MPP Solar LV5048 Bonding & Grounding question.

[SolarBro]

Thanks SolarBro.

I was wondering if this would smoke the inverter but obviously not when it went off grid and went to solar.

Does your AC OUT go to loads (sub)panel. and does your loads panel have its own earth ground or did you just tie into the grid service ground bar?
Our camps have their own 60 amp grid panel installed. Really basic and old. Never upgraded to to 100 amp because the loads are light in these camps. But the camps use alot of power over the year and a small solar will cut the operating costs down over the decade. I had solar in for years but its ancient and needs upgrading.

I'm just going to use a 15-20amp 120v service to feed the 1012LV's.
I appreciate your picture.
Thanks

I used my existing service panel ground bar, ran a 6awg over to my critical loads panel ground bar that tied them together.

 

[jimjones26]

@SolarBro if I may ask a question. I have a completely off grid setup, no grid service at all. We are in an RV. For my AC Input I am using a generator, wiring a 50 AMP input plug, running wire from the plug to a 40 AMP load center, and then running from the 40 AMP load center into the AC Input on the LV5048. For the AC Output on the LV5048, I am running from the inverter to a 100 AMP main lugs load center with a 50 AMP service breaker. From the 50 AMP service breaker I am running to a 50 AMP outlet.

I will plug in a 50 AMP RV cable from the 50 AMP outlet coming from the Inverter into the 50 AMP input on the RV.

There obviously is no grounding rod yet, so I will install one of those next to the RV. My question is, because there is no grid service Main panel with grounding, how do I go about grounding the whole system? I understand I need to jump the AC In and AC Out neutrals on the LV5048, but I am not sure what point in the system I should introduce the ground wire from the grounding rod.

I am also confused about the green ground screw that came with both panels to ground the box. I have read that you only use that in the Mains panel, but neither one of my panels seems to be the mains panel as several people have said the LV5048 is considered the mains panel.

Thanks in advance for any help.

 

[SolarBro]

@SolarBro if I may ask a question. I have a completely off grid setup, no grid service at all. We are in an RV. For my AC Input I am using a generator, wiring a 50 AMP input plug, running wire from the plug to a 40 AMP load center, and then running from the 40 AMP load center into the AC Input on the LV5048. For the AC Output on the LV5048, I am running from the inverter to a 100 AMP main lugs load center with a 50 AMP service breaker. From the 50 AMP service breaker I am running to a 50 AMP outlet.

I will plug in a 50 AMP RV cable from the 50 AMP outlet coming from the Inverter into the 50 AMP input on the RV.

There obviously is no grounding rod yet, so I will install one of those next to the RV. My question is, because there is no grid service Main panel with grounding, how do I go about grounding the whole system? I understand I need to jump the AC In and AC Out neutrals on the LV5048, but I am not sure what point in the system I should introduce the ground wire from the grounding rod.

I am also confused about the green ground screw that came with both panels to ground the box. I have read that you only use that in the Mains panel, but neither one of my panels seems to be the mains panel as several people have said the LV5048 is considered the mains panel.

Thanks in advance for any help.

Im not an electrician, but i can only tell you how it was setup for me.

The principle is that current always wants to return to the source it comes from. It can take multiple parallel paths to do so.

You bond the neutral and ground on the output side so that if there is a ground fault in any of the equipment, using a EGC, this way the current can return to the neutral path via the bonding neutral/ground connection.

TLDR; Make sure your AC output Neutral/ground are bonded in the inverter.

The Grounding electrode/Rod/Plate should be connected to your Ground bar in your first breaker panel with atleast 6awg bare copper on the output side of your LV5048. If you have bonded the neutral/ground ports as i did on both sides of the inverter, your grounding rod will be bonded when the lv5048 switches from Input/Output power sources.

TLDR; make sure you have a jumper on the neutral on both the input/output side of the lv5048. Connect ground rod to the ground bar on the first breaker box of the output of the lv5048.

You can send me a PM on your setup.

 

[jimjones26]

So you bonded the box on both the input and output?

 

[SolarBro]

So you bonded the box on both the input and output?

I would make sure your generator is bonded internally and then do this neutral jumper in the lv5048 continue its bonding down the line.

