Using conduit with THHNIs it against code to create a NM-B to THHN junction inside a conduit body?Can I run 100A service from a 200A panel in a garage to a house with an existing 60A service?Conduit fill size when using multiple cables of different sizesConduit Size for Sub-Panel run?Running NM-B in PVC SCH 40 Conduit from Outdoor Breaker PanelSuitability of disconnect switchinterpretation of conduit vs raceway wet location vs outdoor vs NM NM-BService Panel and New Underground Conduit125amp feed from garage to house, required wire size, PLUS a separate 3-way light switchSub-panel wiring, grounding, disconnect

Why was New Asgard established at this place?

How to make all magic-casting innate, but still rare?

I just entered the USA without passport control at Atlanta airport

Math symbols in math operators

What mathematical theory is required for high frequency trading?

How "fast" do astronomical events occur?

I found a password with hashcat but it doesn't work

In a list with unique pairs A, B, how can I sort them so that the last B is the first A in the next pair?

How is the idea of "girlfriend material" naturally expressed in Russian?

Why is it 出差去 and not 去出差?

Examples of protocols that are insecure when run concurrently

Are intrusions within a foreign embassy considered an act of war?

How would one carboxylate CBG into its acid form, CBGA?

How much steel armor can you wear and still be able to swim?

How can I take pictures like these examples with a yellowish tone and point & shoot film camera look?

How can a warlock learn from a spellbook?

Is Newton's third law really correct?

Scaling an object to change its key

「捨ててしまう」why is there two て’s used here?

How can I prevent a user from copying files on another hard drive?

Boundaries and Buddhism

How are で and いう being used in this context?

Am I legally required to provide a (GPL licensed) source code even after a project is abandoned?

What is the most suitable position for a bishop here?



Using conduit with THHN


Is it against code to create a NM-B to THHN junction inside a conduit body?Can I run 100A service from a 200A panel in a garage to a house with an existing 60A service?Conduit fill size when using multiple cables of different sizesConduit Size for Sub-Panel run?Running NM-B in PVC SCH 40 Conduit from Outdoor Breaker PanelSuitability of disconnect switchinterpretation of conduit vs raceway wet location vs outdoor vs NM NM-BService Panel and New Underground Conduit125amp feed from garage to house, required wire size, PLUS a separate 3-way light switchSub-panel wiring, grounding, disconnect






.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;








3















May I run THHN above ground under a house unprotected or is a conduit required for this? The wires consist of 3 4AWG wires with an 8AWG ground going from a 60A breaker at the (100A) service to a newly built garage via underground wiring from the garage in 1.25" schedule 40 PVC and then under the house, which is raised on piers.










share|improve this question



















  • 1





    Did you mean THHN?

    – Machavity
    Jun 1 at 21:48











  • Are you talking about some sort of crawlspace here, or the space under a house that's been mounted on piers?

    – ThreePhaseEel
    Jun 1 at 23:43






  • 1





    dyslexic I am,...yes and yes to the space under house with piers

    – gchilton3
    Jun 2 at 1:08

















3















May I run THHN above ground under a house unprotected or is a conduit required for this? The wires consist of 3 4AWG wires with an 8AWG ground going from a 60A breaker at the (100A) service to a newly built garage via underground wiring from the garage in 1.25" schedule 40 PVC and then under the house, which is raised on piers.










share|improve this question



















  • 1





    Did you mean THHN?

    – Machavity
    Jun 1 at 21:48











  • Are you talking about some sort of crawlspace here, or the space under a house that's been mounted on piers?

    – ThreePhaseEel
    Jun 1 at 23:43






  • 1





    dyslexic I am,...yes and yes to the space under house with piers

    – gchilton3
    Jun 2 at 1:08













3












3








3








May I run THHN above ground under a house unprotected or is a conduit required for this? The wires consist of 3 4AWG wires with an 8AWG ground going from a 60A breaker at the (100A) service to a newly built garage via underground wiring from the garage in 1.25" schedule 40 PVC and then under the house, which is raised on piers.










share|improve this question
















May I run THHN above ground under a house unprotected or is a conduit required for this? The wires consist of 3 4AWG wires with an 8AWG ground going from a 60A breaker at the (100A) service to a newly built garage via underground wiring from the garage in 1.25" schedule 40 PVC and then under the house, which is raised on piers.







electrical wiring conduit






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Jun 2 at 14:13









ThreePhaseEel

34.9k1155105




34.9k1155105










asked Jun 1 at 21:40









gchilton3gchilton3

163




163







  • 1





    Did you mean THHN?

