New breaker box question

I am prepaing to re wire my 38' Beneteau. The boat went down in Katrina so all the componets were compromised. I am planing on a 30 amp breaker box with 1 30 amp in and 3 15amp out. 1 breaker dedicated to the A/C, 1 for the battery charger, and one I would run to a panel at the nav station that I would run my outlets from. This is not the org. configuration. It was wired direct from the box with no breakers at the nav station. I have a new AC - DC breaker that I would like to use. Does this sound correct? I have heard stories that the DC and AC shouldn't be on one board, but the board came off a relativly new Hunter.

 

It's best not to mix AC and DC on the same board (though if it's done neatly and carefully there's no real reason not to do it). The normal solution is to switch the DC feed into the inverter. You then only need one DC input with several DC outlets. It then means that everything on the panel is non-lethal. This helps greatly if you need to repair the panel at sea.

Naturally, you should size the inlet/outlet cables appropriate for the amount power that you will be drawing. If you are switching large currents you may prefer to use a high-power relay, rather than just using a switch directly.

Tim B.

 

you can put AC and DC in the same panel. ABYC Recommends though that you have them seperate in the panel and that the AC be covered with a shield so you can't make accidental contact with the AC while working on the DC.

 

Thanks guys

One more fast question, because I am also hearing conflicting views. Can I reuse the existing wire assuming the gauge is correct? I was planning to cut back the wire to bright copper then reuse. It will save a lot of time, but others at the yard say I should use all new wire. I have rolls of AC wire so it is not an expense problem. Your opinion? Don't forget the boat was sunk and I had to shovel 2 foot of mud out of her.

 

The lastest studies seem to indicate that water does not migrate up the wire as much as was thought. However, it depends on a lot of variables like, salt or fresh, water temperature, how long it was submerged, how old the wire and so on. I would just replace it. That's my opinion anyway.

 

I'd replace the longest cable runs, but re-use the old cable for the shorter runs. As long asthere are no nicks in it and it all looks to be in good order I can't see there being a problem.

Incidentally, water ingress is more of a problem on crimped cables than it is on soldered cables. This is because some of the insulation melts against the wire when soldering.

Normal AC wire may be a false economy, ( though solder it into the terminations (see above) if you have no choice), it is better to use proper marine-grade caulked wire, just because of the reduced water ingress.

Tim B.

 

I'll do a meter check

I'll do a meter check of each run. If I see a drop I'll know that there is a leak and I'll replace that part. The boat was wired correctly, with the correct gauge, color, GFI's (almost too many), and since they knew more than I do I'm just going to follow their lead, and replace apples for apples. It shouldn't be rocket science.

 

a meter check in good, but a visual check of the insulation is important. A meter check only tells you of severe shorts or opens.

 

The Future of your wiring....

Good Point! Long ago when I worked on wiring and electronics on military aircraft, an old Navy electrical inspector told me "Meters can tell you the present, but only a detailed visual inspection of every connection can tell you the future."

 

I'm ahead of you. I have been pulling out the wires, checking them and then re-pulling to new GFI's and new outlets. So far it has been ok, and I haven't had to replace a run yet. It started because I don't like to work dirty. Even though all the mud is out of the boat (it went down and rolled) there was a dirt film over everything and I couldn't tell what colors the wires were. Little by little I'm taking out the wires, cleaning, checking then reusing. Isn't boating fun!!