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Class 1 Division 2 Electrical Panel Installation Question

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    Class 1 Division 2 Electrical Panel Installation Question

    Hi,

    I have a project in a automotive shop and we are planning on installing our main electrical panels on the ground floor. (class 1 div 2).

    I read sections 501 and 511.3(c).

    If I mount the electrical panel at 18" AFF, do I have to worry about section 501 regarding conduits and fittings?

    I have another situation. We have stub up coming from the concrete ground and the stub up is opening into a wireway. The wireway then leads to a electrical panel that is 18" AFF.

    To make this situation work, can i put a flexible or rigid conduit with listed fittings per per NEC 501.10)B from the stub up to the electrical panel?

    Last edited by Puppy6; 09-25-19, 09:57 PM.

    #2
    Any wiring and equipment in the Divison 2 location are affected. In addition, see Section 511.7. Listed flexible or rigid conduit is usually acceptable in the Division 2 location; however, see below.

    Stub-ups may require a seal between the wiring below 18' and above 18". See Section 501.15(B)(2). I said, "may" because Exception No.1 often applies.
    "Bob"
    Robert B. Alexander, P.E.
    Answers based on 2017 NEC unless otherwise noted.

    Comment


      #3
      Originally posted by rbalex View Post
      Any wiring and equipment in the Divison 2 location are affected. In addition, see Section 511.7. Listed flexible or rigid conduit is usually acceptable in the Division 2 location; however, see below.

      Stub-ups may require a seal between the wiring below 18' and above 18". See Section 501.15(B)(2). I said, "may" because Exception No.1 often applies.
      thanks for the quick response!

      Unfortunately, exception no.1 doesnt apply to our project. The stubup is only about 6".

      I am confused.

      If i put a seal fitting on the 6" stub, and then route the conduit (approved conduit per NEC) from that point to my panel, would that be sufficient enough? (the panel is above 18").

      Comment


        #4
        Originally posted by Puppy6 View Post
        ...
        If i put a seal fitting on the 6" stub, and then route the conduit (approved conduit per NEC) from that point to my panel, would that be sufficient enough? (the panel is above 18").
        This potentially a problem. Section 501.15(B)(2):
        ...
        Rigid metal conduit or threaded steel intermediate metal conduit shall be used between the sealing fitting and the point at which the conduit leaves the Division 2 location, and a threaded connection shall be used at the sealing fitting. The conduit run between the conduit seal and the point at which the conduit leaves the Division 2 location shall contain no union. coupling, box, or other fitting except for a listed explosionproof reducer installed at the conduit seal. Such seals shall not be required to be explosionproof but shall be identified for the purpose of minimizing the passage of gases permitted under normal operating conditions and shall be accessible.
        "Bob"
        Robert B. Alexander, P.E.
        Answers based on 2017 NEC unless otherwise noted.

        Comment

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