Announcement

Collapse
No announcement yet.

live work

Collapse
This topic is closed.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    live work

    There is an article on the NEC that allows an electrician in some instance to do work on a live circuit, because by isolating the power will cause interruption to a process. If am right please let me know the article #. Thanks guys!

    #2
    Originally posted by jsilva View Post
    There is an article on the NEC that allows an electrician in some instance to do work on a live circuit, because by isolating the power will cause interruption to a process. If am right please let me know the article #. Thanks guys!
    It is not in the NEC it is OSHA.

    1910.333(a)(1)

    "Deenergized parts." Live parts to which an employee may be exposed shall be deenergized before the employee works on or near them, unless the employer can demonstrate that deenergizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations. Live parts that operate at less than 50 volts to ground need not be deenergized if there will be no increased exposure to electrical burns or to explosion due to electric arcs.

    Note 1: Examples of increased or additional hazards include interruption of life support equipment, deactivation of emergency alarm systems, shutdown of hazardous location ventilation equipment, or removal of illumination for an area.

    Note 2: Examples of work that may be performed on or near energized circuit parts because of infeasibility due to equipment design or operational limitations include testing of electric circuits that can only be performed with the circuit energized and work on circuits that form an integral part of a continuous industrial process in a chemical plant that would otherwise need to be completely shut down in order to permit work on one circuit or piece of equipment.

    Note 3: Work on or near deenergized parts is covered by paragraph (b) of this section.
    First if you can meet one of the items in Note 1 you could then perform only the things listed in Note 2.

    You are basically limited to testing and troubleshooting, no adding circuits or breakers etc.

    And of course if you are allowed to work live you need to be trained and have the proper protective equipment.

    Comment


      #3
      Not in the NEC itself, but in 70E, Electrical Safety in the Workplace. Section 130.1(A)(2).
      With great power comes great resistance - times current squared, of course.

      Comment


        #4
        live work

        I got it, Thanks again!

        Comment


          #5
          Originally posted by jsilva View Post
          There is an article on the NEC that allows an electrician in some instance to do work on a live circuit, because by isolating the power will cause interruption to a process. If am right please let me know the article #. Thanks guys!
          Read the 70E section very carefully. It does not say you can work live if you are going to interrupt a process. It says you can work live if interrupting power will cause a larger hazard. I don't have my 70E with me to quote the actual section. For the most part there are very very few circumstances where live work is justifiable.

          Comment


            #6
            Originally posted by eric9822 View Post
            Read the 70E section very carefully. It does not say you can work live if you are going to interrupt a process. It says you can work live if interrupting power will cause a larger hazard. I don't have my 70E with me to quote the actual section. For the most part there are very very few circumstances where live work is justifiable.
            You're right, generally. However if you can demonstrate that a deenergized state is infeasible due to operational limitations it is permitted.
            NFPA70E 130.1(A)(2) 2009.
            With great power comes great resistance - times current squared, of course.

            Comment


              #7
              Originally posted by Volta View Post
              You're right, generally. However if you can demonstrate that a deenergized state is infeasible due to operational limitations it is permitted.
              NFPA70E 130.1(A)(2) 2009.
              A lot of people interpret infeasible to mean inconvenient or expensive. In most industries there is no justification.

              Comment


                #8
                Yeah, I think we need to interpret it that way or else they would have said impossible.

                What would you consider an operational limitation?

                Voltage, current, operating temperature come to mind, of course.

                What about a large 24-hour processing facility that would need to be be shut-down to work in a panel to add a circuit?
                With great power comes great resistance - times current squared, of course.

                Comment


                  #9
                  Originally posted by Volta View Post
                  What about a large 24-hour processing facility that would need to be be shut-down to work in a panel to add a circuit?
                  IMO you would have to shut down as much as it took to make it 'dead work'

                  The following is an OSHA Standard Interpretation.

                  December 19, 2006

                  Mr. Alan E. Scales
                  Safety Department
                  Fairchild Semiconductor International
                  333 Western Avenue
                  MS 01-31
                  Portland, ME 04106

                  Dear Mr. Scales:

                  Thank you for your June 6, 2006, letter to the Occupational Safety and Health Administration's (OSHA's) Directorate of Enforcement Programs. You had questions regarding OSHA's Selection and use of work practices standard, 29 CFR 1910.333, as it relates to "continuous industrial processes" and the infeasibility of de-energizing equipment under certain circumstances. Your paraphrased scenario, question, and our response follow.

                  Scenario: The manufacturing of our products involves many discrete pieces of equipment whose individual processes are part of the overall manufacture of integrated circuit components. For example, we have ten pieces of manufacturing equipment fed out of a 480-volt three-phase panel. A new project requires that additional feeders and a 225-ampere circuit breaker be added to the panel to supply a new piece of equipment. To perform the work in a de-energized state, it requires the power to the panel must be disconnected and appropriate LOTO devices applied. This activity would result in the shutdown of the ten pieces of equipment, causing a significant interruption to our ability to manufacture integrated circuits.

                  Question:Response:http://www.osha.gov. If you have any further questions, please feel free to contact the Office of General Industry Enforcement at (202) 693-1850.

                  Sincerely,



                  Richard E. Fairfax, Director
                  Directorate of Enforcement Programs
                  From here "Continuous industrial processes" and the infeasibility of de-energizing equipment under 29 CFR 1910.333.
                  Last edited by iwire; 02-06-10, 03:13 PM.

                  Comment


                    #10
                    Originally posted by Volta View Post
                    Yeah, I think we need to interpret it that way or else they would have said impossible.

                    What would you consider an operational limitation?

                    Voltage, current, operating temperature come to mind, of course.

                    What about a large 24-hour processing facility that would need to be be shut-down to work in a panel to add a circuit?
                    Check out IWire's post. Infeasible and impossible are fairly close to the same same meaning. I work in a 24-hour facility and up until a few years ago it was very common to perform live work even when we could have easily planned a little better and shut down specific pieces of equipment. We have not performed live work in a few years now and we have idled significant portions of the site and dozens of employees for hours at a time when work was required. Interestingly enough the most resistance to enforcing the no live work rule came from the electricians and not management.

                    Comment

                    Working...
                    X