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Old 08-14-2010, 12:03 AM   #1
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Camper Grounding to Prevent Electrical Schock

Fellow Sunliner’s

We have had some recent discussion on how do you know if you have a good camper ground and we have had some folks getting shocked when they entered their camper. Getting a light shock by touching the siding of your camper is a serious concern and can lead to larger potential problems. If this does occur on your camper, one thing I can say for sure is your camper is not properly grounded to earth ground and recommend it be addressed quickly.

Not knowing exactly how Sunline accomplished grounding an entire camper with metal siding to make it safe where ever you touched it, I set out to figure this out. I have gone out to my own camper and checked on just how did they do this. And now seeing this and the reports here of folks on the forum getting shocked, I can see I myself will add one more annual check to the spring camper startup list. Ensure there is a proper earth ground on the camper siding. Before doing this investigation I never gave that much thought about it. Now I do. Live and learn.

I have tried 3 times now to try and keep this short and sweet but the more I come back to, well everyone may not be an electrical type and at least understanding this may help them prevent a serious injury. Once understood they may be able to check for themselves or have someone do it for them. So find 5 minutes and read on. If I get to tech’y let me know I’ll re-explain.

First Lets talk about the wording Earth ground, grounding and the word ground what that all means and why it is so important when we plug our campers into the 120 VAC power post. I will try and break this down into simple camper language so everyone can follow along. If any of our other electrically friendly forums members see something I have posted is not correct or miss-leading, please join the post and help clarify the point. Trying to explain these things in words sometimes can get confusing and be misunderstood. There are volumes on grounding in electronic and electricity but for here I’ll try to keep it to how it applies to our campers. So here goes:

I have been using the wording Earth ground on purpose. To understand this we need to understand a little bit about how the power companies create and deliver power to your home and your camper. And another thing to understand is that to power a home or camper electrical device it takes at least 2 wires to do this. Both of those wires are needed to operate an electrical device, (exp: light bulb, vacuum cleaner, hot water heater etc)

At the power company (at least here in the USA and several other countries but may not be all) all the large transformers used to create electricity have one side of the power wiring connected to earth ground. The earth, (soil, dirt, moisture) conducts electricity and this is used to our advantage. They install large metal conductors underground and attach wires to them to create what we call an “earth ground”. So when we talk earth ground, it is literally the earth acting as a wire as it conducts electricity. Earth ground is used as a safety as it is a path for electricity to complete a circuit back to the main power company if we ever needed to. We normally do not use the earth as part of a normal current carrying wire to power a light bulb or other device but we do use it as part of the grounding safety circuit.

OK so the point is we now know the earth is a conductor of electricity and this is why we use the wording earth ground to describe that conductor. Also to note it is common industrial slang when talking DC voltages in electronics, automotive wiring or even camper/automotive 12 VDC wiring to refer to the DC common or the negative wire in most cases as ground. They do not necessarly mean earth ground but more the negative post on a battery or power converter in most cases. I say most as not every DC power system uses negative as DC common but in most if not all the Sunlines we have, DC common is the negative wire and is nick named ground. Just do not confuse the DC slang wording for DC Common, ground, with 120 VAC earth ground. They are 2 different things. DC common may or may not be connected to earth ground.

Each home or campground that receives power from the electric company has a grounding stake at the main incoming power panel. It is a rod driven in the ground at least 8 feet and a wire connected to it that goes inside the power panel where only in that one spot are all the ground wires connected to. Also in that same one spot they connect the AC neutral wire (1 side of the 2 wires needed to run an electrical device) to that earth ground. Earth ground and AC neutral are only to be common in this on location in the power panel. This is part of what we call “single point grounding” and it is part of the National Electric Code that most all US home are suppose to be wired to.

See this pic of my home grounding stake. That stake and wire connects my house grounding wires in the main power panel to the earth itself and to connect back to the electric power company’s transformers.


I used a new technical word called “single point grounding”. You can search it on the web and read and read. There is a specific safety reason for that I will get to in a minute.

