# PV Solar Grounding



## TOOL_5150 (Aug 27, 2007)

Long story short: Ive never done solar until this job that I was thrown into. I figured out quite a few things, but as far as grounding the panels, the contractor told me "you can zip tie the ground wire to the conduit going to the panels"

I did so, and he failed the inspection. The inspector told him " the ground has to be in a conduit, and the wire cannot be exposed for more than 6 feet"

This is a commercial install, there is 2 fronius inverters sending out 3 phase delta 120/240v. This is in San Francisco, CA

The contractor didn't ask for any code articles that were violated when the inspector was there.

Is the installation up to code, or was I mis-guided?

Its a bare #6 ground that is zip tied to the conduits, and bonds all the rows of panels. It ends up in a sub panel that I installed, and has a crimp connection to the green #6 that goes directly to the neutral in the building service disconnect.

I couldnt find anything specific in 690 that I violated. 

Thanks!


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## TGGT (Oct 28, 2012)

We did a mock install in class the other day. The instructor regularly inspects solar installations. We ran the #6 free air bonding each row to eachother continuous and back to the disconnect. This style of racking was "self bonding", so we didn't have to bond each individual module with the #6.

However as you probably know AHJ can make up whatever BS they want, and sometimes it's better to chalk it up and add it to the cost for the next project. 

Sent from my SM-G360T using Tapatalk


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## backstay (Feb 3, 2011)

TOOL_5150 said:


> Long story short: Ive never done solar until this job that I was thrown into. I figured out quite a few things, but as far as grounding the panels, the contractor told me "you can zip tie the ground wire to the conduit going to the panels"
> 
> I did so, and he failed the inspection. The inspector told him " the ground has to be in a conduit, and the wire cannot be exposed for more than 6 feet"
> 
> ...


Never heard of a six foot rule for bare copper. You have rules for the protection of that #6, but those aren't PV based. And when you said "directly to the neutral" did you mean it is connected to the neutral bus at the service? Here is a picture, note the conduit has a ground clamp too. #6 stranded bare copper tie rapped to the conduit. It's there, tough to see. One rail of every row is bonded. This was inspected by both the regular state electrical inspector and his supervisor who has additional training on solar PV.



TGGT said:


> We did a mock install in class the other day. The instructor regularly inspects solar installations. We ran the #6 free air bonding each row to eachother continuous and back to the disconnect. This style of racking was "self bonding", so we didn't have to bond each individual module with the #6.
> 
> However as* you probably know AHJ can make up whatever BS they want*, and sometimes it's better to chalk it up and add it to the cost for the next project.
> 
> Sent from my SM-G360T using Tapatalk


No they can't.


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## RePhase277 (Feb 5, 2008)

For grounding electrodes, 250.50 thru 250.60, and 250.64 for AC systems

250.166 for grounded DC and 250.169 for ungrounded DC. 250.64 applies to all.

For EGCs, 250.120 (C) might apply. 250.134 and 250.136 are worth a look.


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## TGGT (Oct 28, 2012)

backstay said:


> Never heard of a six foot rule for bare copper. You have rules for the protection of that #6, but those aren't PV based. And when you said "directly to the neutral" did you mean it is connected to the neutral bus at the service? Here is a picture, note the conduit has a ground clamp too. #6 stranded bare copper tie rapped to the conduit. It's there, tough to see. One rail of every row is bonded. This was inspected by both the regular state electrical inspector and his supervisor who has additional training on solar PV.
> 
> 
> 
> No they can't.


But they do, and you have to decide which is more cost effective, proving you're right or doing it their way.


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## backstay (Feb 3, 2011)

TGGT said:


> But they do, and you have to decide which is more cost effective, proving you're right or doing it their way.


I don't know how long you're been an electrician, but after 30 years the most effective way for me is by following the code. In Minnesota, the state inspectors must sight the code ref you have violated. Without it nothing changes. This is a business, not a game. I don't have time to play games. Inspectors have to be held to that.


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## FaultCurrent (May 13, 2014)

690.43 (F) All Conductors Together. Equipment grounding conductors
for the PV array and structure (where installed)
shall be contained within the same raceway or cable or
otherwise run with the PV array circuit conductors when
those circuit conductors leave the vicinity of the PV array.

You can use the racking system if listed for grounding the panels together, or use a open conductor to bond the panels together. Once the grounding conductor leaves the array back to the inverter or combiner they have to be contained in the same raceway with the PV conductors.


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## backstay (Feb 3, 2011)

FaultCurrent said:


> 690.43 (F) All Conductors Together. Equipment grounding conductors
> for the PV array and structure (where installed)
> shall be contained within the same raceway or cable* or
> otherwise run with* the PV array circuit conductors when
> ...


Why do you suppose they gave three options there? Think about it.


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## cuba_pete (Dec 8, 2011)

backstay said:


> ...This is a business, not a game.


So true...you would think that grownups would get that.


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## FaultCurrent (May 13, 2014)

"Why do you suppose they gave three options there? Think about it."

I have. Use something other than a raceway or cable and you may be able to use open conductor. 

