Intermediate Arc-Flash Boundary Equations and Calculator for Arcing Current per IEEE 1584-2018

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Intermediate Arc-Flash Boundary Equations and Calculator for Arcing Current per IEEE 1584-2018

Electrical and Electronics Design and Engineering

The arc flash boundary (AFB) is the minimum 'safe' distance from exposed energized conductors or circuit parts that has a potential for an arc fault.

Arc Flash Hazard Calculations Procedure and Considerations For Medium Voltage System

Preview: Intermediate Arc-Flash Boundary Equations and Calculator for Arcing Current

Equation 1

AFB600 Calculator

Open AFB₆₀₀ Calculator (Pop-up Window)
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Equation 2

AFB2700 Calculator

Open AFB₂₇₀₀ Calculator (Pop-up Window)
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Equation 3

Open AFB₁₄₃₀₀ Calculator (Pop-up Window)
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Equation 4

AFB≤600 Calculator

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Where:

AFB₆₀₀ = arc-flash boundary for Voc = 600 V (mm)
AFB₂₇₀₀ = arc-flash boundary for Voc = 2700 V (mm)
AFB₁₄₃₀₀ = arc-flash boundary for Voc = 14 300 V (mm)
AFB_≤600 = arc-flash boundary for Voc ≤ 600 V (mm)
G = gap between electrodes (mm)
I_{arc_600} = rms arcing current for 600 V (kA)
I_{arc_2700} = rms arcing current for 2700 V (kA)
I_{arc_14300} = rms arcing current for 14300 V (kA)
I_arc = rms arcing current for Voc ≤ 600 V [obtained using "Final Arc Current Equations and Calculator"] (kA)
I_bf = bolted fault current for three-phase faults (symmetrical rms) (kA)
CF = correction factor for enclosure size (CF = 1 for VOA and HOA configurations)
T = arc duration (ms)
lg = log10
k1 to k13 from table given below

Table A Coefficients (AFB₆₀₀ and AFB_≤600 )

600 V	k1	k2	k3	k4	k5	k6	k7	k8	k9	k10	k11	k12	k13
VCB	0.753364	0.566	1.752636	0	0	-4.783E-09	0.000001962	-0.000229	0.003141	1.092	0	-1.598	0.957
VCBB	3.068459	0.26	-0.098107	0	0	-5.767E-09	0.000002524	-0.00034	0.01187	1.013	-0.06	-1.809	1.19
HCB	4.073745	0.344	-0.370259	0	0	-5.382E-09	0.000002316	-0.000302	0.0091	0.9725	0	-2.03	1.036
VOA	0.679294	0.746	1.222636	0	0	-4.783E-09	0.000001962	-0.000229	0.003141	1.092	0	-1.598	0.997
HOA	3.470417	0.465	-0.261863	0	0	-3.895E-09	0.000001641	-0.000197	0.002615	1.1	0	-1.99	1.04

Table B Coefficients AFB₂₇₀₀

2700 V	k1	k2	k3	k4	k5	k6	k7	k8	k9	k10	k11	k12	k13
VCB	2.40021	0.165	0.354202	-1.557E-12	4.556E-10	-4.186E-08	8.346E-07	5.482E-05	-0.003191	0.9729	0	-1.569	0.9778
VCBB	3.870592	0.185	-0.736618	0	-9.204E-11	2.901E-08	-3.262E-06	0.0001569	-0.004003	0.9825	0	-1.742	1.09
HCB	3.486391	0.177	-0.193101	0	0	4.859E-10	-1.814E-07	-9.128E-06	-0.0007	0.9881	0.027	-1.723	1.055
VOA	3.880724	0.105	-1.906033	-1.557E-12	4.556E-10	-4.186E-08	8.346E-07	5.482E-05	-0.003191	0.9729	0	-1.515	1.115
HOA	3.616266	0.149	-0.761561	0	0	7.859E-10	-1.914E-07	-9.128E-06	-0.0007	0.9981	0	-1.639	1.078

Table C Coefficients AFB₁₄₃₀₀

14300 V	k1	k2	k3	k4	k5	k6	k7	k8	k9	k10	k11	k12	k13
VCB	3.825917	0.11	-0.999749	-1.557E-12	4.556E-10	-4.186E-08	8.346E-07	5.482E-05	-0.003191	0.9729	0	-1.568	0.99
VCBB	3.644309	0.215	-0.585522	0	-9.204E-11	2.901E-08	-3.262E-06	0.0001569	-0.004003	0.9825	0	-1.677	1.06
HCB	3.044516	0.125	0.245106	0	-5.043E-11	2.233E-08	-3.046E-06	0.000116	-0.001145	0.9839	0	-1.655	1.084
VOA	3.405454	0.12	-0.93245	-1.557E-12	4.556E-10	-4.186E-08	8.346E-07	5.482E-05	-0.003191	0.9729	0	-1.534	0.979
HOA	2.04049	0.177	1.005092	0	0	7.859E-10	-1.914E-07	-9.128E-06	-0.0007	0.9981	-0.05	-1.633	1.151

VCB: Vertical conductors/electrodes inside a metal box/enclosure
VCBB: Vertical conductors/electrodes terminated in an insulating barrier inside a metal box/enclosure
HCB: Horizontal conductors/electrodes inside a metal box/enclosure
VOA: Vertical conductors/electrodes in open air
HOA: Horizontal conductors/electrodes in open air

Reference:

IEEE 1584-2018

Verify results and send feedback if a discrepancy is found.