Giandel 1200W Open Ground

[Supervstech]

Is there a non-destructive test to determine if the inverter will survive?

None I’m aware of.
Personally, if the inverter doesn’t have wiring connections, I wouldn’t try it.
Use portable inverters mobile, and hard wire optioned inverters for hard wiring.

 

[ejfluhr]

I have a Wagan inverter that just shuts down after ~2secs, learned when I plugged into a panel where neutral and ground were bonded. Took me a while and lots of on/off experiments to figure it out. No damage done to the inverter; I rewired the panel and it works just fine.

I'm hoping Giandel are higher quality than Wagan, i.e. should behave in a safe manner. At least, I just bought one so will be testing that out some weeks down the road.

 

[John Frum]

I have a Wagan inverter that just shuts down after ~2secs, learned when I plugged into a panel where neutral and ground were bonded. Took me a while and lots of on/off experiments to figure it out. No damage done to the inverter; I rewired the panel and it works just fine.

Did the gfci breaker on the inverter trip?

 

[ejfluhr]

Unfortunately the Wagan inverter doesn't have GFCI outlets. It is a cheap 400W MSW inverter I used to prototype a shed solar power setup. I just bought a 600W PSW Giandel to replace it. Hence why I was interested in this thread.

 

[John Frum]

Unfortunately the Wagan inverter doesn't have GFCI outlets. It is a cheap 400W MSW inverter I used to prototype a shed solar power setup. I just bought a 600W PSW Giandel to replace it. Hence why I was interested in this thread.

I'm trying to understand why the inverter shut down.

 

[ejfluhr]

I'm trying to understand why the inverter shut down.

It was due to the N-G bond at the 6-breaker electrical panel {someone else wired it, I didn't pay attention nor know enough about inverters at the time).
As soon as I disconnected the ground rail from neutral, it worked great. I presume the inverter has some internal test, as the shutdown seemed controlled and deliberate.

 

[John Frum]

It was due to the N-G bond at the 6-breaker electrical panel {someone else wired it, I didn't pay attention nor know enough about inverters at the time).
As soon as I disconnected the ground rail from neutral, it worked great. I presume the inverter has some internal test, as the shutdown seemed controlled and deliberate.

Sounds like an internal gfci.

 

[izmail]

Here is how an inverter output may look like - just one of many other possibilities.

I've also seen some schematics where filter capacitors ( they filter out high harmonics) connected to ground, like this

That is why voltage L-G and N-G could 90/30 or 100/20 or in case of capacitors ( they work like voltage divides) it is roughly 1/2 of output voltage.
And that is why Giandell says that grounding one leg may not satisfy their "Hi-pot " test since after grounding one capacitor is at full full line voltage times 1.4. BUT Floating output is not that bad, one need to touch 2 wires to get zapped. Actually most industrial 480 distribution systems are ungrounded. In my case to solve this grounding problem for my 2000w inverter I just installed ACME Single Phase, 240X480 - 120/240V, 2kVA transformer, grounded one leg and got myself NEC legal separately derived power source.

 

[Robkh]

Have Giandel 4000w inverter PS-4000QBR. Installed in off grid solar system in steel garage. Panel is earth grounded to a buried in concrete Ufer. Yet all my outlets test as “open ground”.
Earlier in the setup, neutral was bonded to ground somehow resulting in a short circuit, the Giandel shut down and I discovered the 200 amp fuse between the positive battery terminal to the positive input on the Giandel blew out. The fuse was replaced, the neutral bus was disconnected from the ground bus - all is well.

 

[12VoltInstalls]

Tha

Have Giandel 4000w inverter PS-4000QBR. Installed in off grid solar system in steel garage. Panel is earth grounded to a buried in concrete Ufer. Yet all my outlets test as “open ground”.
Earlier in the setup, neutral was bonded to ground somehow resulting in a short circuit, the Giandel shut down and I discovered the 200 amp fuse between the positive battery terminal to the positive input on the Giandel blew out. The fuse was replaced, the neutral bus was disconnected from the ground bus - all is well.

