Arc Flash Calculator

Summary

Estimate arc flash incident energy (cal/cm²) and protection boundary using the IEEE 1584 simplified method.

How it works

1. Enter the system voltage (208 V – 15,000 V) and electrode gap for your equipment type.
2. Enter the bolted three-phase fault current available at the point of work.
3. Set the arcing current multiplier and the fault clearing time in cycles or seconds.
4. Set the working distance from the potential arc source to the worker.
5. The calculator computes arcing current, normalized incident energy, and final incident energy.
6. The arc flash boundary is found by back-solving for the distance at the 1.2 cal/cm² onset-of-ignition threshold.

Use cases

• Perform a preliminary arc flash hazard assessment before a full IEEE 1584 study.
• Determine the required PPE category for switching or racking operations.
• Estimate how changing clearing time affects incident energy at a switchgear panel.
• Verify that an upstream upstream breaker provides adequate arc flash protection.
• Train electricians on the relationship between fault current, distance, and incident energy.
• Compare incident energy for different working distances during maintenance planning.

Frequently Asked Questions