Duke Power Heat Flux Calculator Documentation

Description

This freeware is offered with no claims from Macron Safety or Duke Power to help you assess your potential for electrical arc. This DOS program will give you the predicted incident energy in cal/cm. You can then get assistance from OSHA or a company offering arc thermal performance value (ATPV) data on their clothing in choosing your clothing.

You will need to enter the following data once you have downloaded the program:

• amps of ground fault available,
• expected duration of the arc in cycles,
• expected length of the arc,
• distance of the worker from the arc and system voltage

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.

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.

Disclaimer:

The Duke Power Heat Flux Calculator is a freeware software product created by Alan Privette of Duke Power. Macron Safety 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. Macron Safety provides no warranty nor accepts any responsibility for any inappropriate use, damage or injury that may result from its use.