That’s because your inverter is not grounded. Giandel is N-G is usually open in the case and instructions indicate bonding through a GFCI outlet after the 120V output with smaller units. In your case 4000W exceeds the capacity of any GFCI outlet I’m aware of.

I would bond in the panel. Because you ate offgrid and are connected to dirt through the ground rod/plate I would make sure the panel is not directly electrically connected from/through the panel to the building by any mounting screws or contact and instead mount it to plywood. Then for safety the building can be grounded by an independent wire and pinch clamp(s) to the N-G connection inside the panel. @timselectric please confirm: is that correct?

 

[timselectric]

Correct, this system is not grounded. Grounding was removed by disconnecting the N/G bond. If it was blowing the fuse before removing the N/G bond, it was doing what it was supposed to do. Removing the protection from the system doesn't correct the issue. It only hides it until it finds a way to do harm or damage.
All is not well

 

[Robkh]

Thank you. My panel is mounted on a wood panel layered under 3/4 in cement board. The ground plug from the Giandel inverter is connected to the ground bar in the panel.

 

[timselectric]

Thank you. My panel is mounted on a wood panel layered under 3/4 in cement board. The ground plug from the Giandel inverter is connected to the ground bar in the panel.

But, the ground bar in the panel isn't grounded. So connecting to it serves no purpose. (As evident by your tester showing no ground)

 

[John Frum]

@Robkh https://diysolarforum.com/resources/grounding-made-simpler-part-1-ac-houshold-grounding.157/

 

[Robkh]

Thanks for the papers which I will review. My panel ground bus is connected to my 4 AWG copper Ufer ground wire.
Is there more grounding I should do or something else I am missing?

 

[timselectric]

Thanks for the papers which I will review. My panel ground bus is connected to my 4 AWG copper Ufer ground wire.
Is there more grounding I should do or something else I am missing?

That's just connected to earth. (Not a ground)
A grounding system starts at the N/G bond.

 

[Robkh]

I read the four papers including one on Inverter Grounding by Model - in that last paper, Giandel model has ground bonded to the AC out neutral inside the inverter.
All my outlets in metal boxes are grounded inside each individual outlet box.
When I put an AC system jumper between neutral and ground in my AC panel, that is when I had problems as there was already a N/G bond inside the inverter.

Are you recommending I establish another N/G bond in my outside panel where the ground bar is directly bonded and joined to the earth ground?

 

[timselectric]

Are you recommending I establish another N/G bond in my outside panel where the ground bar is directly bonded and joined to the earth ground?

Not if the inverter does it automatically. Not convinced that it does, according to your original post.

 

[Zwy]

I read the four papers including one on Inverter Grounding by Model - in that last paper, Giandel model has ground bonded to the AC out neutral inside the inverter.

Can you post up the documentation? I read the manual here https://m.media-amazon.com/images/I...20e790-75ee-4215-9a9b-b1784d20dde5.header_1.2 and on page 5 it states, "The ground terminal has already been connected to the ground wire of the AC output receptacle through the inverter."

That is not neutral according to that information.

When I put an AC system jumper between neutral and ground in my AC panel, that is when I had problems as there was already a N/G bond inside the inverter.

How did you test for it?

Are you recommending I establish another N/G bond in my outside panel where the ground bar is directly bonded and joined to the earth ground?

If the documentation clearly states N-G bond is internal, there is no need for another N-G bond. I did not find it in the manual.

 

[Robkh]

Thanks to @smoothJoey for the references - https://diysolarforum.com/resources/grounding-made-simpler-part-1-ac-houshold-grounding.157/
Previous posts on this subject with replies from Giandel imply that there is already an internal N/G bond and Giandel doesn’t recommend an additional external N/G bond.
So I decided to take @timselectric advice. I turned off the Giandel 4000 W inverter, opened my Subpanel and connected the Neutral bus to the Ground bus.
Voila - the “open ground” fault no longer shows on either the AC outlets on the inverter nor on my wired outlets from the Subpanel.
Everything works well.
Thank you for your advice and for the references.