690.31 Methods Permitted.
(A) Wiring Systems. All raceway and cable wiring methods
included in this Code, other wiring systems and fittings
specifically listed for use on PV arrays, and wiring as part
of a listed system shall be permitted.

Nobody in this area will approve open #6 conductor tie wrapped to the EMT feeders and into a drilled hole in the inverter.


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## backstay (Feb 3, 2011)

FaultCurrent said:


> "Why do you suppose they gave three options there? Think about it."
> 
> I have. Use something other than a raceway or cable and you may be able to use open conductor.
> 
> ...


Why do you think there is a hole drilled in the inverter? You do realize that the EMT is a egc?


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## RePhase277 (Feb 5, 2008)

FaultCurrent said:


> "Why do you suppose they gave three options there? Think about it."
> 
> I have. Use something other than a raceway or cable and you may be able to use open conductor.
> 
> ...


250.134(B) Exception 2 allows the EGC to be routed differently than the circuit conductors in DC installations.


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## telsa (May 22, 2015)

TOOL_5150 said:


> Long story short: Ive never done solar until this job that I was thrown into. I figured out quite a few things, but as far as grounding the panels, the contractor told me "you can zip tie the ground wire to the conduit going to the panels"
> 
> I did so, and he failed the inspection. The inspector told him " the ground has to be in a conduit, and the wire cannot be exposed for more than 6 feet"
> 
> ...


I only ran one job in Oakland, California.

Oakland copies San Francisco, word for word, in its amendments.

Suffice it to say that you'd better find out what amendments SF has appended to the NEC.

Because both cities sit atop astounding earthquake faults... and long memories... there are a TON of NEC over-rides within the SF electrical code.

You'll also find that these amendments have been adopted down the peninsula, too.

Like Chicago, many cities demand EMT in residential construction, too.


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## cuba_pete (Dec 8, 2011)

backstay said:


> Why do you think there is a hole drilled in the inverter? You do realize that the EMT is a egc?


I was waiting for this comment, but I was too lazy to look up the code for PVA's to verify...


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## MechanicalDVR (Dec 29, 2007)

backstay said:


> I don't know how long you're been an electrician, but after 30 years the most effective way for me is by following the code. In Minnesota, the state inspectors must sight the code ref you have violated. Without it nothing changes. This is a business, not a game. I don't have time to play games. *Inspectors have to be held to that*.


While I hear what you are saying I have surely come across more than one with the attitude that they are a deity walking the earth and have no rules.


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## FaultCurrent (May 13, 2014)

RePhase277 said:


> 250.134(B) Exception 2 allows the EGC to be routed differently than the circuit conductors in DC installations.


690.3 Other Articles. Wherever the requirements of other
articles of this Code and Article 690 differ, the requirements
of Article 690 shall apply and, if the system is operated in
parallel with a primary source(s) of electricity, the requirements
in 705.14, 705.16, 705.32, and 705.143 shall apply.


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## RePhase277 (Feb 5, 2008)

FaultCurrent said:


> 690.3 Other Articles. Wherever the requirements of other
> articles of this Code and Article 690 differ, the requirements
> of Article 690 shall apply and, if the system is operated in
> parallel with a primary source(s) of electricity, the requirements
> in 705.14, 705.16, 705.32, and 705.143 shall apply.


690.43 (A)(1) references 250.134


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## FaultCurrent (May 13, 2014)

RePhase277 said:


> 690.43 (A)(1) references 250.134


Are you really saying that tie-wrapping an external ground wire onto EMT is your idea of good work? Why wouldn't you just pull it in the conduit with the PV output conductors?


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## RePhase277 (Feb 5, 2008)

FaultCurrent said:


> Are you really saying that tie-wrapping an external ground wire onto EMT is your idea of good work?


Show me where I said that. We are talking about code, not beauty. You flat out stated it can't be done. I provided code references saying otherwise. That's as far as it goes.



> Why wouldn't you just pull it in the conduit with the PV output conductors?


I have no idea. Another excellent question would be why would the OP let the contractor tell him what's permissible to begin with?


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## frenchelectrican (Mar 15, 2007)

FaultCurrent said:


> Are you really saying that tie-wrapping an external ground wire onto EMT is your idea of good work? Why wouldn't you just pull it in the conduit with the PV output conductors?


Some area they allowed to do that but each area have different seniceairo so hard to see what it is there.,

But my personal option there is couple way you can done with the GEC but I know some of our solar installment in here we do go either route with GEC by useing #6 copper conductor or use the EMT as GEC but if used with emt ya have to watch the expaning and contraction thermal cycling sometime the connection can get loosen up so I think that why some installer just ran it outside of the conduit for that.


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## backstay (Feb 3, 2011)

So we've gone from code violation to it doesn't look good.


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## telsa (May 22, 2015)

backstay said:


> So we've gone from code violation to it doesn't look good.


"It doesn't look good up their on the roof."

The beauty of exterior solid #6 is that it can be inspected with the human eyeball decades after the install.

Anyone familiar with decades old roof-top EMT installs KNOWS that they 'come apart.'

