Shock Approach Boundary Calculator (NFPA 70E)
Look up limited, restricted, and prohibited approach boundaries for shock protection from NFPA 70E Tables 130.4(E)(a) and (b)
Free shock approach boundary calculator for electrical safety review conversations. Enter system voltage, AC/DC type, and fixed or movable conductor context to check the local limited and restricted boundary prompts already embedded in this app.
The output is not energized-work authorization, NFPA 70E compliance, OSHA compliance, PPE selection, LOTO verification, arc-flash boundary calculation, or a substitute for the employer electrical safety program and qualified-person review. Reconcile every local row against current licensed NFPA 70E text, equipment facts, site procedure, and qualified electrical/safety review before field use.
Check arc flash incident-energy assumptions before engineering review
Arc Flash Incident Energy Calculator →Check PPE table-method rows before qualified review
Arc Flash PPE Category (Table Method) →Build an energized work permit template with manual boundary fields
Energized Work Permit Template →How It Works
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Select AC or DC
Choose the voltage type for the local table prompt. Verify the voltage basis against equipment labels, drawings, and current source text before field use.
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Enter System Voltage
Enter the nominal voltage in volts. The app screens a local row only; it does not decide exposure, safe work, or compliance.
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Select Conductor Type
Choose fixed circuit part or movable conductor. Movable conductor context can involve overhead lines, sway, sag, tools, vehicles, and utility controls outside this app.
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Review Source Gaps
Use the warnings, source pointers, and residual gaps to route the output through NFPA 70E, OSHA, LOTO, arc-flash, PPE, employer-program, and qualified review.
Frequently Asked Questions
Learn More
Arc Flash Incident Energy: What the Numbers Mean and How to Get Them Right
IEEE 1584-2018 arc flash calculation explained step by step. Arcing current, incident energy, reduced current scenario, PPE categories, and practical interpretation of results.
Arc Flash PPE Table Method: When to Use It and When You Can't
NFPA 70E Table 130.7(C)(15) PPE category lookup explained. When the table method works, when it doesn't, what exceeds table scope, and how to read PPE categories.
Shock Approach Boundaries: Who Can Cross Which Line
NFPA 70E shock approach boundaries for AC and DC systems. Limited, restricted, and prohibited distances, who needs what training, and what PPE is required at each boundary.
Energized Electrical Work Permits: When You Need One and How to Fill It Out
NFPA 70E 130.2(B) energized electrical work permit requirements. When energized work is justified, what goes on the form, and the approval process.
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