×
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

is necessary grounding CT without connection?

is necessary grounding CT without connection?

is necessary grounding CT without connection?

(OP)
You have CTs of power system with secondary windings without the use. So you have to short-circuit them.
Question: do you have to ground them either?
 

RE: is necessary grounding CT without connection?

Yes.

RE: is necessary grounding CT without connection?

(OP)
Why? Is there some standard?

RE: is necessary grounding CT without connection?

If not grounded, the secondary will tend to capacitivily couple to the primary and rise to primary voltage. A real safety hazard.  

RE: is necessary grounding CT without connection?

(OP)
davidbeach,
do you mean that with capacitive coupling , there will be transfer voltage from primary to secondary?  

RE: is necessary grounding CT without connection?

Yes.  

RE: is necessary grounding CT without connection?

All CT secondary windings need to have ground reference without exception.

RE: is necessary grounding CT without connection?

(OP)
Scottf
I am just receiving a drawing of CT connection for governor.
Each phase-CT is connected to phase current CT channel of governor digital system.
 It is not a three-phase Y-connection(3Ph+1N wiring).
They are connected completed independent.((2+2+2=6 wiring).
There is no ground for neutral because there is no neutral.
Each pair of wire are shielding , with the shelding grounded.
Is this an exception?
  

RE: is necessary grounding CT without connection?

Experts,I have some reservations.In CT( 66kV and above) the primary turn is fully insulated and provided with an external earth shield and earthed.The secondary winding over a toroidal core is placed concentrically to this shielded primary winding.Hence the transferred voltage to secondary due to capacitive coupling may be nil or negligible.

In power transformers, there is a similar case.When stabilising tertiary( unloaded) with all the three terminals are brought out,it is recommended to earth one corner of the delta tertiary.This is done just to drain away the charges on shut down otherwise some one climbing over the transformer tank soon after shut down may get a nasty shock on touching the tertiary terminals.

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