    – Machavity
    Jun 1 at 21:48











  • Are you talking about some sort of crawlspace here, or the space under a house that's been mounted on piers?

    – ThreePhaseEel
    Jun 1 at 23:43






  • 1





    dyslexic I am,...yes and yes to the space under house with piers

    – gchilton3
    Jun 2 at 1:08












  • 1





    Did you mean THHN?

    – Machavity
    Jun 1 at 21:48











  • Are you talking about some sort of crawlspace here, or the space under a house that's been mounted on piers?

    – ThreePhaseEel
    Jun 1 at 23:43






  • 1





    dyslexic I am,...yes and yes to the space under house with piers

    – gchilton3
    Jun 2 at 1:08







1




1





Did you mean THHN?

– Machavity
Jun 1 at 21:48





Did you mean THHN?

– Machavity
Jun 1 at 21:48













Are you talking about some sort of crawlspace here, or the space under a house that's been mounted on piers?

– ThreePhaseEel
Jun 1 at 23:43





Are you talking about some sort of crawlspace here, or the space under a house that's been mounted on piers?

– ThreePhaseEel
Jun 1 at 23:43




1




1





dyslexic I am,...yes and yes to the space under house with piers

– gchilton3
Jun 2 at 1:08





dyslexic I am,...yes and yes to the space under house with piers

– gchilton3
Jun 2 at 1:08










2 Answers
2






active

oldest

votes


















4














Any time you are running bare conductors in a dwelling unit that are not part of a cable system such as NM or MC, then they must be run in a conduit. Once you get to the exterior of the unit you could transition to a Direct burial cable such as UF or you could continue in a conduit system. The most common under ground conduit would be PVC and it could also be used under the house.



good luck



Special note: Most conductor insulation is multi rated but a straight THHN rating is not rated for wet locations it should also be labeled as THWN to be approved for buried circuits.






share|improve this answer






























    3














    Remember you need Schedule 80 PVC where the conduit approaches the surface or in a place subject to potential damage. It is thicker pipe, but the joint surfaces are compatible with Sched 40. (it sacrifices inside diameter).



    Single wires need to be inside a conduit or raceway their entire run. So no, you cannot direct-affix THHN wires. You have several options:



    • Run conduit the entire way. Feel free to switch to EMT once you are out of the earth; you will get less contact cement on your fingers and you won't need expansion joints. Bonus: EMT is the ground path so you don't need that #8 ground. (which is fine by the way).

    • Install a junction box, and splice to a multi-conductor cable for the rest of the run. This will require a Rather Large junction box, and Polaris connectors, and large entry hole, and large cable clamp for the cable - and the cost of all that might be worse than the EMT.

    • The dreaded "cable in conduit" - run appropriate wet-rated cable the entire run, and go through the pain and suffering of cramming the cable through the conduit. Not a fan of this one; fair chance it will overwhelm your DIY skills and force you to pay an electrician a small fortune to pull the cable and finish the job (they won't just pull).

    As an aside, your wet location needs THWN wires, but almost all THHN is dual-marked as both THHN and THWN-2.



    Some other gotchas:



    For a 100A feeder to a subpanel, you need #3 copper (better: #1 aluminum). Lots of people get tripped up by this*. If you are married to #4, you are limited to 70A.



    #include standard "Aluminum is the right stuff for feeder" speech.



    #include standard "compute voltage drop based on practical load not breaker trip, and don't compute based on 3%" speech.




    At an outbuilding, your subpanel will need a shutoff switch. The cheapest way to get a shutoff switch is pick a subpanel that has a main breaker. You're not using it as a main breaker, capische? So don't match the main breaker to he feeder breaker. It's irrelevant and will force poor panel choices, like a 4-space panel for 60A or 12-space for 100A. You want more spaces than that -- really.



    Spaces are dirt cheap when buying a panel. The biggest cliche in home subpanels is spending $400 too much on wire, but saving $40 getting a too-small panel, promptly running out of spaces**, and having to spend another $100 replacing the panel. You want enough breaker spaces that you never run out, because spaces are cheap before you install it, and expensive after.





