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Giandel 1200W Open Ground

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life passes by too quickly to not live in freedom
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^PIC: “open ground” lit (open N looks lit in pic but it is not)

I have been reading with interest the several discussions regarding inverter Neutral - Ground bonding either present or missing.

It occurred to me I couldn’t recall actually testing this on my inverter. I had ordered and received the fluffy-priced Klein circuit/GFCI tester a while back and decided to try it today.

Installation is in a 26’ RV with the 30A RV cord plugged into a GFCI receptacle that is fed from a Giandel PS-1200JCR 1200W pure sine wave inverter.

First thing is “open ground” both at the inverter (with nothing plugged in) and at a ‘kitchen’ receptacle with the cord plugged back in to the inverter. That bothered me.

So I got out the VOM and tested the inverter with these results:
- receptacle G, -12V, and inverter chassis are connected
- H to G is 58.3VAC
- N to G is 59.5VAC
- 118.3V between N and H
- with inverter OFF N to G has no continuity

However, as second pic #2 shows “hot/neu reversed” i retested using ohms (inverter off) using the H leg and
- H to G has no continuity.

GFCI did not trip when I hit the test button on the Klein (although it’s integral test button does trip it).

Questions:
1) how the heck do I get 58V N or H to G if they can’t “see” G according to Klein?
2) should I reverse the L and N inside the Giandel?
3) soooo…do I (since actual shorepower will never ever happen) create a bond in the RV panel? Or
3.1) …join them in the inverter which may not be ‘supported’ (as the other thread muses) and risk emitting factory smoke?
4) is L and N (H & N) being reversed the reason why the GFCI test feature of the Klein did not trip the GFCI? This I don’t understand.

Pretty annoying about this.
 

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Do you have a true earth ground connected to the Inverter?
 
View attachment 75888

Questions:
1) how the heck do I get 58V N or H to G if they can’t “see” G according to Klein?
I suspect it's just an induced voltage from internal circuit board that is causing you to read 58V on the Ground.
It could also be the tester itself passing some voltage through a very high resistor from N-G and since it is not grounded your able to measure it.
The voltmeter is sensitive so it will pick it up but if it had any serious current behind it you would feel a shock.
As far as I know the ground connection on those small Inverters is just connected to the physical case.
The manual states on page 5 it must be grounded to earth or the vehicles Chassis.

2) should I reverse the L and N inside the Giandel?
No.
3) soooo…do I (since actual shorepower will never ever happen) create a bond in the RV panel?
Yes run a ground wire from the Inverter case to the Vehicles Chassis
Or
3.1) …join them in the inverter which may not be ‘supported’ (as the other thread muses) and risk emitting factory smoke?
No I would not do that.
4) is L and N (H & N) being reversed the reason why the GFCI test feature of the Klein did not trip the GFCI? This I don’t understand.
Because there is no current imbalance between the Hot and Neutral wire. Also those testers require that a ground be present in order for them to trip and work properly.
GFCI needs to
Pretty annoying about this.
 
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I have the same tool in my truck, and it is designed for grid connected home wiring. It isn’t really helpful with rv stuff…
I would connect a load to the inverter, and retest voltages to see if N to G voltage still is present, and I would certainly bond the chassis of the inverter to the chassis of the vehicle.
 
Yes run a ground wire from the Inverter case to the Vehicles Chassis
That’s been in place since day one. G, inverter case, and Batt(-) are all showing continuity between them.
could also be the tester itself passing some voltage through a very high resistor from N-G and since it is not grounded your able to measure it.
The voltmeter is sensitive so it will pick it up but if it had any serious current behind it you would feel a shock.
VOM meter shouldn’t have any ability to be ‘passing some voltage through’ right? Nothing was connected to the inverter other than VOM leads.
As far as I know the ground connection on those small Inverters is just connected to the physical case.
It appears to be but I fully expected N and G to be connected in the inverter. I guess I made the mistake of assuming it was.
I would connect a load to the inverter, and retest voltages to see if N to G voltage still is present
Will do that and report back
, and I would certainly bond the chassis of the inverter to the chassis of the vehicle.
It is. Once through the case ground terminal and you could say “a second time” via the inverter’s batt(-) cable.

