Inverter In RV Not Grounded?

jesfl

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Again, I’m a real beginner. I just spent another 4 hours over two days reading info on this forum, and now I am even more confused. Yes, I read "Mobile Grounding Made Simpler . . . and several other threads about RV/mobile inverter grounding, one with a lot of technical debate was waaaaay over my head. I could not find a clear-to-me solution for my issue.

I just bought a new 3000-watt inverter. As careful as I was in attempting to double-check all details before my purchase, I missed one (important?) thing. It is that there are only 2 connectors -- the pos (+) and the neg (-) for the permanent 120 volt AC output wire that goes to my 120V RV breaker panel. There is no ground connection for the permanent wiring to the AC breaker panel? Note: Yes, there is a small ground connection for the aluminum case of the inverter. But, that's completely different, as I understand it.

What do I do with the ground wire on the 3-wire connection from the inverter to the AC breaker panel? I contacted the Amazon seller several days ago and, so far, no response. I watched several YouTube reviews of the inverter before I bought it, which were very positive about the inverter’s performance.

One of the reviewers was kind enough to respond to my question about 120V AC output grounding, saying "In the RV, just connect the (+) and (-) inputs. You can ground the metal housing of the inverter if you'd like." But, as I understand it, chassis grounding the metal housing of the inverter is not properly grounding the 120V AC output to my RV breaker panel and system. That leaves what seems to me to be a critical path grounding connection wire from the inverter to my breaker/120V system panel ungrounded? And, that is VERY scary to me.

Does, or does not, the permanent inverter connection to the 120V RV electrical breaker panel need to be grounded?

If no ground connection is necessary, is this a 100% safe way to wire the permanent 120V connection from the inverter to the breaker panel?

Thanks in advance to all of you who provide such valuable info for beginners. You are amazing.

jesfl
 

Zil

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The green wire in a ac circuit refences back to its source. In my Samlex inverter the green connects to the case. If you are using the RV panel, the green there connects to the chassis for safety when you are plugged into the grid. Connecting the inverter case to my chassis connects my 120v ac panel to the inverter case. You will need GFIC for full protection.
 

jesfl

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What brand and model is your inverter?
Duh. Obviously needed info. Sorry. It is a XIJIA 300W 12 Volt Pure Sine Wave Inverter.

Bought on Amazon, link: https://www.amazon.com/dp/B07VBGM3T6?psc=1&ref=ppx_yo2_dt_b_product_details. Note: When I just connected to that link on Amazon, it shows a different photo than 2 weeks ago, and now says it is no longer available. That's curious, for sure.?

From watching several YouTube video reviews, it appears this same inverter is sold under 3-4 brand names?

The green wire in a ac circuit refences back to its source. In my Samlex inverter the green connects to the case. If you are using the RV panel, the green there connects to the chassis for safety when you are plugged into the grid. Connecting the inverter case to my chassis connects my 120v ac panel to the inverter case. You will need GFIC for full protection.

I think you are saying NO, it is not necessary to connect the ground wire in a 3-wire permanent connection from the 12V AC power panel to the inverter? Correct?

But, that I should connect the case ground to my chassis connection?

How do I add "GFCI" and where? I am not clear about this point? In the wire from the inverter to the AC power panel?

Thanks again to both of you.

jesfl

 

jesfl

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Good morning, again,

Since I responded (above) earlier today, I've been reading more on this DIY Solar Forum and other sites. Given that the unit I bought two weeks ago now shows up on Amazon as "unavailable," I've decided to just return it and buy something else.

One of the appeals of the XIJIA inverter was the soft-start capability, which reviewers tested and worked nicely. My searching, however, has led me to a Giandel 3000W 12V unit also with the soft-start capability built-in. I have watched/read several positive reviews of Giandel products. (No, I'm not going to try to run my RV air conditioner on the inverter, but the soft start just makes sense to me when running some high-drain power tools and the microwave on the 120V system.)

If you, or anyone else, has a recommendation for a 3000W 12V inverter other than the Giandel, your suggestions are welcomed.