    *The reason this mistake happens is people drawing from a table intended for service entrances. This has been such an epidemic that the table has been removed from NEC.



    ** "circuits" don't count as "spaces", so a 12 space/24 circuit panel is in fact only 12 spaces. 24 relies on "double-stuff" breakers, which don't come in AFCI or GFCI, so such a panel is only 24 circuits in an imaginary world where those are not required. Here on Earth it's a 12-circuit.






    share|improve this answer























    • His feeder is 60A, BTW

      – ThreePhaseEel
      Jun 2 at 14:13











    • @ThreePhaseEel for now, yes. But that choice of wire allows him headroom to swap in a 70A breaker at his discretion... my point is, not a 100A and a bump from 4 to 3 will give him 100A.

      – Harper
      Jun 2 at 14:19












    • Noted, I was told as much by codes inspector, but have too many "expert friends" who I need to turn off. Thanks all.

      – gchilton3
      Jun 2 at 20:07











    • how do I vote on this boards help ,4stars, if I knew how.

      – gchilton3
      Jun 2 at 20:17











    • Code inspectors will tell you #4 for 100A @gchilton3, because that is allowed for "service" wire. i.e. every load in the service goes down that wire. They're almost always dealing with that, so it's habit. They are thinking of 310.15b7 which applies to service and whole-service feeder, used to be a table and now is an 83% favorable derate. The correct branch/subfeed table: 310.15b16 using the 60C column <100A and 75C column >=100A. Which is a visual mess.

      – Harper
      Jun 2 at 20:18












    Your Answer








    StackExchange.ready(function()
    var channelOptions =
    tags: "".split(" "),
    id: "73"
    ;
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function()
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled)
    StackExchange.using("snippets", function()
    createEditor();
    );

    else
    createEditor();

    );

    function createEditor()
    StackExchange.prepareEditor(
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: false,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: null,
    bindNavPrevention: true,
    postfix: "",
    imageUploader:
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    ,
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    );



    );













    draft saved

    draft discarded


















    StackExchange.ready(
    function ()
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fdiy.stackexchange.com%2fquestions%2f166407%2fusing-conduit-with-thhn%23new-answer', 'question_page');

    );

    Post as a guest















    Required, but never shown

























    2 Answers
    2






    active

    oldest

    votes








    2 Answers
    2






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    4














    Any time you are running bare conductors in a dwelling unit that are not part of a cable system such as NM or MC, then they must be run in a conduit. Once you get to the exterior of the unit you could transition to a Direct burial cable such as UF or you could continue in a conduit system. The most common under ground conduit would be PVC and it could also be used under the house.



    good luck



    Special note: Most conductor insulation is multi rated but a straight THHN rating is not rated for wet locations it should also be labeled as THWN to be approved for buried circuits.






    share|improve this answer



























      4














      Any time you are running bare conductors in a dwelling unit that are not part of a cable system such as NM or MC, then they must be run in a conduit. Once you get to the exterior of the unit you could transition to a Direct burial cable such as UF or you could continue in a conduit system. The most common under ground conduit would be PVC and it could also be used under the house.



      good luck



      Special note: Most conductor insulation is multi rated but a straight THHN rating is not rated for wet locations it should also be labeled as THWN to be approved for buried circuits.






      share|improve this answer

























        4












        4








        4







        Any time you are running bare conductors in a dwelling unit that are not part of a cable system such as NM or MC, then they must be run in a conduit. Once you get to the exterior of the unit you could transition to a Direct burial cable such as UF or you could continue in a conduit system. The most common under ground conduit would be PVC and it could also be used under the house.



        good luck



        Special note: Most conductor insulation is multi rated but a straight THHN rating is not rated for wet locations it should also be labeled as THWN to be approved for buried circuits.






        share|improve this answer













        Any time you are running bare conductors in a dwelling unit that are not part of a cable system such as NM or MC, then they must be run in a conduit. Once you get to the exterior of the unit you could transition to a Direct burial cable such as UF or you could continue in a conduit system. The most common under ground conduit would be PVC and it could also be used under the house.



        good luck



        Special note: Most conductor insulation is multi rated but a straight THHN rating is not rated for wet locations it should also be labeled as THWN to be approved for buried circuits.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Jun 2 at 1:46









        Retired Master ElectricianRetired Master Electrician

        9,615627




        9,615627























            3














            Remember you need Schedule 80 PVC where the conduit approaches the surface or in a place subject to potential damage. It is thicker pipe, but the joint surfaces are compatible with Sched 40. (it sacrifices inside diameter).



