radios & electronics, lightning protection
 

i am curious what you do for lightning protection to keep your boat's
electronics from getting zapped in the middle of the big ocean. i know
you can install lightning protection into the boat, that is, basically
a lightning rod and ground plate, etc, but that wasn't really what i
was wondering. what i am curious about is do you have some kind of
procedures you go through when a storm approaches that has a lot of
crackle in it, some procedures for disconnecting sensitive electronics
or somehow disengaging them from the boat's electrical system so that
they won't suffer if the boat gets hit ? i guess that might be
non-sense since stormy times are exactly when you most rely on a lot of
those electronics but i thought i would ask. i was just curious.

radios & electronics, lightning protection
 

purple_stars wrote:
i am curious what you do for lightning protection to keep your boat's
electronics from getting zapped in the middle of the big ocean. i
know you can install lightning protection into the boat, that is,
basically a lightning rod and ground plate, etc, but that wasn't
really what i was wondering. what i am curious about is do you have
some kind of procedures you go through when a storm approaches that
has a lot of crackle in it, some procedures for disconnecting
sensitive electronics or somehow disengaging them from the boat's
electrical system so that they won't suffer if the boat gets hit ? i
guess that might be non-sense since stormy times are exactly when you
most rely on a lot of those electronics but i thought i would ask. i
was just curious.

Some sailors trail the anchor chain overboard, connected to the mast, but I
wouldn't know how effective this is is protecting your electronics.

radios & electronics, lightning protection
 

On 6 May 2006 01:50:59 -0700, "purple_stars"
wrote:

i am curious what you do for lightning protection to keep your boat's
electronics from getting zapped in the middle of the big ocean.

When you get a full hit, anything can get destroyed, even when you
disconnect antenna cables and/or power cords.
I put my laptop, spare handheld gps, portable vhf in the (switched
off) oven or microwave (any Faraday cage will do) so I'll still have
some backup afterwards.

Fair winds, Len.

radios & electronics, lightning protection
 

Lighting is pretty damn hard to protect against, as predicting the path
a priori is very, very difficult. As a storm approaches you can take
some preventative action by placing sensitive electronics such as GPS,
Radios, etc in a Faraday cage (info on web on how to build it), but
anything that isn't inside it is still subject to damage including all
the wiring and permanently mounted devices such as the radar array.


One critical issue is to insure that the path taken by the lighting does
not include going directly through your hull as this could result in
catastrophic loss. Make sure your chain plates are grounded, that there
is adequate grounding plates to your engine, mast, etc. to avoid the
possibility of the lighting burning through the hull on its way to the sea.

One other sure fire solution is to place a golfing 4 iron at the top of
your mast. As any golf pro can tell you, even God can't hit a 4 iron. :-)

Cheers,

Robb



purple_stars wrote:
i am curious what you do for lightning protection to keep your boat's
electronics from getting zapped in the middle of the big ocean. i know
you can install lightning protection into the boat, that is, basically
a lightning rod and ground plate, etc, but that wasn't really what i
was wondering. what i am curious about is do you have some kind of
procedures you go through when a storm approaches that has a lot of
crackle in it, some procedures for disconnecting sensitive electronics
or somehow disengaging them from the boat's electrical system so that
they won't suffer if the boat gets hit ? i guess that might be
non-sense since stormy times are exactly when you most rely on a lot of
those electronics but i thought i would ask. i was just curious.

radios & electronics, lightning protection
 

"to keep your boat's electronics from getting zapped" is quite simple
in theory. Lightning seeks earth (ocean). If that path goes through
electronics, then electronics are damaged. Eliminate either an
incoming or outgoing path through electronics and electronics is not
damaged. That's the easy part. The hard part is identifying all those
paths.

For example, wood is a conductor. Maybe not to electricity as you
know it. But to lightning, wood (ie a church steeple) is a good
conductor to ground. Will lightning enter a radio via antenna and exit
via desktop? Maybe. This demonstrates that one does not stop or block
lightning. So that lightning does not take that path, one must provide
an alternative and shorter path to ocean.

Protection means firstmost providing lightning a more conductive and
shorter path - ie a chain from mast to ocean. Other solutions such as
faraday cage can help. But a faraday cage is often insufficient. A
first step is always provide lightning with a non-destructive, shorter
path to ocean.

If lightning does not find a path through electronics, then
electronics is not damaged. Not only must that shorter path be
conductive. It must also be shortest, no sharp bends, not inside
metallic conduit, and no wire splices - factors that otherwise can make
wire appear electrically too long.

