Fibreglass Boler Camper ,Lightning and Solar Power

System
System Posts: 2,511 admin
I have a 130w solar panel 5ft x 27inch aluminum frame ,bolted down which can be taken off if necessary on the roof of my Trillium Fibreglass trailer . It is wired to my controller ,batteries, inverter etc etc .

Question : do I ground the solar panel to the metal frame of the trailer and run a heavy wire from the frame to a ground rod into the ground for lightning ?

Just don't want to be burnt toast while sleeping in a lightning storm . :confused:

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Fibreglass Boler Camper ,Lightning and Solar Power

    Run a 6 awg wire minimum from the solar panel frame, down the outside (or in the outside wall, down to the metal frame of the trailer.

    Connecting to a ground rod--Really only matters if you are entering/exiting the trailer or if you have shore power. I cannot believe that many people drive an 8' - 10' ground rod or bury a rectangular metal plate into the earth for a couple days camping (perhaps somebody does).

    www.johndeerelandscapes.com/_Professional_R_S/_Articles/Arti_surge_prod.asp
    [FONT=Arial, Helvetica, sans-serif]The copper grounding plate assemblies must meet the minimum requirements of section 250 of the NEC. They are to be made of a copper alloy intended for grounding applications and will have minimum dimensions of 4” x 96” x0.0625”[/FONT]

    A fiberglass trailer is probably of limited safety in a lightning storm. A metal car or trailer is probably much safer.

    Perhaps, if you are in lightning prone areas with your trailer, you would be better off setting up a temporary lightning rod sticking up 2x higher or more than the trailer nearby to attempt to attract strikes away from the trailer... At least something to look into.

    Atempting to attract lightning to a near by grounded antenna vs doing nothing to hop the lightning passes you buy... Neither may be a good option.

    Basically, you are only safe in a metal car or metal clad trailer (or dwelling/building/etc.).

    www.lightningsafety.noaa.gov/outdoors.htm

    Boats can be made relatively safe from lightning--and perhaps you can follow their methods:

    www.boatsafe.com/nauticalknowhow/lightning.htm
    So how does a lightning protection system work? In a boat, the "cage" is formed by bonding together, with heavy conductors, the vessel's mast and all other major metal masses. A marine electrician must tie in the engines, stoves, air conditioning compressors, railings, arches etc. with a low resistance wire which would ultimately provide a conductive path to ground (the water) usually via the engine and propeller shaft, keel bolts, or better yet, a separate external ground plate at least 1 square foot in dimension. It is important that you ensure that your crew fall within the protection of the "cage," something not always feasible when the vessel is not built of steel or aluminum. On fiberglass or wooden boats it is advantageous to have a mast or other conductive metal protrusion extending well above the vessel, creating what is known as a "cone" or zone of protection.

    It is generally accepted that this cone of protection extends 45 degrees, all around, from the tip of the metal protrusion. This means that if the aluminum mast of the average sailing vessel is properly bonded to the vessel's other major metal masses and is given a direct, low-resistance conductive path to ground, the entire boat should fall within the protected zone. If the vessel has a wooden or composite mast, a marine electrician can achieve the same effect by installing a 6 to 12 inch metal spike at the top and running a heavy conductor down the mast and as directly as possible to ground, usually through the engine and propeller shaft. Again, refer to the ABYC standards and have a professional marine electrician install your lightning protection. This is not a do-it-yourself project.

    So, a metal tower at your trailer, or perhaps a metal frame (box, 4 legs with a center pipe or simple box shape at the roof line or just above made from copper or galvanized steel that you could setup like a box around your trailer. Ground the box to your trailer frame and -- Perhaps, a flat plate at one (or all four) legs at the ground or even partially buried or big nails driven into the earth....

    I don't know--this is not a naturally safe thing to do--camping in lightning prone areas without a metal clad vehicle at the very minimum.

    www.usatoday.com/weather/resources/askjack/archives-lightning-safety.htm
    More lightning fatalities occur from current traveling across the ground than from a direct strike. A lightning rod placed sufficiently near camp so as to decrease the chances of a direct strike would increase the chance of a ground current reaching camp. Rather than erecting a lightning rod, do all you can to avoid being near the tallest isolated object. If you are camping amongst trees, avoid sheltering near an isolated tree or one that is significantly taller than adjacent trees.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Fibreglass Boler Camper ,Lightning and Solar Power

    Are you likely to park someplace where lightning is abundant? Is the trailer over 30 feet tall?
    Frankly I'd say the possibility of it being struck is very small, and even if you did drive a post 10' into the ground ever time you camped lightning can still destroy whatever it wants to. The "lightning protection" you hear so much about really only drains off stray Voltage found ambient in areas where lightning strike occur; there is NO way to protect against a direct hit.