            Single wires need to be inside a conduit or raceway their entire run. So no, you cannot direct-affix THHN wires. You have several options:



            • Run conduit the entire way. Feel free to switch to EMT once you are out of the earth; you will get less contact cement on your fingers and you won't need expansion joints. Bonus: EMT is the ground path so you don't need that #8 ground. (which is fine by the way).

            • Install a junction box, and splice to a multi-conductor cable for the rest of the run. This will require a Rather Large junction box, and Polaris connectors, and large entry hole, and large cable clamp for the cable - and the cost of all that might be worse than the EMT.

            • The dreaded "cable in conduit" - run appropriate wet-rated cable the entire run, and go through the pain and suffering of cramming the cable through the conduit. Not a fan of this one; fair chance it will overwhelm your DIY skills and force you to pay an electrician a small fortune to pull the cable and finish the job (they won't just pull).

            As an aside, your wet location needs THWN wires, but almost all THHN is dual-marked as both THHN and THWN-2.



            Some other gotchas:



            For a 100A feeder to a subpanel, you need #3 copper (better: #1 aluminum). Lots of people get tripped up by this*. If you are married to #4, you are limited to 70A.



            #include standard "Aluminum is the right stuff for feeder" speech.



            #include standard "compute voltage drop based on practical load not breaker trip, and don't compute based on 3%" speech.




            At an outbuilding, your subpanel will need a shutoff switch. The cheapest way to get a shutoff switch is pick a subpanel that has a main breaker. You're not using it as a main breaker, capische? So don't match the main breaker to he feeder breaker. It's irrelevant and will force poor panel choices, like a 4-space panel for 60A or 12-space for 100A. You want more spaces than that -- really.



            Spaces are dirt cheap when buying a panel. The biggest cliche in home subpanels is spending $400 too much on wire, but saving $40 getting a too-small panel, promptly running out of spaces**, and having to spend another $100 replacing the panel. You want enough breaker spaces that you never run out, because spaces are cheap before you install it, and expensive after.





            *The reason this mistake happens is people drawing from a table intended for service entrances. This has been such an epidemic that the table has been removed from NEC.



            ** "circuits" don't count as "spaces", so a 12 space/24 circuit panel is in fact only 12 spaces. 24 relies on "double-stuff" breakers, which don't come in AFCI or GFCI, so such a panel is only 24 circuits in an imaginary world where those are not required. Here on Earth it's a 12-circuit.






            share|improve this answer























            • His feeder is 60A, BTW

              – ThreePhaseEel
              Jun 2 at 14:13











            • @ThreePhaseEel for now, yes. But that choice of wire allows him headroom to swap in a 70A breaker at his discretion... my point is, not a 100A and a bump from 4 to 3 will give him 100A.

              – Harper
              Jun 2 at 14:19












            • Noted, I was told as much by codes inspector, but have too many "expert friends" who I need to turn off. Thanks all.

              – gchilton3
              Jun 2 at 20:07











            • how do I vote on this boards help ,4stars, if I knew how.

              – gchilton3
              Jun 2 at 20:17











            • Code inspectors will tell you #4 for 100A @gchilton3, because that is allowed for "service" wire. i.e. every load in the service goes down that wire. They're almost always dealing with that, so it's habit. They are thinking of 310.15b7 which applies to service and whole-service feeder, used to be a table and now is an 83% favorable derate. The correct branch/subfeed table: 310.15b16 using the 60C column <100A and 75C column >=100A. Which is a visual mess.

              – Harper
              Jun 2 at 20:18
















            3














            Remember you need Schedule 80 PVC where the conduit approaches the surface or in a place subject to potential damage. It is thicker pipe, but the joint surfaces are compatible with Sched 40. (it sacrifices inside diameter).



            Single wires need to be inside a conduit or raceway their entire run. So no, you cannot direct-affix THHN wires. You have several options:



            • Run conduit the entire way. Feel free to switch to EMT once you are out of the earth; you will get less contact cement on your fingers and you won't need expansion joints. Bonus: EMT is the ground path so you don't need that #8 ground. (which is fine by the way).

