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How does your inverter deal with ground.

Thanks again. I'm now more confident my setup has a lower risk of electrocuting my family while burning the house down.

Always more to learn. I'd love to get some sort of official training in systems like this, but the only way seems to be a four year apprenticeship. Not really practical while working full time. Maybe it's time to look at online engineering degrees.

There are for-profit schools offering one or two year programs in various technician and nursing fields, for about $30,000.
Similar programs in junior colleges, for a lot less money (but popular programs are sometimes full.)

Universities like Cal State have more advanced programs at higher cost than a J.C. but cheaper than (officially) for-profit schools. Easy enough to qualify to be admitted. The big universities are more selective. But both kinds will let people take some classes without being admitted, space available. (Even Stanford, but you have to pay for a full load even if only taking one class.) Berkeley, I noticed undergrad quantum physics was always full, but graduate level had space available. (If I'd had the initiative to self-study and master the undergrad I might have considered attending. The units could have counted toward a degree I got elsewhere.)

But if you just want to learn, not get a sheepskin, check out "MIT Open Courseware", video of lectures and copies of assignments. Based on prior year texts, which you can find on Amazon much cheaper than this years texts.


Or if you want a degree, maybe your employer will pay?

I went full-time to SJSU during my year of unemployment, then took one or two classes at a time, often skipping a semester, until I finished. (Tuition covers 2 courses, more costs extra. Can skip a semester without being dropped.)

Some big employers even pay the university to teach a tailored program on-site (about triple the tuition cost.)
 
This thread comes at a good time, as I recently installed a Samlex PST-2000-12 inverter (hardwired to a Samlex STS-30 transfer switch) in my van. The setup works fine on both shore and inverter power, but I would not mind confirmation with regards to grounding.

The Samlex manuals are quite detailed and I followed them the best I could. The inverter does have internal neutral-ground bond, and the manual specifically describes how to connect both the devices (section 8.6 in the inverter’s manual).

So in the van, the inverter is hardwired to the transfer switch, which is wired to the breaker panel, which feeds only GFCI outlets. To have a single grounding point, the only grounding connection I have is through the inverter’s ground lug, to the chassis.

Is this correct?

TIA
 
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There are for-profit schools offering one or two year programs in various technician and nursing fields, for about $30,000.
Similar programs in junior colleges, for a lot less money (but popular programs are sometimes full.)

Universities like Cal State have more advanced programs at higher cost than a J.C. but cheaper than (officially) for-profit schools. Easy enough to qualify to be admitted. The big universities are more selective. But both kinds will let people take some classes without being admitted, space available. (Even Stanford, but you have to pay for a full load even if only taking one class.) Berkeley, I noticed undergrad quantum physics was always full, but graduate level had space available. (If I'd had the initiative to self-study and master the undergrad I might have considered attending. The units could have counted toward a degree I got elsewhere.)

But if you just want to learn, not get a sheepskin, check out "MIT Open Courseware", video of lectures and copies of assignments. Based on prior year texts, which you can find on Amazon much cheaper than this years texts.


Or if you want a degree, maybe your employer will pay?

I went full-time to SJSU during my year of unemployment, then took one or two classes at a time, often skipping a semester, until I finished. (Tuition covers 2 courses, more costs extra. Can skip a semester without being dropped.)

Some big employers even pay the university to teach a tailored program on-site (about triple the tuition cost.)
Plenty to think about. I am in Australia. Most of our universities derive most of their funding from international students. Since the borders closed, this has almost totally collapsed so I suspect these institutions will be much less selective about who they take. My day job is teaching high school engineering and related technical subjects, so there is a chance my employer would be supportive.
 
I have an AIMS 24vdc to 115vac 1500W/3000W pure sine wave. I have been having an issue do to it being under powered, unrelated to this thread but during the course of troubleshooting the problem I discovered that a circuit checker indicates an open ground. AIMS Tech Support says that is a normal reading as the neutral line carries voltage, (I didn't get the value), and must be left to float from ground. He also said that connecting the neutral to ground would damage the inverter.
Same problem here, just got my new AIMS 48v 6000w inverter last night, hooked it up, saw the open ground. So I thought, oh I'll just bond the ground-neutral externally. Emailed Aims to make sure that's okay, and good thing I did because I got this reply:

"You CAN NOT bond the neutral and ground on this inverter as it is a high frequency style inverter and creates 60V on the neutral and 60V on the hot line. Bonding these will force the power to the hotline and cause damage to the inverter that is not covered under warranty."

