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  • Bare grounding cable inside conduit?

    I had been designing my system to not have conduit on the roof as it would have to cross the firefighter stand off, but then it dawned on me. If i'm running EMT through the roof, can the bare grounding cable run through that same conduit?

  • #2
    I don't believe bare ground wires are allowed in conduit. But there is nothing saying you can't use an insulated wire on the roof.
    You could also splice the wires in the junction box, but it may need to be an irreversible compression splice.

    Comment


    • #3
      Originally posted by emartin00 View Post
      I don't believe bare ground wires are allowed in conduit.
      They are allowed under NEC. (local AHJ can write additional rules, so it's possible for a local AHJ to have additional requirements - but probably unlikely for this)

      A bare wire (or any ground) should be bonded at both ends (usually via locknut->metal-j-box->groundscrew at each end of the conduit)

      And a bare wire (which will be solid, not stranded) will be a little more difficult to pull through a conduit.

      Comment


      • #4
        Originally posted by emartin00 View Post
        I don't believe bare ground wires are allowed in conduit.
        Please do not give advice or answer questions because you have no clue what you are talking about. Ground wires can be Bare, Insulated, Stranded, or Sold. Can bare or insulated go in conduit? Absolutely it can. In fact no ground wire is even required because if you use the proper fittings, you use the EMT as the wire. So please just be a reader or ask questions because you do not know what you are talking about..

        MSEE, PE

        Comment


        • #5
          Originally posted by foo1bar View Post
          A bare wire (or any ground) should be bonded at both ends (usually via locknut->metal-j-box->groundscrew at each end of the conduit)
          False statement. The only conductor required to be bonded to the metallic raceway is the Ground Electrode Conductor, and there can only be 1 single GEC, and the GEC is ran from your AC Service Neutral to the Ground Electrode attachment point which has nothing to do with solar panels.

          MSEE, PE

          Comment


          • #6
            Originally posted by Sunking View Post
            "A bare wire (or any ground) should be bonded at both ends (usually via locknut->metal-j-box->groundscrew at each end of the conduit)" -me

            False statement. The only conductor required to be bonded to the metallic raceway is the Ground Electrode Conductor, and there can only be 1 single GEC, and the GEC is ran from your AC Service Neutral to the Ground Electrode attachment point which has nothing to do with solar panels.
            You would be right to say that it isn't a requirement for an EGC to bond both ends of the conduit. (But I think if you have a metal jbox at each end that you will bond it that way anyhow.)
            It *is* a requirement for a GEC to bond both ends (and probably I was conflating EGC and GEC rules )

            I think you're wrong that the metallic raceway (conduit) isn't required to be bonded to the EGC:
            NEC 250.86 Other Conductor Enclosures and Raceways. Except as permitted by 250.112(I), metal enclosures and raceways for other than service conductors shall be connected to the equipment grounding conductor.

            Comment


            • #7
              Originally posted by foo1bar View Post

              You would be right to say that it isn't a requirement for an EGC to bond both ends of the conduit. (But I think if you have a metal jbox at each end that you will bond it that way anyhow.)
              It *is* a requirement for a GEC to bond both ends (and probably I was conflating EGC and GEC rules )
              Will there be any conductors of any kind in the conduit with what you are calling a Ground Wire? Be careful how you answer because if there are other conductors inside the conduit means the only ground conductors you can run with them is Equipment Bonding Jumpers, and have nothing to do with ground. A Ground Wire can be ran in raceway. If the raceway is ferrous metal (magnetic), you are required to bond the conductor to the raceway to eliminate choking effect. No other circuit conductors are allowed to be ran with Ground Conductors.

              Here is the take away. What you are calling a ground conductor is not a ground conductor, it is a Equipment Bonding Jumper formerly mistakenly called Equipment Grounding Conductor, or Green Wire Ground to confuse communist. .

              Originally posted by foo1bar View Post
              I think you're wrong that the metallic raceway (conduit) isn't required to be bonded to the EGC:
              NEC 250.86 Other Conductor Enclosures and Raceways. Except as permitted by 250.112(I), metal enclosures and raceways for other than service conductors shall be connected to the equipment grounding conductor.
              What does this have to do with Knob & Tube wiring, Isolation Bushings, or Other Services? EMT is the Equipment Bonding Jumper. 250.86 is for Other Services as stated. All it is telling you if you run a circuit from one service to another that is isolated must have the raceways bonded to minimize shock hazard. You mostly see this with Underground Services and Knob & Tube wiring which has nothing to do with the topic.