Now we need to talk about how does that earth ground wire get into our camper? Simply put it comes in on the shore line cord as a 3rd wire into our power converter where it then joins all the individual ground wires coming from all over the camper. Again they all join in one spot. There are suppose to be grounding connections to all metal objects in the camper, inside or out that can be exposed to 120 VAC live voltage if everything is wired right. That is no small task if we are talking about a camper built with putty tape and other insulating things between metal parts. Since the 120 VAC wiring runs in the walls of the camper, it can touch the side walls and if the insulation is worn and the wiring is exposed it has the ability to power up the sides of the camper. By grounding the camper walls and everything else metal we create a better path for electricity to flow thru then thru our body. More on this later.

The campground power post needs to have (must have) a plug that looks like this for the 120VAC 30 amp plug we use on most campers. Larger campers use a 50 amp service and that is a different setup but still grounded the same.


That receptacle pic is from the Levinton web site. A well trusted name in electrical hardware. It is also interesting the electrical industry actually makes this special TT plug and receptacle just for campers. http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?item=107467&section=10959&min isite=10026

That receptacle contains a wire that leads back to earth ground in the main power panel and then outside to the stake in the earth, aka earth ground wire. And your TT shore line plug also contains a wire that will connect to it. See here:


Here is the inside. The green wire is used to indicate ground.


Something I want to mention that is a good habit to get into when plugging into the campground power post. This pic is not high enough up to show but there are circuit breakers in that power post that service the contained receptacles. Before plugging in or unplugging, shut the power off with the breaker, plug in, then turn the power on. If there is a short in the plug or if you are some way touching the hot blade of the plug, 30 amps of 120 VAC hurts and can do serious harm depending on where it enters and exits your body. Turning the power off while plugging and unplugging greatly eliminates the hazards.



So now we know how the earth ground wire gets hooked up to your camper. So why is this so important? It has to due with reducing the risk of electrical shock. There where 2 other wires in that shore line cord plug I showed you above, the green wire was the ground, the white wire is what we call AC Neutral and the Black wire is what we call AC hot. The AC neutral was tied to the earth ground wire back in the main power panel and only there. Remember I said that was part of single point grounding. Since those 2 wires are common to each other, if the white wire ever touched something connected to earth ground there would not be a hazard as they are common to begin with. There is no live voltage difference between the white wire and earth ground. This eliminates 50% of the shocking hazards as there is now only 1 wire that is live in relation to earth ground for you to get shocked with.

However the AC hot is just that, a high voltage (120VAC) running thru it in relation to earth ground and the AC neutral so the black wire is “hot” or “live”. If the AC hot ever touches the AC neutral or earth ground directly it is what we call a “dead short” and it will try and pull full amperage until the circuit breaker or fuse blows if it can get enough conductance or the wire melts if the fuse does not blow.

The white wire (AC neutral) is to be used to complete the 2 wire circuit with the black hot wire providing the power to power an electrical device. Example A light bulb, a HW heater element etc. The earth ground wire is to be attached to all metal objects that can come in contact with the black AC hot wire. If the earth ground wire is intact and working then if the AC hot wire ever comes in contact with metal parts of the camper, the grounding system then absorbs the power as it is a very good path for current to flow thru.

If the grounding system is not intact then the metal object becomes live and just waits from someone or something to create a better path to earth ground then the wiring was suppose to do. In this case, if you have wet hands or feet or just plain normal sweat on your skin you are a grounding rod when you are standing on the ground. Sometimes you get lucky and your shoes “might” insulate you but not if you have damp feet and normal shoes or sandals.

When your hand touches a metal object with stray voltage applied to it, you then become the grounding connection and you get shocked as the voltage flows thru you back to earth ground. You have become a better path to earth ground then the wiring in the camper. And that is not good. This now leads us on how to check that and how did Sunline create a grounding system that goes thru every metal part on the camper exposed to 120 VAC wiring?

