Online Arc Flash Calculator IEEE 1584 (2002 and 2018)

Calculate Arc Flash Boundary and Arc Flash Incident Energy with the Free Arc Flash Calculator. Supports IEEE 1584-2002, IEEE 1584-2018, and the Ralph Lee Method.

Standard
Unit of measure
Voltage Vac
Fault current kA
Arcing time for Iarc ms
Arcing time for Iarc_min  ms
Equipment type
Working distance  in
Enclosure width in
Enclosure height in
Enclosure depth in
Electrode configuration
Conductor gap  mm

See Also

Parameters for the IEEE 1584 2018 Arc Flash Calculator

Parameters for the IEEE 1584 2002 Arc Flash Calculator

Ralph Lee Method

The calculator also supports the Ralph Lee Method, which is one of the proposed methods in the NFPA 70E standard.

PPE Categories in NFPA 70E 2018

There are two official Arc Flash Analysis (Study) methods defined by NFPA 70E:

You can read more about it in What is an Arc Flash Study? Two Official Methods Described

This calculator is based on the Incident Energy Method.

According to NFPA 70E, PPE Categories should not be used when the Incident Energy Method is used. However, NFPA 70E allows site-specific PPE requirements on Arc Flash Labels, and in many cases, sites adopt the PEE Categories anyway.

For more information see 5 Minimum Arc Flash Label Requirements from NFPA 70E 2018

Therefore, I have included the mapping to Arc Flash Categories in the calculator.

The PPE in NFPA 70E is defined into 4 categories.

Table 1: NFPA 70E PPE Categories
Category Minimum arc rating of PPE
01.2 cal/cm2
14 cal/cm2
28 cal/cm2
325 cal/cm2
440 cal/cm2

Note that Category 0 is not listed in NFPA 70E. I have included it here when the incident energy is less than 1.2 cal/cm2. In other words, when the Arc Flash Boundary is less than the working distance.

Equipment types with typical distances and sizes for IEEE 1584 2018

Abbreviations used in Table 2 and Table 3:

Gap  Conductor Gap (mm)
WDWorking distance (inch or mm)
HEnclosure height (inch or mm)
WEnclosure width (inch or mm)
DEnclosure depth (inch or mm)

Table 2: Equipment Types with Typical Imperial Distances and Measurements (IEEE 1584 2018)
Equipment typeGap mmWD inH inW inD in
15 kV Switchgear15236453030
15 kV MCC15236363636
5 kV Switchgear, Large10436363636
5 kV Switchgear, Small10436453030
5 kV MCC10436262626
LV Switchgear3224202020
LV MCCs and Panels, Shallow251814128
LV MCCs and Panels, Deep251814129
Cable Junction Box, Shallow131814128
Cable Junction Box, Deep131814129

Table 3: Equipment Types with Typical Metric Distances and Measurments (IEEE 1584 2018)
Equipment typeGap mmWD mmH mmW mmD mm
15 kV Switchgear1529141143762762
15 kV MCC152914914914914
5 kV Switchgear, Large104914914914914
5 kV Switchgear, Small1049141143762762
5 kV MCC104914660660660
LV Switchgear32610508508508
LV MCCs and Panels, Shallow25457355.6305203
LV MCCs and Panels, Deep25457355.6305229
Cable Junction Box, Shallow13457355.6305203
Cable Junction Box, Deep13457355.6305229

Equipment types with typical distances and sizes for IEEE 1584 2002

Table 4: Typical Conductor Gaps in IEEE 1584 2002
System voltageEquipment typeConductor gap
0.208-1 kVOpen air10-40 mm
Switchgear32 mm
MCCS and panels25 mm
Cables13 mm
>1-5 kVOpen air102 mm
Switchgear13-102 mm
Cables13 mm
>5-15 kVOpen air13-153 mm
Switchgear153 mm
Cables13 mm

Table 5: Typical working distances in IEEE 1584 2002
SystemWorking distance
15-kV switchgear910 mm
5-kV switchgear910 mm
Low-voltage switchgear610 mm
Low-voltage MCCs and panelboards455 mm
Cable455 mm

How to calculate the Arc Flash Boundary with IEEE 1584 2018?

The Arc Flash Boundary is calculated according to IEEE 1584 2018 as follows:

  1. Calculate the intermediate arching currents Iarc_600, Iarc_2700 and Iarc_14300 at 600 V, 2700 V and 14300 V.
  2. Calculate the final arcing current Iarc at the specified open circuit operating voltage Voc.
  3. Calculate the enclosure size correction factor CF for the relevant electrode configuration and enclosure size.
  4. Calculate the intermediate arc flash boundaries AFB600, AFB2700 and AFB14300 at 600 V, 2700 V and 14300 V.
  5. Calculate the final arc flash boundary AFB at the specified open circuit operating voltage Voc.

How to calculate the Arc Flash Incident Energy with IEEE 1584 2018?

The Arc Flash Incident Energy is calculated according to IEEE 1584 2018 as follows:

  1. Calculate the intermediate arching currents Iarc_600, Iarc_2700 and Iarc_14300 at 600 V, 2700 V and 14300 V.
  2. Calculate the final arcing current Iarc at the specified open circuit operating voltage Voc.
  3. Calculate the enclosure size correction factor CF for the relevant electrode configuration and enclosure size.
  4. Calculate the intermediate arc flash boundaries E600, E2700 and E14300 at 600 V, 2700 V and 14300 V.
  5. Calculate the final Incident Energy E at the specified open circuit operating voltage Voc.

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