              There is only one Ground Conductor recognized in NEC, the Ground Electrode Conductor aka GEC

              MSEE, PE

              Comment


              • #8
                Originally posted by Sunking View Post
                Here is the take away. What you are calling a ground conductor is not a ground conductor, it is a Equipment Bonding Jumper formerly mistakenly called Equipment Grounding Conductor, or Green Wire Ground to confuse communist. .
                Whether you like it or not, the EGC is commonly referred to as a ground wire.

                But back to what you said: "The only conductor required to be bonded to the metallic raceway is the Ground Electrode Conductor,"
                The EGC is a conductor, and is required to be bonded to the metallic raceway.

                I think 250.86 is applicable. I don't see anything that indicates it is not applicable. I don't see anything that states "Other Services" as you say.
                But even if it isn't applicable, there's also 250.97

                Comment


                • #9
                  Originally posted by Sunking View Post
                  Please do not give advice or answer questions because you have no clue what you are talking about. Ground wires can be Bare, Insulated, Stranded, or Sold. Can bare or insulated go in conduit? Absolutely it can. In fact no ground wire is even required because if you use the proper fittings, you use the EMT as the wire. So please just be a reader or ask questions because you do not know what you are talking about..
                  Way to be an A$$hole. You'll notice I didn't specifically say that I knew it was prohibited. And in fact it is in some places.
                  I also gave legitimate solutions if it was an issue.

                  Comment


                  • #10
                    Originally posted by foo1bar View Post

                    Whether you like it or not, the EGC is commonly referred to as a ground wire.

                    But back to what you said: "The only conductor required to be bonded to the metallic raceway is the Ground Electrode Conductor,"
                    The EGC is a conductor, and is required to be bonded to the metallic raceway.

                    I think 250.86 is applicable. I don't see anything that indicates it is not applicable. I don't see anything that states "Other Services" as you say.
                    But even if it isn't applicable, there's also 250.97
                    You do not know what you are talking about. EGC is not a Ground Conductor. You cannot even find EGC defined in NEC anymore. It was removed two code cycles ago. It is called Equipment Bonding Conductor (EBC) which is defined in NEC. It has nothing to do with earth except referenced to it by the GEC.

                    You seem to forget I sat on NEC Code Making Panel 9 for 6-years (Those are the morons that write 250 and various other articles in the NEC) and I moderate a NEC Code Forum and chief moderator for Bonding ,Batteries, and Sensitive Electronics. I know exactly what the code says and the intent of the code. Some how you cannot read and interpret what the code actually says.

                    250.86 is for OTHER SERVICES like your CATV and TELCO lines which says their raceways shall be bonded. Somehow you came up with meaning EBC must be bonded to the Raceways which is just nonsense. The other half of 250.86 is if you have an isolated section of raceway like EMT carrying your CATV and Telco line inside the house shall be bonded. That can be done with a EBC or BJ.

                    Now you come up with 250.97 which cover circuits of over 250 volts. OK that could be your conduit carrying your PV conductors to the Inverter. So what? That gives you two options:

                    1. You can carry a EBC in the conduit
                    2. Leave it out and use the Conduit as the EBC

                    Either way works because the EMT is the EBC if you followed code and used approved Clamps and Connectors which make continuity all the way to the GEC at the service panel.

                    Here is a very simple application where 250.86 would apply. A client is building a new stick built home. Me being the EC is going to use NM-B aka Romex wiring. I go to the electrical supply house to buy Junction Boxes for Splices, Receptacles. and Switches. I tell the counter help I want Plastic Boxes. Counter help tells me they are trying to clear out steel boxes out of inventory and cut cost to half what plastic cost, saving me $2000 on materials that goes right into my pocket. So I get the Steel Boxes. Now 250.86 applies. I will be required to bond the bare EBC inside the Romex to the Metal Boxes and the Switch/Receptacle plates. If I ran conduit from the Breaker panel, I am not required to even run a EBC or connect the bare wire in the ROMEX because the EMT is the EBC. However I would connect it because I wear a both a belt and suspenders. That will get me two green check marks from the smiling inspector because I have redundant fault paths. Code only requires ONE, take your pick or use both.

                    By your logic, you would call any conductor without a fuse or breaker a Ground. You would certainly call the Grounded Circuit Conductor a ground by your logic right? I promise it is not called a ground. Do you even know what a grounded circuit conductor is?
                    Last edited by Sunking; 10-17-2018, 04:35 PM.
                    MSEE, PE

                    Comment


                    • #11
                      Originally posted by foo1bar View Post
                      I think 250.86 is applicable. I don't see anything that indicates it is not applicable. I don't see anything that states "Other Services" as you say.
                      Open NEC 250.86 and read the TITLE.

