Conrad Posted August 9, 2019 Share Posted August 9, 2019 Bit stormy this today and this weekend, set me thinking what's the best option if there's an electric storm and you're in your motor caravan? Anyone have authoritative advice? Link to comment Share on other sites More sharing options...
Keithl Posted August 9, 2019 Share Posted August 9, 2019 I thought you where asking how to lighten your MH then realised you where actually talking about the weather! "The Difference Between Lightening and Lightning Lightening with an “e” is the present participle of the verb lighten. We use the verb lighten in two senses—one has to do with colour and the other refers to weight. ... Lightning is the electrical discharge that happens during an electrical storm." My advice would be to unplug the mains cable then you are in a 'Faraday cage' and so would be perfectly safe. Keith. Link to comment Share on other sites More sharing options...
monique.hubrechtsgm Posted August 9, 2019 Share Posted August 9, 2019 Agree. And keep a distance from a row of trees and metal fences like farmers have. Link to comment Share on other sites More sharing options...
Robbo Posted August 9, 2019 Share Posted August 9, 2019 Lightning can create an electrical surge in the 230v EHU cable via the local mains distribution network. This in turn has been known to blow sensitive electronic control system components within the MH. So, as Keith suggests, remove the EHU lead from the MH and EHU bollard (unless of course you're putting yourself at risk from a lightning strike) >:-( Link to comment Share on other sites More sharing options...
Clive_Adams Posted August 9, 2019 Share Posted August 9, 2019 Four rubber air filled tyres off the ground, you have no earth, so no problems Faraday Cage, just unplug the EHU, you may be able to sleep better but I guess the accompanying thunder and ran is going to stop you doing that anyway, Link to comment Share on other sites More sharing options...
plwsm2000 Posted August 10, 2019 Share Posted August 10, 2019 Clive_Adams - 2019-08-09 10:24 PM Four rubber air filled tyres off the ground, you have no earth, so no problems Faraday Cage, just unplug the EHU, you may be able to sleep better but I guess the accompanying thunder and ran is going to stop you doing that anyway, Actually, the rubber tyres will do nothing to limit a direct strike since the voltages involved are so high. A lightning strike can be as high as 1 billion volts and it will just jump across the few inches of rubber. The rubber tyres do however, give some protection to ground currents generated by a strike close by. The very high voltage at the point of the strike will need a certain distance to disipate to safe levels. If you are unlucky enough to be in the area of the strike, there could be a high voltage difference across different ground points (i.e. across the wheels or your two feet!). Ground currents generally cause more fatalities that direct strikes just because of the area it can cover. In Norway in 2016, over 300 Reindeer were killed by a lightning strike. Animals tend to be more affected than humans as their legs are usually further apart and the current passes through the vital organs (the organs it passes through in humans standing on two feet are not as vital when you get to our age :-). In addition to unplugging the EHU lead (don't just switch it off), I would probably consider lifting any self-leveling legs too. Link to comment Share on other sites More sharing options...
Conrad Posted August 10, 2019 Author Share Posted August 10, 2019 OK, thanks for the spelling lesson, Keith. Now for the physics lesson - what's a Faraday cage?! Link to comment Share on other sites More sharing options...
Clive_Adams Posted August 10, 2019 Share Posted August 10, 2019 I stand corrected "Most people believe the rubber tires on a car prevent lightning strikes. Ironically, it’s not the rubber tires insulating the car, but rather the conductive metal framing which protects you by conducting the electricity around the vehicle and its occupants. The truth is, rubber tires don’t prevent lightning strikes in the least bit. By the time a lightning bolt reaches your car, it has been traveling for miles and miles through the air, which is many orders of magnitude more resistant than a few inches of rubber. So if the lightning bolt can overcome the resistance of air, it can easily overcome the resistance of a rubber tire. The video on the left shows a car being struck by lightning. If the rubber tires were truly responsible for insulating a car, then it would have never been struck. As mentioned earlier, the one thing that does protect you from a lightning strike while in your car is the conductive metal framing. If your car happens to be struck, chances are the metal framing will direct the electric current around the passenger compartment at which point it will arc to the ground. Sometimes this electric arc will jump from the the lower chassis of the car directly to the ground below or other times the electric current will pass right through the tires by way of the metal wheel rims (blowing them out of course). Sometimes the car will suffer little or no damage at all. Other times, the car can suffer an immense amount of damage. Here’s a good example of this principal in action. It’s called a Faraday Cage. As you can see, the man inside a conductive metal cage is perfectly safe even though hundreds of thousands of volts are hitting it. That’s because the electricity is being channeled by the conductive metal cage around the man and then directly into the floor where it dissipates. Had the cage been made of a less conductive material, the man would most likely have been electrocuted. It’s this same principal that protects the occupants of a vehicle. It has nothing to do with the rubber tires. On vary rare occasions, the electricity from a lightning bolt may pass through the car by way of wires and other conductive surfaces. When this happens, a lot of damage can ensue. Here are some pictures of a van that had a majority of its insides destroyed by a lightning strike. By looking at the outside of the van, you can hardly see any damage at all. Because a lightning bolt is on average 5 times hotter than the surface of the sun (50,000°F), it instantly vaporizes and super heats any moisture. This steam explosion can blow up concrete, trees and as was the case with the van, melt plastic. It doesn’t take that much moisture to do a lot of damage when it is instantly heated to 50,000°F. Unfortunately for a passenger, there is no way of knowing what path the electric current might take once your car has been struck by lightning. It could go through electrical wires, the metal steering wheel, the car antenna, or it may never enter your car at all. Nevertheless, if you find yourself caught in a thunderstorm it is much safer to be inside your car than out in the open." Link to comment Share on other sites More sharing options...
Muswell Posted August 10, 2019 Share Posted August 10, 2019 Does a grp motorhome make a Faraday cage? Link to comment Share on other sites More sharing options...
Don636 Posted August 10, 2019 Share Posted August 10, 2019 Go onto YouTube and search for Topgear lightning test where they stuck Hammond in a car and subjected it to a mock lightning strike. Unfortunately he was unharmed!! Link to comment Share on other sites More sharing options...
tonyishuk Posted August 10, 2019 Share Posted August 10, 2019 Muswell - 2019-08-10 7:25 AM Does a grp motorhome make a Faraday cage? Probably not, as grp is not a conductor. Maybe if it has been raining and the outside is wet ? Rgds Ps. Pause for thought as our Rapido is grp *-) Link to comment Share on other sites More sharing options...
plwsm2000 Posted August 10, 2019 Share Posted August 10, 2019 Muswell - 2019-08-10 7:25 AM Does a grp motorhome make a Faraday cage? No - not unless it also has an Aluminium skin with the roof and side walls electrically bonded together. Even so, a direct lightning strike would probably cause severe damage to the motorhome and its electrics. Any solar panels, sat dishes etc. would be outside of the so-called Faraday cage and are likely to couple the high voltages to the inside of the van in any case (even for a PVC). Fortunately, the chances of getting a direct strike are pretty low. If you are caught in a bad thunderstorm, it is best to keep away from the metalwork and any wiring inside Link to comment Share on other sites More sharing options...
Charles Posted August 10, 2019 Share Posted August 10, 2019 Carry a 3m length of copper pipe and make a lightning conductor... Err as fast as you can (lol) Link to comment Share on other sites More sharing options...
Muswell Posted August 10, 2019 Share Posted August 10, 2019 plwsm2000 - 2019-08-10 5:10 PM Muswell - 2019-08-10 7:25 AM Does a grp motorhome make a Faraday cage? No - not unless it also has an Aluminium skin with the roof and side walls electrically bonded together. Even so, a direct lightning strike would probably cause severe damage to the motorhome and its electrics. Any solar panels, sat dishes etc. would be outside of the so-called Faraday cage and are likely to couple the high voltages to the inside of the van in any case (even for a PVC). Fortunately, the chances of getting a direct strike are pretty low. If you are caught in a bad thunderstorm, it is best to keep away from the metalwork and any wiring inside Exactly, I was trying to stop plastic motorhomers feeling too complacent when there is lightning around :-D Best get out and crouch on the ground, feet together B-) Link to comment Share on other sites More sharing options...
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