Itinerant wrote:
We are having difficulties figuring out the shorepower. Everything
was working fine on 30A, but now that we have moved to a new dock
where there is only 110 we have attached our pig tail to take the 30
to 110 but it trips the breaker on the dock as soon as we plug it in.
We tried using the neighbour's pigtail (which works for him) and it
still trips it. We have the Xantrex inverter/charger and have
adjusted the powershare level to 10 (from 30).

Any ideas?

after shutting off all breakers in the 120 v circuit, put a voltmeter
inline with the pigtail to see if, in fact, you are still drawing
current. I'll be you are. You will need to trace / fix that.

You probably have an unswitched appliance

Ernest Scribbler wrote:
"Paul Cassel" wrote
after shutting off all breakers in the 120 v circuit, put a voltmeter
inline with the pigtail to see if, in fact, you are still drawing current.

Volt meter? Inline? To measure current? Huh?


Yeah, stupid me. I mean multimeter.

On Dec 9, 7:40 pm, Brian Whatcott wrote:
On Sun, 9 Dec 2007 22:29:15 -0500, "Ernest Scribbler"

wrote:
"Brian Whatcott" wrote
the famous "American Neutral to Ground" connection.
That's the way American consumers are wired, after all!

Say what?

What is it that you don't understand? See code of practice for first
drop at domestic distribution transformer.....

Brian W


I think this is the problem.

Theoretically, both "sides" of the AC should be "floating" - that is,
both Line (black) and Neutral (white) should only be connected to the
load, not to ground, or case, or anything. The third wire is Ground
(green) and should be connected to ground/chassis/frame/etc.

In the "two-wire" system (with the polarized plug), the Neutral is
also ground. So... a lot of systems connect neutral to ground.
Everything goes OK until some Bright Individual says both AC lines are
floating so it doesn't matter which one is which.... so you end up
with Line going to Neutral and vice versa. This works OK until someone
grounds the Neutral, and POOF.

I suspect either your boat, your marina, or your cords have line and
neutral reversed, and then grounded. You or a licensed Electrician
needs to check what wire goes to which connection on all the plugs and
connectors.

BTW: If you're a Vancouver boater, check out the BC Boatnet forum!

druid - "Coatue" Crown 28
http://www.bcboatnet.org

"Brian Whatcott" wrote
What is it that you don't understand?
See code of practice for first
drop at domestic distribution transformer.....

I understand that ground and neutral are connected to a common bus at the
service entrance. Are you saying the OP's problem may be that ground and
neutral are connected at his shore power connection? That would just be
plain wrong. I'm not trying to be confrontational, just trying to understand
what you're getting at.

On Mon, 10 Dec 2007 16:03:27 -0500, "Ernest Scribbler"
wrote:

"Brian Whatcott" wrote
What is it that you don't understand?
See code of practice for first
drop at domestic distribution transformer.....

I understand that ground and neutral are connected to a common bus at the
service entrance. Are you saying the OP's problem may be that ground and
neutral are connected at his shore power connection? That would just be
plain wrong. I'm not trying to be confrontational, just trying to understand
what you're getting at.


Sadly, though just the first drop is specified to cross connect, in
older practice, follow on drops were also sometimes connected.
As you say, it's just plain wrong.

Brian W

On Dec 9, 8:16 pm, (Richard Casady) wrote:
On Sat, 08 Dec 2007 17:19:29 -0800, Peter Bennett

wrote:
More details would be useful. As it stands, your description doesn't
make sense to me, as the common North American 30 amp shore power
service _is_ 110 volts. Do you mean that the boat has a 30 amp power
inlet and shore power cord, but the dock only has a household-style 15
amp/110V outlet?

There is also the twenty amp outlet. The plug's blades are at ninety
degrees. Only such plugs I have ever seen were for window type air
conditioners. They make the outlets with the 'T' shaped holes to take
both those and the fifteen amp ones with the parallel blades.

Casady

Here in Canada we often use those 'horizontal pin' plugs for 230
volts.
In our garage, for example, we have 115 volt vertical pin outlets and
a 230 volt so we can plug in both types of tools. Both are breakered
at 15 amps.
On a workshop workbench we also have both.

"Edgar" wrote in message
...

"Itinerant" wrote in message
...


FWIW,

I have discovered that some inverters that are based on switching power
supply technology just don't get along well with ground fault (GFI)
protected circuits. When power is first applied, and within the first half
cycle of the 60Hz, the impedance of the switching power supply appears as a
dead short to ground, tripping the GFI type breaker. There's nothing wrong
with the circuit, it's just a characteristic of the supply type.

Xantrex happens to be one that I've experienced problems with before in
this regard.

Eisboch

"Eisboch" wrote
I have discovered that some inverters that are based on switching power
supply technology just don't get along well with ground fault (GFI)
protected circuits.

Do marinas commonly use GFCIs on their shore power circuits?

"Eisboch" wrote in
news
the impedance of the switching power supply appears as a
dead short to ground, tripping the GFI type breaker. There's
nothing
wrong with the circuit, it's just a characteristic of the
supply type.




The input of any switching power supply is merely a full wave
bridge rectifier and some LARGE electrolytic capacitors, which
are what causes the huge surge when you plug them in...charging
those caps.

They use large caps for a reason.....to reduce the effects of
powerline pulses, especially OFF pulses that blink your lights.
The large caps can hold up the output DC for several hundred
milliseconds during those brief power "blinks".

Unfortunately, the idiots are trying to see how few parts they
can make them out of so leave out any surge-reducing varistors or
even low value surge resistors from the primary circuit that
would stop the huge pulse and plug-in-arcing.

Larry
--
Merry Christmas!
http://youtube.com/watch?v=Qi_NhFS4xEE

"Ernest Scribbler" wrote in
:

Do marinas commonly use GFCIs on their shore power circuits?




Not around here. All the breakers at our marinas are the old rusty
types with the half-broken-off handles...(c;

GFCI's are way too expensive for marinas, trying to extract maximum
profits in the shortest length of time.

Larry
--
Merry Christmas!
http://youtube.com/watch?v=Qi_NhFS4xEE