                      250.86 OTHER CONDUCTOR ENCLOSURES AND RACEWAY

                      What do you think that means? You cannot even understand what you wrote yourself in post #6 and I quote you directly:

                      Originally posted by foo1bar View Post
                      NEC 250.86 Other Conductor Enclosures and Raceways
                      That would be your CATV, Telephone, Internet, AV equipment, ect... anything other than Electrical building power and lighting conductors. They are all required to be BONDED. Has nothing to do with dirt other than referenced to dirt via GEC at the Service Panel. There is only one ground conductor.

                      Last edited by Sunking; 10-17-2018, 04:00 PM.
                      MSEE, PE

                      Comment


                      • #12
                        Originally posted by emartin00 View Post
                        Way to be an A$$hole.
                        Thank you. You still do not know what you are talking about and should not be answering any questions. Ask all the questions you want.

                        MSEE, PE

                        Comment


                        • #13
                          Originally posted by Sunking View Post
                          You cannot even find EGC defined in NEC anymore. It was removed two code cycles ago.
                          Let's check 2017 NFPA 70 (aka 2017 NEC) which is the most recent code.

                          Here's what it has:

                          "Grounding Conductor, Equipment (EGC), the Conductive path(s) that provides a ground-fault current path and connects normally non-current-carrying metal parts of equipment together and to the system grounded conductor or to the grounding electrode conductor, or both (CMP-5)"


                          It is called Equipment Bonding Conductor (EBC) which is defined in NEC. It has nothing to do with earth except referenced to it by the GEC.
                          It's still called EGC - and is commonly called the ground wire.
                          I'd bet if you took a survey of electricians and ask them what they most often call the bare copper wire in a chunk of romex and gave them the choices of EBC, EGC, or ground wire you would get an overwhelming response that they still call it the ground wire. Even though they may know the technical difference of an EGC and GEC.

                          You seem to forget I sat on NEC Code Making Panel 9 for 6-years (Those are the morons that write 250 and various other articles in the NEC) and I moderate a NEC Code Forum and chief moderator for Bonding ,Batteries, and Sensitive Electronics. I know exactly what the code says and the intent of the code. Some how you cannot read and interpret what the code actually says.
                          I think we've established above that you do NOT know exactly what the code says.
                          And I don't think anyone would expect you to know exactly what the code says for every part of it.
                          OTOH, when you're making false statements about it (ex. EGC definition above) and claiming to be an expert who knows exactly what it says you shouldn't be surprised to get a response correcting you.

                          Does the NEC Code forum you moderate provide a method to do a survey?
                          You claim metal conduit is not required to be bonded to the EGC or anything else - except if it has the GEC inside it - and then it has to be bonded at both ends.
                          Is that an accurate statement of your claim?
                          I claim a metal conduit IS required to be bonded to the EGC - at least at one end of it - unless it meets one of the exceptions listed.
                          I think the overwhelming response on it would be that a metal conduit must be bonded to the EGC.
                          If it's mikeholt website you're talking about, any of us could even see the responses you get.

                          250.86 is for OTHER SERVICES
                          250.86 in NEC 2017 does not mention other services
                          It says "Other Conductor enclosures and raceway"
                          Looking at it in context the "other conductor" appears to be referring to "other than service conductors"

                          In addition, the first exception is explicitly talking about electrical wiring (ex. "nonmetallic-sheathed cable"), and not CATV/telco.
                          So I think you're the one who is not reading the code here - it does not say other services.


                          So I get the Steel Boxes. Now 250.86 applies.I will be required to bond the bare EBC inside the Romex to the Metal Boxes and the Switch/Receptacle plates. If I ran conduit from the Breaker panel, I am not required to even run a EBC or connect the bare wire in the ROMEX because the EMT is the EBC.
                          I will assume you meant to say "If I ran metal conduit ..." - because if you run PVC conduit you certainly are required to connect the bare wire in the romex.
                          But - why do you now say 250.86 applies? I have consistently said it applies to electrical wiring (other than service conductors). Until now you've been saying it's just "other services" like CATV and phone. NM cable and switch/receptacles wouldn't be "other services".