Each camper should have a grounding wire that comes out of the power converter box and attaches to the TT frame and the TT siding. See here on mine. I do not have a pic of a non slide camper in this area, maybe someone from the Club can provide one. This pic is on a slide model where the bottom siding is made a little different.


That area of wires is the point that we need to focus on. You see a bare copper wire and you may see a green wire going to the frame lug/ camper siding.

Now the testing part. Here you do need an Ohm meter. An ohm is the unit of measure of resistance simply put. An object with infinite resistance or ohms does not conduct electricity. An object with 0 ohms is a very good conductor of electricity. Ohms measure in less then single digits (milli) ohms all the way to millions of ohms (mega ohms) and there are a 1,000 ohms or a killohm. See here for more http://en.wikipedia.org/wiki/Ohm

The meter you see here is a higher end meter. I use this for work and use it for all kinds of trouble shooting. I also have a cheapy one, $10 from Harbor Freight, or $4 bucks on sale in the camper. Radio Shack also sells them and I have one of them too. And they make them in analog meter with a needle dial. Have them too. Over the years they collect. Both the cheapy one and the higher end one will trouble shoot about anything on a camper electrically. You need to turn it to the ohms scale so it will read out in ohms and have the test leads in the right receptacles for measuring ohms.


Once you turn on the meter and are going to measures resistance it is standard practice to test the meter on ohms. On the digital meters the display will read OL for over load/over range when you 1st turn it to ohms. That is because the test leads are out in the open and are reading infinite resistance between them. On an analog meter the needle may wiggle but will not move much if any. To test that the meter is working right we cross (connect) the test leads creating a good connection. The digital should go to 0 or may float at 1 to 2 or a little higher pending how clean and tight you hold the leads. Here you see mine at 0.6 ohms. The analog meter will go to 0 on the scale. Reason is you have no resistance as this is a positive connection that fully conducts.


Now you know the meter is working so lets start testing. Grab the shore line cord plug. Put one test lead on the center half round blade. The other on one of the plug blades on an angle.


Now do ground to the other blade.


You should get OL or infinite resistance to ground on either the AC hot or AC neutral to ground. If you get resistance or very low resistance that means something is not correct and has to be sorted out.

Next is to put the test leads across the 2 blades. AC hot and AC neutral. This will give some resistance as what you are measuring is the resistance of the power converter transformer inside your camper. If the circuit breaker is off to the converter then this would read OL. Each converter may (will most likely) read a different number then what it shows here on mine as they are made different. Mine is reading 383.9 ohms


Now that the wiring is showing that the earth ground wire is separate from AC neutral and AC hot we can keep on checking. If this comes up wrong, need to have that issue fixed. So we hang one lead on the ground blade and start checking the sides of the camper to see if they are connected and how well to earth ground.

I started out testing the metal boxes I have on the rear of the camper. 11.9 ohms. That is a little bit of resistance but not a lot. That says is there is 11.9 ohms of resistance between earth ground and my rear metal boxes the way the camper is made. That is good so far.


Now to a screw on the window frame. 12.1 ohms. Now the pic does not show it but that is a shinny stainless screw. No paint or rust. Paint and rust can create resistance and to the point you do not get any resistance. That does not mean you do not have a ground necessarly it may mean your test point is no good. You need to pick test points that will have the ability to conduct.


Now the door key slot.


The door holder post


A shiny bolt on the TT frame

And now I went into the fridge compartment. There is a 120 VAC receptacle there


I am testing the earth ground on that receptacle. Notice the resistance is now 0.5 ohms. That is a shift from the approx 10 ohms I had on all the TT siding and frame parts. Why?


Well the reason for the shift is the 120 VAC receptacle ground is wired direct all the way to the shore line cord ground pin in the plug. It should read real close to 0 ohms. If not then there is an issue. This tells me the fridge receptacle has a very good earth ground.

Now to test the frame grounds on the fridge. This is back to the 10.8 ohms range. That is just like the other siding measurements because it is coming thru the camper siding ground and TT frame ground. In this case these wires are also DC common (negative). So they are both common to earth ground and DC negative. More on this in a moment.

