on this stuff is to make a list of everything you will, or expect you will install, requiring electricity. There will be three lists, a 120 VAC, a 12 VDC and a combo (requires both 120 and 12 volt power, like a portable fridge) each broken down to every switch, relay, light, motor, sending unit, etc. Armed with these lists and your new found understanding (because you got a book or two) you may find it a bit tedious, but very doable work. I enjoy electric work.

The Marine Electrical and Electronics Bible - by John Payne. About 25 bucks new, half used.
Sailboat Electrics Simplified - by Don Casey. About 15 bucks new.

One or both of these books will get you there.

 

Thanks Par,
I think I was making it too complicated. I do own one of the books you mentioned. I'll look for the other.
We exchanged information about a year ago. You sent me the design for the River Barge you were working on. Did it ever get built?
Just for the heck of it I'm attaching a new progress picture of my boat. It was taken about 6 months ago.

Jerry

 

Hey Jerry, didn't recognize your screen name. That 27 footer is looking much better. How did you address the rudder issues? When are you going to put a stick on her?

Belle the riverboat is under construction, hull and deck structures completed, being fitted out with her systems. She'll be in service by the end of the year.

 

This week-end I am going to prep the mast for painting. I was able to pick up a mast, boom, with sails and rigging (including a roller ferling (sp?)) after the hurricains for $400.00. It is off an Erwin 28 so the system should work. As for the rudder, I salvaged a rudder off a 30' S2. It is alittle big and I had to reshape the top angle and weld an extention to the shaft, but for $20.00 It's perfect! I am still looking for a rudder head for a 1 1/2" shaft, Hard to find. I don't want to pay Edson $375.00. That's the only place I could find that makes them.
My son is still at UCF, so my threat to stop by your place still holds.
Nice to hear from you again,
Jerry