Bornas At

1ZSE 2750-100 en, Rev. 3, 2006-03-15

Bushings for High Voltage AC Applications
Selection guide

During selection of bushings for high voltage applications several important factors have to be considered to ensure that the correct equipment is chosen. This Selection Guide has been produced to simplify the selection process and to ensure that sufficient information exists to allow thecorrect selection to be made. The technical information pertaining to bushings manufactured by ABB has been divided in separate documents, with one document for each type. The information provided in this document is intended to be general and does not cover all possible applications. Any specific application not covered should be referred directly to ABB, or its authorized representative. ABB makes nowarranty or representation and assumes no liability for the accuracy of the information in this document or for the use of such information. All information in this document is subject to change without notice.

Table of contents
The selection process for AC bushings __________________ Input data ____________________
Type of application ___________________ Electrical requirements________________ Ambient conditions including mecanical requirements _______________ 3 4 4 4 4 5 6 6 8 9

Selection _____________________ Product scope ________________
Oil Impregnated Paper (OIP) bushings ____ Resin Impregnated Paper (RIP) bushings __ Bushings for special applications ________

Product documentation _________

10 Technical guide ______________________ 10 Installation and maintenanceguide _______ 10 Product informations __________________ 11

2

The selection process for AC bushings
Below is a schematic plan, showing the selection process. Before the selection can start, a number of different input data have to be collected. After that the selection guide can be used to select the most suitable bushing for the application in question. When the type of bushing isidentified, the selection of the right size is made in the applicable Technical Guide. In the Technical Guide, the special features, such as connection details, oil level indicator, inclination of the bushing etc. are chosen. Information about mounting and service is given in the Installation and Maintenance Guide, available for all types. For special questions, product informations giving more detailedinformation are available upon request. For any further assistance, please do not hesitate to contact ABB.

Input data
Electrical requirements Referred standards (IEC 60137, ANSI/IEEE, others) Ambient conditions including mechanical requirements

Selection guide
Selection (p. 5): Quick reference for transformer bushings Application Nominal voltage Lightning impulse Switching impulse AC 1 min.dry AC 1 min. wet Phase-to-ground voltage Current Creepage distance

ABB
Sales department

Installation and maintenance guide

General product informations

Technical guide
Ratings for all standard sizes of bushings Dimensions for all standard sizes of bushings Special options for the bushings

Order

3

Input data
Type of application
ABB AC bushings are made for five differentapplications: • • • • • Oil to Air Oil to Oil Oil to SF6 Air to Air Air to SF6 Required maximum power factor limits if other than IEC or ANSI This is made as a routine test on all bushings. IEC requires the bushing to have a power factor below 0.7 %. ANSI requires the bushing to have a power factor below 0.5 %.
Air temperature Transformer oil temperature rise above ambient Maximum hot spot in OIPbushings Maximum hot spot in RIP bushings IEC 30 °C 60 K 105 °C 120 °C ANSI 40 °C 65 K 105 °C 120 °C

For DC application, please contact ABB for further information.

Electrical requirements
The following electrical data must be known prior to commencing the selection process: Referred standard Generally ABB bushings fulfil the electrical requirements according to IEC (IEC 60137) and ANSI...