Just a thought

[Pete-B]

 

Now that I've had the EP levelers fitted, when deployed, are we still safe in a thunder storm or will we become fried meat? Not sure if it's still a Faraday Cage.

[Derek Uzzell]

It’s a myth that being in a vehicle will provide protection from lightning due to the vehicle’s rubber tyres acting as insulators. In fact, lightning flows around the outside of a car’s metal body and the majority of the current then flows from that body into the ground below, bypassing the occupants inside the vehicle.

 

As it’s the vehicle’s metal structure that acts like a mobile Faraday cage, I can’t see that having your metal ‘legs’ extended to reach the ground would make you any less safe if your motorhome were struck by lightning.

 

That’s just an inexpert opinion, of course, so in the highly unlikely event of lightning striking your motorhome when its levellers are down and you being fried, perhaps you could provide a follow-up post to the forum saying that I was wrong. ;-)

[Pete-B]

 

Derek,

 

I wouldn't be able too, if we got fried the Duchess would blame me and finish me off with a good roasting!

[Gman]

As my old science teacher used to say,

"If you hear the thunder you are OK" :-D

 

Steve.

[tonyishuk]

Debate for this evening; relative safety of metal bodied , or plastic bodied, mhomes when wet or dry ? When sitting in a thunder storm.

 

:->

 

Rgds

[colin]

Many years ago a TV programme showed a car subjected to artificial lighting, it may have had conductors trailing from chassis to earth I can't recall.

It drove around a small circle/oval and passed under a van da graf generator or some such thing, iirc every time it was struck the rear window wiper worked and I think a couple of dash lights flickered.

[plwsm2000]

Lightning strikes can cause problems in different ways. Most of the discussions so far relate to a direct strike on your motorhome. Although you would be pretty unlucky to get a direct hit, your rubber tyres, levellers etc. would not withstand the millions of volts and just arc across as though they were a short circuit.

 

The other mechanism that people tend to forget is a ground strike quite close to where they are standing. Depending on the soil conductivity, you can get as much as a few thousand volts per meter difference in the ground (dry sand is probably the worse as it is a reasonable good insulator so the high voltage gradient will cover a wider area before the charge properly dissipates). If you get caught in the open during a lightning storm, it is best to keep as low as possible and to keep your feet together to prevent the current going up one leg and down the other through some important body parts!. 4 legged animals are more prone to lightning strike than humans since the current would pass across their heart and also their legs are further apart. The reason why we are told not to take shelter under a tree, is not because the tree might fall on you or catch fire, it is because of the high ground currents under the tree if it gets hit.

 

As far as the motorhome is concerned, I would certainly unplug the ehu at the point where is enters the van (obviously unplugging the other end first). This reduces the effects of a ground strike and (more likely) a surge on the 230V destroying your ebl and other electrics. Your tyres should withstand a few thousand volts and in any case, the current would just flow harmlessly through the chassis.