Thanks again.

jesfl
 

time2roll

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I recommend 24v if going above 2000 watts. Especially if full surge performance is needed.
 

12VoltInstalls

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anyone else, has a recommendation for a 3000W 12V inverter other than the Giandel,
IMHO that’s a good unit in that category
my Giandel has been running 3+ years

A longer term view may be or is probably better served in the +$1000 price point

I’m not cheap but I’m frugal, but I like my frugality to have some wisdom behind it. Giandel seems to be up to snuff
 

Zil

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I think you are saying NO, it is not necessary to connect the ground wire in a 3-wire permanent connection from the 12V AC power panel to the inverter? Correct?

But, that I should connect the case ground to my chassis connection?

How do I add "GFCI" and where? I am not clear about this point? In the wire from the inverter to the AC power panel?

Thanks again to both of you.

jesfl
I did not say "No". Any three prong 120Vac outlet has a green wire that must connect back to the source of the power. Using an inverter the green connects back to the case lug. If wiring into the RV OEM 120Vac breaker panel, as that panel's green should connect to the RV chassis, the inverter case can connect to the RV chassis. Saves wire. The battery negative connects to the RV chassis as well.
I use GFCI outlets. My inverter came with a GFCI outlet. I also hard wired one other GFCI outlet for my microwave.
 

jesfl

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I did not say "No". Any three prong 120Vac outlet has a green wire that must connect back to the source of the power. Using an inverter the green connects back to the case lug. If wiring into the RV OEM 120Vac breaker panel, as that panel's green should connect to the RV chassis, the inverter case can connect to the RV chassis. Saves wire. The battery negative connects to the RV chassis as well.
I use GFCI outlets. My inverter came with a GFCI outlet. I also hard wired one other GFCI outlet for my microwave.
Thanks again. Yet, my limited knowledge still leaves me slightly confused. So, I've just read another hour's worth of posts on this forum, and I admit a little hopefulness in the fact that I am not the only beginner having trouble with explanations here and asking for comments to be "dumbed down."

(1) I read elsewhere on this forum that the "case grounding connection" on an inverter is not the same as a "proper ground" (my terminology) for the 3-wire 120V AC connection from the inverter to the RV power panel. If that is correct/true, then a connection to the case lug for the direct wire from the inverter to 120V AC RV power panel is not a grounded connection and really does nothing? True or false?

That is why I said "not necessary to connect the ground wire in a 3-wire permanent connection from the 120V AC (previous typo) power panel to the inverter?" You are saying the case lug IS a proper ground and that is where the green/ground wire in my 3-wire (higher power) direct connection to the AC power panel gets connected. OK, I can do that.

(2) You also wrote: " . . . the inverter case can connect to the RV chassis. So, I also run a wire from the case lug to my chassis ground connection. To be sure, that means I am connecting 2 "ground" wires to the inverter case lug. Correct?

(3) Yes, there are OEM chassis grounds for the RV 120V AC power/breaker panel.

(4) Yes, the battery negative connects to the chassis ground.

(5) The inverter I now have does not have the luxury of GFCI outlets. BUT, I don't think it matters, because I will not be using the built-in inverter 120V outlets (non-GFCI) anyway. I only want to use the "higher power" direct connection to the RV's AC power/breaker panel.

(6) The 120V outlet for the microwave in my RV is not a GFCI outlet. I can replace that with a GFCI, of course. But, I guess I am not sure why? The microwave is the only appliance on the power panel circuit to which it is connected. Doesn't the power panel breaker serve the same purpose as the GFCI outlet would? I guess I don't understand the difference between a GFCI outlet/plug and a power panel breaker?

All of this thinking causes me to ask one related question. Would it be wise to add a secondary breaker on the direct connection wire from the inverter before/into the RV power panel? Would that in any way safeguard the entire power panel/RV 120V electrical system should the inverter, or something else, blows/burns up in my solar system?

Thank you for any follow-up thoughts and clarifications.

jesfl
 

mikefitz

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Read page 15 of this install manual,


Quality inverters suitable for a permanent install will have similar wording in their instructions.
Many of the low cost inverters on eBay and Amazon , besides not being able to perform to specification, may not be suitable for a permanent install. Connecting a single appliance direct to the output socket of the inverter is reasonably safe, but when connecting the inverter to a power distribution system care is needed.