Edit: 8-14-10 for clarity Note: When I tested the 10.8 ohms the 120 VAC plug was unplugged. So I was only testing earthground thrugh the camper frame. When I plug the 120 VAC plug in, this ground location goes closer to 0 ohms because there is a ground wire in the 120 VAC cord that then makes a better path to earth ground. It should minic the white recptacle ground pin I just measured. The green wire you can barley see in the pic is the ground wire thru the fridge 120 VAC power cord. Since the fridge is not double insulated it must have it's own earth ground coming in with the power cord.




Now we go back down to the camper grounding wire area. We do a test from the shore line cord ground blade to the copper wire coming from the power converter area. Here we get 0.1 ohms as I am testing the copper wire. This tells me something.


And I get 0.1 ohms on the copper lug on the siding.


So I have a difference of about 10 ohms between the copper wire and the TT siding and frame. What this says is there is 10 ohms of resistance between the earth ground wire and the camper siding. Or basically putting it, there is some small level of corrosion between the copper plug and the TT frame and the TT siding. 10 ohms if not much but if this number is a lot higher you could have a high level of corrosion on that bonding lug.

To correct this unbolt the copper lug, scrape the metal back to bare steel. Ideally use a stainless steel bolt in this case or at least a new plated bolt. Put some dielectric grease on the bolt, the lug and the frame and bolt it back together. The grease does not conduct electricty and helps keep the corrosion down.
http://www.permatex.com/products/automotive/specialized_maintenance_repair/electrical_system_maintenance/Permatex_Bulb_Lamp_Electrical_Connector_Dielectric _Grease.htm

You can buy dielectric grease at any auto parts store. They also label it tune up grease.

http://www.permatex.com/products/Automotive/specialized_maintenance_repair/electrical_system_maintenance/auto_Permatex_Dielectric_Tune-Up_Grease.htm

The copper lug can at times contain a steel plated screw that rusts. If you have a real bad corroded one, replace it with a new one.

Checking for the camper siding ground can only be done with a meter that I can come up with. You can have a perfectly good wall outlet ground but the siding may be not grounded due to corroded connections or a broken ground wire. This will go on my annual camper check up list.

A few more things. Here you see a heavy white ground wire from the LP gas line pipe to the TT frame. This is to earth ground the LP pipe. It is a electrical code requirement and a safety feature not have any current running thru a LP gas pipe. Never use the gas pipe as a source to hook up a ground to run something.




Another handy checker many use is one of these circuit testers. These tell if the campground receptacle contains a earth ground to start with. And you can use it inside the camper to see if the wall plugs has a earth ground. When used inside the camper in a wall plug it can show if you have the AC neutral and AC hot polarity mixed up. However this will not tell you if you have a earth ground on the side of your camper. Need to use the ohm meter to test that.

This is what I use every time I plug in at a campground. It has the 30 amp adapter down to standard 15 amp plug configuration. They sell the tester in Home Depot, Lowes, Hardware stores etc. The adapter, I found mine at Wal-mart although not all sites carry that combo.






Well if you made it this far reading…. Hopefully now you realize a few things about how the grounding system on your camper is suppose to work and how to test for it.

Hope this helps someone in the future

John
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Old 08-14-2010, 09:00 AM   #2
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Wow! Love it, thanks.

How 'bout making this a sticky?

Teach
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Old 08-15-2010, 06:25 PM   #3
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I think I'll stick to dry camping.
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Old 08-16-2010, 07:53 AM   #4
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Thanks John...this is a significant effort you've made to inform us all on this subject. It is in keeping with the many other excellent thread you've authored on a variety of subjects.

I almost want to rent your trailer to camping in since it is likely to be the best maintained Sunline of all. Here and there I tend to the various needs on my Sunny. The list of whats possible just steadily grows with each additional article you write, and I cannot imagine ever doing it justice as you obviously do. But knowing some of the major pitfalls is a valuable aid to us owners. It at least allows for some level of enhanced preparedness on our part if we are reading the good information you provide. Many thanks again to your never ending efforts to support the Sunline community.