Do not assume lightning protectors are protection. Effective
lighting protectors make a temporary connection to the ocean. No
protector will stop, block, or absorb what three miles of sky could not
stop. An effective protector simply becomes a temporary conductor -
hopefully a shortest path - to the ocean. Anything that cannot always
be connected to the ocean and operate, then uses a protector to make
that ocean connection only during a lightning strike. Effective
protectors make temporary grounding during a transient. Ineffective
protectors are easily identified: 1) have no dedicated grounding
connection, and 2) avoid all discussion about grounding. Effective
protectors use a grounding wire to connect lightning as short as
possible to the ocean.

purple_stars wrote:
i am curious what you do for lightning protection to keep your boat's
electronics from getting zapped in the middle of the big ocean. i know
you can install lightning protection into the boat, that is, basically
a lightning rod and ground plate, etc, but that wasn't really what i
was wondering. what i am curious about is do you have some kind of
procedures you go through when a storm approaches that has a lot of
crackle in it, some procedures for disconnecting sensitive electronics
or somehow disengaging them from the boat's electrical system so that
they won't suffer if the boat gets hit ? i guess that might be
non-sense since stormy times are exactly when you most rely on a lot of
those electronics but i thought i would ask. i was just curious.

radios & electronics, lightning protection
 

purple_stars wrote:
i am curious what you do for lightning protection to keep your boat's
electronics from getting zapped in the middle of the big ocean. i
know you can install lightning protection into the boat, that is,
basically a lightning rod and ground plate, etc, but that wasn't
really what i was wondering. what i am curious about is do you have
some kind of procedures you go through when a storm approaches that
has a lot of crackle in it, some procedures for disconnecting
sensitive electronics or somehow disengaging them from the boat's
electrical system so that they won't suffer if the boat gets hit ? i
guess that might be non-sense since stormy times are exactly when you
most rely on a lot of those electronics but i thought i would ask. i
was just curious.

During the recent (worst on record) electrical storm over West Scotland I
felt secure as my TV's are all cable, my PC was switched off, and I was able
to relax, thinking about my poor old neighbours who had Sky and terrestial
TV.

One tremendous explosive flash put paid to that. It zapped my cable modem
completely. This was the only item I had failed to disconnect. Just shows.
Several million volts hitting the ground will even affect underground
cabling enough to zap a device connected to that cabling.

radios & electronics, lightning protection
 

I disconnect and put all my 'sensitive' electroniics, etc. inside the
stainless steel oven (Faraday Cage). Been hit twice, once frying all
the electronics outside the oven but all the stuff inside was OK.

Just gotta remember to remove the stuff before lighting the pilot
light. ';-)

radios & electronics, lightning protection
 

"purple_stars" wrote in news:1146905459.251848.62440
@g10g2000cwb.googlegroups.com:

i was just curious.


http://www.thomson.ece.ufl.edu/lightning/SGEB17.html

radios & electronics, lightning protection
 

Larry wrote:
"purple_stars" wrote in news:
i was just curious.


http://www.thomson.ece.ufl.edu/lightning/SGEB17.html

WOW, great article, thanks larry!

and thanks to everyone else who answered my post also.

radios & electronics, lightning protection
 

"purple_stars" wrote in news:1148176300.916132.42590
@j55g2000cwa.googlegroups.com:

WOW, great article, thanks larry!


Quite welcome. Don't worry about lightning in the radios and gadgets too
much. The really dangerous parts is when it hits the mast and HOLES THE
HULL. That's much more an issue when the water's pouring in, but doesn't
happen very often.

During the storms at sea, anyways, you're way too busy trying to stay alive
to worry about lightning hits, way in the background when that mountain of
water comes thundering down on you...(c;

radios & electronics, lightning protection
 

"Dennis Pogson" wrote in
:

Some sailors trail the anchor chain overboard, connected to the mast,
but I wouldn't know how effective this is is protecting your
electronics.



near Zero. There is no protection for 100 million amps at 100 million
volts. It flashes over anywhere it wants. The pulse is so fast, with such
a huge, short risetime, that any inductance in series with this amazing
EMP, even a smooth rounded turn angle of a grounding bridgecable carefully
heliarced to the bottom of the tower, is enough series inductance to create
several thousand volts of induced voltage across that inductance, far more
than is necessary to zap the radios.

One of my musical instrument customers had a lightning hit on a fireplace
chimney on the North side of her home. TWO ROOMS away from the fireplace,
her computerized electronic theatre organ sat, UNPLUGGED as I instructed
her to try to protect it from power line lightning hits. The organ was too
destroyed by the induced EMP (electromagnetic pulse) to repair. Insurance
replaced it, along with a lot of other electronics.

It's that powerful.....