×
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

Three winding transformer commissioning test sheet

Three winding transformer commissioning test sheet

Three winding transformer commissioning test sheet

(OP)
Can someone please post/mail me a typical commissioning scedule for power transformers including all transformer tests and functional tests.

RE: Three winding transformer commissioning test sheet

A typical list would include, but not be limited to:

Transformer Windings
  Insulation Resistance (windings and core)
  Insulation Power Factor
  TTR

Bushings
  Insulation Power Factor
  Capacitance

Transformer Oil Dielectric Strength

Instrument Transformers
   Excitation Tests
   Insulation Resistance
   Ratio Tests


Current Transformers

RE: Three winding transformer commissioning test sheet

If the transformer has OLTC in HV side is advisable to perform the Excitation Current test in all taps.
If in MV also has NLTC, for having a benchmarking test the contact resistance of all taps (usually 5 taps)

IEEE-STD 62-1995 (I think so) is a good reference.

Insulation power factor including capacitance test is advisable also.

This tests will be important as zero test (benchmarking) for future diagnostics.

RE: Three winding transformer commissioning test sheet

(OP)
okay. We have a 5MVA, 88/33kV transformer that we want to put in service. It was bought around 1985 (Iam told)but was neverput in commission.Over time the nameplate was removed and no one seems to have the details except that it was to be used to step down from 88/33kV at one of our stations. The transformer was stored undressed and blanked nicely. Initial tests indicated that the winding insulation is okay. Now we want to establish its vector group. How can this be done on site? And assuming we did not know the rated voltage ratios, how this be determined? (just to be sure). I would appreciate some guidelines or literature on this.

RE: Three winding transformer commissioning test sheet

Vidima, have you considered energizing the primary with low voltage {380Y/220?}; then making ratio and vector-group checks with a voltmeter and phase-angle meter?  It may then be possible to energize the transformer at 33kV or some intermediate voltage for an idling period before placing into full service.

RE: Three winding transformer commissioning test sheet

Vector group and voltage ratios are easily determined with a Turns Ratio Tester, such as those manufactured by Biddle.  The voltage used by the TTR is only about 10 volts.  You should be able to determine who built the transformer by checking bushing nameplates, transformer prints, purchase orders, by comparing with other transformers, and possibly by examination of auxiliary equipment on the transfomer.  Transformer manufacturers normally maintain records of their products and you should be able to get a replacement nameplate, test data, copies of the original drawings, etc.  

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