                          The example you're giving seems to agree with what I have stated previously - that you would bond the EMT by connecting it to the metal box, and connecting the EGC to the metal box via a ground screw. (if you have EMT or other metal conduit going all the way back to the ground bar in the main panel, that would also bond the conduit to the EGC)

                          Comment


                          • #14
                            Go read 250.118 Types of Grounding Conductors

                            1. Copper, aluminum, cooper-steel clad, stranded, solid, bare, insulated wire of any type or busbar.
                            2. Rigid Metal Conduit RMC
                            3. Intermediate Metal Conduit IMC
                            4. Electrical Metal Tubing EMT
                            5. Listed Flexible Metal Conduit
                            6. Liquidtight

                            So I run EMT from my breaker panel out to on top of the house to feed an Air Conditioner Compressor. Am I required to run a equipment ground wire ( using your antiquated term) ?

                            Answer is NO, none required because the conduit is the ground, again your terms. Most EC's including myself would run a bonding conductor, but there is no requirement to do so.

                            Next question. I install panels on the roof, and I use EMT to penetrate the roof, but the EMT dead ends in the attic and transitions to PVC going to Inverter. What are you required to do with a isolated conduit run?

                            Answer is refer to 250.86. You would run a Equipment Bonding Conductor to the panels and bond it to the Junction Box under that big GREEN SCREW inside of it. Bond your panels and you are done. The conduit is now bonded via the Junction Box and meets the requirement of 250.86.

                            Got a piece of metal conduit you use to run CATV and Telephone line inside the house? What are you required to do?

                            Answer is refer to 250.86. CATV and Telephone circuits are OTHER CONDUCTORS, meaning the conductors are not Power and Lightning. You would be required to bond the Conduit, to the nearest access point. Generally both services if up to code are bonded are using an Intersystem Bonding Terminal. (IBT) You would bond that conduit with an Auxiliary Bonding Jumper to the IBT. Although the IBT is connected to the GEC or Electrodes, it is not called Ground.

                            All your arguments are blown out of the water with 250.118. Run any type of metal conduit, no Bonding Conductors required. So why are you bonding Conduit? It is already bonded. Run all the ground wires you want. They are used to bond the equipment like your toaster oven, gadget, gizmo, air conditioner, or whatever you got connected to it. Its purpose is to minimize touch potential and provide a planned fault path back to the Grounded Circuit Conductor which you did not answer; What is the Grounded Circuit Conductor and why is it not called Ground?

                            If it were my panels on my roof, no Equipment Bonding Jumpers would be ran, I would use PVC so there is no path to earth through my home. I would not use my option afforded to me using a Equipment Bonding Conductor ran with circuit conductors. That is just stupid and dangerous. Nope I would treat the panels like Air Strike Terminals and use Down Conductors and connect directly to one of the Bonded Ground Electrodes. If I had to use metal conduit to run the down conductors you treat it just like the GEC and would be required to bond it to the raceway to eliminate Magnetic Choking. But it is not called a Ground Conductor because there can only be 1 ground conductor; the GEC. Everything else is a Bonding Conductor like a Equipment Bonding Conductor or Auxiliary Bonding Conductor, Main Bonding Jumper, and the list goes on. If someone tells you to ground something does not tell you anything. So to eliminate confusion names of conductors were changed to differentiate the conductors. The word ground was replaced with Bonding. The only conductor referred to as "Ground" is the Ground Electrode Conductor and that is a very specific conductor and there is only one of them .
                            Last edited by Sunking; 10-18-2018, 12:21 AM.
                            MSEE, PE

                            Comment


                            • #15
                              Originally posted by Sunking View Post
                              Next question. I install panels on the roof, and I use EMT to penetrate the roof, but the EMT dead ends in the attic and transitions to PVC going to Inverter. What are you required to do with a isolated conduit run?

                              Answer is refer to 250.86. You would run a Equipment Bonding Conductor to the panels and bond it to the Junction Box under that big GREEN SCREW inside of it. Bond your panels and you are done. The conduit is now bonded via the Junction Box and meets the requirement of 250.86.
                              Ok - so now you agree that the conduit from the OP's original question DOES need to be bonded to the EGC.
                              Glad you came around to what I've been saying.

                              All your arguments are blown out of the water with 250.118. Run any type of metal conduit, no Bonding Conductors required. So why are you bonding Conduit? It is already bonded.
                              How does 250.118 cause my arguments to be "blown out of the water"?
                              It just gives different ways that the conduit could be connected to the EGC.
                              Nothing in what I have posted says that you can't use conduit and metal junction boxes as your EGC pathway all the way back to your main panel.

                              The word ground was replaced with Bonding. The only conductor referred to as "Ground" is the Ground Electrode Conductor
                              Perhaps that's going to be in the next revision, but at least as of NEC 2017 it still refers to EGC.

                              Comment

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