Shock Approach Boundaries (NFPA 70E Table 130.4)
Looks up the NFPA 70E Table 130.4 AC shock approach boundaries by nominal voltage.
Example
You enter
- Nominal voltage (phase-to-phase, AC) 151-750 V
You get
- Limited approach - fixed circuit part 3 ft 6 in
- Restricted approach 1 ft 0 in
- No boundary No
Checked against published worked examples from: NFPA 70E-2024.
Details, formula, and sources
ScopeThe limited approach (separate distances for an exposed movable conductor vs a fixed circuit part) and the restricted approach. Below 50 V no boundary is specified. Shock boundaries only (the arc-flash boundary is separate); the employer's safety program and 70E govern.
Formula or tablelookup by nominal phase-to-phase AC voltage band: limited approach (exposed movable conductor vs exposed fixed circuit part) and restricted approach; below 50 V no boundary is specified.
Source and editionAC shock approach boundaries, NFPA 70E-2024 Table 130.4, by name.
Free accessNFPA 70E is free to read at nfpa.org/freeaccess. These are shock boundaries only; the arc-flash boundary is a separate determination. Crossing the restricted approach requires a qualified person, an energized-work permit, and shock PPE.
What governsEstimate. AHJ and licensed electrician govern. Verify against the NEC edition adopted in your jurisdiction.
API field namesnominal_v_ac, limited_fixed, restricted, no_boundary
- Limited approach the boundary an unqualified person must not cross; the larger distance applies to an exposed movable conductor, the smaller to an exposed fixed circuit partNFPA 70E Table 130.4
- Restricted approach the boundary requiring a qualified person, an energized-work permit, and shock PPE to crossNFPA 70E Table 130.4