Arc Flash Calculations

Procedure:

1. Enter in data below.
2. Enter the fault clearing time for a bolted three phase fault current from the protective device time current curve.
3. Calculate the arc flash values by clicking calculate.
4. Get the arcing fault current value from the calculation.
5. Re-calculate the arc flash incident energy with the clearing time for the arcing fault current.
6. Using the clearing time for the arcing fault current will calculate the most accurate incident energy.
7. Arc flash calculations are a computer model approximation, real world arc flash incident energies can be different than calculated.

Project:
Case Number:

System Voltage KV:

Avalable Fault Current KAmps:

Fault Clearing Time Seconds:

Working Distance Inches:

Electrode Type:



Enclosure Height Inches:

Enclosure Width Inches:

Enclosure Depth Inches:

Typical Enclosures Dimensions H X W X D:
15KV Switchgear 45 X 30 X 30 inches
5KV Switchgear 36 X 36 X 36 inches
5KV MCC 26 X 26 X 26 inches
Low Voltage Switchgear 20 X 20 X 20 inches
Low Voltage MCC/Panelboards 14 X 12 X 8 inches
Low Voltage Jbox 14 X 12 X 7 inches


Conductor Gap Inches:

Typical Gaps: 15KV Switchgear 152mm=5.98in, 5KV Switchgear/MCC 104mm=4.09in, Low Voltage Switchgear 32mm=1.26", Low Voltage MCC/Panelboards 25mm=0.984in Low Voltage Jbox 13mm=0.512in




The National Electric Code (NEC) specifies the minimum size for cable tray systems which includes ladder, ventilated trough, ventilated channel, solid bottom and other similar structures. It’s important to note that cable trays are mechanical support systems and not raceways. Raceways are included in another section of the code.

Proper cable tray sizing is complicated and often existing cable trays are overloaded per the code. If you have questions or would like some engineering assistance to properly size your cable tray installation please contact us.

Result here