Previous in Forum: Current Before and After VFD   Next in Forum: Maximum Possible Size of Downstream Transformer
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
5 comments
Rate Comments: Nested
Anonymous Poster

Current Transformers in Series

02/18/2010 9:58 AM

If i placed three toroid CTs in three different phases of voltage rating 220volts. is it possible to connect the output of these CTs in series? what happen in this condition?

If this possible then where should we connect the current indicator and what will it measure(right current or not)?
Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
JohnDG
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9684
Good Answers: 468
#1

Re: Current Transformers in series

02/18/2010 10:26 AM

It is possible to connect them in series, but the output would be zero (unless the currents in the three phases were not equal).

__________________
 "Love justice, you who rule the world" - Dante Alighieri
Reply
Anonymous Poster
#2

Re: Current Transformers in series

02/18/2010 11:19 AM

This is the principle of RCD (provided you have folowed the correct sequence).

The phasor sum of 3 currents (balanced or unbalanced) should be zero - KCL-unless some current leaks out.
Reply
DannyD
Associate

Join Date: Oct 2009
Location: kuruman NC. SOUTH AFRICA
Posts: 51
Good Answers: 1
#3

Re: Current Transformers in Series

02/19/2010 4:00 AM

If it is balance system you will defenitely measure zero on your current indicator, unless ther is a leakage current.

__________________
 Dan Segami
Reply
sidhu16
Commentator
India - Member - New Member Engineering Fields - Electrical Engineering - New Member Technical Fields - Technical Writing - New Member

Join Date: Feb 2010
Location: India
Posts: 92
Good Answers: 2
#4

Re: Current Transformers in Series

02/19/2010 4:16 AM

You actually get no output current from this connection. If there is any mismatch between CT's then you can have few leakage currents.
Reply
Anonymous Poster
#5

Re: Current Transformers in Series

02/19/2010 6:27 AM

If its a delta system (3 WIRE) it should be zero. If its a Y (3 phases + neutral) you should get the save value as one CT on the neutral line.
Reply
Reply to Forum Thread
Have a Different Question?
5 comments
Copy to Clipboard

Users who posted comments:

Anonymous Poster (2); DannyD (1); JohnDG (1); sidhu16 (1)

Previous in Forum: Current Before and After VFD   Next in Forum: Maximum Possible Size of Downstream Transformer

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Electrical Engineering:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (63 right now)
Show Members
Advertisement