Help with shore power plug

flapbreaker · Posted: Thu Dec 20, 2007 10:43 pm Post subject:

Just to be clear, I have no intention of trying to plug into 30 amp service using a plain ol' extension cord. I did buy a 25' 30 amp shore power cable. I only use the 30amp to extension cord adapter to plug the boat in at home to charge the batteries. I wasn't sure if I was clear on that in the beginning.

Cutty Sark · Posted: Fri Dec 21, 2007 10:29 am Post subject:

I have a question, what is needed to duplicate the factory shorepower setup? Obviously Shore power cord, inlet, 30 amp breaker and a GFCI outlet, but what else? Galvanic Isolator? I have Nigel Calders book, But cant seem to figure out exactly what I need to setup my shore power.

Sark

marvin4239 · Posted: Fri Dec 21, 2007 11:07 am Post subject:

Factory setup now comes with a Galvanic Isolator. You'll need a distribution panel also.

Cutty Sark · Posted: Fri Dec 21, 2007 11:29 am Post subject:

The distribution panel usually has the breaker in it right?

Sark

marvin4239 · Posted: Fri Dec 21, 2007 11:47 am Post subject:

marvin4239 · Posted: Fri Dec 21, 2007 12:35 pm Post subject:

marvin4239 · Posted: Fri Dec 21, 2007 12:49 pm Post subject:

The Sea Dog panel numbers are 423132 for the distribution panel it also has a reverse polarity light. The distribution panel number is 423142 and has a 5 amp 10 amp and 15 amp breaker.

Cutty Sark · Posted: Fri Dec 21, 2007 1:47 pm Post subject:

Thanks for all the info, thats exactly what I was looking for. Got to love this place.

Sark

mikeporterinmd · Posted: Fri Dec 21, 2007 3:53 pm Post subject:

mikeporterinmd · Posted: Fri Dec 21, 2007 4:05 pm Post subject:

Blue Sea http://bluesea.com/ makes some nice panels. I peruse their
website and then look up the part numbers on northeastmarineelectronics.com
and order from them. Most of this stuff, including chargers, can be had
for a substantial discount if you order online. If you are doing a CD-22,
look at my photo album.

The inlet location I chose is somewhat non-traditional, but I really like it.
No tripping over the cord when boarding. I was hoping it would let me
use a 25' cord at home, too. But, as luck would have it, the outlet is
on the wrong side of the slip.

On a CD-22, the run from the inlet at the transom to the panel over
the tank is less than 10', and therefore within spec. However, I chose
to run the cable in PVC conduit for extra protection. If the run is
longer than 10', you need a breaker near the inlet. I wouldn't be against
installing one there in any case, but didn't see a good location.

Oh, there is a seller on ebay for Ancor brand cable. You'll find 10 gauge
cable to be quite expensive, so it makes sense to order online. You
shouldn't use home style NM-B since it is solid conductor; you should
use stranded on a boat.

The inlet is still clean and shiny after the first season, but we are not in
salt water.

I did not install a galvanic isolator. I probably should. Defender marine has
the best selection I've seen. It's a hard call because there is so little metal
in the water on a CD-22. Of course, you must bond DC negative to AC
ground, but if you have Nigel Caulder's book, that requirement has been
hammered into your head!

Mike

mikeporterinmd · Posted: Thu Dec 27, 2007 12:48 pm Post subject:

marvin4239 · Posted: Thu Dec 27, 2007 1:05 pm Post subject:

We just picked up a little ceramic house with a light weight, UL rated
light. The plug contains a 5 amp fuse to protect the light weight wire.
So, you are partially correct. Or perhaps lots of homes in America have
unsafe wiring.

Mike[/quote]

Actually Mike I think many of the houses in America do have unsafe wiring. If you want to know why I think this just go out to any large housing project while they are roughing in the wiring and take a look. Some areas of the country have more stringent building codes for instance Chicago area still requires houses be wired in conduit. In Florida where I live and have been a licensed electrician for 35 years the people doing electrical work don't even have to be licensed. Inspection departments in my area are a joke. We just had a 6 story parking garage collapse here and while it isn't official yet it appears it was due to pvc conduit in the slabs being installed incorrectly (all bundled together) which weakened the slab. I agree if something has a UL listing it should be safe but isn't always. Sorry to drift of topic.

marco422 · Posted: Tue Dec 30, 2008 6:13 pm Post subject:

[quote="mikeporterinmd"]
If the cord is plugged into a 30 amp outlet and something damages the
cord and causes a short, how are you going to prevent more than 15
amps from flowing?

Mike[/quote]

I believe a short would lead to a temporary current of over 15 amps (in fact over 30 amps since resistance is almost zero) until the 30 amp breaker on the dock tripped, which would take only a second or two. Too short a time to cause a cord fire I think. Also, only the cord between the plug and the short would heat up, not the section beyond the short.

Current capacity for a given wire gauge is calculated for continuous use with existing heat dissipation (insulated, conduit or free air). It doesn't take into account very short periods of overcurrent due to shorts.

While the installation technically does not meet codes, I believe it is reasonably safe.