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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
0 1.2 cal/cm2
1 4 cal/cm2
2 8 cal/cm2
3 25 cal/cm2
4 40 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)
WD Working distance (inch or mm)
H Enclosure height (inch or mm)
W Enclosure width (inch or mm)
D Enclosure depth (inch or mm)

Table 2: Equipment Types with Typical Imperial Distances and Measurements (IEEE 1584 2018)
Equipment type Gap mm WD in H in W in D in
15 kV Switchgear 152 36 45 30 30
15 kV MCC 152 36 36 36 36
5 kV Switchgear, Large 104 36 36 36 36
5 kV Switchgear, Small 104 36 45 30 30
5 kV MCC 104 36 26 26 26
LV Switchgear 32 24 20 20 20
LV MCCs and Panels, Shallow 25 18 14 12 8
LV MCCs and Panels, Deep 25 18 14 12 9
Cable Junction Box, Shallow 13 18 14 12 8
Cable Junction Box, Deep 13 18 14 12 9

Table 3: Equipment Types with Typical Metric Distances and Measurments (IEEE 1584 2018)
Equipment type Gap mm WD mm H mm W mm D mm
15 kV Switchgear 152 914 1143 762 762
15 kV MCC 152 914 914 914 914
5 kV Switchgear, Large 104 914 914 914 914
5 kV Switchgear, Small 104 914 1143 762 762
5 kV MCC 104 914 660 660 660
LV Switchgear 32 610 508 508 508
LV MCCs and Panels, Shallow 25 457 355.6 305 203
LV MCCs and Panels, Deep 25 457 355.6 305 229
Cable Junction Box, Shallow 13 457 355.6 305 203
Cable Junction Box, Deep 13 457 355.6 305 229

Equipment types with typical distances and sizes for IEEE 1584 2002

Table 4: Typical Conductor Gaps in IEEE 1584 2002
System voltage Equipment type Conductor gap
0.208-1 kV Open air 10-40 mm
Switchgear 32 mm
MCCS and panels 25 mm
Cables 13 mm
>1-5 kV Open air 102 mm
Switchgear 13-102 mm
Cables 13 mm
>5-15 kV Open air 13-153 mm
Switchgear 153 mm
Cables 13 mm

Table 5: Typical working distances in IEEE 1584 2002
System Working distance
15-kV switchgear 910 mm
5-kV switchgear 910 mm
Low-voltage switchgear 610 mm
Low-voltage MCCs and panelboards 455 mm
Cable 455 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.