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Thread: Using raceways to support other raceways

  1. #1
    Join Date
    Oct 2017
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    Wisconsin
    Posts
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    Using raceways to support other raceways

    Hello all,

    Can I use a raceway to support other (multiple) raceways?
    As shown in the picture below?
    https://ibb.co/hBHBvb

    Thanks
    Phillip

  2. #2
    Join Date
    Dec 2010
    Posts
    1,325
    300.11

    (B) Raceways Used as Means of Support. Raceways
    shall be used only as a means of support for other raceways,
    cables, or nonelectrical equipment under any of the
    following conditions:
    (1) Where the raceway or means of support is identified as
    a means of support
    (2) Where the raceway contains power supply conductors
    for electrically controlled equipment and is used to support
    Class 2 circuit conductors or cables that are solely
    for the purpose of connection to the equipment control
    circuits
    (3) Where the raceway is used to support boxes or conduit
    bodies in accordance with 314.23 or to support luminaires
    in accordance with 410.36(E)
    The more they overthink the plumbing, the easier it is to stop up the drain

  3. #3
    Join Date
    Jan 2009
    Location
    Maryland
    Posts
    12,427
    Maybe, doubtful. If the liquidtight has power conductors, no. If the liquidtight meets condition (2), possibly.

    2014 NEC

    300.11
    (B) Raceways Used as Means of Support. Raceways
    shall be used only as a means of support for other raceways,
    cables, or nonelectrical equipment under any of the
    following conditions:

    (1) Where the raceway or means of support is identified as
    a means of support

    (2) Where the raceway contains power supply conductors
    for electrically controlled equipment and is used to support
    Class 2 circuit conductors or cables that are solely
    for the purpose of connection to the equipment control
    circuits
    "Electricity is really just organized lightning." George Carlin


    Derek

  4. #4
    Join Date
    Oct 2017
    Location
    Wisconsin
    Posts
    18
    Thank you for the responses so far!

    All these raceways (conduits, in this case) are ran to a control panel. This control panel contains a 24VAC PLC and 24VAC transformer, a 460VAC/120VAC transformer, plus a bunch of contactors operating at 460VAC. The PLC powers about a dozen pieces of instrumentation.

    Having said this, I guess I'm not sure what is meant by "Class 2 circuit conductors or cables". Thoughts on this?

    Quote Originally Posted by jumper View Post
    Maybe, doubtful. If the liquidtight has power conductors, no. If the liquidtight meets condition (2), possibly.

    2014 NEC

    300.11
    (B) Raceways Used as Means of Support. Raceways
    shall be used only as a means of support for other raceways,
    cables, or nonelectrical equipment under any of the
    following conditions:

    (1) Where the raceway or means of support is identified as
    a means of support

    (2) Where the raceway contains power supply conductors
    for electrically controlled equipment and is used to support
    Class 2 circuit conductors or cables that are solely
    for the purpose of connection to the equipment control
    circuits

  5. #5
    Join Date
    Jan 2009
    Location
    Maryland
    Posts
    12,427
    Class 2 circuits are discussed in article 725 and also see tables 11(A) and (B) in Chapter 9.

    Your 24V transformer would be marked as a Class 2 if it is one.

    All these raceways (conduits, in this case) are ran to a control panel.
    Is the EMT enclosing power/460V conductors feeding the equipment and the liquidtight containing 24V control conductors?
    "Electricity is really just organized lightning." George Carlin


    Derek

  6. #6
    Join Date
    Oct 2017
    Location
    Wisconsin
    Posts
    18
    Quote Originally Posted by jumper View Post
    Class 2 circuits are discussed in article 725 and also see tables 11(A) and (B) in Chapter 9.

    Your 24V transformer would be marked as a Class 2 if it is one.



    Is the EMT enclosing power/460V conductors feeding the equipment and the liquidtight containing 24V control conductors?
    The EMT has power/460V conductors for a pump. The liquidtight has 24V control conductors for devices other than this pump.

    From a "practical" standpoint:
    Is it advisable to run an EMT conduit with 460VAC directly next to a liquidtight conduit with 24VAC cabling?
    I guess I ask if there’s any concern because of Electromagnetic Interference (EMI)?

    Thanks.
    Last edited by rustydud; 10-12-17 at 02:36 PM.

  7. #7
    Join Date
    Dec 2010
    Posts
    1,325
    Quote Originally Posted by jumper View Post
    Maybe, doubtful. If the liquidtight has power conductors, no. If the liquidtight meets condition (2), possibly.
    The EMT is supporting the liquidtight, not "circuit conductors or cables". The liquidtight needs to be supported separately.

    EMI should not be an issue.
    The more they overthink the plumbing, the easier it is to stop up the drain

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