EG4 Hand Cart 3,000watt Inverter Bonded Neutral/Ground

[Firebear Energy]

Hi DIY community!

I built this Portable HandTruck battery & inverter. 48volt EG4 Lifepower4 battery & the new EG4 3,000watt inverter. I later found out that the inverter has a Bonded Neutral/Ground that is causing me to have voltage on the entire handtruck frame and battery casing. About 22volts from the Positive terminal to the frame and battery casing and the same from the Negative terminal to the handtruck frame or battery casing. The only conductive connection from the inverter to the hand truck is the frame of the inverter and the 3 bolts that tighten it down to the unistrut. It has worked very well for a few days before I discovered that I had voltage across the entire frame.

Is there a way to properly ground this battery and inverter and keep it portable?
Can I remove the bonded neutral/ground in this inverter and properly have a separate neutral and a separate ground?
Do I need to get a different inverter?
How would you safely make this work and keep it portable???



I got the idea from my design here:

I am guessing he is using an inverter that does not have a bonded neutral/ground?

How does a Goal Zero Yeti 6000x inverter not need a ground?

Yeti 6000X

Equipped with 6,071 Watt Hours and seven versatile ports for power-hungry devices and appliances, the Yeti 6000X can power essential home circuits, RVs, trailers, work sites, and more. features YETI 6000X HIGHLIGHTS Goodbye Gas Generator. Hello Yeti X. With a lithium-ion battery at its core, the...

www.goalzero.com

My goal is to be able to use this as a portable battery and plug it into a reliance transfer switch to power my homes essentials off grid. Or if needed wheel it to my well pump and plug it into my well pump. Or take it camping and plug it into my toy hauler.

I am learning a lot and appreciate your input! Thank you in advance ?


Electric Regards,
?? Firebear

 

[jonnycoder]

I too am curious about this as I am interested in building a mobile cart.

Equipment grounding still confuses me, so does this mean a hot lead is touching the metal of the EG4?
Does the frame have voltage only when connected to PV?
Is AC input not connected to the EG4, thus providing a ground in the system to the main panel?

 

[73powerstroke]

Hi DIY community!

I built this Portable HandTruck battery & inverter. 48volt EG4 Lifepower4 battery & the new EG4 3,000watt inverter. I later found out that the inverter has a Bonded Neutral/Ground that is causing me to have voltage on the entire handtruck frame and battery casing. About 22volts from the Positive terminal to the frame and battery casing and the same from the Negative terminal to the handtruck frame or battery casing. The only conductive connection from the inverter to the hand truck is the frame of the inverter and the 3 bolts that tighten it down to the unistrut. It has worked very well for a few days before I discovered that I had voltage across the entire frame.

Is there a way to properly ground this battery and inverter and keep it portable?
Can I remove the bonded neutral/ground in this inverter and properly have a separate neutral and a separate ground?
Do I need to get a different inverter?
How would you safely make this work and keep it portable???

View attachment 99673

I got the idea from my design here:

I am guessing he is using an inverter that does not have a bonded neutral/ground?

How does a Goal Zero Yeti 6000x inverter not need a ground?

Yeti 6000X

Equipped with 6,071 Watt Hours and seven versatile ports for power-hungry devices and appliances, the Yeti 6000X can power essential home circuits, RVs, trailers, work sites, and more. features YETI 6000X HIGHLIGHTS Goodbye Gas Generator. Hello Yeti X. With a lithium-ion battery at its core, the...

www.goalzero.com

My goal is to be able to use this as a portable battery and plug it into a reliance transfer switch to power my homes essentials off grid. Or if needed wheel it to my well pump and plug it into my well pump. Or take it camping and plug it into my toy hauler.

I am learning a lot and appreciate your input! Thank you in advance ?


Electric Regards,
?? Firebear

The growatt. Has a disconnect. Will did a video about this

 

[Firebear Energy]

The growatt. Has a disconnect. Will did a video about this

I found the video. That makes sense. Is there a way to safely remove the ground neutral bond on the eg4 3000 inverter or do I just need to buy the grow watt that doesn’t have a ground neutral bond?

