×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Arc Flash - Current required to sustain an arcing current

Arc Flash - Current required to sustain an arcing current

Arc Flash - Current required to sustain an arcing current

(OP)
I am using PTW's Arc Flash software which has a default parameter "Cleared Fault Threshold" which is the percentage of initial arcing current which when interrupted results in arc being extinguished.
The default setting for the "Cleared Fault Threshold" current is 80%. ie. the assumption is that the remaining 20% of arcing current can not sustain the arc. Using Warrington's empirical formula for arc resistance, an arcing current of 1.74kA across a 'Gap' ( arc length ) of 25mm has a resistance of only 0.0208 Ohm. I am therefore reluctant to assume that the arc can not be supported after the 'Cleared Fault Threshold" current is interrupted.
Does anyone with arc experience know what magnitude of current will sustain an arc in a system where the 'Gap' is approx. 25mm and the phase to phase voltage is 415V, 50Hz ?
 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources