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Thread: Main Disconnect

  1. #1
    Join Date
    Feb 2003
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    North Dakota
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    1

    Main Disconnect

    The main disconnect switch is about 30' away from the control panel. The control panel operates two submersible pumps for a lift station. The pumps have circuit breakers in the control panel. Is there a restriction on how far away the main disconnect switch can be?

  2. #2
    Join Date
    Feb 2003
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    120

    Re: Main Disconnect

    I believe that the two units must be within sight (up to 50' apart)of each other. See Article 430-102(A)

    Rick Miell

  3. #3
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    Feb 2003
    Location
    New Hampshire
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    67

    Re: Main Disconnect

    Unless the two circuit breakers are operable with the control cabinet closed and disconnect their respective pump motor control thus serving as the controller disconnecting means; the main disconnect would become the "controller disconnecting means" and would have to be "in sight" (and less than 50 ft per art. 100 - definitions) of the pump motor controls. art.# 430.102a

    [ February 20, 2003, 07:20 PM: Message edited by: Len_B ]

  4. #4
    Join Date
    Feb 2003
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    249

    Re: Main Disconnect

    THE BREAKERS MUST ALSO BE ABLE TO LOCKED IN THE OPEN POSITION
    Jeff Cook
    Master Electrician

  5. #5
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    Illinois
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    Re: Main Disconnect

    There is no NEC requirement for a "lockable" disconenct when the disconnect is within sight of the equipment served by the disconnect.
    Don
    Don, Illinois
    "It is the first responsibility of every citizen to question authority." B Franklin

  6. #6
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    Feb 2003
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    New Hampshire
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    Re: Main Disconnect

    I agree that there is no "lockable" requirement under NEC, unless exceptions to "in sight" requirements are used for:
    1)controller over 600v --- 430.102a except.1
    2)motor uses controller disconnecting means as motor disc. means --- 430.102b except.

    There may, however, be other lockout requirements under OSHA LO/TO. In addition, NFPA 70E, Standard for Electrical Safety Requirements for Employee Workplaces; or NFPA 79 Electrical Standard for Industrial Machinery, may (I'm not 100% sure) have "lockable" requirements that could also be enforced by OSHA.

    Len

    [ February 21, 2003, 05:04 PM: Message edited by: Len_B ]

  7. #7
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    Location
    Illinois
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    Re: Main Disconnect

    Len,
    I don't think so. OSHA permits tag out without a lock. The utility in our area does not permit the use of any locks on disconnects within their generating plants. Yes, they are not under the NEC, but they are covered by OSHA.
    Don
    Don, Illinois
    "It is the first responsibility of every citizen to question authority." B Franklin

  8. #8
    Join Date
    Feb 2003
    Location
    New Hampshire
    Posts
    67

    Re: Main Disconnect

    Don,
    Thanks. I wasn't sure about possible OSHA requirements that might apply to this specific situation.
    In addition to "in-house" tag only policies, many times locks simply can't be attached, requiring tag out only. BTW, If "tyrap" alone is used for LOTO, I believe it must be 50 pound rated (Code ref ?)

    Len

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