Hello everybody,
I have just upgraded from a GRP 30ft sloop to a steel hull 40ft sloop.
Everything is in excellent state except for the electrical wiring which will
certainly consume most of my winter weekends....

My main worry before everything else is to plan for electrical grounding and
I have read the most opposite opinions.

Can somebody share his experience with me, please ?

Cheers
Joao

I have a 1967 aluminium boat with electrical negative bound to the hull as
well as the ground from the 110v. The boat has no visible sign of any
corrosion.

ANdré


"Joao Penha-Lopes" wrote in message
...
Hello everybody,
I have just upgraded from a GRP 30ft sloop to a steel hull 40ft sloop.
Everything is in excellent state except for the electrical wiring which
will
certainly consume most of my winter weekends....

My main worry before everything else is to plan for electrical grounding
and
I have read the most opposite opinions.

Can somebody share his experience with me, please ?

Cheers
Joao

On Thu, 4 Sep 2003 17:18:03 +0100, "Joao Penha-Lopes"
wrote:

Hello everybody,
I have just upgraded from a GRP 30ft sloop to a steel hull 40ft sloop.
Everything is in excellent state except for the electrical wiring which will
certainly consume most of my winter weekends....

My main worry before everything else is to plan for electrical grounding and
I have read the most opposite opinions.

Can somebody share his experience with me, please ?

Cheers
Joao

Joao,

I have a 43 foot steel hull and deck sailboat. I make sure that all
electrical wiring and connections are kept away from the hull and
deck. I do not ground to the hull and highly recommend that you not
ground there either. I even try to keep the engine as disconnected
electrically from the hull as possible. For example, the alternator
and the starter have their own negative cables back to the battery
bank rather than using the engine block as the negative.

I recommend the Nigel Calder book, Boatowner's Mechanical And
Electrical Handbook (or Manual).

I feel that connecting anything electrical to your steel hull is
asking for serious trouble. One mistake and you could completely
destroy your hull.

Lee Huddleston
s/v Truelove

Lee, how many zincs do you run on the hull or in contact with it? How
long do they last?



On Thu, 09 Oct 2003 02:46:35 GMT, (Lee
Huddleston) wrote:

On Thu, 4 Sep 2003 17:18:03 +0100, "Joao Penha-Lopes"
wrote:

Hello everybody,
I have just upgraded from a GRP 30ft sloop to a steel hull 40ft sloop.
Everything is in excellent state except for the electrical wiring which will
certainly consume most of my winter weekends....

My main worry before everything else is to plan for electrical grounding and
I have read the most opposite opinions.

Can somebody share his experience with me, please ?

Cheers
Joao

Joao,

I have a 43 foot steel hull and deck sailboat. I make sure that all
electrical wiring and connections are kept away from the hull and
deck. I do not ground to the hull and highly recommend that you not
ground there either. I even try to keep the engine as disconnected
electrically from the hull as possible. For example, the alternator
and the starter have their own negative cables back to the battery
bank rather than using the engine block as the negative.

I recommend the Nigel Calder book, Boatowner's Mechanical And
Electrical Handbook (or Manual).

I feel that connecting anything electrical to your steel hull is
asking for serious trouble. One mistake and you could completely
destroy your hull.

Lee Huddleston
s/v Truelove



Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?

That was the Royal Navy's choice when they specified Fintry thirty
years ago and we will continue this with her new electrical system.
The only electrical connections to the hull will be green safety
ground and radio ground for the SSB (which is isolated from electrical
ground).

We will have ground fault alarms on both the DC and the AC systems so
that if either gets shorted to the hull we'll know about it early.
Shore power will come aboard through isolation transformers.

Jim Woodward
www.mvFintry.com



(Lee Huddleston) wrote in message . ..
On Thu, 4 Sep 2003 17:18:03 +0100, "Joao Penha-Lopes"
wrote:

Hello everybody,
I have just upgraded from a GRP 30ft sloop to a steel hull 40ft sloop.
Everything is in excellent state except for the electrical wiring which will
certainly consume most of my winter weekends....

My main worry before everything else is to plan for electrical grounding and
I have read the most opposite opinions.

Can somebody share his experience with me, please ?

Cheers
Joao

Joao,

I have a 43 foot steel hull and deck sailboat. I make sure that all
electrical wiring and connections are kept away from the hull and
deck. I do not ground to the hull and highly recommend that you not
ground there either. I even try to keep the engine as disconnected
electrically from the hull as possible. For example, the alternator
and the starter have their own negative cables back to the battery
bank rather than using the engine block as the negative.

I recommend the Nigel Calder book, Boatowner's Mechanical And
Electrical Handbook (or Manual).

I feel that connecting anything electrical to your steel hull is
asking for serious trouble. One mistake and you could completely
destroy your hull.

Lee Huddleston
s/v Truelove

Lee, how many zincs do you run on the hull or in contact with it? How
long do they last?

Larry W4CSC

Larry,

I have four large zinc bricks bolted to the full keel (or cutaway full
keel), one on each side at the front and one on each side at the back
of the keel. Then I have a smaller zinc near the engine raw water
intake. The large bricks are Vetus 25s (not sure what the 25 stands
for -- not pounds -- probably metric)

I just replaced the large bricks which had been put on in the Spring
of 2001. But, Truelove has been docked in brackish water all that
time -- unfortunately, due to peculiar circumstances, not even moved
during that time. Oddly enough, the small brick (not sure of size --
is a teardrop shape) did not need replacing.

The brackish water probably makes the zincs last a lot longer than
normal salt water, but being in a marina might make them last shorter
due to stray current. I really do not know yet. I am trying like
hell to retire ASAP and hope to do some extensive sailing very soon.
That will be a much better test.

