Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations SDETERS on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

What does this nameplate information mean on a BUCK AUTO transformer? 1

Status
Not open for further replies.

bdn2004

Electrical
Jan 27, 2007
799
"This transformer is self protecting when used on a 275 MVA system." Is this just simply multiplying the Amps x Volts x 1.732 ?

Buck_Boost_Transformer_b7acrm.jpg
 
Replies continue below

Recommended for you

Internal fuses that can interrupt currents up to 25 times rated current; beyond that external impedance (system or specifically added) must provide that current limitation. At that level, through faults will not cause damage.

I’ll see your silver lining and raise you two black clouds. - Protection Operations
 
Once you include the final zero in 2750 MVA, it is just Amps x Volts x 1.732 x 25.

A rating of 4292 amps seems really big for internal fuses. Although there is a type of pole mounted transformer called Completely Self Protected (CSP), the CPS transformers max out around 167 kVA.

I had assumed self protecting was simply a redundant way of indicating no external impedance was needed at low fault levels. IEEE C57.12.00 list various withstand requirements for various categories of transformers. Note that there is also a maximum duration of fault the transformer is designed to withstand.



 
Status
Not open for further replies.

Part and Inventory Search

Sponsor