Arc flash assessment, hazard study and short circuit fault current calculation  
  Frequently Asked Questions
 
 
   Home Page
 
  SHORT CIRCUIT:
   SCA Software
   Label Maker
   Reference Data
 
  ARC FLASH:
   AFA Software
   Online Calc
   Comparison
   Video Tutorials
 
  SERVICES:
   Label Printing
 
   Info / FAQ
   Examples
 
   Newsletters
   Contact Us
   Testimonials
   Terms of Use
   News & Links
   Site Map

Label Printing Services
Arc Flash Label
Printing Services

arc flash webinar
Join A Free Webinar

 
How does your arc flash calculator deal with single phase faults? Back to FAQ

"I'm dealing with a number of single phase transformers and considering the possibility of arcing faults at the secondary terminals. I'm not sure how to handle this."

The Duke Power Heat Flux Calculator is most often cited when single phase arc incident energies are to be determined. The Duke Power Flux Calculator guide also explains how to calculate 3 phase arc using single phase arc data (see page 9). The calculator assumes the arc incident is being sustained by a single phase source. The Guide says To correct for the involvement of all three phases, multiply the incident energy value from the Heat Flux Calculator by a factor of 2.8. We do not know the calculation procedure behind the the Duke program as it does not seem to be ever published. However, if you trust the factor, you can use it to calculate single phase arc using three phase arc data obtained using the IEEE 1584 procedure and dividing the resulting value by 2.8.

We find the IEEE procedure more advanced comparing to the Duke because it calculates arc current based on prospective bolted fault current value, geometry and configuration of the equipment. Unfortunately, the Duke software does not give any guidance on how to calculate single phase arcing current using single phase short circuit current value.

Although IEEE 1584 guide has been developed primary for three phase arc fault analysis, the guide states that "A theoretically derived model, based upon Lee’s paper, is applicable for three-phase systems in open air substations, and open air transmission and distribution systems. This model is intended for applications where faults will escalate to three-phase faults. Where this is not possible or likely, this model will give a conservative result. Where single-phase systems are encountered, this model will provide conservative results."


Creative Safety Supply
arc flash handbook
Arc Flash Software
arc flash software
arc flash software for iOS
arc flash software for Android
arc flash train
Write us at: