66kV Tap
Changer TYPE–ABS66

Type ABS66 is a 3-phase, single compartment, externally mounted on-load tap changer. This OLTC works on the principle of high speed transition resistance and is suitable for both star and delta connected transformers with linear tap arrangement.

There are two different models, 17 positions 300A and 23 positions 300A (refer technical data for details). The OLTC 17 position rated for 300A follows an asymmetrical pennant cycle whereas the 23 positions 300A OLTC follows a bi-directional flag cycle. The tap changers have a maximum current and voltage rating of 300A and 72kV respectively.

Advantages

These OLTCs may be used on transformers up to 60 MVA. They are available for a maximum of 23 positions, so they can be applied to a winding of 22 steps to give 23 different voltages.
It has a compact design, easy maintenance and low oil requirement.
The tap changer is protected by an oil surge protective relay (OSR) which is connected to a conservator.

Key Features

The entire tap changer unit with a selector switch and a drive mechanism chamber are housed in a sheet metal enclosure.
The fixed contacts are mounted on phase boards. The moving contact slides over these fixed contacts and selects the tap.
The selector switch combines the functions of a tap selector and a diverter switch.
The drive mechanism is coupled to this selector switch by a drive shaft and series of gears. It also has an energy storage device that releases the energy to drive the selector switch.