×
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

Current Transformer

Current Transformer

Current Transformer

(OP)
Hi,

May I know if a current transformer can be overloaded?
Let say I have a 100/5A CT and continuous current at primary varies from 140 to 210Amps,
Is there a possible that this CT will fail due to overloading?

Thank you and hoping any reply.

RE: Current Transformer

To answer that question you would need the CT thermal rating factor. 100/5 is the ratio. The thermal rating factor could be 1, but it is more likely to be something else.

Regards
Marmite
https://www.google.com.au/url?sa=t&rct=j&q...

RE: Current Transformer

(OP)


Thank you for the reply,
but how can I identify the CT TRF for the attached CT Specs?

Regards,
22574

RE: Current Transformer

From the attached list a 100/5 A CT withstand 1 sec 100*100=10 kA ,the maximum current
permissible in order to maintain the protection class error [ALF] it is 10 times the rated[1000 A] and the metering accuracy factor [SF]=5 -class 0.2.
rated output is 10 VA for 0.2 class and 15 VA for 0.5 class.
See for more information- for instance:
file:///D:/D_My%20Documents/Engineering/Metering/Current%20Transformers%20Cahier%20Shneider%20Electric%20194.pdf

RE: Current Transformer

(OP)
The 1000A permissible current to withstand is only 1second,
How about the max permissible continuous current ?

Thank you.

22574

RE: Current Transformer

Unless you can find a thermal rating factor, you will have to limit continuous current to the rated primary current (100A).

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