    My cabin is in an area of high lightning strikes (which cause hundreds of forest fires every year - you'd think there'd be nothing left by now). Never been hit; has no lightning rods. The solar panels' frames/mounts are grounded through the common system ground to "bleed off" any stray Voltage. Never a problem in the past 10 years of having the system up. Never even had antennas hit in previous years.

    Of course you could say that all those trees around make for effective lightning rods. :p
    But that doesn't explain the ground strikes.

    Make of it what you will; others may have different opinions.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Fibreglass Boler Camper ,Lightning and Solar Power

    as was said lightning goes where it pleases and is somewhat unpredictable. i should say that under a high enough voltage potential that all things that we might consider as insulators then become conductors of electricity. that means that even with the fiberglass covering on the trailer that you are essentially in the open to lightning and that was before any pvs are placed. a savings grace might be that you, yourself, aren't in direct contact with the soil, but it can still happen, although rarely. now you have a metal frame for the fiberglass, but it is ungrounded meaning it is still up in the air if you will get hit or be in its path. could the metal increase the odds of a hit? maybe.

    as to the pv needing earth grounded i say no more than the trailer frame needs it. if it makes you feel better you can go ahead and ground it, but the ground won't be as good as one would get for a regular permanent ground for i don't see you pulling an 8ft rod back out to reuse. now, do i believe the metal increases the chances of a hit? yes as it's more metal going higher up. even without an earth ground the emp of a nearby hit can induce voltages to the metal and fry things. to what end and good a smaller ground rod or screen may be in a trailer is hard to say as all is a compromise. under these conditions that compromise will allow a path to earth and in and of itself could make the strike more apt to happen.

    think of it this way, would you be worried if you were driving or parked in a car during a storm. no, not normally, but if it should hit a car (or trailer) and you are in it, don't be touching anything metal.
  • System2
    System2 Posts: 6,290 admin
    Re: Fibreglass Boler Camper ,Lightning and Solar Power

    Thanks for the info . The place we camp mostly is in Nova Scotia at the minus basin I guess there isn't alot of lightning storms there just the odd hurricane :D .

    I will just block the frame of the trailer on wood off the ground about a foot .

    I will eventually get solar panels on our home . I have been running some appliances TV ,lights ,and computer in the house from the boler trailer in the driveway
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Fibreglass Boler Camper ,Lightning and Solar Power

    if you go to the same spot all of the time you go there, then you could put a rod in if you wish.
  • System2
    System2 Posts: 6,290 admin
    Re: Fibreglass Boler Camper ,Lightning and Solar Power

    Maybe I will stick a rod in the ground ,as it is our empty lot in NS .
    Question : how far from the trailer and how long of a rod would I put in the ground and do I connect it to the frame of the trailer ?
    Would I have to put a lightning rod ,taller than the trailer ,like a metal pipe from the back of the trailer bumper frame ?
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Fibreglass Boler Camper ,Lightning and Solar Power

    I'd skip the lightning rod. In my opinion they have a tendency to attract bolts, which is not desirable.
    But if you can put a 10' rod in the ground and connect the trailer to it when there it may help with the those troublesome EMF's. I'd connect the panel frame(s) to the metal chassis of the trailer, which will no doubt also have connection to the battery (-). Then ground the frame to Earth via the fixed rod.

    Beyond that there's not much more you can do, unless someone here sees something I missed.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Fibreglass Boler Camper ,Lightning and Solar Power

    I would do more research before I did anything... But one model would be like a boat... Tall metal mast, tie metal components together, run to a ground plate/rod buried in the ground with conductive fill (if permanent installation).

    Installing a lightning rod will probably increase the chance of a strike in the area and possibly make it more dangerous for people not inside the trailer. So you could be adjusting the risks to lessening in the trailer but increasing them for people outside. From some of what I have read, your chances of being injured by lightning is higher on open ground (~80%).

    Building a simple metal frame around the outside of the trailer from iron or copper water pipe (connecting all metal together with lightning rated braid) may be a better solution than just a tall lightning rod (see Faraday Cage). Lighting is relatively low frequency and a simple cube frame around the trailer/safe zone may be more than good enough:
    Faraday cage

    You need to design a place where you may spend entire afternoons (working at a desk, reading a book, etc.) while waiting out a possible lighting storm.

    Here is some lightning information that has been discussed here before.

    Off Grid Grounding Technique?
    Another Question, this time about Lightning
    Lightning Protection for PV Systems

    I have no idea about the companies or their products like this one which monitor LF and/or VLF radio frequencies ($200) and even have a pager sized personal receiver (less than $100) or this one which monitor local electric fields that spike before a lightning strike ($2,000)... I don't know if they will help or are just for the paranoid.

    I am not that knowledgeable about lightning--So please do not make your decision only on what I or others are typing here.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset