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690.4 of the 2011. Does even apply here.

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    690.4 of the 2011. Does even apply here.

    Greetings,

    I currently have Solar panels, with Enphase microinverters, on my house and want to add some more to a detached garage. The house and garage are connected by 4 inch electrical PVC pipe that has two AC circuits in it for lighting and receptacles in the garage. I want to add a 50 AMP sub panel in the garage dedicated to the solar that will be installed on that roof.


    The inspector is attempting to use Article 690.4 of the 2011 code that says "Identification and Grouping. [COLOR=#ff0000]PV source circuits[/COLOR] and [COLOR=#ff0000]PV output circuits[/COLOR] shall not be contained in the same raceway, cable tray, cable, outlet box, junction box, or similar fitting as conductors, feeders, branch circuits of other non-PV systems or inverter output circuits unless the conductors of the different systems are separated be a partition." to deny me from installing solar on my garage. I have countered that the 50 AMP AC circuit is neither a [COLOR=#ff0000]"PV Source Circuit" or a "PV Output Circuit"[/COLOR], which both carry DC, but he is insisting that this AC wiring is solar related and such cannot be in the same conduit with non solar related AC cables. He is basically interpreting the code as it it were written as ""Identification and Grouping. PV source circuits, PV output [COLOR=#ff0000]AND INVERTER OUTPUT CIRCUITS[/COLOR] circuits shall not be contained in the same raceway, cable tray, cable, outlet box, junction box, or similar fitting as conductors, feeders, branch circuits of other non-PV systems or inverter output circuits unless the conductors of the different systems are separated be a partition."

    IMO the 50 AMP cable from the house to the garage is another "FEEDER" cable that just so happens to have a load center panel that contains inverter output circuits. If instead of solar this 50 AMP panel had a welder receptacle off of it that would be perfectly fine.


    As an alternate option I suggested that I would pull the existing 15 and 20 AMP AC wiring from the conduit and use the single 50 AMP wire to also provide electrical service to the lights and receptacles in the garage as well as solar. This was unacceptable to this inspector as well. But he would not clarify why.


    I am having trouble seeing why it is OK for the AC wires, that run to the solar panels installed on my house roof, to run inside my attic alongside other light and receptacle AC wires but the same is not true when they are run underground in a 4 inch PVC conduit. Yes the Solar on my house was approved by the county inspector. Running a separate PVC conduit between the house and garage would require the tear-up of a patio and walkway that were installed over the existing conduit. This is an expense I do not wish to incur.

    I am all for safety but I do not see a risk in these three AC circuits sharing a pipe that is buried under the ground. If something unlikely did cause the cables to short together the breakers on either end of the cables would trip.

    Expert opinions on this topic appreciated.

    Frank

    #2
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    Comment


      #3
      I will allow this thread since the OP has a solar contractor and an electrical contractor doing the work
      They say I shot a man named Gray and took his wife to Italy
      She inherited a million bucks and when she died it came to me
      I can't help it if I'm lucky

      Comment


        #4
        If it can be done, I would consider snaking a smaller flexible conduit through the 4" PVC to provide separation.
        The inspector does not have a logical leg to stand on, but overriding him might take too long.

        Comment


          #5
          Originally posted by GoldDigger View Post
          If it can be done, I would consider snaking a smaller flexible conduit through the 4" PVC to provide separation.
          The inspector does not have a logical leg to stand on, but overriding him might take too long.
          I was thinking this exactly while reading the OP.
          [COLOR=RoyalBlue]I will have achieved my life's goal if I die with a smile on my face.[/COLOR]

          Comment


            #6
            The distance between the house and the garage is 140 feet and the PVC pipe has three 90 degree curves in them so I do not feel it would be possible to pull the 1 inch flex conduit through along with the 15 amp and 20 amp cables that are already present. Not to mention it would be a challenge to get 3 #4 and 1 #8 through 140 feet of 1 inch flex conduit.

