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01-12-2020, 04:47
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#31
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Registered User
Join Date: Apr 2016
Location: Back on dirt in Florida
Boat: Currently in between
Posts: 1,338
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by Paul L
It may be anecdotal evidence, but I bet it made you a believer.
Did you have any electronic items that were not plugged into anything and not in the oven? Did they fry too?
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Yes, we are believers! Trying anything is better than trying nothing..
I forgot to unplug my MacAir charger from the wall, it was fried. Our son had his XBox controllers laying on a shelf near the TV, they never worked again nor did the XBox console. The TV was unplugged but mounted on the wall so nothing we could do about protecting it. The TV somewhat survived, it did work but screen was discolored and had lines in it.
Bacchus has three electrical winches, all three survived the strike but one died shortly after. I chalked that failure up to the supposed "Gremlins" that can appear some time later after a strike. The winch, motor, brushes and wiring all seemed fine. I gave up and called in an expert who found the problem, a small electrical or electronic relay. Confirmed, at least in my mind, it was a result of the strike.
__________________
SV Bacchus - Living the good life!
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01-12-2020, 08:06
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#32
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Senior Cruiser
Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,085
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Re: Protecting a pelican case from lightning
FWIW: You can listen to thunder, after lightning, and tell how close you came to getting hit.
Seconds twixt flash & bang ÷ 5 = miles distant (or seconds ÷ 340 = meters).
If you don't hear it, never mind, you got it.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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01-12-2020, 08:45
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#33
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Registered User
Join Date: Apr 2016
Location: Back on dirt in Florida
Boat: Currently in between
Posts: 1,338
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by GordMay
If you don't hear it, never mind, you got it.
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I agree with that. It was 2AM in the morning and I was awake listening to the storm.
Looking thru the rear stateroom porthole I saw a bright blue/white flash seemingly running around the lifelines and AT THE SAME time I heard "Zizisizisiz Zzisizisiz Zzisizisiz". Please don't laugh at spelling, I have no idea how to truly spell the sound I heard, kind of electrical shorting or something similar.
Gord is right, I did not hear a clap of thunder, I was at ground zero! What I did hear was my tricolor/anchor light combo hitting the coach roof as the lightening blew it of the top of the mast.
__________________
SV Bacchus - Living the good life!
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02-12-2020, 07:42
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#34
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Registered User
Join Date: Aug 2008
Location: Sydney, Australia
Boat: Roberts 45
Posts: 1,033
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by Cadence
That and the few inches of possibly wet tires and the lightning voltage, I'd have to believe what saved my ass was a discharge to ground.
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One could argue the other way around: without a path to ground the lightning would not have struck the chassis in the first place.
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02-12-2020, 07:45
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#35
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Senior Cruiser
Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,085
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by GordMay
FWIW: You can listen to thunder, after lightning, and tell how close you came to getting hit.
Seconds twixt flash & bang ÷ 5 = miles distant (or seconds ÷ 340 = meters).
If you don't hear it, never mind, you got it.
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Meant to conclude: "... never mind, you got Hit."
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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02-12-2020, 10:15
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#36
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Registered User
Join Date: Dec 2008
Location: SC
Boat: None,build the one shown of glass, had many from 6' to 48'.
Posts: 10,208
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by hzcruiser
One could argue the other way around: without a path to ground the lightning would not have struck the chassis in the first place.
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That's something I've pondered. Is grounding asking to be hit or a way to provide an easier path to ground? It's a craps shoot.
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02-12-2020, 16:44
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#37
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Registered User
Join Date: Apr 2016
Location: Back on dirt in Florida
Boat: Currently in between
Posts: 1,338
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by Cadence
That's something I've pondered. Is grounding asking to be hit or a way to provide an easier path to ground? It's a craps shoot.
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I've often thought that myself..
__________________
SV Bacchus - Living the good life!
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02-12-2020, 16:47
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#38
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Senior Cruiser
Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,085
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by Cadence
That's something I've pondered. Is grounding asking to be hit or a way to provide an easier path to ground? It's a craps shoot.
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No, it's not.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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04-12-2020, 09:36
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#39
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Registered User
Join Date: Jul 2016
Location: Vernon BC
Boat: Catalina 27 tall rig
Posts: 13
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by thunderhoof
A faraday cage is is a uniformly conductive shell. Not important for it to be made from high permeability material (magnetizable) but it is important to have no long non-conductive openings. External grounding of the cage is irrelevant.
It operates by causing a zero electric field inside itself when the cage is subjected to an electric field (such as nearby lightning strike), protecting the contents from conductive currents or high electric field damage.
Yes, I have a degree in this stuff.
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I have worked in faraday cage and equipotential work practices- we also bonded conductive material together in the 'zone' to eliminate potential voltage differences within. Might be worth considering, however challenging to implement on a boat.
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04-12-2020, 09:50
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#40
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Registered User
Join Date: Mar 2013
Posts: 115
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by hzcruiser
One could argue the other way around: without a path to ground the lightning would not have struck the chassis in the first place.
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Then why do airplanes get hit?
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04-12-2020, 11:09
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#41
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Registered User
Join Date: Dec 2017
Posts: 58
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Re: Protecting a pelican case from lightning
We keep our backup hard drives, SD cards and the like in tins (biscuit tins, cake tins etc) and the handheld devices join them when there's lightning about. We've been hit and some wiring and electronics was wiped out but all the stuff in the tins was fine.
Keeping stuff in the oven and metal cooking pots sounds as though it would work too. As long as you remember to take it out before cooking!
I'm not sure about wrapping stuff in foil. Yes, you are creating a Faraday cage around your items but lightning carries huge currents. We burnt out some pretty stout cables when we were hit and I suspect that aluminium foil might just melt under those conditions. However, the foil doesn't melt when I'm roasting chicken at 200ºC! Big surface area but very thin; I've no idea how hot it might get with a few thousand amps going through it. If anyone can do the sums or has practical experience of foil protection, I'm all ears.
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04-12-2020, 11:23
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#42
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Registered User
Join Date: Jan 2011
Location: Norfolk, VA
Boat: 1970 Hatteras 38DC
Posts: 27
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Re: Protecting a pelican case from lightning
A microwave oven is designed to block microwaves from escaping. It is a type of Faraday Cage. A microwave is an electromagnetic wave. Lightning strokes emit an electromagnetic pulse that can damage sensitive electronics. A microwave oven will block these EMP's. Having said that, nothing is completely lightning proof, it is to powerful and unpredictable.
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04-12-2020, 11:41
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#43
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Registered User
Join Date: Apr 2009
Posts: 27
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Re: Protecting a pelican case from lightning
I’ve been using Faraday Cage bags that I bought on Amazon 6 years ago, I haven’t been hit by lightning, so no first hand experiences, but sure makes me feel better.
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04-12-2020, 12:27
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#44
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Senior Cruiser
Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,085
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by col50
Then why do airplanes get hit?
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Most aircraft lightning events occur when the aircraft itself triggers the lightning, when flying through a heavily charged (ionized) region of a cloud. In these instances, the lightning flash originates at the airplane, and extends away in opposite directions.
If an aircraft flies into a cloud, that is about to emit a lightning strike to another cloud, or to ground, the extra conductivity of the plane, and maybe its initial charge, or maybe it's slightly ionized chem-trails can (all) trigger a cloud to plane, or cloud to cloud, or cloud to ground bolt, that just happens to intersect the plane. This is less common, because pilots avoid thunderclouds.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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04-12-2020, 12:48
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#45
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Registered User
Join Date: Sep 2010
Posts: 2,909
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Re: Protecting a pelican case from lightning
Quote:
Originally Posted by Cadence
I can attest to that, My pickup was hit and I'm still here. I would guess is jumped to the wet pavement. Wiped the truck wiring out with hipot shorts. so the body wasn't total protection. I believe you would be better off with a metal grounded case and the GPS raped in a good dielectric.
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I had a friend killed in high school who about to get into a car with three other people already inside, when he or the car was hit by lightning. He died, no one in the car was injured at all.
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Founding member of the controversial Calypso rock band, Guns & Anchors!
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