Honestly I was startled by this. I thought I went through this when I installed it but maybe I just thought about it.

2) should I reverse the L and N inside the Giandel?
I feel like this is a confusing issue. How the heck are these reversed? “My” wiring is obviously fine because I get the same results directly at the inverter (with nothing connected to its 120V outputs) and at an outlet in the kitchen when reconnected.

I apparently don’t know enough to:
1) understand L and N being reversed at the inverter (that’s how it came from the manufacturer)
2) comprehend how the Klein GFCI test feature didn’t trip the GFCI. I need to find my $5 GFCI tester that just crosses internally or buy another one. I’m not sure the wizardry of the Klein is giving me a good test (if that’s possible)
 
Giandel sent the following responses.
I’ll quote my correspondence to them and then post their responses.

“…Here is the problem: I have a 1200W ‎PS-1200JCR inverter. It’s been running great.
For other reasons I recently plugged a Klein GFCI tester into an RV outlet. It indicated Neutral and Hot were reversed which surprised me. I initially thought I made a mistake (very unlike me in this circumstance) but with nothing else connected the inverter itself produced the same result.
It also showed an open ground- not bonded.
These are each safety concerns, are they not?

Should I remove the case and reverse the Nuetral and Hot connections?

And what about the neutral / ground bond?”

Response1
“Hello, I understand your concerns now, so many users have the same query when they use the tester to test the ground.
But in fact, the grounding tester is only suitable for city power, it will always show OPEN GROUND and give your FAULT indicator when you test any inverters.
A receptacle, or AC outlet, tester plugged into a Giandel Power inverter indicating an "open ground" fault. It's impossible to get this indicator to shut off unless connected to a metal rod in the Earth, which is impossible in a boat and/or car that's moving.
When using a power inverter on a boat or RV, the tester will indicate an open ground fault. This is because it is not connected to a “true Earth ground”, meaning it is not connected to a metal rod stuck in the Earth. It would be impossible to do so in a boat or car while moving. For this reason, certain appliances and/or tools cannot be used while boating or driving. The power inverter DOES NOT and cannot create a true Earth ground on its own. However, the input electricity is partially grounded out by the negative DC connection and by mounting the inverter to a metal frame. These two safety precautions ensure the ability to use most of the appliances desired for a boat or RV. This is why it’s still okay, and standard practice, to use inverters in boating and RV applications.
City power is always grounded to a true Earth at your house, but if you're in an RV, boat or something mobile, it’s not going to have a true Earth ground. That's okay — just know that some devices need an Earth ground to work, such as the new, big, stand-up refrigerators.
Hope these will be helpful for you.
All the inverters have to be like this when you use a grounding tester to test it.
So it is normal, please don't worry.”


Response2
“Inverter's grounding design is different with City Power, it is a separate power system, it can not be same as city power to connect the GN to earth from somewhere.
If you want the tester show "GROUNDed",that is also possible, just connect the inverter's LN to Ground terminal, but this is dangerous, will cause electric shock,also can not pass HIPOT testing. Unless you use a GFCI socket to connect the inverter's Neutral and ground. Please see the connection on the following picture:”

0DAFD990-18F1-4571-92B6-636E5C89276D.png
“About neutral and hot being reversed--- because the inverter's AC outlet is not a GFCI socket, the GFCI tester can be only suitable for testing a standard GFCI socket.”
 
Odd that it is showing neutral and ground reversed. I don’t know if they are correct.
 
Odd that it is showing neutral and ground reversed. I don’t know if they are correct.
Yes because I get the same result after the GFCI, in the GFCI and at the inverter. They said this:
“…because the inverter's AC outlet is not a GFCI socket, the GFCI tester can be only suitable for testing a standard GFCI socket…”
And then followed up by instructing me to connect the neutral and ground together at the GFCI.
Which is different than the diagram they sent which shows N/G connected in the panel and the ground not connected in any way at the GFCI.

