08 Prius struck by Lightning!

[jayman]

Originally Posted by David Beale

Trying to guess why some computers died while others didn't will drive you crazy! Some that still work may or may not fail in the near future due to partial damage. Just be happy you found the ones that currently don't work!

This point in particular is cause for concern, down the road. The car may experience random issues maybe a few months down the road. I've seen it with cell tower BST's

Electronic circuits that initially survive a massive surge will be stressed. Overall, the long-term reliability is compromised

Have you ever been inside a large industrial building utility entrance when lightning zaps the primary? That can be an ... *interesting* experience. Fresh underwear change recommended

I was standing about 20 ft from the transformer pothead during a lightning storm. Suddenly this loud CRACK! came from the pothead and the utility lightning went out, the backups came on

I have healthy respect for lightning. At my hobby farm, I use Rayvoss at the service entrance for strike protection

[jayman]

Originally Posted by Bear68

Ahhh... but a car is safe in a thunderstorm, for the occupants that is....

A typical car - Corvette excluded - may not be a perfect Faraday Cage, but it's usually good enough

[Rokeby]

Originally Posted by jayman

A typical car - Corvette excluded - may not be a perfect Faraday Cage, but
it's usually good enough

jayman,

It's an interesting point you make there.

Thinking about the push towards ultralight construction and the use of
non-metal structures. I take it it would matter --lightning wise -- if there
was an included metal roll cage, passenger safety zone, whatever.

Would the passage of lightning through such a structure create temps
high enough to set the thermo-plastics afire?

[Ichabod]

Originally Posted by jayman

A typical car - Corvette excluded - may not be a perfect Faraday Cage, but it's usually good enough

I'm no electramajiggy expert, but I think "Faraday Cage" is specific to static charges, and therefore not applicable to lightning strikes. "Skin Effect" on the other hand is what protects the occupants of a metal cage.

At the Boston Museum of Science they have a huge Van de Graaf generator (actually built by Dr. Van de Graaf) with a metal cage that's raised up on a pneumatic shaft. The occupant of the cage can actually touch the metal while it's being hit with arcs from the generator and not get shocked. If they reach through the bars and touch the outside of the metal, ouch! I'd guess for this reason that most of the current going into this car went around the car into the ground, and only a small portion went into frying electronics.

At the museum, they can ensure that arcs strike the same spot on the cage by putting a tiny metal clip on one of the bars... I guess lighting likes pointy protrusions, sort of like this car's antenna. I wonder if that's the case with most car-lightning encounters.

[David Beale]

Lightning -can and does- start fires, but most plastics will not continue to burn without external energy, especially the ones being currently used in composite structures. Keep in mind, most lightning caused fires happen when the lightning jumps through the air (or wood etc) between metal structures. Which is why the codes for lightning protection require all metal parts of structures be bonded together. For example, in my house, the lightning protection cables are bonded to both the electrical system ground and the water pipes, even though the lightning protection system has its' own ground rods. They even bonded the eve troughs, gas chimney, and turbine attic vent to the main ground cable.

"Pointy bits" tend to concentrate the electric field in the air, which makes it easier for the lightning leader to travel to them. Note that they also concentrate the current in less metal, so can be more susceptible to actually melting at the tip when struck. I've had to replace several "air terminals" and radio site antennas due to this.

[Bear68]

[quote=jayman;682176]This point in particular is cause for concern, down the road. The car may experience random issues maybe a few months down the road. I've seen it with cell tower BST's

Electronic circuits that initially survive a massive surge will be stressed. Overall, the long-term reliability is compromised

That was the reason for a 150 mile test drive.... Wellllll...... that and I love driving Prius......