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Old 08-16-2010, 10:11 PM   #5
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Gee Bob, Iím humbled. Thanks for the kind words.

I like doing these kind of techíy things and truly hope it helps someone in the future. I too learn from them like this one where I never gave the siding much of a thought, but now do.

Happy Camping

John

PS no need to rent the camper, if you ever get over this way, we can both go camping.
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Old 04-23-2012, 01:27 PM   #6
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Frame Grounding

I saw on another forum where there was considerable debate on just how many ground wires should be connected to the frame. They talked about ground loop. Does it really matter how many DC grounds are connected to the frame?

The brakes are grounded to the frame.
The LP is grounded to the frame.
The DC is grounded to the frame.
The AC is grounded to the frame.
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Old 04-23-2012, 07:01 PM   #7
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I would like to add any metal frame camper motor home or house has an insolated neutral unlike a stick built house. The reason is for reversed campground/home wiring if it shared the ground you run a risk of a hot trailer frame if there is a poor receptacle ground. So never bond the ground wire to the neutral wiring in your panel box in the camper. White and green 120 volt stuff don’t mix. You’ll find white 12 volt wires grounded that’s OK that will have no effect on your health. As far as numbers of grounded wires there is no limit (provided they are supposed to be grounded) modern cars/trucks have dozens of frame grounds.
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Old 04-25-2012, 07:13 PM   #8
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Quote:
Originally Posted by drcrypto View Post
I saw on another forum where there was considerable debate on just how many ground wires should be connected to the frame. They talked about ground loop. Does it really matter how many DC grounds are connected to the frame?

The brakes are grounded to the frame.
The LP is grounded to the frame.
The DC is grounded to the frame.
The AC is grounded to the frame.
Hi drcrypto,

I'll try and explain some of what they where referring to.

In a sensitive DC control circuit it is common practice to have 1 main point of grounding. This is called single point grounding. All ground wires from the devices are wired to this one common point and then attached to earth ground in a grounded system OR left to float in an ungrounded DC system. This is for DC.

This single point grounding also applies to the AC circuits too. Our campers are wired this way on purpose and Mainah was referring to this.

What is not wanted to be done in these sensitive DC equipment cases is to use parts of a machine as a "wire". In these cases components mounted on the machine end up with ground path current going through the machine on the way to the grounding post. This electrical noise by AC motors and other things raises great havoc on sensitive DC circuits heading to the grounding post. Sort of like you hit the machine with a lightning bolt and everything along the way was shocked. There are special DC systems that create a faraday cage principal but that does not apply to our campers and it will only confuse the situation.

Now to our campers. Sunline practiced this single point grounding method for sure on the AC side and for the most part on the DC side as well. From the battery to the power converter is a wire on the DC neg. side verses using the TT frame as the wire. And inside the camper all DC negatives are run to each fixture and back to the converter where they are tied to one common buss bar. And this DC buss bar is tied to the frame and to the earth ground wire going out to the power post to reach earth ground.

In this case the wire is a better more positive conductor then the frame which can get rusted and create voltage drop. When you only have 12 volts to start with every 0.1 volts counts.

You will see the gas pipe having a wire from it to the DC common and the frame which is tied to earth ground through the power post. This is a safety requirement so that the gas pipe never ends up accidentally carrying electrical current.

It could be questionable about ground loops on the DC side of the camper like we have to worry about on sensitive DC electronic equipment. There is more potential of not having good connections as a result of not running a DC neg wire direct back to the converter and then to the battery. The fridge for one really needs a good DC negative and using the frame as a wire just invites corrosion issues. Same on the furnace.

I myself would limit to almost not using the frame as a DC current carrying wire. Run the wire instead. The body lights are about the only cheap out I would do. Electrical noise in a camper is low as there is not much creating it. However a power surge or lighting strike at the CG is real.

