Arc Flash Study
We calculate incident energy and arc flash boundary per panel with the IEEE 1584 method. The study does not end with printing labels: because clearing time drives incident energy most, we review the protection settings and report options to reduce the risk at its source.
Which questions does this study answer?
Arc flash is built on the short-circuit and protection coordination studies; if the layers below are wrong, its result cannot be trusted.
Which panels have high incident energy?
Incident energy and arc flash boundary are calculated for each panel; the highest-energy points are brought forward.
What changes if clearing time is shortened?
At a fixed fault current, incident energy rises roughly in proportion to clearing time; the effect of a setting change is compared between the existing and proposed situation.
What is the effect of working distance and electrode configuration?
Enclosure geometry, electrode configuration and working distance assumptions are stated explicitly and their effect on the result is assessed.
Are the labels current?
When a transformer, feeder or grid supply changes, the fault current changes; without a current model, label data loses its validity.
Required data
The more complete the input data, the more reliable the incident energy calculation.
- Single-line diagram and current short-circuit study results
- Protection device settings and trip curves
- Enclosure geometry and electrode configuration (vertical/horizontal, enclosed box)
- Bus voltage and working distances
- Planned changes to the facility
Working steps
The steps are sequential: the output of each is the input of the next.
01
Input and model verification
Panel and device data are collected; inconsistencies between the single-line diagram and field information are flagged.
02
Short-circuit and protection update
Fault currents and device clearing times are taken from the current ETAP model.
03
Incident energy calculation
Incident energy and arc flash boundary are calculated for every panel with the IEEE 1584 method in ETAP.
04
Reduction options
Settings that shorten clearing time and options such as a maintenance mode are compared without giving up selectivity.
05
Reporting
Results are delivered, document-controlled, together with their assumptions and limitations.
How does clearing time affect incident energy?
At a fixed fault current, incident energy is roughly proportional to clearing time. Move the slider to see the relative effect of clearing time.
Relative incident energy (500 ms = 100%)
%90
This is an educational illustration, not a calculation: real incident energy also depends on fault current, electrode configuration, working distance and voltage, and is calculated with the IEEE 1584 method.
Reference standards
The frameworks below are referenced. This is a reference framework, not a certification or accreditation statement.
- IEEE 1584-2018
- Guide for performing arc-flash hazard calculations
- NFPA 70E
- Electrical safety requirements for employee workplaces; selecting protective equipment from incident energy
Calculation software: ETAP
Delivered documents
- Incident energy and arc flash boundary table per panel
- Effect of existing and revised protection settings on incident energy
- Reduction proposals
- Label data (referenced to the current model)
- Statement of assumptions and limitations
- Document control record (prepared by / checked by / approved by, revision)
Scope and limits
- The calculation rests on the IEEE 1584 method; protective equipment is read from incident energy within the NFPA 70E framework.
- Label printing, field implementation and training are a separate scope.
- Results depend on the input data; they must be updated when the system changes.
The clearing-time chart on this page is educational and not a calculation; a real study uses the full set of IEEE 1584 inputs.
Arc flash study for your facility
Let us start from your single-line diagram and clarify the scope and the data needed together.
Request a technical pre-assessment