Appendix S. WORKING DEFINITIONS FOR APPROACH BOUNDARIES

SHOCK PROTECTION BOUNDARIES
2004 NFPA 70E, Table 130.2

Limited Approach Boundary — Defines the closest approach to an exposed electrical hazard, (conductor, component, etc.), for non-qualified personnel, unless escorted by a qualified worker. Determines the minimum safe distance for the placement of barricades for shock protection. If the qualified electrical workers are unable or unwilling to provide escort for unqualified workers, the unqualified worker may not enter the limited approach boundary.

Restricted Approach Boundary — Qualified and Authorized electrical workers only. All required PPE appropriate to the shock hazard must be worn. The worker is now working near the exposed hazard.  The worker must have an approved plan for the work they are to perform. They may cross the restricted boundary only to the extent that is necessary to perform their work.

Prohibited Approach Boundary — All of the requirements for limited and restricted boundaries apply. Any work inside the prohibited boundary is considered the same as being in contact with the exposed uninsulated conductor. No electrically uninsulated part of the body may cross the prohibited approach boundary.

ARC FLASH PROTECTION BOUNDARY
2004 NFPA 70E, Article 130.3

Flash Protection Boundary — Set at the distance from the arc source for a second degree burn. Qualified electrical workers only.

May be placed outside the limited approach boundary. If so, then the flash protection boundary is the outer most defining boundary and will determine the placement of barricades. The requirements for working inside this boundary are identical to the requirements for working inside the restricted approach boundary, plus arc flash protection appropriate to the arc-flash hazard.