Here is the video if anyone is looking for it in the future:

 

[Firebear Energy]

I too am curious about this as I am interested in building a mobile cart.

Equipment grounding still confuses me, so does this mean a hot lead is touching the metal of the EG4?
Does the frame have voltage only when connected to PV?
Is AC input not connected to the EG4, thus providing a ground in the system to the main panel?

Hey Jonny,

It means that the neutral and the ground are connected/bonded “touching”
The frame has voltage anytime the battery is on. Even without PV connected. And for a little time after the battery is turned off even.

If you don’t hook up a ground with the EG4 inverter the electricity doesn’t have anywhere to flow, it then takes the path of least resistance and sends voltage onto the casing of the inverter which in my case is bolted to the frame of the handcart which is also conductively touching the battery making everything metal hot with around 22volts.

I do not have the AC input hooked up to anything.

More information on Bonded Neutral Grounds here:

 

[Zwy]

Hi DIY community!

I built this Portable HandTruck battery & inverter. 48volt EG4 Lifepower4 battery & the new EG4 3,000watt inverter. I later found out that the inverter has a Bonded Neutral/Ground that is causing me to have voltage on the entire handtruck frame and battery casing.

Just remember, power returns to source. If you create a parallel path between N and G, then G will have current.

About 22volts from the Positive terminal to the frame and battery casing and the same from the Negative terminal to the handtruck frame or battery casing.

You are referring to the Line terminal and it has voltage potential to the frame which is connected to G? It should have 120V AC, not 22V.

Positive/negative terminal is referred to with DC systems. So the question becomes, just what exactly are you measuring?

You need to use correct terminology in order to accurately discuss your "problem".

The only conductive connection from the inverter to the hand truck is the frame of the inverter and the 3 bolts that tighten it down to the unistrut. It has worked very well for a few days before I discovered that I had voltage across the entire frame.

In order to give accurate advice, we need you to use correct terminology.

Is there a way to properly ground this battery and inverter and keep it portable?
Can I remove the bonded neutral/ground in this inverter and properly have a separate neutral and a separate ground?

If you remove the grounding screw then how would ground fault detection occur?

N-G are bonded at the inverter under inverter power for the purpose of ground fault clearing, if there is a ground fault, then a breaker will trip.

Do I need to get a different inverter?
How would you safely make this work and keep it portable???

The inverter model will work fine, you need to show a diagram on how you wired it. You could just have a defective battery or inverter, we don't know for certain if you are measuring AC or DC voltage potential.

View attachment 99673

I got the idea from my design here:

I am guessing he is using an inverter that does not have a bonded neutral/ground?

How does a Goal Zero Yeti 6000x inverter not need a ground?

Yeti 6000X

Equipped with 6,071 Watt Hours and seven versatile ports for power-hungry devices and appliances, the Yeti 6000X can power essential home circuits, RVs, trailers, work sites, and more. features YETI 6000X HIGHLIGHTS Goodbye Gas Generator. Hello Yeti X. With a lithium-ion battery at its core, the...

www.goalzero.com

My goal is to be able to use this as a portable battery and plug it into a reliance transfer switch to power my homes essentials off grid. Or if needed wheel it to my well pump and plug it into my well pump. Or take it camping and plug it into my toy hauler.

Regarding a transfer switch, you would need to install a 3 pole double throw in order to switch neutral. This would be the same as installing a generator that has N-G bond.

I am learning a lot and appreciate your input! Thank you in advance ?


Electric Regards,
?? Firebear

 

[12VoltInstalls]

electricity doesn’t have anywhere to flow, it then takes the path of least resistance and sends voltage onto the casing of the inverter which in my case is bolted to the frame of the handcart which is also conductively touching the battery making everything metal hot with around 22volts.

It doesn’t take the path of least resistance- it’s always there. That’s something I learned (relearned?) here and something that makes perfect sense when you think about- electricity takes all available paths or any available paths the have a difference in potential and have some any means of being part of a circuit.