            Comment


              #7
              Originally posted by Frank.B.Smith View Post

              The inspector is attempting to use Article 690.4 of the 2011 code that says "Identification and Grouping. [COLOR=#ff0000]PV source circuits[/COLOR] and [COLOR=#ff0000]PV output circuits[/COLOR] shall not be contained in the same raceway, cable tray, cable, outlet box, junction box, or similar fitting as conductors, feeders, branch circuits of other non-PV systems or inverter output circuits unless the conductors of the different systems are separated be a partition." to deny me from installing solar on my garage. I have countered that the 50 AMP AC circuit is neither a [COLOR=#ff0000]"PV Source Circuit" or a "PV Output Circuit"[/COLOR], which both carry DC, but he is insisting that this AC wiring is solar related and such cannot be in the same conduit with non solar related AC cables. He is basically interpreting the code as it it were written as ""Identification and Grouping. PV source circuits, PV output [COLOR=#ff0000]AND INVERTER OUTPUT CIRCUITS[/COLOR] circuits shall not be contained in the same raceway, cable tray, cable, outlet box, junction box, or similar fitting as conductors, feeders, branch circuits of other non-PV systems or inverter output circuits unless the conductors of the different systems are separated be a partition."
              Your inspector is mistaken. PV source circuits and PV output circuits are DC by definition. In an Enphase system there are no PV output circuits, and the only PV source circuits are the leads between the modules and the microinverters.

              Comment


                #8
                Originally posted by Frank.B.Smith View Post
                The distance between the house and the garage is 140 feet and the PVC pipe has three 90 degree curves in them so I do not feel it would be possible to pull the 1 inch flex conduit through along with the 15 amp and 20 amp cables that are already present. Not to mention it would be a challenge to get 3 #4 and 1 #8 through 140 feet of 1 inch flex conduit.
                A challenge for sure, but not impossible. Rent a tugger. Questionably non-compliant but I'd pull the single conductors through the flex before pulling into the PVC.

                It's either that or challenge the inspector... or go the subpanel route.
                [COLOR=RoyalBlue]I will have achieved my life's goal if I die with a smile on my face.[/COLOR]

                Comment


                  #9
                  Originally posted by Frank.B.Smith View Post
                  Greetings,He is basically interpreting the code as it it were written as ""Identification and Grouping. PV source circuits, PV output [COLOR=#ff0000]AND INVERTER OUTPUT CIRCUITS[/COLOR] circuits shall not be contained in the same raceway, cable tray, cable, outlet box, junction box, or similar fitting as conductors, feeders, branch circuits of other non-PV systems or [COLOR=#0000cd]inverter output circuits[/COLOR] unless the conductors of the different systems are separated be a partition."
                  How can inverter output circuits not be in the same raceway (etc.) as inverter output circuits?

                  FWIW, the blue part is only in the 2104 code, not the 2011. Maybe he hasn't seen it yet, and pointing this out to the inspector will convince him?

                  It must be frustrating to deal with a guy who's either to stupid to read the code or too stubborn to admit he was wrong. (Does he have a colleague or supervisor you could appeal to?) Good luck.

                  Comment


                    #10
                    Thank you all for the replies and private messages to my post.

                    Tomorrow I have a conference call with the inspector and his boss. When I previously spoke with his boss on my own he seemed to agree with my arguments supporting the running of multiple AC circuits in the same 4 inch PVC pipe. I have just composed my latest email to the inspector with my "closing arguments" for my case. Here is that email for your inspection.

                    Gregory,

                    All this time I have been trying to understand the risk of having the multiple AC circuits in the same 4 inch PVC. I could not imagine a scenario where arcing or spontaneous combustion would simply occur in an underground conduit that could not also occur when the same wires are run through attic and knee-wall spaces inside a house. I then came across the answer in the April / May 2011 edition of SolarPro Magazine.


                    Here is the text from that article


                    "As explained by Brooks: “The added identification and grouping requirements found in 690.4(B)(1) through (4) take requirements found elsewhere in the NEC and bring them specifically into 690. These are important changes due to the
                    general lack of identification and grouping in existing systems. These deficiencies have resulted in several fires during system commissioning due to mispolarized wiring and poor identification practices.” PV source, output and inverter circuits must now be identified at all points of termination, connection and splices. Per 210.5(C) and 215.12(C), the means of identification can be “color coding, marking tape, tagging, or other approved means.” Best practice would be to use properly colored PV or USE-2 wire for PV source circuits. If using only black PV or USE-2 wires, as allowed by 200.6(A)(6), then correct marking tape is always necessary for grounded and ungrounded current-carrying conductors. You should also use callout tagging, such as “PV source circuit 1” or “PV inverter output circuit 2.” If color-coded tags are used, you should provide a key for identifying the color codes. In addition, conductors associated with multiple inverters should be grouped using wire ties or other means when they occupy the same raceway, junction box or equipment. For example, inverter output circuits sharing a common gutter would need to be separately grouped at least once, and then at intervals not exceeding 6 feet. There are exceptions to 690.4(B)(3) and (4) that permit identification and grouping to be omitted if spacing, arrangement or the use of separate raceways make their identification obvious.


