Connecting Solar System Ground To House's Ground Rods?

[organic farmer]

This is one reason DIY gets tricky and dangerous.

Reading a page out of NEC and applying it may be the wrong page.

So are you saying that we should ignore the manufacturers of the Inverter, the Charge-Controller, etc ?

That none of these components need to be connected to ground?



When you buy a new car, the manufacturer says to change the oil every 5,000 miles, do you suggest that everyone should ignore that because changing the oil is dangerous?

Which wiring diagrams do we ignore, and which wiring diagrams do we decide to comply with?

[sensij]

What is right for one system may not be for another. OP has not provided enough information. The advice given so far has been irresponsible.

[russ]

So are you saying that we should ignore the manufacturers of the Inverter, the Charge-Controller, etc ?

That none of these components need to be connected to ground?



When you buy a new car, the manufacturer says to change the oil every 5,000 miles, do you suggest that everyone should ignore that because changing the oil is dangerous?

Which wiring diagrams do we ignore, and which wiring diagrams do we decide to comply with?

Work with an electrician that knows what he is about and follow code.

Your analogy is pure BS.

[DanS26]

It is a common misconception that lightning goes straight into the ground. In most cases lightning will radiate from point of entry in a spoke pattern usually very close to the surface. If you have unbonded ground rods in that voltage gradient then it is quite likely that the high voltage differential created by the gradient field will now travel thru your equipment and above ground conductors to stabilize the gradient.

That is why you do not sink ground rods willy nilly all over your property without having them bonded together underground as ONE system.

[foo1bar]

OP has not provided enough information. The advice given so far has been irresponsible.

I agree - is this PV system completely separate?
Or is it connected with the main house wiring already?

If it's completely separate (ex. is there for a standalone building that has no electrical service), having a separate ground rod I believe would be OK - just as having a separate ground rod for my house vs. my neighbor's house is OK (and required in that case)

If it's not completely separate, then there's a lot more that should be described about how it's set up.

[J.P.M.]

Since advice on this forum is free, and free means I pay nothing, I try to keep in mind that I get what I pay for with no guarantees expressed or implied.

[Sunking]

The wiring diagrams and instructions for my Combiner-box / Charge-Controller / Inverter / panel call for these devices it to be grounded.

I never said not to ground them.

I said you cannot have isolated or separate Ground Electrode System aka GES per NEC definitions. The GES must be common for all electrical systems. Otherwise if you were to have a fault or more importantly lightning strike near by, (does not have to hit your house, anywhere near by) would create a potential difference of thousands of volts. That is a recipe to be killed or have a fire start.

[sdold]

Sunking may know a little about grounding, but the best description of the hows and more importantly the whys of grounding I've ever read is here. This guy knows grounding.

[rs14smith]

Just to clear up some confusion about my system's setup, my system is "not" connected to my house, but, the 400Watt PV array is located very close to my house (on my houses deck to be exact). My 30A charge controller, 12v battery, and 500W inverter is located in a garage.

My PV array consists of 4x 12v 100Watt solar panel hooked up in parallel producing about 23Amps with direct sunlight.

From what I've found from some quick research is that, according to NEC section 690.41, it states that only PV systems greater than 50V are required to be solidly grounded. I have a 12v system. However, I feel there is a "but" somewhere in this article that I'm still trying to learn about. I still need to ground my solar panels in case lighten hits them, but I'm trying to determine if I can just ground them straight to the ground rod my house is using?

Sunking may know a little about grounding, but the best description of the hows and more importantly the whys of grounding I've ever read is here. This guy knows grounding.

Edit
From the link sdold provided, if I use multiple ground rods in my property, or add a grounding rod, I need to bond all the grounding rods together. But, if a grounding rod is already pretty close to where I have my small PV array, I would think it should be fine to use the house's grounding rod connection? If I install a "separate" ground rod too close to my house's grounding rods, I could run into noise issues, and other issues I probably haven't read about or have little knowledge about?