 

[Supervstech]

I would make sure your generator is bonded internally and then do this neutral jumper in the lv5048 continue its bonding down the line.

View attachment 30637

Where did you find this hack recommended?

 

[SolarBro]

Where did you find this hack recommended?

It was discussed here.

MPP Solar LV5048 Bonding & Grounding question.

I'm working on slow install of my LV-5048 and I had a question and a crude diagram of my question. 1. Do I bond my Neutral and Ground on the critical loads panel? 2. Should I run a ground wire from my main service panel to my Critical loads panel grounding bar? Im not sure how MPP solar...

diysolarforum.com

Turns out a good solution for bonding.

 

[jimjones26]

I would make sure your generator is bonded internally and then do this neutral jumper in the lv5048 continue its bonding down the line.

View attachment 30637

My generator is bonding internally. I now have the AC Out panel bonded with the green screw, and then a ground wire out to a ground rod. The only thing I am still uncertain of is if my AC input box needs to be bonded with the green screw as well.

The generator has a separate ground rod that it is connected to.

 

[SolarBro]

My generator is bonding internally. I now have the AC Out panel bonded with the green screw, and then a ground wire out to a ground rod. The only thing I am still uncertain of is if my AC input box needs to be bonded with the green screw as well.

The generator has a separate ground rod that it is connected to.

If your generator is bonded, the AC input panel should NOT be bonded. Make sure you still run the 4 wires from the gen to your input panel though.

Generator should be bonded, lv5048 Neutrals connected internally, and the output panel of the lv5048 should be bonded.

This way if the lv5048 bypasses through to generator, it carries on the bonding for the generator.

When running on solar and battery, the bonding on your first AC output panel will carry the bonding from the inverter.

 

[SolarBro]

Here is something i just considered. Are you running any loads directly from the gen? (As in plugged into it) Or is this gen only being used to feed the lv5048?

Because a simplier solution would be to unbond the generator, only bond the AC output panel and carry the neutral jumper internally in the lv5048.

Then the bonding for the generator would be the AC output panel screw traveling through the jumper in the lv5048.

Just a thought.

 

[jimjones26]

Here is something i just considered. Are you running any loads directly from the gen? (As in plugged into it) Or is this gen only being used to feed the lv5048?

Because a simplier solution would be to unbond the generator, only bond the AC output panel and carry the neutral jumper internally in the lv5048.

Then the bonding for the generator would be the AC output panel screw traveling through the jumper in the lv5048.

Just a thought.

No, I don't run any other loads directly from the generator. However, the generator is internally bonded, I'm not sure I want to try and undo that.

 

[jimjones26]

Thanks for your help, I am up and running and everything seems to be working great. I just need to figure out the best settings for charging my batteries now.

 

[copec]

I moved my critical circuits from the main panel to a subpanel with the LV5048 in-between, but I also have an interlock with another breaker from the grid so I can bypass the inverter for maintenance - thus the subpanel always has the main panel ground/neutral always connected and thus the neutral/ground bond in the main panel.

Testing it with my multimeter the in/out ground of the inverter doesn’t seem to be bonded when it is off, I have the “in” ground coming from the main panel and the “out” ground going to the subpanel, but then the subpanel ground is also directly connected to the main panel.

I’m trying to make sense of what the in and out ground serve. Does the inverter need to have ground routed through it to properly detect faults?

 

[SolarBro]

I moved my critical circuits from the main panel to a subpanel with the LV5048 in-between, but I also have an interlock with another breaker from the grid so I can bypass the inverter for maintenance - thus the subpanel always has the main panel ground/neutral always connected and thus the neutral/ground bond in the main panel.

Testing it with my multimeter the in/out ground of the inverter doesn’t seem to be bonded when it is off, I have the “in” ground coming from the main panel and the “out” ground going to the subpanel, but then the subpanel ground is also directly connected to the main panel.

I’m trying to make sense of what the in and out ground serve. Does the inverter need to have ground routed through it to properly detect faults?

Lv5048 does not have ground fault protection on its solar inputs. Youll need a GFDI breaker for the DC solar inputs.

Its also not bonded. As a work around i bonded the neutrals on the output and input using a jumper to fix this issue.

