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Exposed to energized parts within a Panelboard

Question asked by Brian Stover on Mar 21, 2016
Latest reply on Apr 13, 2017 by mmurphy1

Recently a manufacturer  procured new IP-20 style panel-boards.   These new panel-boards are designed to eliminate/reduce(???) arc flash exposure to personnel working within the energized panels.   their has been great debate concerning the branch circuit conductors (exposed live part??) within the branch circuit wireway section of the segmented panel-board.  The question:  Are the energized branch circuits within the panel-board considered  "live parts" when the panel is open  for a installer to new branch circuits? 

Scenario:  contractor has a project to install new branch circuits within the panel-board, the installation requires contractor to punch a penetration for the conduit, pull wire, terminate, label, test  to an existing breaker.  the  panel-board has no exposed live parts inherent to the new design(no debate concerning the exposure) however their are existing energized branch circuits. the Arc flash risk assessment is determined to be a Category 0 with an actual calculated calorie rating of .45/cm2. all the branch circuit conductors are type THHN.  The new panel design eliminates the exposed branch breaker terminations (live parts) completely.  Their are no exposed live parts inherent to the panel-board.    It is the contractors interpretation  that when they open the panel-board no longer are the branch circuit conductors considered to be protected and must be treated as bare conductors (exposed live part), reference NEC article 300.   the contractor/owner are required to comply with NFPA70E make every attempt to turn off (LOTO) the branch circuits to eliminate the exposure to energized branch circuit wiring. 

their is an argument that the insulated branch circuit conductors are not considered as live parts and therefore their is no exposure.  the owner(manufacturer)  purchased these panels with the intention of reducing/eliminate the cumbersome assessment process required to perform energized work under the "Operational limitations"  clause of NFPA 70E.  the contractor knows that their is an inherent risk associated with the installation and believes that they are required to request that the branch circuits should be de-energized per NFPA70E.  if they can not be de-energized due to operational limitations then the hot work permit process must be adhered too.  Are the branch circuits to be considered as bare/energized and require de-energization or Hot work Permit?

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