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Thread: LOTO in industrial facilities

  1. #11
    Join Date
    Feb 2005
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    Quote Originally Posted by pfalcon View Post

    Thanks much. Unfortunately my experience has been that the circuits being reset by operators are just such circuits as to qualify for the note.
    Not following your logic, unless you have a trip unit with indication showing what type of fault it tripped on it is pretty hard to know it was an overload.

  2. #12
    Join Date
    May 2004
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    Indiana
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    Quote Originally Posted by OSHA 1910.334(b)(2)
    Reclosing circuits after protective device operation. After a circuit is deenergized by a circuit protective device, the circuit may not be manually reenergized until it has been determined that the equipment and circuit can be safely energized. The repetitive manual reclosing of circuit breakers or reenergizing circuits through replaced fuses is prohibited.

    Note: When it can be determined from the design of the circuit and the overcurrent devices involved that the automatic operation of a device was caused by an overload rather than a fault condition, no examination of the circuit or connected equipment is needed before the circuit is reenergized.

    http://www.osha.gov/pls/oshaweb/owad...ARDS&p_id=9911

    Quote Originally Posted by don_resqcapt19 View Post
    How do they know that the trip was caused by an overload?
    Quote Originally Posted by zog View Post
    Not following your logic, unless you have a trip unit with indication showing what type of fault it tripped on it is pretty hard to know it was an overload.
    As much as I would like to agree with you, your questions are argumentative, legally speaking. Meaning by posing the question you're attempting to make the note to be "of no effect". The presence of the note means that it can be done reasonably with proper design and installation.

    For example: Providing the overload is proximate to the motor and upstream OCPD is provided for other fault conditions, the likelihood of of the overload tripping for any other fault condition is negligible.

    And please, don't argue negligible. Because after doing a live-dead-live test there's still a negligible chance the dead circuit you plan to work on is actually live. Which if we don't permit overlooking negligible conditions then all circuits are always energized even after lockout.
    A rose by any other name is tax deductible [1978 Wayne Wilcox]
    People who read too many books get quirky. [2000 John Taylor Gatto]

  3. #13
    Join Date
    Feb 2003
    Location
    Illinois
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    If you have a motor starter with a tripped breaker, that to me indicates that there is an issue other than an overload and you need to determine the cause of the trip before reclosing the breaker.
    Don, Illinois
    "It is the first responsibility of every citizen to question authority." B Franklin

  4. #14
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    May 2004
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    Indiana
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    Quote Originally Posted by don_resqcapt19 View Post
    If you have a motor starter with a tripped breaker, that to me indicates that there is an issue other than an overload and you need to determine the cause of the trip before reclosing the breaker.
    OR: It may indicate the machine was designed to trip overloads during jam conditions to prevent equipment damage. Which when combined with upstream OCPD would demonstrate both design and assignable cause.

    Please understand Don, our site banned operators and jobsetters from resetting overloads and breakers long ago. Done well before approach boundaries would have reinforced it. And I thoroughly believe that any protective device should pop an investigation before being reset. But OSHA says what OSHA says.

    To advance your position to where it would no longer be considered argumentative in court you actually have to provide the criteria for meeting the note. Otherwise the judiciary would be wrong if they failed to discard your opinion. You don't have to agree with the note. You don't have to agree with what it permits. But you're not allowed to rewrite OSHA.

    As many people would say about the NEC, if you don't like what OSHA says then get involved and try to change it. That's easier done than it appears. The NFPA70E is considered to supercede a lot of the OSHA electrical regulations according to OSHA letters of interpretation. Find in the 70E where it bans the practice - or get it modified to ban the practice - and you'll have succeeded. OSHA considers the hazards identified in the current (2012) edition of the 70E to be recognized hazards. They're subject to indirect regulation through the general duty clause.
    A rose by any other name is tax deductible [1978 Wayne Wilcox]
    People who read too many books get quirky. [2000 John Taylor Gatto]

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