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Thread: Magnetic vs. non-magnetic EMT

  1. #1
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    Magnetic vs. non-magnetic EMT

    Hello I'm having trouble determining whether to model EMT as magnetic or non-magnetic in short circuit calculations as I know this will have an impact on an overall cable's impedance.

    Is the majority of EMT out there magnetic rather than non magnetic or vice versa? Does the conduit being rigid or not play a role? Most of the time in the feeder schedules I am given show whether it's PVC or EMT and if it's rigid or not. Any tricks for how to make a sound assumption based on that information? Your help would be appreciated. Thanks!

  2. #2
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    Welcome to the forum

    All the emt I have seen is magnetic.

  3. #3
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    Quote Originally Posted by Dennis Alwon View Post
    Welcome to the forum

    All the emt I have seen is magnetic.
    Isn't there aluminum EMT?

  4. #4
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    Quote Originally Posted by ggunn View Post
    Isn't there aluminum EMT?
    Yes

    http://www.americanconduit.com/produ...ubing-emt.html
    The more they overthink the plumbing, the easier it is to stop up the drain

  5. #5
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    Quote Originally Posted by ggunn View Post
    Isn't there aluminum EMT?
    Yes.

    http://www.americanconduit.com/produ...ubing-emt.html
    Cheers and Stay Safe,

    Marky the Sparky

  6. #6
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    Well then, unless you have an aluminum magnet...

  7. #7
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    Quote Originally Posted by ish1284 View Post
    Is the majority of EMT out there magnetic rather than non magnetic or vice versa?
    Assume that EMT will be regular steel, and thus magnetic. Stainless-steel and aluminum EMT do exist, but they would be called out in a spec.

    Quote Originally Posted by ish1284 View Post
    Does the conduit being rigid or not play a role?
    No, only the metal composition.

  8. #8
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    Quote Originally Posted by ggunn View Post
    Isn't there aluminum EMT?

    Yes, there is but that is not a standard install.

  9. #9
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    We typically model raceway as non-magnetic unless we know for sure it is magnetic.

    Non-magnetic will provide worst case short circuit values. Arc Flash incident energies might end up not be worst case (higher fault current makes OCPDs open faster, thus sometimes lower level PPE called out), but you need to pick your poison.
    Ron

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