 

[copec]

Lv5048 does not have ground fault protection on its solar inputs. Youll need a GFDI breaker for the DC solar inputs.

Its also not bonded. As a work around i bonded the neutrals on the output and input using a jumper to fix this issue.

 

[GoinOffGrid]

I definitely would not put a jumper between the input and output neutral lugs as this would create a potentially dangerous situation. The AC input feeds into the charge controller and the AC output comes from the inverter and there is no electrical connectivity between the two - other than grounding. By jumping the neutral lugs you connect half of the circuits. The problem is that when you shut off the input circuit breaker you expect both the load and neutral wires to be dead. By jumping the neutral lugs you create a situation where the input side neutral wire can still be carrying current even with the input circuit breaker shut off.

Personally, I put a small breaker box on the output side, bonded neutral to ground there and connected the ground bus bar to the GEC.

 

[Supervstech]

I definitely would not put a jumper between the input and output neutral lugs as this would create a potentially dangerous situation. The AC input feeds into the charge controller and the AC output comes from the inverter and there is no electrical connectivity between the two - other than grounding. By jumping the neutral lugs you connect half of the circuits. The problem is that when you shut off the input circuit breaker you expect both the load and neutral wires to be dead. By jumping the neutral lugs you create a situation where the input side neutral wire can still be carrying current even with the input circuit breaker shut off.

Personally, I put a small breaker box on the output side, bonded neutral to ground there and connected the ground bus bar to the GEC.

Lv5048 does not have ground fault protection on its solar inputs. Youll need a GFDI breaker for the DC solar inputs.

Its also not bonded. As a work around i bonded the neutrals on the output and input using a jumper to fix this issue.

No no no… neutral is an energized circuit… it needs isolation, and secure disconnecting… bonding can ONLY be tied to neutral in one location downstream of the first energy supply to the building… it CANNOT BE CONNECTED TO NEUTRAL ANYPLACE ELSE…

 

[copec]

I definitely would not put a jumper between the input and output neutral lugs as this would create a potentially dangerous situation. The AC input feeds into the charge controller and the AC output comes from the inverter and there is no electrical connectivity between the two - other than grounding. By jumping the neutral lugs you connect half of the circuits. The problem is that when you shut off the input circuit breaker you expect both the load and neutral wires to be dead. By jumping the neutral lugs you create a situation where the input side neutral wire can still be carrying current even with the input circuit breaker shut off.

Personally, I put a small breaker box on the output side, bonded neutral to ground there and connected the ground bus bar to the GEC.

That is effectively the same circuit path though, right? Now the neutral is bonded to ground both on the input and output side of the inverter, the grounds are connected to each other at the GEC. So when the inverter is in grid mode - that is, it is providing grid power on its output from its input - there is now a parallel path and return grid current is going to go through the connected input/output neutral AND the connected ground path wiring.

 

[GoinOffGrid]

I did a bunch of research on these units. There is a relay on the output that switches either the AC input to the system output or the inverter output to the system output. When it is running in line mode the relay connects the AC input to the output and the bonding is provided by the grid service. However, when it is in battery mode the relay switches to the inverter output and it is no longer connected physically to the AC input so it is no longer bonded. The UL spec calls for a neutral to ground bonding relay that is open in line mode but closes in battery mode so that the system is always bonded.

These units in particular do not have a built-in neutral to ground bonding relay. Instead, when you enable program option 38 the dry contacts basically become a switch that energizes an external relay. You would run the hot (black) wire to the C port of the dry contact and then run a black wire from the NO port to one side of the external relay coil. The other side of the relay coil would connect to the neutral (white) wire. Then connect the neutral and ground to C and NO contacts of the relay. When the unit is running in line mode, the dry contacts will be open so the external relay coil will not be energized and the neutral and ground wires will not be connected by the relay - the bonding at the grid main will be used. When the unit switches to battery mode, the dry contacts will close and the external relay coil will be energized. That will close the relay contacts and bond neutral to ground there.

 

[copec]

^ In my particular instance I didn’t need to do that because it was a subpanel in the same structure, after the inverter so it has ground and neutral from the main panel - which has the bond. So even if the inverter is in inverter mode, the neutral and ground are still bonded in the main panel.