            • Install a junction box, and splice to a multi-conductor cable for the rest of the run. This will require a Rather Large junction box, and Polaris connectors, and large entry hole, and large cable clamp for the cable - and the cost of all that might be worse than the EMT.

            • The dreaded "cable in conduit" - run appropriate wet-rated cable the entire run, and go through the pain and suffering of cramming the cable through the conduit. Not a fan of this one; fair chance it will overwhelm your DIY skills and force you to pay an electrician a small fortune to pull the cable and finish the job (they won't just pull).

            As an aside, your wet location needs THWN wires, but almost all THHN is dual-marked as both THHN and THWN-2.



            Some other gotchas:



            For a 100A feeder to a subpanel, you need #3 copper (better: #1 aluminum). Lots of people get tripped up by this*. If you are married to #4, you are limited to 70A.



            #include standard "Aluminum is the right stuff for feeder" speech.



            #include standard "compute voltage drop based on practical load not breaker trip, and don't compute based on 3%" speech.




            At an outbuilding, your subpanel will need a shutoff switch. The cheapest way to get a shutoff switch is pick a subpanel that has a main breaker. You're not using it as a main breaker, capische? So don't match the main breaker to he feeder breaker. It's irrelevant and will force poor panel choices, like a 4-space panel for 60A or 12-space for 100A. You want more spaces than that -- really.



            Spaces are dirt cheap when buying a panel. The biggest cliche in home subpanels is spending $400 too much on wire, but saving $40 getting a too-small panel, promptly running out of spaces**, and having to spend another $100 replacing the panel. You want enough breaker spaces that you never run out, because spaces are cheap before you install it, and expensive after.





            *The reason this mistake happens is people drawing from a table intended for service entrances. This has been such an epidemic that the table has been removed from NEC.



            ** "circuits" don't count as "spaces", so a 12 space/24 circuit panel is in fact only 12 spaces. 24 relies on "double-stuff" breakers, which don't come in AFCI or GFCI, so such a panel is only 24 circuits in an imaginary world where those are not required. Here on Earth it's a 12-circuit.






            share|improve this answer























            • His feeder is 60A, BTW

              – ThreePhaseEel
              Jun 2 at 14:13











            • @ThreePhaseEel for now, yes. But that choice of wire allows him headroom to swap in a 70A breaker at his discretion... my point is, not a 100A and a bump from 4 to 3 will give him 100A.

              – Harper
              Jun 2 at 14:19












            • Noted, I was told as much by codes inspector, but have too many "expert friends" who I need to turn off. Thanks all.

              – gchilton3
              Jun 2 at 20:07











            • how do I vote on this boards help ,4stars, if I knew how.

              – gchilton3
              Jun 2 at 20:17











            • Code inspectors will tell you #4 for 100A @gchilton3, because that is allowed for "service" wire. i.e. every load in the service goes down that wire. They're almost always dealing with that, so it's habit. They are thinking of 310.15b7 which applies to service and whole-service feeder, used to be a table and now is an 83% favorable derate. The correct branch/subfeed table: 310.15b16 using the 60C column <100A and 75C column >=100A. Which is a visual mess.

              – Harper
              Jun 2 at 20:18














            3












            3








            3







            Remember you need Schedule 80 PVC where the conduit approaches the surface or in a place subject to potential damage. It is thicker pipe, but the joint surfaces are compatible with Sched 40. (it sacrifices inside diameter).



            Single wires need to be inside a conduit or raceway their entire run. So no, you cannot direct-affix THHN wires. You have several options:



            • Run conduit the entire way. Feel free to switch to EMT once you are out of the earth; you will get less contact cement on your fingers and you won't need expansion joints. Bonus: EMT is the ground path so you don't need that #8 ground. (which is fine by the way).

            • Install a junction box, and splice to a multi-conductor cable for the rest of the run. This will require a Rather Large junction box, and Polaris connectors, and large entry hole, and large cable clamp for the cable - and the cost of all that might be worse than the EMT.

            • The dreaded "cable in conduit" - run appropriate wet-rated cable the entire run, and go through the pain and suffering of cramming the cable through the conduit. Not a fan of this one; fair chance it will overwhelm your DIY skills and force you to pay an electrician a small fortune to pull the cable and finish the job (they won't just pull).

            As an aside, your wet location needs THWN wires, but almost all THHN is dual-marked as both THHN and THWN-2.



