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"Grounding Basics" Not Basic Enough for Me :)

reg

Winter: New York City Summer: Atlantic Canada
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I've been reading @FilterGuy's excellent series in Resources titled Grounding Basics, and I was particularly interested in Part 4: Mobile Systems.

However, I'm interested in using a battery/inverter/AC outlet on a standalone basis, for example in a park or while camping with a tent, rather than in conjunction with a motor vehicle or a boat. I'm unclear whether grounding is an issue for me, and, if so, what I should do to "get grounded". What I have in mind is akin to using something like a Jackery quite independently of a vehicle.

To get down to specifics, I want to use a 12V 40Ah Valence battery connected to a Morningstar SureSine inverter. It is a 12V 300W inverter, which will handle brief peaks to 600W. The Morningstar is a bit unusual in that it doesn't have an integrated AC outlet. I have to connect it to one, which will be a GFCI outlet. I'll mount the Morningstar and the outlet on a plastic or plywood board, whichever is the preferred material. The battery, inverter and AC outlet will be wired together, but not to anything else. Any device that I plug into the AC outlet will itself be free-standing. I do not plan to use this gear during a thunderstorm :)

So the question is What, if anything, do I have to do about grounding?

The two screen captures below are from the Morningstar Installation and Operation Manual. The first shows the DC wiring, and the second shows the AC wiring. This is the full 15 page Installation & Operation Manual.

Much obliged for assistance.

Morningstar SureSine DC Wiring.jpeg


Morningstar SureSine AC Wiring.jpeg
 
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It's small loads, and small capacity.
You probably can get away without grounding.
Personally, I would just hook up a wire to the inverter housing and put an 25cm iron pin in the soil.
Attach th wire to that, and don't forget to pull out when you leave the camping site.

Even small inverters can (will) get electric charged, up to a point where people with pacemaker can have problems if they touch.
 
Think of grounding as introducing a "known fault condition" One of the leads, the negative in DC, neutral in AC is "shorted" (connected) to ground. From there you can make decisions on what to do, the main decision is that you can have a fuse blow if the positive or phase accidentally shorts to the ground. There are rare situations, you might not want a ground, so people spend money on using an isolating transformer.

If you are in a tent, you can do away with ground, but you'd need to check your wiring, which for temporary wiring is always a good idea, For example when I roll up an extension cord, I ALWAYS start at the male end to make sure it is unplugged, and slide my hand along the cord and feel for any irregularities, places where the outer insulation could have become damaged. In a tent, that would be probably be enough, providing you check once a week.

In a van you can't do the visual test, at least not everywhere, you could do an aditional test to see if you have a voltage between the wires and the chassis once a week, but that does not mean faults can't occur in between and you will have to ask yourself if you have the self discipline to check often. If you can and do test often, you could argue that not grounding is a better idea, but as an electrician I would get a rather painful reminder to be more careful every 6 months on average (and people get killed that way) At the same time, I don't want to frighten you too much, you are more likely to be killed in a car accident then from electric shock, but at the same time, we never think it will be us...

There is a third option and that is to do an insulation test, but for that, you will have to disconnect any electronics in the van before the test and reconnect after. You might want to do that once a year at the beginning of the season regardless if you use grounding or not and more often if you don't ground.

So make your decisions for your particular situation, my advise it to follow the rules, not because they are perfect, but they exists for good reasons.
 
Seems to me you are making a portable “generator” that doesn’t generate (no solar panels, no fuel powered alternator).

That said, none of the portable generators I know of are grounded for operation. If you happen to plug it into an outlet for charging, it gets grounded through the outlet (wherever there isn’t galvanic isolation). Do what you will with this tidbit for thought. My opinion is that worrying about it is torturing yourself over nothing. Do keep in mind that if you plug it into a vehicle to attached to a charging system, you should follow proper wiring, fusing, and chassis grounding procedures.
 
Thanks for the comments. As noted in my first post, I plan to use this the same way that people use a Jackery Portable Power Station. As far as I can tell, a Jackery is essentially a battery connected to an inverter and an AC outlet. If I misunderstand what a Jackery is, or if a Jackery addresses grounding in some way, I'd like to know.

Note that Jackery's latest product, the Explorer 2000 Power Station, has four 2200W AC ports. It's not just selling low capacity "power stations". There is not a word about grounding in the Explorer 2000 User Manual. It's a separate issue, but I also can't find anything on Jackery's site that talks about grounding in relation to its solar panels. Indeed, a search on its site for the words "ground" and "grounding" comes up blank.

If a Jackery Power Station (leaving aside use with a solar panel) and my unit don't have to be grounded, it would be interesting to know exactly what triggers a need for grounding. Interestingly, Jackery makes a point of saying, for all of its power stations, that they can be used indoors.
 
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Thanks for the comments. As noted in my first post, I plan to use this the same way that people use a Jackery Portable Power Station. As far as I can tell, a Jackery is essentially a battery connected to an inverter and an AC outlet. If I misunderstand what a Jackery is, or if a Jackery addresses grounding in some way, I'd like to know.