                    The intent of 690.4(B)(4) is that conductors of more than one subarray or inverter be separately grouped whenever they occupy the same equipment or raceway with a removable cover. Using wire ties to group conductors within gutters is an easy way to meet these new requirements."


                    Suddenly it was clear to me. The Article 690.4 was to prevent any confusion during the initial wiring or any subsequent changes. I now understand what they are trying to prevent. If I had a typical 2 inch conduit that connected directly up to a utility box and inside that conduit was a collection of multiple random wires for multiple purposes I could see where you would have a valid argument to deny. But as my pictures show, the existing circuits have the individual insulated wires in an additional insulating "romex partition" cover which provides the required "grouping" that is half of what Article 690.4 is all about. The new wiring is also clearly grouped where it enters and exits the PVC pipe by the 1 inch carflex.


                    While 690.4 of the 2011 code basically says the same thing as Article 690.31 Section B of the 2014 edition, The 2014 edition makes it less confusing to the intent of the Article.


                    From Article 690.31 Section B of the 2014 edition.


                    690.31(B)(3). Conductors of Multiple Systems. Where conductors of more than one PV system occupy the same junction box, raceway, or equipment, the conductors of each system shall be identified at all termination, connection and splice points.
                    Exception: Where the identification of the conductors is evident by the spacing or arrangement, further identification shall not be required.


                    690.31(B)(4). Grouping. Where the conductors of more than one PV system occupy the same junction box or raceway with a removable cover(s). the AC and DC conductors of each system shall be grouped separately by cable ties or similar means at least once and shall then be grouped at intervals not to exceed 1.8 m (6 ft).
                    Exception: The requirement for grouping shall not apply if the circuit enters from a cable or raceway unique to the circuit that makes the grouping obvious.


                    Thank you,


                    Frank Smith

                    Comment


                      #11
                      Originally posted by Frank.B.Smith View Post
                      Tomorrow I have a conference call with the inspector and his boss. When I previously spoke with his boss on my own he seemed to agree with my arguments supporting the running of multiple AC circuits in the same 4 inch PVC pipe. I have just composed my latest email to the inspector with my "closing arguments" for my case. Here is that email for your inspection.

                      Gregory,

                      All this time I have been trying to understand the risk of having the multiple AC circuits in the same 4 inch PVC. I could not imagine a scenario where arcing or spontaneous combustion would simply occur in an underground conduit that could not also occur when the same wires are run through attic and knee-wall spaces inside a house. I then came across the answer in the April / May 2011 edition of SolarPro Magazine.

                      ...

                      Not sure your letter speaks directly to the issues at hand. The real issue here, and intent of the code, is that DC and AC circuits not share raceways. (An exception might be a gutter or other large enclosure where they can be separated by a partition.) And the confusion you're dealing with, which is common, is people thinking that inverter output circuits are PV circuits: they are not. They are AC circuits and for most purposes, including the issues here, should be treated like any other AC circuits supplied by the utility. Many inspectors do not realize that when you disconnect an interactive inverter output circuit from the utility, that AC circuit is dead. It does not continue to be energized or powered by the PV system. That's part of the UL 1741 standard. This is probably the biggest thing that inspectors just aren't educated about and need to have explained to them, especially if PV systems are new to them.

                      PV circuits (i.e. DC) are very different and the dangers of getting them mixed up with AC circuits and connected to each other are serious and various. Mixing inverter output circuits with other AC circuits does not present those issues.

                      (The requirement that circuits be grouped for identification is a general code requirement for AC circuits as well as for PV circuits as required in 690.)

                      Of course, Bill Brooks is also a great authority to appeal to, so if just dropping his name sways them then more power to you.

                      Comment


                        #12
                        Triumph!

                        The Inspector has approved!

                        Comment

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