Duke Power Heat Flux Calculator Instructions

The Duke Power Heat Flux Calculator is a freeware software product created by Alan Privette of Duke Power.  Graphic Products, Inc. is providing a free download of this software on this web site. Graphic Product, Inc. is a manufacturer and dealer of industrial-quality labeling machines that are used to make labels and signs, including arc flash labels.  We are not an electrical safety consultant.

Disclaimer: Environmental Safety Group, Inc. is making this software available for free download as a service to visitors to our web site.  Use of this software is the sole responsibility of the user. ESG, Inc. provides no warranty nor accepts any responsibility for any inappropriate use, damage or injury that may result from its use.

Keep in mind that every application is unique.  If you are not sure about a particular application, please contact your electrical safety manager, or use the services of an electrical safety consultant.

The Duke Power Heat Flux Calculator has a simple user interface.  You will be prompted to enter five numbers.  If you make a typo you can not go back and correct the entry.  You’ll need to start over.  You can exit from the calculator by holding down the CTRL key and pushing the BREAK key on your keyboard. (Located next to the function keys on the right side of the keyboard)

The software does not include error checking.  If you get an “overflow” error message, that means a calculation has resulted in infinity as the answer.  Most likely zero was entered as one of the numbers.  Push any key to close the software and start over.

The numbers you’ll be asked to enter are:

• The arc current in amps.  This is the maximum amount of current that is available to create an arc.
  
  
• The arc gap in inches.  This is the distance the arc will flow through the air.  This is typically the distance between bus bars, or the distance between a bus bar and ground.
  
  
• The supply voltage in volts.  Notice that the voltage must be entered in volts without using a comma.  For example, 5000 would be correct.  Do not enter 5,000 or 5kA.

The calculator will let you know if the voltage is sufficient to sustain an arc.  If it is not, a smaller gap distance can be entered so that the calculation can proceed.  You cannot go back and change the gap distance.  You must exit from the software (CTRL-Break) and restart it.

After this number is entered the software will perform some calculations and display the results on the screen.

•  Distance from the arc to the receiving surface.  The receiving surface is the person who is near the device when the arc flash occurs.
  
  
• Duration of the arc in number of cycles.  The number will be based on the clearing time of the fuse or breaker in the circuit.

The software will now calculate the total calories per square centimeter at the receiving surface.