Positive-negative Cage Tap Changer

A tap changer is a device fitted to power transformers for regulation of the output voltage to required levels. This is normally achieved by changing the ratios of the transformers on the system by altering the number of turns in one winding of the appropriate transformer/s. Supply authorities are under obligation to their customers to maintain the supply voltage between certain limits. Tap changers offer variable control to keep the supply voltage within these limits. About 96% of all power transformers today above 10MVA incorporate on load tap changers as a means of voltage regulation.

Positive-negative automatic cage off load tap changer is also called vertical electric cage tap changer with round flange. It is applicable to oil immersed furnace transformer.

Furnace Transformers are Arc, Submerged Arc, Ladle, Induction, Up to 10 MVA, Up to 33kV,ONAN/OFWF Cooling A high current furnace transformer is provided having the low-voltage windings arranged in a closed delta configuration within the transformer enclosure. Bus bar terminals are mounted exterior to the enclosure for providing electrical connection with the low-voltage windings.

Model Explanation 

 WSL □D□ □/□-□╳□F/Y
    W:  off-circuit
    S :  three-phase
    L :  cage type
    □:  voltage regulation model
    D:  automatic electric  
    □:  L for vertical ; W for horizontal
    □:  rated current
    □:  rated voltage
    □:  number of tapping heads
    □:  number of tapping position
    F/Y: square flange or round flange
Voltage Regulation Model
    I  :  linear regulating
    II :   central point
    III :  neutral point
    IV :  Y-△ conversion
    V :   series-parallel connection
    VI :  positive and negative regulation

Samples Technical Data