ABB GSB 245, Technical Manual

14

TR A N S FOR M E R BUS H I NG S T Y PE G S B 

T EC H N I C A L  G U I D E

∅

152.5

D2

125

L2

25

60

L5

64 45

M12 (4x)

Threaded 
hole M8 for 
pulling wire

H1 
min 200

Additional 
joint on 
request

Bottom contact type 1

(standard)

Bottom contact type 2

(only for customized end-shields 

and draw rod)

Draw rod system

The draw rod system offers the following advantages 
compared to other methods used for high currents:
•  No manholes required in the transformer tank.
•  The bushing tube is used as a conductor.
•  No special supports required in the transformer, as is the 

case with plug contacts.

•  Perfect guiding of the bushing into the transformer.

The center tube of the bushing is used as conductor. The 
transformer leads are fitted with cable lugs, bolted to a 
bottom contact. This contact is tightened to the lower end 
of the bushing tube by a steel draw rod. The upper end of 
this rod is bolted to a spring device, which consists of two 
concentric tubes of different materials, designed to give the 
required contact load at all temperatures. The draw rod is 
divided into two parts at level with the flange. The lower 
draw rod includes bottom contact, guide cone, rod and joint. 
The upper draw rod consists of compensating device, rods, 
joints, washer and nut.

—
09 Draw rod system.

If required to meet the transport conditions, an additional 
joint can be positioned at any desired level below the flange. 
This must be stated in the order. The lower part with contact 
and end-shield can then be secured to the transport cover 
during transport and storage of the transformer.

Bottom contacts with 4 threaded holes for cable lugs are 
available. The bottom contacts are made of copper in one 
piece. There are standard end-shields for type 1 bottom 
contacts available; see Standard end shield and Table 8. The 
type 2 bottom contact is intended to use with customized 
shields, using three M10 holes at diameter 125 mm for shield 
assembly. Special bottom contacts are available on request.

—

Table 7. Draw rod system.

Cat. No.

Type of draw rod

1ZSC999006

Lower draw rod

1ZSC999007

Upper draw rod