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Thread: Fused disconnect for xfmr secondary > 10' ?

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    Fused disconnect for xfmr secondary > 10' ?

    Is a fused disconnect required if transformer secondary conductors are over 10 feet?

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    Quote Originally Posted by cppoly View Post
    Is a fused disconnect required if transformer secondary conductors are over 10 feet?
    Or a circuit breaker. Unless it is a single phase 2-wire secondary or three phase 3-wire secondary and complies with 240.21(C)(1).

    Transformer secondary conductors protection must comply with one of the methods in 240.21(C)(1) through (C)(6).

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    Thanks, I should have kept reading the section but there is a section for <25' secondary conductors.

    But, does anyone have the 2014 NEC handbook? Transformer section 240.21(C)(2) commentary gives a transformer example and says to apply section 240.21(C)(2) (transformer secondary not over 10’) to determine minimum secondary conductor size. But the example, applies 1/10th rating of the primary OCPD which has nothing to due with the rules of section 240.21(C)(2). Unless I’m reading this wrong, is this commentary not correct??

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    Quote Originally Posted by cppoly View Post
    But the example, applies 1/10th rating of the primary OCPD which has nothing to due with the rules of section 240.21(C)(2). Unless I’m reading this wrong, is this commentary not correct??
    See 240.21(C)(2)(4).

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    Thanks

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