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 I_arc	ms
Arcing time for I_{arc_min}	ms
Equipment type

Working distance	in
Enclosure width	in
Enclosure height	in
Enclosure depth	in
Electrode configuration

Conductor gap	mm

Parameters for the IEEE 1584 2018 Arc Flash Calculator

Standard: Select IEEE 1584-2018 or IEEE 1584-2002.
Unit of measure: Imperial (in) or Metric (mm). Note that Conductor Gap is always in metric.
Voltage (Vac): Enter an AC voltage between 208 V and 15,000 V. AC voltage levels outside of this range, and DC voltage levels, are not supported by the IEEE 1584-2018.
Fault current (kA): Three-phase bolted prospective fault current in kA.
Arcing time for I_arc (ms):
- The fault clearing time for the calculated normal arching current.
- Include the protection relay and circuit breaker clearing time.
- Follow a three-step process to specify the arching time:.
- Step 1: Leave the default time value, and click on Calculate.
- Step 2: Use the calculated arcing current I_arc to determine the actual fault clearing time for your protection system,
- Step 3: Click on Calculate again, to calculate the Incident Energy and Arc Flash Boundary.
- Note that the time does not affect the magnitude of the acing current.
Arcing time for I_{arc_min} (ms):
- The purpose of this is to calculate the Incident Energy and Arc Flash Boundary for a scenario where the fault clearing time may be longer due to a reduced arcing current.
- This is the arcing time for the calculated reduced arcing current.
- Follow the same steps as explained above for the arcing time for the normal arcing current.
Working distance (inch or mm): The working distance from the arc location. This field is pre-populated with typical distances from IEEE 1584 2018, which is based on the Equipment Type.
Equipment Type:
- The Equipment Type is used to pre-populate the following distances and sizes with typical values from the IEEE 1584 2018:
  - Working Distance.
  - Enclosure Sizes (width, height, and depth).
  - Conductor Gap.
- You can change these values after you have selected the equipment type.
- The Equipment Type is not used in the calculations. Only the values are used.
Enclosure width, height and depth (inch or mm): You can change the typical enclosure (box) sizes here. These values are pre-populated with typical values from IEEE 1548 2018, based on the selected Equipment Type.
Electrode configuration: Choose from the following:
- VCB: Vertical conductor (electrode) in a box.
- VCBB: Vertical conductor (electrode) in a box terminated in an insulating barrier.
- HCB: Vertical conductor (electrode) in a box.
- VOA: Vertical conductor (electrode) in open air.
- HOA: Horizontal conductor (electrode) in open air.
Conductor gap (mm): The distance between the conductors (electrodes). This value is always in mm. It is pre-populated with typical values from IEEE 1548 2018, based on the selected Equipment Type.

Parameters for the IEEE 1584 2002 Arc Flash Calculator

Standard: Select IEEE 1584-2018 or IEEE 1584-2002.
Unit of measure: Imperial (in) or Metric (mm). Note that Conductor Gap is always in metric.
Voltage (Vac): Enter an AC voltage between 208 V and 15,000 V. AC voltage levels outside of this range, and DC voltage levels, are not supported by the IEEE 1584-2002.
Fault current (kA): Three-phase bolted prospective fault current in kA.
Arcing time for I_arc (ms):
- The fault clearing time for the calculated normal arching current.
- Include the protection relay and circuit breaker clearing time.
- Follow a three-step process to specify the arching time:.
- Step 1: Leave the default time value, and click on Calculate.
- Step 2: Use the calculated arcing current I_arc to determine the actual fault clearing time for your protection system,
- Step 3: Click on Calculate again, to calculate the Incident Energy and Arc Flash Boundary.
- Note that the time does not affect the magnitude of the acing current.
Working distance (inch or mm): The working distance from the arc location. This field is pre-populated with typical distances from IEEE 1584 2018, which is based on the Equipment Type.
Equipment Type:
- The Equipment Type is used to pre-populate the following distances and sizes with typical values from the IEEE 1584 2002:
  - Working Distance.
  - Conductor Gap.
- You can change these values after you have selected the equipment type.
- The Equipment Type is used in the calculations.
Grounding: The grounding type is used in calculations.
Conductor gap (mm): The distance between the conductors (electrodes). This value is always in mm. It is pre-populated with typical values from IEEE 1548 2018, based on the selected Equipment Type.

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:

Incident Energy Analysis Method
Arc Flash PPE Category Method

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:

Calculate the intermediate arching currents I_{arc_600}, I_{arc_2700} and I_{arc_14300} at 600 V, 2700 V and 14300 V.
Calculate the final arcing current I_arc at the specified open circuit operating voltage V_oc.
Calculate the enclosure size correction factor CF for the relevant electrode configuration and enclosure size.
Calculate the intermediate arc flash boundaries AFB₆₀₀, AFB₂₇₀₀ and AFB₁₄₃₀₀ at 600 V, 2700 V and 14300 V.
Calculate the final arc flash boundary AFB at the specified open circuit operating voltage V_oc.

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:

Calculate the intermediate arching currents I_{arc_600}, I_{arc_2700} and I_{arc_14300} at 600 V, 2700 V and 14300 V.
Calculate the final arcing current I_arc at the specified open circuit operating voltage V_oc.
Calculate the enclosure size correction factor CF for the relevant electrode configuration and enclosure size.
Calculate the intermediate arc flash boundaries E₆₀₀, E₂₇₀₀ and E₁₄₃₀₀ at 600 V, 2700 V and 14300 V.
Calculate the final Incident Energy E at the specified open circuit operating voltage V_oc.