The also said my GFCI tester won’t work because I don’t have a earth ground rod. Which makes no sense; the tester doesn’t know where the bare/earth/ground originates. But if I follow the first instruction/diagram and connect N/G in the panel because neutral and hot are reversed then is not G energized? Same with connecting at the GFCI.

I have not heard back yet after they said they need their engineer to review my questions. I sent this:
“…the diagram you sent shows the Neutral and bare/Ground connected in the panel. So because N and H are reversed a) this would make the G energized if connected at the GFCI (or the panel) and b) it would then be incorrect if connected in the panel and the shorepower cord was plugged into a mains power socket….Please provide a diagram of connecting N and G at the GFCI because my diagram (that I sent) is exactly my installation and is an electrical circuit identical to the drawing you sent to me (although your diagram left off the GFCI ground screw connection)”

I’m not obsessing for no purpose. I figure their answer will be useful to others.

Maybe because I don’t know everything there is to know - but I don’t get how modifying the inverter internally by bonding N and G is electrically any different than connecting them downstream after 7- or 8’ feet of wire.
 
Odd that it is showing neutral and ground reversed. I don’t know if they are correct.
I will explore that further.
I’m going to implement Giandel’s most recent instruction which is the attached diagram.

However, before I do that I’m going to power-down everything, disconnect the inverter from the GFCI, pull some continuity to chassis/batt(-) from various 120V devices including the panel, and confirm there is no ‘resident’ N to G bond. While I’m pretty sure I did that four years ago I don’t specifically remember.E4466BA0-845D-489B-BCB8-50680E159550.jpeg

I sent them this henscratch to confirm their instruction. Not because I’m unsure but because I’m disconcerted over their several different recommendations for the same singular question. I see no difference between the following circuit and establishing N/G bond within the inverter. A recent similar thread covered some of this 4FCC739F-C074-4C2F-A15B-BE34A2AC5676.jpeg
would connect a load to the inverter, and retest voltages to see if N to G voltage still is present
I still need to do that - and before anything else gets changed just for curiosity and ‘the record.’
 
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I will explore that further.
I’m going to implement Giandel’s most recent instruction which is the attached diagram.

However, before I do that I’m going to power-down everything, disconnect the inverter from the GFCI, pull some continuity to chassis/batt(-) from various 120V devices including the panel, and confirm there is no ‘resident’ N to G bond. While I’m pretty sure I did that four years ago I don’t specifically remember.View attachment 78040

I sent them this henscratch to confirm their instruction. Not because I’m unsure but because I’m disconcerted over their several different recommendations for the same singular question. I see no difference between the following circuit and establishing N/G bond within the inverter. A recent similar thread covered some of this View attachment 78041

I still need to do that - and before anything else gets changed just for curiosity and ‘the record.’
Your drawing has neutral and hot reversed on the outlet…
 
Your drawing has neutral and hot reversed on the outlet…
Geesh that’s freaking embarrassing. ?
Total oversight on my part. And I copied the mistake on my second hensketch. >rolleyes <

You’ll notice on the diagram they marked up that I ‘corrected’ H and N on the sketch. I don’t know why I thought it was wrong; it was late at night when I sketched that and I even drew the prong inlets correctly! On paper it served it’s purpose.

Nevertheless, the GFCI in place is correctly wired white to silver, black to gold.

How’s your ADD? Mine’s doing GREAT!!
 
connect a load to the inverter, and retest voltages to see if N to G voltage still is present
And it is.
~58VAC on both H and N to G.
Ran coffeemaker; inverter battery cables read 62 amps with the clamp meter which is a pretty decent load for a 1200W inverter.

I also verified the cord G is open to chassis(batt(-) as well. (And checked N and H for entertainment value)

I’m going to rearrange my battery cables first now that I have everything for that. Then bond at the GFCI.

I am actually relocating all the various components using the dubious “piece of plywood” method anyway, so probably will move the GFCI box and mount it right next to the inverter and wrestle the 30A cord out of the cabinets. The 30A cord hasn’t been plugged into grid for 4 years so I don’t think that’s an issue.

I don’t like that, however. Not very professional looking and it would bother me forever. I don’t have a hank of 10-3 on hand or I’d use that and install the glorious transfer switch @roadtoad installed. I’ll probably never use it but my install would be cleaner and having options is nice.
 