You also asked this:

The LP is grounded to the frame. As I stated above this is the current drain to prevent any electrical current from potentially traveling down the gas pipe. It is not to use the gas pipe as a wire to transfer current.

The DC is grounded to the frame. Yes this is an automotive thing. They tie the battery negative to the frame. The body lights and the TT brakes use the frame as a wire. Ideally the brakes do not do this as again corrosion is a big thief of voltage. You will notice all the inside DC is wired direct to the buss bar in the converter.

The AC is grounded to the frame.
Yes, it must be per NEC code because of the electrical shock hazard with the 120VAC. Since the frame is metal it conducts electricity and if you happen to touch it with a stray hot AC wire touching it, you could be the ground path. By grounding the frame to the earth ground line coming in the shore power line, that ground wire is a better path for the shock to go to ground then through your body to the ground.

Hope this helps. If you need more I can try and break it down on what are you do not understand. Our campers have both AC and DC and the 2 worlds have different needs.

John

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Old 04-26-2012, 06:33 PM   #9
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In the case of the camper they generally run a DC return wire (- wire) to a single point ground because wooden frames do not conduct well so every thing gets it’s own ground wire. If you look at your panel box you'll see a nice fat white wire and a bunch of little ones the big one returns to the battery and actually does not need a frame ground -- except that it is intermixed with 120 volt wiring and could come in contact with a 120 volt hot lead, an extreme case but not imposable and that would not be a good thing so every thing shares a frame ground. It's all about safety there are many people out there that consider them self’s experts because they twisted two wires together once and it worked. The neutral wire in the 120 volt system is also white so you can see what might happen. If you need some thing to put you to sleep pick up the latest NEC book. All of the stuff they come up with is possible most of it highly unlikely but not impossible. Be safe out there. Get a $3 test light with 3 bulbs from the hardware store and leave it plugged in to one of your outlets it’s real cheap insurance if your campground outlet fails don’t use it.
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Old 06-07-2018, 03:38 PM   #10
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JohnB... Excellent explanation!! Your ability to explain in basic terms has prompted me to hope you could shed some understanding for an unrelated project that has barely even hit the drawing board (and **yes**, before rubber meets pavement serious professionals will be consulted, but in the meantime I’d like to gain a basic understanding)...

Question involves grounding heavy duty (100K Amp) lightning arrestors and multi kilojoule surge suppressors planned to protect sensitive electronics on a mobile vehicle. The shore power line is of such light gauge I certainly wouldn’t trust it to discharge a multi-megawatt surge, and when shore power isn’t available and the equipment is being powered by an onboard PTO generator/batteries/inverters, well, then what? Does one connect to the frame? (Eek - vehicle’s own electronics). Would one interconnect the feeble shore power grounding wire, the frame, and several portable grounding stakes pushed into the earth (connected with more robust 4/0 copper wire)? Again the curiosity is where to send the diversionary discharge lines from the protection devices, both for when on shore power? ...And also for when on internal power (where should protective equipment divert the energy to for exposed accessories and antennas?)

PS - Admin: I don’t own a sunline, but of my internet searching JohnB’s explanation was definitely one of the better ones. Though I have a pretty good handle on electronics, I had to jump on here to toss this question at him. If required you may remove me, but if that’s the case please first forward the question & my email to him. Thanks. ��
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Old 06-07-2018, 07:11 PM   #11
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Quote:
Originally Posted by John1 View Post
JohnB... Excellent explanation!! Your ability to explain in basic terms has prompted me to hope you could shed some understanding for an unrelated project that has barely even hit the drawing board (and **yes**, before rubber meets pavement serious professionals will be consulted, but in the meantime Iíd like to gain a basic understanding)...

