United States — NFPA 70 (NEC), 2026 edition
Electrical installation code family. Edition adoption and local amendments vary by jurisdiction; check the applicable authority having jurisdiction (AHJ).
Official NFPA catalog ↗Wiring
Cable Short-Circuit Withstand Calculator
Compare a user-supplied short-circuit event with a user-supplied conductor thermal constant.
02 / Screening result
User-data thermal result
Enter the required values and k provenance, then calculate.
Method and boundaries
Event I²t = I² × t; adiabatic threshold = k²S². The tool converts entered conductor area to mm², current to A and clearing duration to seconds before comparison.
The symmetrical RMS current is treated as constant over the entered duration. This is an adiabatic thermal screen only; it excludes waveform asymmetry/DC offset, non-adiabatic corrections, parallel and return paths, joints, electrodynamic forces, protective-device let-through, breaker ratings, coordination and code approval.
Regional standards context
Official catalogs and applicability boundaries
These links identify standards, scope or regulatory catalogs; they do not automatically provide a k value for this calculator. Catalogs checked: 2026-10-12.
China — GB/T 42397-2023
SAMR catalog lists the recommended national standard as current; its subject includes non-adiabatic short-circuit current calculation. This calculator is only an adiabatic screen.
Official SAMR record ↗China — GB/T 16895.3-2024
SAMR catalog metadata for earthing arrangements and protective conductors. This reference does not supply k, candidate sizes or code sizing rules to the calculator.
Official SAMR record ↗Japan — METI electrical technical standards index
METI index lists the Electrical Equipment Technical Standards Interpretation, revised 2025-11-20. It is regulatory context only; no Japanese k values are encoded here.
Official METI index ↗International — IEC 60949:1988
IEC catalog scope covers thermally permissible short-circuit current calculation with non-adiabatic heating effects; the paid standard is not reproduced.
Official IEC catalog ↗International — IEC 60364-4-43:2023
Low-voltage installation protection against overcurrent, including protection coordination. It does not supply this calculator with embedded conductor constants.
Official IEC catalog ↗International — IEC 60364-5-54:2011+A1:2021
IEC catalog metadata for earthing arrangements and protective conductors. This reference does not provide the calculator with normative sizing rules or k values.
Official IEC catalog ↗FAQ
What does this calculator compute?
Event let-through is I² × t. The adiabatic threshold is k²S². The tool converts area to mm², current to amperes, and clearing duration to seconds before comparing them.
What current does the comparison assume?
The symmetrical RMS current is treated as constant over the duration you enter. It is an adiabatic thermal screen only.
What is excluded?
Waveform asymmetry and DC offset, non-adiabatic cooling, parallel and return paths, joints, electrodynamic forces, protective-device let-through, breaker ratings, coordination, and code compliance are excluded.
Source records
This calculation record stores no external source. Thresholds you enter on the page are not a verified standard limit.