On 3/18/14, 8:01 AM, Mr. Luddite wrote:
On 3/18/2014 7:42 AM, KC wrote:
On 3/18/2014 3:34 AM, Mr. Luddite wrote:
On 3/18/2014 12:22 AM, KC wrote:
On 3/17/2014 7:57 PM, Mr. Luddite wrote:
On 3/17/2014 7:14 PM, wrote:
On Mon, 17 Mar 2014 18:19:42 -0400, KC wrote:

On 3/17/2014 6:01 PM, david@righthere... wrote:
I've been on 30A 120V power at the dock for years and would now
like
to upgrade
to 50A 220V, or what they refer to as 50A 250V at the marina
office.
I haven't
put a meter on it yet but so far suspect it's closer to 220 than
250. The socket
on the pedestal is like the one pictured he

http://www.catagle.com/68-153/CWD_Ar...uyersGuide.htm

They say it's 3-pole 4-wire. I'm guessing X and Y are the two hot
legs and W is
the neutral. Between X or Y and W would be 120V+/- and between X
and
Y is the
220/250V. Right? How does the ground tie into it though? With
only 3
poles do we
run a separate wire from the boat to the pedestal, and if so how do
we tie in?

Also can anyone suggest the cheapest place to get a plug like that?
So far the
best price I've found is $68.18 he

http://www.ktool.net/servlet/the-581...-63CR65/Detail






Thank you for any help!
David


The plug is 10-20 bucks at home depot or lowes, Scottys whatever you
have. It's a dryer plug basically... As to the wiring, I forget
but I
have a book I always use when I do the wiring.. It was about 20
bucks at
home depot, I have had it for as long as I have owned a house...

Not true at all, sorry.

This is a non-NEMA twist lock 50a plug, that is corrosion resistant.

A dryer plug is a NEMA 14-30 straight blade that would go south
pretty
quickly on a pier.



Yup. I think Scotty should stick to building websites and not wiring
boats.



Why, cause I took a quick look and made a mistake? I have done a lot of
wiring in my time including my whole house to code in Essex from moving
in with full Knob and Tube... I have done barns, and wells. When you
have a 100 year old house you tend to pick up stuff. You should see me
sweat a pipe.... even if I don't know all the right terminology. Either
way, that's why I always keep my electrical book with me to check my
own
work as I go....


Scott, the OP didn't say if he was re-wiring his *boat* for a 50 amp,
240v marine split service. He might be just trying to use one leg of it
to supply 50 amps to his existing 30 amp, 120v boat panel. If so, he's
taking a big risk because it's not just the plug in question. The
primary feed wires in the boat that run from the power inlet to the
power panel needs to be changed at a minimum. Plus, if the existing
power panel has a 30 amp main, supplying it with 50 amps isn't going to
do him any good. If he changes that to a 50 amp breaker without doing
any changes to the wiring, he could overheat the primary feed wiring in
the boat, causing a fire.

My comment was more than pointing out that a split, 50 amp marine
service plug is not a dryer plug.

I did what I think he is trying to accomplish on the Grand Banks we had.
It had a standard, 30 amp, 120v service. I wanted to add two
air-conditioning units to the boat. Rather than change everything over
to a 50 amp, 240v split service I simply added another 30 amp, 120v
marine inlet connector, wiring (marine type) and a small, dedicated
breaker box with two 15 amp breakers in it, one for each of the AC
units.

I don't know a lot about many things and nothing about some things
however electrical power distribution and wiring happens to be one thing
I *do* know something about. I'd hate to see someone hurt or killed
because they received bad input.

Now, I have a question for you. Let's say your house has a 200 amp
service. Your main breaker is a double pole, 200 amp per pole breaker.
There's 240vac between the two "hot" legs and 120vac between either of
them and neutral. Each hot leg from the utility pole is sized for 200
amps for each side of the service, yet the neutral is also only sized
for 200 amps. Why isn't it sized for 400 amps, the sum of both sides of
the total service?

See if the answer is in your "electrical" book.








Is this a job you are gonna' do yourself? snerk


No, it's not a job. It's a question. Can you answer it with all your
experience wiring homes, barns and whatever?

Look, any handyman can do basic wiring in their house. It's not rocket
science. But knowing something about current capacities, codes and
particularly how the power in a house, commercial building or a *boat*
is distributed requires more than a handy dandy DIY book from the Home
Depot.

I am not an electrician. I am an electrical engineer. If I wanted a
new power service installed in my house or was doing a major upgrade to
the existing service, I'd hire a licensed, master electrician to do the
job.

BTW, the answer to the question I asked is because the two "hot" legs
are 180 degrees out of phase relative to each other, so the net current
flowing through the neutral leg adds algebraically. The current through
the neutral leg can never exceed 200 amperes.


Algebra! Holy smoked salmon!