            Some other gotchas:



            For a 100A feeder to a subpanel, you need #3 copper (better: #1 aluminum). Lots of people get tripped up by this*. If you are married to #4, you are limited to 70A.



            #include standard "Aluminum is the right stuff for feeder" speech.



            #include standard "compute voltage drop based on practical load not breaker trip, and don't compute based on 3%" speech.




            At an outbuilding, your subpanel will need a shutoff switch. The cheapest way to get a shutoff switch is pick a subpanel that has a main breaker. You're not using it as a main breaker, capische? So don't match the main breaker to he feeder breaker. It's irrelevant and will force poor panel choices, like a 4-space panel for 60A or 12-space for 100A. You want more spaces than that -- really.



            Spaces are dirt cheap when buying a panel. The biggest cliche in home subpanels is spending $400 too much on wire, but saving $40 getting a too-small panel, promptly running out of spaces**, and having to spend another $100 replacing the panel. You want enough breaker spaces that you never run out, because spaces are cheap before you install it, and expensive after.





            *The reason this mistake happens is people drawing from a table intended for service entrances. This has been such an epidemic that the table has been removed from NEC.



            ** "circuits" don't count as "spaces", so a 12 space/24 circuit panel is in fact only 12 spaces. 24 relies on "double-stuff" breakers, which don't come in AFCI or GFCI, so such a panel is only 24 circuits in an imaginary world where those are not required. Here on Earth it's a 12-circuit.






            share|improve this answer













            Remember you need Schedule 80 PVC where the conduit approaches the surface or in a place subject to potential damage. It is thicker pipe, but the joint surfaces are compatible with Sched 40. (it sacrifices inside diameter).



            Single wires need to be inside a conduit or raceway their entire run. So no, you cannot direct-affix THHN wires. You have several options:



            • Run conduit the entire way. Feel free to switch to EMT once you are out of the earth; you will get less contact cement on your fingers and you won't need expansion joints. Bonus: EMT is the ground path so you don't need that #8 ground. (which is fine by the way).

            • Install a junction box, and splice to a multi-conductor cable for the rest of the run. This will require a Rather Large junction box, and Polaris connectors, and large entry hole, and large cable clamp for the cable - and the cost of all that might be worse than the EMT.

            • The dreaded "cable in conduit" - run appropriate wet-rated cable the entire run, and go through the pain and suffering of cramming the cable through the conduit. Not a fan of this one; fair chance it will overwhelm your DIY skills and force you to pay an electrician a small fortune to pull the cable and finish the job (they won't just pull).

            As an aside, your wet location needs THWN wires, but almost all THHN is dual-marked as both THHN and THWN-2.



            Some other gotchas:



            For a 100A feeder to a subpanel, you need #3 copper (better: #1 aluminum). Lots of people get tripped up by this*. If you are married to #4, you are limited to 70A.



            #include standard "Aluminum is the right stuff for feeder" speech.



            #include standard "compute voltage drop based on practical load not breaker trip, and don't compute based on 3%" speech.




            At an outbuilding, your subpanel will need a shutoff switch. The cheapest way to get a shutoff switch is pick a subpanel that has a main breaker. You're not using it as a main breaker, capische? So don't match the main breaker to he feeder breaker. It's irrelevant and will force poor panel choices, like a 4-space panel for 60A or 12-space for 100A. You want more spaces than that -- really.



            Spaces are dirt cheap when buying a panel. The biggest cliche in home subpanels is spending $400 too much on wire, but saving $40 getting a too-small panel, promptly running out of spaces**, and having to spend another $100 replacing the panel. You want enough breaker spaces that you never run out, because spaces are cheap before you install it, and expensive after.





            *The reason this mistake happens is people drawing from a table intended for service entrances. This has been such an epidemic that the table has been removed from NEC.



            ** "circuits" don't count as "spaces", so a 12 space/24 circuit panel is in fact only 12 spaces. 24 relies on "double-stuff" breakers, which don't come in AFCI or GFCI, so such a panel is only 24 circuits in an imaginary world where those are not required. Here on Earth it's a 12-circuit.







            share|improve this answer












            share|improve this answer



            share|improve this answer










            answered Jun 2 at 14:01









            HarperHarper

            82.9k557168




            82.9k557168












            • His feeder is 60A, BTW

              – ThreePhaseEel
              Jun 2 at 14:13











            • @ThreePhaseEel for now, yes. But that choice of wire allows him headroom to swap in a 70A breaker at his discretion... my point is, not a 100A and a bump from 4 to 3 will give him 100A.

