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Thread: 240.21 (C)(4) and T450.3(B)

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    240.21 (C)(4) and T450.3(B)

    I need to power-up a 230V, 3ph, 3/4Hp motor...the only power source available is a 3ph 480V panelboard. I want to install a 480-240V transformer and run directly into a combo starter from the secondary side of the Xfmr - which is installed outdoors at approx. 90 feet from the motor. The starter will have a MCP and thermal overloads set at 125% of motor FLA. Is the cable from Xfmr secondary side adequately protected per 240.21(C)(4)?

    Thanks in advance.

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    Quote Originally Posted by Isaiah View Post
    Is the cable from Xfmr secondary side adequately protected per 240.21(C)(4)?
    It's not likely that the MCP will provide the required by 240.21(C)(4).

    The secondary conductors may be protected by the primary OCPD per 240.41(C)(1)

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    Quote Originally Posted by david luchini View Post
    It's not likely that the MCP will provide the required by 240.21(C)(4).

    The secondary conductors may be protected by the primary OCPD per 240.41(C)(1)
    I'm thinking the same thing...I was hoping the thermal overload relay would suffice.

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