RTUs in particular come to mind. Some ancient work is frightful. The EMT has come apart at the compression connector, the wires are visible, and there is no bonding// grounding conductor -- plainly. 

I regard an exterior bonding conductor to be superior technique.

The LAST thing you should want to see is the PV array 'floating away' from local ground potential.


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## TOOL_5150 (Aug 27, 2007)

TGGT said:


> We did a mock install in class the other day. The instructor regularly inspects solar installations. We ran the #6 free air bonding each row to eachother continuous and back to the disconnect. This style of racking was "self bonding", so we didn't have to bond each individual module with the #6.
> 
> However as you probably know AHJ can make up whatever BS they want, and sometimes it's better to chalk it up and add it to the cost for the next project.
> 
> Sent from my SM-G360T using Tapatalk


This racking is self bonding, and I used a UL approved ground strap on the end of each row. It is continuous, and is crimped to the EGC in the panel, which then goes directly to the building disconnect.

I do not agree with the statement "inspectors can make up anything" No, That is NOT their job.


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## TOOL_5150 (Aug 27, 2007)

backstay said:


> Never heard of a six foot rule for bare copper. You have rules for the protection of that #6, but those aren't PV based. And when you said "directly to the neutral" did you mean it is connected to the neutral bus at the service? Here is a picture, note the conduit has a ground clamp too. #6 stranded bare copper tie rapped to the conduit. It's there, tough to see. One rail of every row is bonded. This was inspected by both the regular state electrical inspector and his supervisor who has additional training on solar PV.
> 
> 
> 
> No they can't.


Yes, connected to the neutral bus in the service disconnect for the building.

This is almost exactly my installation, I will find pictures.


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## TOOL_5150 (Aug 27, 2007)

FaultCurrent said:


> 690.43 (F) All Conductors Together. Equipment grounding conductors
> for the PV array and structure (where installed)
> shall be contained within the same raceway or cable or
> otherwise run with the PV array circuit conductors when
> ...


We used a self grounding racking system. There are 2 different groups of panels on the roof, the DC conductors are within an EMT raceway and jump out next to each panel row. The Ground is zip tied to the EMT and runs open air to ground the end of each row. there are 3 Different EMT's going into the inverters, where the 2 ground wires jump into the 3R panel and are both crimped to the EGC, where from there is ran inside the 2" EMT down to the service. So - the ground wire is ran free air for the DC, and is in the EMT on the AC side.


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## TOOL_5150 (Aug 27, 2007)

FaultCurrent said:


> Are you really saying that tie-wrapping an external ground wire onto EMT is your idea of good work? Why wouldn't you just pull it in the conduit with the PV output conductors?


I agree with you, but this is not the question. Next time, now that I know the workings of a PV array, I will do it differently. However, this is how I was told to run the ground for the panels. I questioned it when he contractor told me to do it that way, and he told me that "This is how its done, I have done many installs around the bay area, and passed each time" He install a PV array on his house across the street from me, and did the exact same method for grounding the panels and his installation passed as well.

I was initially hired to install the panel on the roof for the new RTU's and the solar inverters, Then hook up the AC side of the inverters and hook up the RTUs'. Things changed and I ended up installing the whole system, minus the racking and installation of the panels. So, I took this as a learning experience and just want to know the code compliant way of a proper installation.

I still dont know if I want to advertise that I can do solar, nor do I think only having a C-10 license legally allows me to do so, But I do want to know how to do it for the future.


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## TOOL_5150 (Aug 27, 2007)

RePhase277 said:


> I have no idea. Another excellent question would be why would the OP let the contractor tell him what's permissible to begin with?


I answered that question in the post above me. No, that is NOT how I usually do business, but this one time I was out of time, and this guy has/had a solar license. Ive also seen solar installs with the ground wire strapped to the DC EMT, so I didnt bother bringing this subject up back then. Now I realize I should have. Lesson learned!:thumbsup:


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## backstay (Feb 3, 2011)

TOOL_5150 said:


> I agree with you, but this is not the question. Next time, now that I know the workings of a PV array, I will do it differently. However, this is how I was told to run the ground for the panels. I questioned it when he contractor told me to do it that way, and he told me that "This is how its done, I have done many installs around the bay area, and passed each time" He install a PV array on his house across the street from me, and did the exact same method for grounding the panels and his installation passed as well.
> 
> I was initially hired to install the panel on the roof for the new RTU's and the solar inverters, Then hook up the AC side of the inverters and hook up the RTUs'. Things changed and I ended up installing the whole system, minus the racking and installation of the panels. So, I took this as a learning experience and just want to know the code compliant way of a proper installation.
> 
> I still dont know if I want to advertise that I can do solar, nor do I think only having a C-10 license legally allows me to do so, But I do want to know how to do it for the future.


One installation does not make you a solar installer.


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## TOOL_5150 (Aug 27, 2007)

backstay said:


> One installation does not make you a solar installer.


Your input is greatly appreciated.:thumbsup:


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## frenchelectrican (Mar 15, 2007)

backstay said:


> One installation does not make you a solar installer.


That true and the more ya work on it will become easier to dealt with it.


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