Note that Jackery's latest product, the Explorer 2000 Power Station, has four 2200W AC ports. It's not just selling low capacity "power stations". There is not a word about grounding in the Explorer 2000 User Manual. It's a separate issue, but I also can't find anything on Jackery's site that talks about grounding in relation to its solar panels. Indeed, a search on its site for the words "ground" and "grounding" comes up blank.

If a Jackery (leaving aside use with a solar panel) and my unit don't have to be grounded, it would be interesting to know exactly what triggers a need for grounding.
i don’t think it’s that they don’t “need” it, it’s that earth grounding (much like in an RV) isn’t exactly practical with a portable application like that.

With that said, if I were permanently installing a jackery into my car or house, I would want to ground it according to specifications and best practices for the application.

Have you seen Will’s portable solar generator “milk crate” videos?
 
With that said, if I were permanently installing a jackery into my car or house, I would want to ground it according to specifications and best practices for the application.

Jackery makes a point of saying, for all of its power stations, that they can be used indoors. For example, this is from the FAQ in the Explorer 2000 User Manual, Question #8:

Q. Can I use it indoors?
A. Yes, the Explorer 2000 is safe to use indoors.

Jackery doesn't have any "specifications" for grounding. What are the "best practices" you're referring to? What are you protecting against?
 
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Jackery makes a point of saying, for all of its power stations, that they can be used indoors.

Jackery doesn't have any "specifications" for grounding. What are the "best practices" you're referring to? What are you protecting against?
Electric shock. I can’t explain it any better than the resources available on this forum.
 
Electric shock. I can’t explain it any better than the resources available on this forum.

As noted above, Jackery says specifically that its power stations, including its new 2200W unit, are "safe to use indoors". Jackery not only has no specifications for grounding, there are no references to grounding in its user manuals or on its website. I just did a Google search to find out if anybody has reported suffering electric shock from use of a Jackery. The search came up blank. As far as I can tell, grounding a Jackery, if there is even a way to do it, would be a make-work project.

To get back to my original question, I'd like to know whether there is a substantive difference, when it comes to grounding, between a Jackery and the battery/inverter/AC outlet unit that I'm making. If there isn't a difference, it would be interesting to know exactly what triggers a need for a ground, and what kind of injury - a buzz? a heart attack? - the ground is protecting against.

Cheers
 
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As noted above, Jackery says specifically that its power stations, including its new 2200W unit, are "safe to use indoors". Jackery not only has no specifications for grounding, there are no references to grounding in its user manuals or on its website. I just did a Google search to find out if anybody has reported suffering electric shock from use of a Jackery. The search came up blank. As far as I can tell, grounding a Jackery, if there is even a way to do it, would be a make-work project.

To get back to my original question, I'd like to know whether there is a substantive difference, when it comes to grounding, between a Jackery and the battery/inverter/AC outlet unit that I'm making. If there isn't a difference, it would be interesting to know exactly what triggers a need for a ground.

Cheers

if you were doing a permanent installation you would be using it [the jackery] in a way it wasn’t really intended (it is meant to be portable); therefore, “make-work” would be for the sake of covering your safety bases. “Safe to use inside” does not mean the same thing as “permanent installation”.
 
Electric shock. I can’t explain it any better than the resources available on this forum.
Then you want GFCI, which, contrary to the name, really has no dependency on ground. Even in your house, the ground wire doesn't protect you from electric shock - you could grab hold of a pair of hot and ground wires and enjoy the tingle all day long. Your body has enough resistance it'll never trip a 15 or 20A breaker. The ground wire's primary job is to protect equipment and wiring from fire.
 
Then you want GFCI, which, contrary to the name, really has no dependency on ground. Even in your house, the ground wire doesn't protect you from electric shock - you could grab hold of a pair of hot and ground wires and enjoy the tingle all day long. Your body has enough resistance it'll never trip a 15 or 20A breaker. The ground wire's primary job is to protect equipment and wiring from fire.
Wrong. The breaker protects from fire. If there is a short to a case, and that case isn’t grounded, then you touch the case and are grounded..you might have a fun trip to the hospital. However, if the case is grounded, the short to case also shorts to ground resulting in enough current to trip a breaker or fuse and thereby disconnecting The source of electricity.

edit: not wrong, but not entirely right.
 
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Wrong. The breaker protects from fire. If there is a short to a case, and that case isn’t grounded, then you touch the case and are grounded..you might have a fun trip to the hospital. However, if the case is grounded, the short to case also shorts to ground resulting in enough current to trip a breaker or fuse and thereby disconnecting The source of electricity.
Which is precisely what I sad. Good talk.
 
if you were doing a permanent installation you would be using it [the jackery] in a way it wasn’t really intended (it is meant to be portable); therefore, “make-work” would be for the sake of covering your safety bases. “Safe to use inside” does not mean the same thing as “permanent installation”.

This thread raised a specific scenario and asks specific questions, one of which is how good the analogy is between normal use of a Jackery and my own proposed setup.

In any event, Jackery says, without qualification, that its power stations are safe to use indoors. It does not distinguish between impermanent and permanent use. On a nuts and bolts level, I have no idea what it means to talk about permanently installing a Jackery. Nor do I know how one would ground one. Jackery, as the designer and manufacturer, doesn't specify a method, doesn't even talk about it, and clearly thinks that it's unnecessary.

As a practical matter, there are undoubtedly lots of people using a Jackery indoors on a regular basis. As noted above, I can't find a single case of someone experiencing an electric shock. If it's happened, apparently it wasn't worth talking about.
 
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Jackery says, without qualification, that its power stations are safe to use indoors. It does not distinguish between impermanent and permanent use. On a nuts and bolts level, I have no idea what it means to talk about permanently installing a Jackery. Nor do I know how one would ground one. Jackery, as the designer and manufacturer, doesn't specify a method, doesn't even talk about it, and clearly thinks that it's unnecessary.

As a practical matter, there are undoubtedly lots of people using a Jackery indoors on a regular basis. As noted above, I can't find a single case of someone experiencing an electric shock. If it's happened, apparently it wasn't worth talking about.

This thread raised a specific scenario and asks specific questions, one of which is how good the analogy is between normal use of a Jackery and my own proposed setup. You appear to be talking about an unrelated, invented scenario.
As far as I could tell, you were talking about making your own “portable” solution, inquired about grounding, and got an answer that suggested you follow up with resources from the forum. You didn’t like the answer. Going back and forth with me tit for tat isnt helping your understanding. You could be spending your time reading through the forum resources, as suggested.

Which is precisely what I sad. Good talk.
Actually it is not what you said. Would you like to scroll back and read what you said?
 
As far as I could tell, you were talking about making your own “portable” solution, inquired about grounding, and got an answer that suggested you follow up with resources from the forum. You didn’t like the answer. ... You could be spending your time reading through the forum resources, as suggested.

Please read the title of this thread and the first sentence of the first post. There's even a link to the four-part article in the forum's Resource area called Basic Grounding aka Grounding Made Simpler, in particular to Part 4: Mobile Systems.

I think that the scenario that I outlined, accompanied by two screen captures of wiring, and the questions that I asked are clear. I've received a number of responses that are both relevant and helpful. I look forward to any further comments that are about the issues raised in the thread. In case there's any doubt, I'm talking about a portable, mobile battery/inverter/AC outlet that will be used in a way that is analogous to how a Jackery is used. I am not talking about a permanent installation. When it comes to a Jackery, as stated above I don't know what permanent installation means. So far, the concept of permanent Jackery installation, whatever it entails, doesn't sound relevant to what I'm asking about.

Cheers
 
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Please read the title of this thread and the first sentence of the first post. There's even a link to the four-part article in the forum's Resource area called Basic Grounding aka Grounding Made Simpler, in particular to Part 4: Mobile Systems.

I think that the scenario that I outlined, accompanied by two screen captures of wiring, and the questions that I asked are clear. I've received a number of responses that are both relevant and helpful. I look forward to any further comments that are about the issues raised in the thread. In case there's any doubt, I'm talking about a portable, mobile battery/inverter/AC outlet that will be used in a way that is analogous to how a Jackery is used. I am not talking about a permanent installation. When it comes to a Jackery, I don't know what permanent installation means. Whatever it means, it doesn't sound relevant to what I'm asking about.

Cheers
And i suggested using the resources available on this forum to explain grounding. Perhaps, again, rather than arguing with me, you should use the link marked “forum search” in my signature and make use of the plentiful resources here in the forum on the subject.
 
And i suggested using the resources available on this forum to explain grounding. Perhaps, again, rather than arguing with me, you should use the link marked “forum search” in my signature and make use of the plentiful resources here in the forum on the subject.

Thanks for your suggestion. Could we move on now? I look forward to comments from others on the scenario and questions that I have raised.

Cheers
 
Please read the title of this thread and the first sentence of the first post. There's even a link to the four-part article in the forum's Resource area called Basic Grounding aka Grounding Made Simpler, in particular to Part 4: Mobile Systems.

I think that the scenario that I outlined, accompanied by two screen captures of wiring, and the questions that I asked are clear. I've received a number of responses that are both relevant and helpful. I look forward to any further comments that are about the issues raised in the thread. In case there's any doubt, I'm talking about a portable, mobile battery/inverter/AC outlet that will be used in a way that is analogous to how a Jackery is used. I am not talking about a permanent installation. When it comes to a Jackery, as stated above I don't know what permanent installation means. So far, the concept of permanent Jackery installation, whatever it entails, doesn't sound relevant to what I'm asking about.

Cheers
I suggest hitting the "ignore" option on Derpsy. Made this thread infinitely better for me anyway.
 
I'm unclear whether grounding is an issue for me, and, if so, what I should do to "get grounded". What I have in mind is akin to using something like a Jackery quite independently of a vehicle.
You will probably get 10 different opinions for every question you ask especially when it comes to grounding. My opinion is you should contact the manufacturer and let them know what you would like to use the inverter for.

As far as I know Jackery and others isolate the AC input and output so they do not require a ground. Similar to using a 1:1 isolation transformer but those are rather large and heavy.

I use a cheap Bestek 300 watt SW inverter with my two Valence batteries and it does not require grounding. I like the inverter you linked to and I can imagine why you chose it.
 
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