If I'm not too late, whenever I have had a "Gremlin" running loose in a system I always tried to get the gremlin before any other changes were implemented.
May sound strange but you may just give it somewhere else to hide.;)
 
Which gremlin are you referring to; the reversed H and N, or the GFCI not testing out?
 
I did not get the ‘bond’ done. A bunch of other stuff and setting up panel string breakers, and hours wrestling the old 2/0 cables out. Eventually won with dish soap and a sawzall.

Got the new longer 2/0 cables fished to get the inverter off the floor and onto the wall. Terminal blocks installed. PV cables installed. Now I only have a pair of 2/0 and the battery temp sensor leading outside; the SCC, 12V panel, and RV power are all served at the inside busbars.

Weird thing: I discovered I could crimp the 2/0 terminal ends with the 1/0 max hex crimper. I progressively swaged the ferrule by rotating it 5 or 6 times and partially crimping each time, then finishing. No “wings.” Not ideal for time but I think it came out better than the hammer crimps do.
12 crimps at 2/0; 7 at 2ga.
I’ll buy a decent 2/0 crimper someday but how often would I need it? I haven’t really done anybody else’s stuff since covid began and my job doesn’t leave time to moonlight anymore.

Giandel’s latest communication:
“Thank you for your patience of our discussion, now this newest wire diagram is correct! If you have any further query still need our help , please let us know.”
No mention of my mislabeling. Ahem.

Once N/G bond is done and proper GFCI operation is verified I’m going to figure out/troubleshoot the “reverse hot / neutral.”
Unfortunately- other than one EE- in my friend group I’m the most electrically competent. One electrician I know professionally isn’t familiar with off-grid, and haven’t talked again to the other.
However, the opinions were as mine: that either the inverter has to be wired wrong from the factory, or that it may “correct itself” once G is at the same potential as N. Either way these guys think the Klein tester can’t know if it’s testing grid/mains circuits or an RV circuit. The electrical principles are the same.

Dunno. I figure there’s 3 possible outcomes. It will fix itself, or I’ll need a fire extinguisher, or it will still read reversed.
 
Basically your inverter is giving you a floating 110v referenced to nothing. The ground lug is connected to the metal case, nothing else. You might as well connect it to a potato for all the good it goes. You cannot think of it like your house supply. Just like holding a 9v battery up in the air. The terminals have voltage and anything you connect will light up and work.
110v will hurt you but not likely kill you. I'm wondering if you would even feel it if you grabbed only 1 wire.
RV's are a tricky subject when it comes to power. Safest option should have been 24/48 volts DC from day 1.
 
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Which gremlin are you referring to; the reversed H and N, or the GFCI not testing out?
Sounds like you have begun disassembly/reassembly already so some of this may not be valid.
I was thinking about the open ground as well as 58 & 59 volts running around where it shouldn't be.
Company's replies were not exactly comforting either.

Hot & Neutral ?
Is that an actual issue, is it still testing inverted, or is it just a mistake on the drawings? I don't think I will ever understand that.

Then there is the GFCI test. Is that a result of one of the aforementioned issues?

Perhaps taking it apart and putting it back together is the best idea.
It would be a perfect world if Company could give you straight answers that make sense before reassembly. It's not their first rodeo, they should be able to provide diagrams to solve every problem.
I do not see "this newest wire diagram" which company mentions prior to your "Ahem" in post 16.

Was just throwing an idea out there.
 
Hopefully I won't confuse things more, here goes...
- H to G is 58.3VAC
- N to G is 59.5VAC
H is the un-grounded conductor
N is the grounded conductor
G is the grounding conductor

Bonding N to G makes the potential difference between N and G 0 volts.
Which makes the potential difference between H and N 120 volts.
Logically the potential difference between H and G should also be 120 volts.

Sound reasonable?
 
Hopefully I won't confuse things more, here goes...
Sound reasonable?
Yep, sounds perfect to me.

So "Splain this one to me Lucy", where the heck is 58 & 59 volts coming from. I've chased weird gremlins like that before. Sometimes find them, sometimes not. ?
 
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