×
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

ANSI HV & MV Breaker Ratings

ANSI HV & MV Breaker Ratings

ANSI HV & MV Breaker Ratings

(OP)
The Australian Standard for HV circuit-breakers AS 62271.100 is based on the IEC Standard.
The SKM-PTW software breaker library has following ANSI parameters which I do not understand :
- "Rated SC Rating (kA)" - Is this the symmetrical or asymmetrical current at instant of contact parting ?
- "Parting Time (Cyc.)" - Is this the time between receipt of trip signal at the breaker and the first contact parting "?
- "Speed (Cyc.)" - Is this the total clearing time including arcing time ?

RE: ANSI HV & MV Breaker Ratings

Note that ANSI terminology has changed over the years and you must apply the standard in force at the time the breaker was built and tested.

But in general:

1. symmetrical (since 1964 or so - definitely if made after 1970)
2. Time from start of fault to contact parting
3. Yes

As with IEC, the ANSI breaker short circuit ratings are complicated. Conrad St. Pierre's "A Practical Guide to Short Circuit Calculations" covers both ANSI and IEC breaker standards in great detail.

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