Mike
 

jesfl

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I recommend 24v if going above 2000 watts. Especially if full surge performance is needed.

I appreciate the recommendation. And, I am beginning to understand the value of a 24V system. But, that's not really in the cards for me with my very limited barely-beginner knowledge level. Further, and perhaps more importantly, I am learning I don't really need a 3000-watt inverter, at all?

I first purchased a basic 2000-watt inverter as shown in one of Will's beginner's solar system videos. After I got it installed and used it through two extension cords connected to the inverter's two built-in 120V outlets, I decided that to plug in and unplug appliances constantly when on shore power or boondocking with inverter power was very frustrating.

The 2000-watt inverter worked adequately for my needs. It powered my 1100 watt microwave perfectly. And, the microwave is by far my highest power drain appliance.

But, I decided to buy an inverter that could be directly connected to my RV's power panel, and eliminate the regular plugging/unplugging exercise. At the time of the new inverter purchase, I figured why not go up to a 3000-watt size, just in case I needed some extra power someday. Probably a bad decision. Now as I am learning, I see I don't really need more than the 2000-watts of power. (Note: I have pondered a small, portable 120V air conditioner addition for the RV's small bedroom, someday. But, it would draw less power than the microwave and I would never be running both at the same time.)

So I am now thinking of backing down to a 2000- to 2500-watt inverter. Even then, I don't see any time I would really use all of that inverter power. That should be more than I need, unless I am missing something?

(Note: I do have a 15,000 BTU air conditioner in my RV, but I also have a generator to power that, if I ever desperately need the air conditioning when boondocking. I've only run the geerator to power the AC 3 nights during my first 20 months of RV full-time travel.)

So, thank you again, to all.

jesfl
 

Zil

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The "proper" ground for the 120vac side of the inverter is the inverter case. Most inverters have a bolt/lug/screw to provide a place to make this "proper" ground connection. Using a RV OEM 120vac panel a triplex wire can be run from the inverter to the panel, black, white, green. The green goes to the inverter case. The green must connect to the RV chassis at the oem panel. If you use a duplex wire, black & white. The green can be a quality connection to the RV chassis. As fuses and breakers protect the wire it would be correct to have a breaker on the hot wire at the inverter. Fuses and breakers serve a different purpose than GFCI outlets. Google GFCI for more information. Note; There are GFCI circuit breaker combination devices that install in the panel. Fuses and breakers protect wires, GFCI's protect people.
Using a 2000W inverter at 12vdc can be powered with 2/0 cable from the battery. 3000W at 12vdc would require 4/0 cable and a hefty battery.
 

jesfl

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Read page 15 of this install manual,


Quality inverters suitable for a permanent install will have similar wording in their instructions.
Many of the low cost inverters on eBay and Amazon , besides not being able to perform to specification, may not be suitable for a permanent install. Connecting a single appliance direct to the output socket of the inverter is reasonably safe, but when connecting the inverter to a power distribution system care is needed.

Mike

Thank you. I just read the page about grounding three times, and some of the rest of the Samlex manual. I do not understand it all. And, further, an expensive inverter like a Samlex or Victron is not in the budget for me. I recognize they may be better quality over the long term, but I am a retiree on a very limited income and I am struggling with the many costs of just getting an inverter to work. I just want an inverter to work for my minimal RVing needs for 24 months, if I live that long.

As I read it, also, it basically says every outlet to be run on the inverter should be a 20 amp GFCI outlet? Which means I would have to install 20 amp GFCI outlets to replace every outlet in my RV? Also not in the cards or budget.

What do you mean, specifically, by " . . . when connecting the inverter to a power distribution system care is needed?"

I have a quality marine 120V on/off switch awaiting wiring for the 120V line from the inverter to the RV power panel. I asked elswhere if I also need a sub-panel/single breaker in that wire from the inverter before the power panel?

Is there something else specific that falls under your generalized "may not be suitable for a permanent install" and/or "care should be taken" comments? I am hoping for specific, tangible suggestions.

I will appreciate further clarification.

jesfl
 

jesfl

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I just bought this one I am happy with it. Starts and runs my 10K BTU AC with no problem.


I looked at the EDECOA, and have it on my list. But, I am now thinking/learning the 3000-watt size is probably overkill for my needs?

When you say it runs your 10K BTU AC with no problem, what type AC is that. The little portable 6000 BTU AC unit I looked at draws 930 watts/10.4 amps which is less than my small microwave.

Thanks for letting me know your EDECOA is performing well. I'll now look closer at those.

jesfl
 

jesfl

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IMHO that’s a good unit in that category
my Giandel has been running 3+ years

A longer term view may be or is probably better served in the +$1000 price point

I’m not cheap but I’m frugal, but I like my frugality to have some wisdom behind it. Giandel seems to be up to snuff

Since I am now thinking that downsizing is smart for my limited inverter needs, I am focused on the Giandel 2200-watt unit (the one without the built-in solar charger controller) instead of a larger 3000-watt unit. I'd love to throw my very limited budget to the wind and buy a supposedly higher quality $1000 unit, but, that's just not possible.

If I can get just two years from a Giandel, I'll be the proverbial very "happy camper."
 

acdoctor

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Other things to consider are you going to connect to shore power ever? With the inverter connecting to the power panel what will that look like? If you purchase a inverter with a transfer switch built in. That gets a lot simpler especially the ground neutral interface that you are struggling with. However most transfer switch inverters the shore power current rating is not as large as the inverter rating. Read and understand the documentation before purchase. I recommend drawing a wire diagram and submit it here for review, you can let all the smoke out of that new inverter.
 

12VoltInstalls

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focused on the Giandel 2200-watt unit (the one without the built-in solar charger controller) instead of a larger 3000-watt unit.
I’d give you a thumbs up.

The unit you’re considering: does it have 3-prong AC outlets? Or is it panel-feed/lug configured?
If AC outlets are present, this is what I did:
10ga high-quality “outdoor” extension cord plugs into inverter. The other end (female) is cut off and wired into a duplex box with a 20A GFCI outlet. I used an adapter to plug the 30A RV cord into that outlet which powers the RV through the OEM breaker panel. I do not have a ‘converter’ (sic).
That way I can use grid or a generator if ever I choose… however I neither have a generator nor have I been near grid power and the cord has not been unplugged in over three years, so…

Simple, cheap, safe.
The "proper" ground for the 120vac side of the inverter is the inverter case. Most inverters have a bolt/lug/screw to provide a place to make this "proper" ground connection. Using a RV OEM 120vac panel a triplex wire can be run from the inverter to the panel, black, white, green. The green goes to the inverter case. The green must connect to the RV chassis at the oem panel.
Proper depends… there’s a recent thread I cannot find atm where someone succinctly described how to determine how/where/if an inverter is ‘grounded’ or tied in the inverter to assure you’re not energizing the whole camper chassis. Generator applications, too. Maybe someone has a link?
The point is GFCI needs that green or bare wire path in place correctly to actually function.
 
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Zil

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Disclaimer. I am talking about a plain old inverter. Not a inverter/charger as found in many RVs. And Yes. a switch needs be installed to prevent having mains power connected at same time as inverter power, or generator power. This is why my inverter only powers certain outlets and shore only powers other certain outlets.
The 120vac created by the inverter can only reference back to the inverter. The inverter case is always the reference ground. We can be shocked connecting our hand from the hot to the case. Or if chassis connected, the inverter hot to chassis. If short circuit of hot to case then there should be a breaker to open. But a GFCI will protect you from shock from a shorted device. I think you are referring to an article about hot and neutral connections. Maybe by Mike Holt. Mike Sokol

No. GFCI compares the current moving through hot and neutral. It doesn't depend on the green ground circuit.
 
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chrisski

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This is the manual on grounding for my SAMLEX 12 volt PST 2000 watt inverter which has built in GFCI:

1632662142359.png
This is done with the grounding lug in the back:

1632662220714.png
 
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