              – Harper
              Jun 2 at 14:19












            • Noted, I was told as much by codes inspector, but have too many "expert friends" who I need to turn off. Thanks all.

              – gchilton3
              Jun 2 at 20:07











            • how do I vote on this boards help ,4stars, if I knew how.

              – gchilton3
              Jun 2 at 20:17











            • Code inspectors will tell you #4 for 100A @gchilton3, because that is allowed for "service" wire. i.e. every load in the service goes down that wire. They're almost always dealing with that, so it's habit. They are thinking of 310.15b7 which applies to service and whole-service feeder, used to be a table and now is an 83% favorable derate. The correct branch/subfeed table: 310.15b16 using the 60C column <100A and 75C column >=100A. Which is a visual mess.

              – Harper
              Jun 2 at 20:18


















            • His feeder is 60A, BTW

              – ThreePhaseEel
              Jun 2 at 14:13











            • @ThreePhaseEel for now, yes. But that choice of wire allows him headroom to swap in a 70A breaker at his discretion... my point is, not a 100A and a bump from 4 to 3 will give him 100A.

              – Harper
              Jun 2 at 14:19












            • Noted, I was told as much by codes inspector, but have too many "expert friends" who I need to turn off. Thanks all.

              – gchilton3
              Jun 2 at 20:07











            • how do I vote on this boards help ,4stars, if I knew how.

              – gchilton3
              Jun 2 at 20:17











            • Code inspectors will tell you #4 for 100A @gchilton3, because that is allowed for "service" wire. i.e. every load in the service goes down that wire. They're almost always dealing with that, so it's habit. They are thinking of 310.15b7 which applies to service and whole-service feeder, used to be a table and now is an 83% favorable derate. The correct branch/subfeed table: 310.15b16 using the 60C column <100A and 75C column >=100A. Which is a visual mess.

              – Harper
              Jun 2 at 20:18

















            His feeder is 60A, BTW

            – ThreePhaseEel
            Jun 2 at 14:13





            His feeder is 60A, BTW

            – ThreePhaseEel
            Jun 2 at 14:13













            @ThreePhaseEel for now, yes. But that choice of wire allows him headroom to swap in a 70A breaker at his discretion... my point is, not a 100A and a bump from 4 to 3 will give him 100A.

            – Harper
            Jun 2 at 14:19






            @ThreePhaseEel for now, yes. But that choice of wire allows him headroom to swap in a 70A breaker at his discretion... my point is, not a 100A and a bump from 4 to 3 will give him 100A.

            – Harper
            Jun 2 at 14:19














            Noted, I was told as much by codes inspector, but have too many "expert friends" who I need to turn off. Thanks all.

            – gchilton3
            Jun 2 at 20:07





            Noted, I was told as much by codes inspector, but have too many "expert friends" who I need to turn off. Thanks all.

            – gchilton3
            Jun 2 at 20:07













            how do I vote on this boards help ,4stars, if I knew how.

            – gchilton3
            Jun 2 at 20:17





            how do I vote on this boards help ,4stars, if I knew how.

            – gchilton3
            Jun 2 at 20:17













            Code inspectors will tell you #4 for 100A @gchilton3, because that is allowed for "service" wire. i.e. every load in the service goes down that wire. They're almost always dealing with that, so it's habit. They are thinking of 310.15b7 which applies to service and whole-service feeder, used to be a table and now is an 83% favorable derate. The correct branch/subfeed table: 310.15b16 using the 60C column <100A and 75C column >=100A. Which is a visual mess.

            – Harper
            Jun 2 at 20:18






            Code inspectors will tell you #4 for 100A @gchilton3, because that is allowed for "service" wire. i.e. every load in the service goes down that wire. They're almost always dealing with that, so it's habit. They are thinking of 310.15b7 which applies to service and whole-service feeder, used to be a table and now is an 83% favorable derate. The correct branch/subfeed table: 310.15b16 using the 60C column <100A and 75C column >=100A. Which is a visual mess.

            – Harper
            Jun 2 at 20:18


















            draft saved

            draft discarded
















































            Thanks for contributing an answer to Home Improvement Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid


            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.

            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function ()
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fdiy.stackexchange.com%2fquestions%2f166407%2fusing-conduit-with-thhn%23new-answer', 'question_page');

            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            Wikipedia:Vital articles Мазмуну Biography - Өмүр баян Philosophy and psychology - Философия жана психология Religion - Дин Social sciences - Коомдук илимдер Language and literature - Тил жана адабият Science - Илим Technology - Технология Arts and recreation - Искусство жана эс алуу History and geography - Тарых жана география Навигация менюсу

            Club Baloncesto Breogán Índice Historia | Pavillón | Nome | O Breogán na cultura popular | Xogadores | Adestradores | Presidentes | Palmarés | Historial | Líderes | Notas | Véxase tamén | Menú de navegacióncbbreogan.galCadroGuía oficial da ACB 2009-10, páxina 201Guía oficial ACB 1992, páxina 183. Editorial DB.É de 6.500 espectadores sentados axeitándose á última normativa"Estudiantes Junior, entre as mellores canteiras"o orixinalHemeroteca El Mundo Deportivo, 16 setembro de 1970, páxina 12Historia do BreogánAlfredo Pérez, o último canoneiroHistoria C.B. BreogánHemeroteca de El Mundo DeportivoJimmy Wright, norteamericano do Breogán deixará Lugo por ameazas de morteResultados de Breogán en 1986-87Resultados de Breogán en 1990-91Ficha de Velimir Perasović en acb.comResultados de Breogán en 1994-95Breogán arrasa al Barça. "El Mundo Deportivo", 27 de setembro de 1999, páxina 58CB Breogán - FC BarcelonaA FEB invita a participar nunha nova Liga EuropeaCharlie Bell na prensa estatalMáximos anotadores 2005Tempada 2005-06 : Tódolos Xogadores da Xornada""Non quero pensar nunha man negra, mais pregúntome que está a pasar""o orixinalRaúl López, orgulloso dos xogadores, presume da boa saúde económica do BreogánJulio González confirma que cesa como presidente del BreogánHomenaxe a Lisardo GómezA tempada do rexurdimento celesteEntrevista a Lisardo GómezEl COB dinamita el Pazo para forzar el quinto (69-73)Cafés Candelas, patrocinador del CB Breogán"Suso Lázare, novo presidente do Breogán"o orixinalCafés Candelas Breogán firma el mayor triunfo de la historiaEl Breogán realizará 17 homenajes por su cincuenta aniversario"O Breogán honra ao seu fundador e primeiro presidente"o orixinalMiguel Giao recibiu a homenaxe do PazoHomenaxe aos primeiros gladiadores celestesO home que nos amosa como ver o Breo co corazónTita Franco será homenaxeada polos #50anosdeBreoJulio Vila recibirá unha homenaxe in memoriam polos #50anosdeBreo"O Breogán homenaxeará aos seus aboados máis veteráns"Pechada ovación a «Capi» Sanmartín e Ricardo «Corazón de González»Homenaxe por décadas de informaciónPaco García volve ao Pazo con motivo do 50 aniversario"Resultados y clasificaciones""O Cafés Candelas Breogán, campión da Copa Princesa""O Cafés Candelas Breogán, equipo ACB"C.B. Breogán"Proxecto social"o orixinal"Centros asociados"o orixinalFicha en imdb.comMario Camus trata la recuperación del amor en 'La vieja música', su última película"Páxina web oficial""Club Baloncesto Breogán""C. B. Breogán S.A.D."eehttp://www.fegaba.com

            What should I write in an apology letter, since I have decided not to join a company after accepting an offer letterShould I keep looking after accepting a job offer?What should I do when I've been verbally told I would get an offer letter, but still haven't gotten one after 4 weeks?Do I accept an offer from a company that I am not likely to join?New job hasn't confirmed starting date and I want to give current employer as much notice as possibleHow should I address my manager in my resignation letter?HR delayed background verification, now jobless as resignedNo email communication after accepting a formal written offer. How should I phrase the call?What should I do if after receiving a verbal offer letter I am informed that my written job offer is put on hold due to some internal issues?Should I inform the current employer that I am about to resign within 1-2 weeks since I have signed the offer letter and waiting for visa?What company will do, if I send their offer letter to another company