So now I have to waste hundreds of $$$ on shipping and "restocking fees" to return this garbage, and get something with a real 120 hot wire, and that can be bonded properly.
 

EPEVER UP3000-HM10022
Hybrid Inverter

Just Been through this exact same senario with Epever, initially contacted them about their output Neutral Ground /Earth bonding and after confirming its suitability i found out that infact when supplied by a Mains TNC-S supply( Neutral Earthing bond at the Main switchboard ) operating in Bypass Mode the earthing system configuration passes through to the output correctly', but when placed in inverter mode the inverter output creates an IT system /isolated supply -unbonded system , therefor in Australia the outputs downstream RCD protection would not be configured correctly for correct operation as its looking for a TNC-S supply

In simple terms the output should be neutral earth bonded but cannot be because when in bypass it already is and then placing a second neutral earth bond at the output places this in parallel to the first, should the inverter supply be by a RCD / GFCI circuit then nuisance tripping will occur whilst protective earth would share load current with the neutral that's not permitted

So moral to this story , understand your local standards and the accepted earthing system to be employed , because there are a multitude of earthing systems and the language varies by country , ie GFCI,RCD, Neutral Earth Bonded, MEN system , TNC, TNCS , IT , Earthing Conductor , Grounding Conductor, being very clear with your inverter supplier of what you require in the manuals i have read, this topic is definitely not clear when you start dealing with Clone type inverters and Languages or in Australia we say the Lingo

The solution to the above is now not that easy , an inverter with a configurable earthing system is what's required or a system as shown in filter guys inverter drawings where the output is automatically reconfigured, please look at the variances and i congratulate the Filter Guy for trying to clarify and hope i have added some further incite
 
Anyone has info about Solark / Deye configuration=?
The manual does not explicitly describe the grounding and bonding, but from what it does say I am pretty confident in the following:

1) The SolArk does *not* create a Neutral-Ground Bond in any situation.
2) The Neutral is common throughout the system. (there is no difference between AC neutral in and AC neutral out)
3) The Ground is common throughout the system. AC Ground in, AC Ground Out, and the Sol-ark chassis are all tied together.

For a home installation, the sol-ark is pretty straight forward. For a mobile situation, there is a need to create a Neutral-Ground Bond when not on shore power. Conversely, when on shore power there should not be a bond. This could be done with a 120V relay that is powered by shore power.

Here are a few things from the manual:

1630115410734.png

The requirement that the Solar PV is not grounded is because the built in ground fault protection is providing grounding of the PV circuit. However, the frames of the panels still need to be grounded (See below)

1630115484530.png
Notice that in the diagram above, the loads and the Solark are both tied to the main panel neutral bar.

1630115525267.png

The following is in a section about wiring the solar panels
1630115625921.png
 

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@FilterGuy I've read your 2nd paper, and you may recall me as the guy trying to figure out a grounding issue with the MPP LVX6048 on another thread. Setting that aside for a moment, and assuming (yeah I know, don't say it) that their wiring is like SOL-ARKs given the also have you connect both neutral & ground to both AC input & AC output sides. Does the following seem right. I've never bothered to ground my Battery before or my PV input lines.

Please take a look and offer any feedback you think appropriate.

I appreciate all you do here sir, you're willingness to give is inspirational

Thanks in advance
 

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Mostly correct..... but....

1630187144572.png

A small nit: I would draw (and implement) the wire that is grounding the DC as green and connect it to the grounding bus. In your setup it is electrically equivalent but if you use a white wire and connect it to common, it might be confusing to anyone looking at the system.

I found this in the manual:

1630187900767.png

Many/most of the all-in-ones have built in PV Ground fault protection these days and I am pretty sure the 6048 does as well. You should NOT connect the PV- input circuit to ground (The PV circuit will be grounded by the internal ground fault protection and doing another external ground connection will probably either disable or trigger the internal ground fault protection)

As is the case with most manuals from MPP, they say precious little about how it handles grounding. Therefore I can not say for sure if the battery circuit is grounded internally or should be grounded externally. (NEC does require 48V battery circuits to be grounded) My working assumption is that it should be grounded externally as you kinda show.