The real question is: is that 22V DC or AC? Everyone commenting seems to assume AC but 22V neither aligns logically with 48VDC nor 120VAC.

If DC it suggests a poorly conductive ‘leak’ either within the battery or your wiring. Test the amps with a jumper… see if it’s “something” or sub-milliamperes. Volts can be measured even across your body holding a wet nickel… but no current to speak of. Figure out what it is.

If AC voltage that’s a concern, imho.

One odd thing to look at: do you get voltage if cart is electrically isolated from dirt… no reason to specify but was a weird question that crossed my mind.

 

[LithiumSolar]

I went and checked my cart after seeing this thread. I too see ~20V DC when measuring between the inverter output ground and the positive or negative terminal of the battery. I also checked N+G with my meter and confirmed they are not bonded. This is not an international-version inverter.

Out of curiosity, I then went and checked my AIMS 10kW inverter (which is output N+G bonded) and I see ~40V DC from ground to battery positive (unbalanced 2000W load on inverter) and nothing to battery negative.

Lastly, I checked my LV6548 (with bond screw removed) and I see the same ~20V DC from inverter negative to both battery posts (with 2500W load).

I have not tried applying a resistor across to see if any current flows. Based on seeing similar on 3 different brand/model inverters and knowing none of them have battery conductors bonded to ground, I am going to conclude this is to be expected. I'm not an engineer and if someone has an explanation, would love to hear it!

 

[robby]

I have seen this video actually pop up on Google news.
So looking at this from an Engineering standpoint he has a high voltage Inverter and a battery bolted and grounded to a metal cart that is then insulated from Earth Ground by rubber wheels and a rubber covered handle.
If something happens, like a sprinkle of rain and power is being shorting to ground, there is nothing to absorb it except for the next unlucky person who touches any part of the equipment or the trolly.

 

[73powerstroke]

I guess the inverter could be mounted were it's isolated or floating. Alot of inverters have ac power on the ground pin. The 3 I have here all show ac voltage on the ground plug. And battery terminals. I made a quick video to show you. It's not just the case.
For amateur radio these things suck.

 

[12VoltInstalls]

I have seen this video actually pop up on Google news.
So looking at this from an Engineering standpoint he has a high voltage Inverter and a battery bolted and grounded to a metal cart that is then insulated from Earth Ground by rubber wheels and a rubber covered handle.
If something happens, like a sprinkle of rain and power is being shorting to ground, there is nothing to absorb it except for the next unlucky person who touches any part of the equipment or the trolly.

If it is AC. I think it’s DC battery but he needs to prove it

 

[12VoltInstalls]

The 3 I have here all show ac voltage on the ground plug

But what are the amps?

There was a thread last year where @Hedges or @superveestech or someone else explained that mystery 58V or whatever and pretty much stated it was not unexpected or a deep concern. I can’t recall exactly but it’s “half” of a sine wave

The OP seems to have voltage at an unexpected voltage

 

[73powerstroke]

But what are the amps?

There was a thread last year where @Hedges or @superveestech or someone else explained that mystery 58V or whatever and pretty much stated it was not unexpected or a deep concern. I can’t recall exactly but it’s “half” of a sine wave

The OP seems to have voltage at an unexpected voltage

There shouldnt be ac voltage on ground. Imagine if you wired it up to your house grid. And dumping electricity into the ground cant be efficient lol

 

[Zwy]

I went and checked my cart after seeing this thread. I too see ~20V DC when measuring between the inverter output ground and the positive or negative terminal of the battery. I also checked N+G with my meter and confirmed they are not bonded. This is not an international-version inverter.

Out of curiosity, I then went and checked my AIMS 10kW inverter (which is output N+G bonded) and I see ~40V DC from ground to battery positive (unbalanced 2000W load on inverter) and nothing to battery negative.