[DanS26]

Just to clear up some confusion about my system's setup, my system is "not" connected to my house, but, the 400Watt PV array is located very close to my house (on my houses deck to be exact). My 30A charge controller, 12v battery, and 500W inverter is located in a garage.

My PV array consists of 4x 12v 100Watt solar panel hooked up in parallel producing about 23Amps with direct sunlight.

From what I've found from some quick research is that, according to NEC section 690.41, it states that only PV systems greater than 50V are required to be solidly grounded. I have a 12v system. However, I feel there is a "but" somewhere in this article that I'm still trying to learn about. I still need to ground my solar panels in case lighten hits them, but I'm trying to determine if I can just ground them straight to the ground rod my house is using?



From the link sdold provided, having multiple grounding rods in your properly close by that aren't "bonded/connected" together could create issues? If that's correct, that would mean I definitely need to use my house's ground rod as my PV's connection to ground?

All that information and yet you still do not understand........no wonder the old timers on this site are frustrated.

[rs14smith]

All that information and yet you still do not understand........no wonder the old timers on this site are frustrated.

Eventually we youngsters will get it, but I'm just trying to confirm some of my findings to check if any of it is valid or not. It's a lot to take in if this is something new you are getting into, and just because I have a ton of information thrown my way, I still need to make sure I comprehend the information.

So what exactly am I misunderstanding or not connecting the dots?

[DanS26]

Eventually we youngsters will get it, but I'm just trying to confirm some of my findings to check if any of it is valid or not. It's a lot to take in if this is something new you are getting into, and just because I have a ton of information thrown my way, I still need to make sure I comprehend the information.

So what exactly am I misunderstanding or not connecting the dots?

Maybe I'm being too harsh....it's hard to give you a definite answer to your questions because I do not have every fact about your situation. You have to take the information given and apply to your exact electrical setup.

Use the information given or hire an electrician.

[Sunking]

Sunking may know a little about grounding, but the best description of the hows and more importantly the whys of grounding I've ever read is here. This guy knows grounding.

Thanks. I assume you know I am KF5LJW right? You forgot Part Two and Part Three

[rs14smith]

Maybe I'm being too harsh....it's hard to give you a definite answer to your questions because I do not have every fact about your situation. You have to take the information given and apply to your exact electrical setup.

Use the information given or hire an electrician.

I typically don't give up that easy within a forum if I'm still not sure about a few things. If you don't have enough information about my system, tell me what else I need to provide to help you help me. If no one here at this forum can help with my misunderstandings, then that's when I move to plan C and hire someone.

[Sunking]

From what I've found from some quick research is that, according to NEC section 690.41, it states that only PV systems greater than 50V are required to be solidly grounded. I have a 12v system. However, I feel there is a "but" somewhere in this article that I'm still trying to learn about.

Hold the bus here as you left out keywords and do not understand what it is telling you because you do not know the difference between Grounded System or Grounded. Here it is:

690.41 System Grounding


For a photovoltaic power source, one conductor of a 2-wire
system with a photovoltaic system voltage over 50 volts and
the reference (center tap) conductor of a bipolar system shall
be solidly grounded or shall use other methods that accomplish
equivalent system protection in accordance with
250.4(A) and that utilize equipment listed and identified for
the use.

Grounded System means one of the circuit conductors is grounded like the negative polarity or Neutral in a AC system. That has nothing to do with grounding the equipment which is always required.

There are two ways to provide Over Current Protection using Over Current Protection Device like fuses, breakers, and ground fault interrupter. For a Grounded System all that is required is a simple fuse or breaker at the source like batteries, panels, generators, and AC Service. What 690.41 is telling you is systems under 50 volts does not require the system to be grounded and can be floated.

However if you float the system, you still have to use OCPD's to protect the wiring, but is more expensive and complicated. It would require fuses on both polarities and a Ground Fault Detector to alert the operator one of the ungrounded system circuit conducts has a fault to ground. You still have to ground the equipment.