The documentation also does not discuss bonding so I can't say for sure what should or should not be done for N-G bonding on the critical loads panel. My working assumption is that it should *not* have an N-G bond.

BTW: I assume your 200A main breaker panel is tied to earth ground. That should be the only place in the system that gets tied to earth ground. (Do not tie the critical loads box to a separate earth ground.

BTW2: The neutral bus in the critical loads panel must be electrically isolated from the metal box of the panel. The metal box of the panel should be tied to the grounding circuit.
 
I think grounding is necessary if you're using RCDs
There are a few scenarios where an RCD/GFCI would still trip without an earth ground....They all center on power going from the hot wire to the equipment grounding system (The 'ground wire') that is not connected to earth ground. However, it is also true that there are a lot of cases that are not covered if there is no earth ground.
 
Anyone do the testing for any of the GroWatt inverters yet?
Following this thread myself with my GroWattSPF3000. I don't have the GW grounded directly, don't think there is an option/lug for it. However, I do have it connected to grid via AC IN with Hot/Neutral/Ground. Testing output from device with an open ground plug tester, everything seems to be fine (according to $10 tester from Home Depot) in both direct grid power mode and inverter mode to AC OUT.
 
My 1000W inverter is in my shed, so to ground it, I have to create a ground by burying some pipe in the earth (earth ground) and have proper wire (14AWG) BUT I'm curious about something, I've only ever plugged in appliances/devices the do NOT have a ground prong, i.e. only 2 prong...so would having a ground even benefit this situation? I'm on the fence as to where I should make a ground.

If I decide to ground (or if it recommended) what would a proper earth ground be in this case? a 6ft copper pipe (hollow or solid? and what diameter)...thanks!
 
Same problem here, just got my new AIMS 48v 6000w inverter last night, hooked it up, saw the open ground. So I thought, oh I'll just bond the ground-neutral externally. Emailed Aims to make sure that's okay, and good thing I did because I got this reply:

"You CAN NOT bond the neutral and ground on this inverter as it is a high frequency style inverter and creates 60V on the neutral and 60V on the hot line. Bonding these will force the power to the hotline and cause damage to the inverter that is not covered under warranty."

So now I have to waste hundreds of $$$ on shipping and "restocking fees" to return this garbage, and get something with a real 120 hot wire, and that can be bonded properly.
Another popular inverter (only because of the cheap price) is the high-frequency Reliable WZRELB. Most will measure a floating 60V hot-ground and 60V neutral-ground, as was tested on my 48V 2500W.

As a test I back-fed my house breaker panel by terminating all three leads, effectively bonding the inverter neutral and grounding the case. However I temporarily connected a neutral inline 5A fuse in the event of a 60V short. Worked just fine, no smoke and did not blow the 5A fuse after loading to around 4.5A. Since then I have pushed the WZRELB hard multiple times, especially during the great Houston freeze where it ran my furnace to keep the pipes from bursting. No problems so far with the grounding.

I always connect the inverter to the breaker panel first before powering it on. Maybe AIMS felt the connection sequence would be a liability.
 

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Another popular inverter (only because of the cheap price) is the high-frequency Reliable WZRELB. Most will measure a floating 60V hot-ground and 60V neutral-ground, as was tested on my 48V 2500W.

Do you think AC output is galvanically isolated from battery, or not?
Measure AC voltage from ground to battery negative terminal, and to positive terminal. I'm thinking depending on how it is designed, it might drive one of those to 60Vrms (and the other higher due to DC riding on top of that.)
 
Maybe AIMS felt the connection sequence would be a liability.
Yeah, could be. What I didn't mention in my original comment (or to AIMS) was that I actually *did* bond its ground and neutral and ran it for a while. It seemed fine. But after I getting their dire earnings against it, I decided I didn't want to deal with it blowing up at some later point and them not covering the warranty.
 
Hi, folks.

I've measured my solar inverter VM II PLUS 5500W and this is the typical installation at home. (simplified... really)
Does everything seem normal at first glance? I'm confused about the N-G bond at the inverter (and why the bond "oscillates" between AC-IN and AC-OUT terminals, regarding the BYPASS or INVERT mode?) . This way it's making a second one. (I already have one bond at mains enclosure)
After discussing this installation, I will have one more important question for different scenario, if I may ask.

The yellow lines indicate the internal physical connections in the inverter itself, between the terminals.

TN-C Inverter.jpg
 
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