Ran across this gem regarding AIMS. https://diysolarforum.com/threads/how-does-your-inverter-deal-with-ground.17138/post-326876

Lastly, I checked my LV6548 (with bond screw removed) and I see the same ~20V DC from inverter negative to both battery posts (with 2500W load).

Bond screw removed. The case is no longer referenced to ground.

I have not tried applying a resistor across to see if any current flows. Based on seeing similar on 3 different brand/model inverters and knowing none of them have battery conductors bonded to ground, I am going to conclude this is to be expected. I'm not an engineer and if someone has an explanation, would love to hear it!

If your multimeter has the amps function, it will suffice as the leads create a path.

 

[Zwy]

I believe part of what is being seen for the AC voltage on the battery terminals is the ripple effect of the switching of the HF inverter to create AC current. This switching causes a ripple of battery DC voltage which many interpret as AC voltage.

Two things can reduce the ripple effect. A larger battery bank will reduce the fluctuations as more cells will smooth out the DC voltage. Some inverters specifically state to use a minimum size battery bank to achieve this. Second would be use of a capacitor to smooth out the dc voltage waveform.

 

[Zwy]

For those more curious about this subject, read this post: https://diysolarforum.com/threads/how-is-inverter-bus-capacitance-chosen.32877/post-402743

One thing that can have a huge effect is battery cable routing and if the cables are taped/tied together to reduce inductance ringing.

 

[LithiumSolar]

Ran across this gem regarding AIMS. https://diysolarforum.com/threads/how-does-your-inverter-deal-with-ground.17138/post-326876

The 10kW AIMS is low-frequency inverter. It seems like that post is referring to a high-frequency inverter. I have a "Reliable" brand inverter that does the 60/60 thing but that's not one of the 3 that I tested.

Bond screw removed. The case is no longer referenced to ground.

The screw that was removed from the LV6548 (per the advice of MPP Solar's customer support) was for the neutral + ground bond. So yes, the case is still bonded to ground.

 

[12VoltInstalls]

believe part of what is being seen for the AC voltage on the battery terminals is the ripple effect of the switching of the HF inverter to create AC current

There shouldnt be ac voltage on ground. Imagine if you wired it up to your house grid. And dumping electricity into the ground cant be efficient lol

powerstroke: what a meter can ‘see’ VS what is affective cannot be assumed to be equal. That’s why you use a jumper and study the current characteristics before drawing a conclusion- on one hand it could be “nothing” while on the other hand if it is “something” it could dangerous.

What stands out to me is that everyone seems to be assuming an escaped AC inverter voltage but I’m not convinced. A Giandel I have had voltage like you show but after testing it doesn’t ‘go’ anywhere, no amps. Maybe if I licked it it would shock me but I didn’t take the risk of attempting that particular test…

 

[73powerstroke]

powerstroke: what a meter can ‘see’ VS what is affective cannot be assumed to be equal. That’s why you use a jumper and study the current characteristics before drawing a conclusion- on one hand it could be “nothing” while on the other hand if it is “something” it could dangerous.

What stands out to me is that everyone seems to be assuming an escaped AC inverter voltage but I’m not convinced. A Giandel I have had voltage like you show but after testing it doesn’t ‘go’ anywhere, no amps. Maybe if I licked it it would shock me but I didn’t take the risk of attempting that particular test…

I thought the more expensive stuff didn't have this issue? I'm not sure it's important for non sensitive electronics. My so called pure sine makes things run funny. Go figure

 

[Zwy]

The 10kW AIMS is low-frequency inverter. It seems like that post is referring to a high-frequency inverter. I have a "Reliable" brand inverter that does the 60/60 thing but that's not one of the 3 that I tested.

Still, there has to be switching in order to produce AC power from DC. I believe you are seeing the voltage ripple of the DC circuit from the switching.

The screw that was removed from the LV6548 (per the advice of MPP Solar's customer support) was for the neutral + ground bond. So yes, the case is still bonded to ground.

If the case is still bonded to ground, then the case should be at zero voltage potential as it should be earthed........

Again, you seeing the voltage ripple when measuring the case voltage to the battery.