Question involves grounding heavy duty (100K Amp) lightning arrestors and multi kilojoule surge suppressors planned to protect sensitive electronics on a mobile vehicle. The shore power line is of such light gauge I certainly wouldnít trust it to discharge a multi-megawatt surge, and when shore power isnít available and the equipment is being powered by an onboard PTO generator/batteries/inverters, well, then what? Does one connect to the frame? (Eek - vehicleís own electronics). Would one interconnect the feeble shore power grounding wire, the frame, and several portable grounding stakes pushed into the earth (connected with more robust 4/0 copper wire)? Again the curiosity is where to send the diversionary discharge lines from the protection devices, both for when on shore power? ...And also for when on internal power (where should protective equipment divert the energy to for exposed accessories and antennas?)

PS - Admin: I donít own a sunline, but of my internet searching JohnBís explanation was definitely one of the better ones. Though I have a pretty good handle on electronics, I had to jump on here to toss this question at him. If required you may remove me, but if thatís the case please first forward the question & my email to him. Thanks. ��
The camper power cord is a #10 wire it is grounded to the campground wiring and the utility co ground, the power posts are in essence a ground they are 4 feet deep in the ground and connected to the utility ground with a 2 aught the posts are rated 100 amps. Anything beyond the power post breaker is considered a sub panel this also includes generators as they are the power source. So the neutral wire and the ground are separated in your camper. The camper grounds are all tied together aluminum body parts framework and the round pin in a power cord even the battery. There is nothing that will protect you from a lighting strike to say a tree nearby in a campground or a primary falling on a neutral because the ground at that point becomes high voltage. I run ham radio gear in my camper it's DC is connected to the power ground along with everything else with no issues. Our radio tower sites are another story 100 foot towers are good lighting rods our grounds include halos, ring grounds, ufer grounds, and are linked with 4/0 copper or flat copper plates. A camper is pretty well protected for what it is and actually is a fairly good Faraday shield! Does that help you?
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Old 06-07-2018, 09:18 PM   #12
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HI John1,

Welcome. I can appreciate your dilemma. When it comes to a lightning strike like you are referring too, I will say that is not something I myself have been into. I would be interested in learning on this one, but I cannot offer a technical way how to arrest it.

Mainah is closer to this world and he did a better job on your question then I can do.

No need to delete your reply or your account. You are welcome to be here and share RV'ing kind of info.

Thanks

John
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Old 06-07-2018, 11:44 PM   #13
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Mainah & JohnB... Thanks

Mainah, in re-reading this I thought of something...aircraft. They play a short portion of lightning circuits all the time, with hundreds of people and millions upon millions of dollars of highly sensitive onboard electronics unaffected. As long as energy can be redirected from flowing through the sensitive lines instead being rerouted to ground (aka vehicle frame) should I consider it (relatively) safe in the sense that the ground’s charge, whatever it is, would be distributed and even, discharging itself as an arc from the frame on its way to the real ground (and spectacularly obliterating that #10 wire). Without flow...a closed circuit...the charge potential whether nothing or a million volts is meaningless (much like high power line workers can crawl along live quarter million volt lines). So in reality as long as the frame handles the surge flow instead of the hots, commons, comm lines, etc. conducting the flow between the entry & exit wounds (with heavy duty commercial grade equipment redirecting any dangerous flows away from the tenders into the ground/frame instead), all’s good(ish), yes?

Granted, this doesn’t address any post strike residual voltage potentials and the associated safety concerns that would create, but that’s a different question.

Mainah - Is my thought process in the ballpark on this?
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Old 06-08-2018, 06:48 PM   #14
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Well aircraft are a pretty good Faraday shields as lighting tends to travel on the surface of an aluminum air craft this does not mean they are lighting proof but great deal of things have been taken into account as far as protecting things mainly fuel, gaps are bridged sensitive wiring is deeper into the interior etc. I do electrical work at a local campground we had a lighting strike between two campers one big MH another one a 30 foot camper it hit a tree right between the two there was not much that was not damaged electrically except for the occupants of the camper. Again the ideal of a Faraday shield protected them. The electrical damage was incoming electricity from the power lines/cords not the fact it could not exit the effect was because of excessive line voltage at hundreds of times above normal line voltage. As far as power line workers as long as they are above ground of the voltage potential yes that is possible it's kind of like birds on power lines.
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