Lee

On 10 Oct 2003 07:54:37 -0700, (Jim Woodward)
wrote:

That was the Royal Navy's choice when they specified Fintry thirty
years ago and we will continue this with her new electrical system.
The only electrical connections to the hull will be green safety
ground and radio ground for the SSB (which is isolated from electrical
ground).

We will have ground fault alarms on both the DC and the AC systems so
that if either gets shorted to the hull we'll know about it early.
Shore power will come aboard through isolation transformers.

Jim Woodward

Jim,

Would you have a recommendation for an isolation transformer? The
only one that I have found so far ate up a lot of the power before it
could get into the boat. That seemed strange to me, but maybe I was
reading the specs incorrectly. Also the price seemed to be very high.
Of course, protecting my beloved boat from galvanic corrosion is
probably worth a lot if that is what is necessary.

By the way, you mentioned DC and AC ground fault alarms. Who makes
them and are they available to private individuals?

Thanks in advance for your help.

Lee

Lee:

Yes, they are pricey, heavy, and hot. Transformers are typically
around 95% efficient, so pay attention to heat generation -- they do
get hot.

I found a bunch of Topaz 5kw ultra isolation transformers when we were
outfitting Swee****er in 1995 and bought them at US$100. I still have
two. Surplus sales of Nebraska has them new for $1395:
http://www.surplusales.com/Transform...tionXmers.html

However, the good news is that any transformer is an isolation
transformer for our purposes -- it won't do quite as good a job on
keeping out unwanted frequencies, but we're primarily interested in
1) keeping out DC and
2)establishing an ungrounded AC system.
So take a look at things like
https://www.surpluscenter.com/item.a...tname=electric

It will do 5KW. You can put in 240 and take out 120/240 three wire
just like your house, or put in 120 and take out 120.
(240x480 means you can put in either 240 or 480)
(120/240 means you can take out 120, 240, or both)
(You do 120120 by hooking it up like 240240)

BTW, you do not want an autotransformer -- which will change voltage
but does not isolate.

If you feel more comfortable with a "real" isolation transformer, I
ran into a guy at the Maine BoatBuilders' show that was having them
made.
WesTran Power
5160 NW Five Oaks Drive
Hillsboro, OR 97124

(no web site)

He was selling a "marine grade" (whatever that means) 6KW unit with
pretty good specs for $900.

As far as ground fault alarms go, the typical big ship installation is
a light in series with a push button wired from one of the hot wires
to the hull, and then the same thing on the other hot wire. The two
push buttons are on the same actuator (a dpst). The bulbs are
typically rated for the system voltage, so when you push the buttons,
both come on at half voltage. If there's a fault on either side, that
light is shorted out and stays dark, while the other light is getting
full voltage, so it's brighter than usual.

Like this (sometimes ASCII graphics actually work, maybe):

hot1---pb---light---hull---light---pb---hot2

(with the two pb on one frame).

Jim Woodward
www.mvFintry.com





(Lee Huddleston) wrote in message . ..
On 10 Oct 2003 07:54:37 -0700, (Jim Woodward)
wrote:

That was the Royal Navy's choice when they specified Fintry thirty
years ago and we will continue this with her new electrical system.
The only electrical connections to the hull will be green safety
ground and radio ground for the SSB (which is isolated from electrical
ground).

We will have ground fault alarms on both the DC and the AC systems so
that if either gets shorted to the hull we'll know about it early.
Shore power will come aboard through isolation transformers.

Jim Woodward

Jim,

Would you have a recommendation for an isolation transformer? The
only one that I have found so far ate up a lot of the power before it
could get into the boat. That seemed strange to me, but maybe I was
reading the specs incorrectly. Also the price seemed to be very high.
Of course, protecting my beloved boat from galvanic corrosion is
probably worth a lot if that is what is necessary.

By the way, you mentioned DC and AC ground fault alarms. Who makes
them and are they available to private individuals?

Thanks in advance for your help.

Lee

Thanks, Lee. Sorry you're not getting much use out of your boat.

If you have a DC milliammeter function in your Digital multimeter or
VOM pocket meter, put it on the milliamp function, sometime, between
that hull and the AC ground on the dock. That's the electrolysis
current to the electric ground, which is most interesting.

I always feel sorry for someone with his engine block hooked to the AC
line ground.....eating away at his fizzing zincs.



On Wed, 15 Oct 2003 02:14:17 GMT, (Lee
Huddleston) wrote:


Lee, how many zincs do you run on the hull or in contact with it? How
long do they last?

Larry W4CSC

Larry,

I have four large zinc bricks bolted to the full keel (or cutaway full
keel), one on each side at the front and one on each side at the back
of the keel. Then I have a smaller zinc near the engine raw water
intake. The large bricks are Vetus 25s (not sure what the 25 stands
for -- not pounds -- probably metric)

I just replaced the large bricks which had been put on in the Spring
of 2001. But, Truelove has been docked in brackish water all that
time -- unfortunately, due to peculiar circumstances, not even moved
during that time. Oddly enough, the small brick (not sure of size --
is a teardrop shape) did not need replacing.

The brackish water probably makes the zincs last a lot longer than
normal salt water, but being in a marina might make them last shorter
due to stray current. I really do not know yet. I am trying like
hell to retire ASAP and hope to do some extensive sailing very soon.
That will be a much better test.

Lee


Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?

Jim Woodward wrote:
Lee:
snip
However, the good news is that any transformer is an isolation
transformer for our purposes --
snip

This is not correct. An autotransformer has a single winding and does
not provide isolation.
Jim