SELECTOR SWITCH DRIVE MECHANISM TERMINAL BOARD

66KV TAP CHANGER

TYPE ABS 66

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 300 A

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.

These OLTCs may be used on transformers up to

60MVA. 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. The compact

design, easy maintenance and low oil requirement

adds advantages to this tap changer.

The entire tap changer unit with a selector switch and a

drive mechanism chamber are housed in a sheet metal

enclosure. The switch chamber and the drive mechanism

are separated by a metal sheet. The fixed contacts are

mounted on phase boards. The moving contact slides

over these fixed contacts and selects the tap. This is

done in all the three phases simultaneously by a selector

switch. 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.

MOUNTING ON TRANSFORMER :

The tap changer is mounted on the transformer by

taking out leads via the epoxy cast terminal board of the

tap-changer, which is supplied with the OLTC.

PROTECTIVE DEVICE :

The tap-changer is protected by an oil surge protective

relay (OSR) which is connected to a conservator. Though

OSR is supplied with the tap changer, the conservator

and transformer oil are not part of our supply. A pressure

relief device can be provided in addition as per customer

requirements.

TECHNICAL DETAILS

CONSTRUCTION DETAILS

www.onloadgears.com

A

C

E

D

B

C

L TERMINAL BOARD

L PORT &

C

13

L PORTC

L TERMINAL BOARDC 12

47

61

2

9

60

31

6

30

1.OIL FILLING AND FILTERING VALVE FLANGE

2.WINDOW FOR TAP NUMBER COUNTER

3.DOOR HANDLE

4.REMOVABLE INSPECTION COVER

5.TERMINAL BARRIER BOARD

6.LIFTING LUG

7.OIL SURGE BUCHHOLZ RELAY

12.SUPPORTING LUG

11.OIL DRAIN AND FILTERING VALVE FLANGE

8.DRIVE MECHANISM DOOR

9.PUSH BUTTON SWITCHES

13.REMOVABLE CRANK ANDLE

10.CABLE ENTRY GLAND PLATE

ANO OF POSITIONS B C D E

17 POSITIONS 1858 1135 935 1330 1360

23 POSITIONS 1300 1866 1452 1370 1483

NOTE:

1.ALL DIMENSIONS ARE MARKED IN MM

2.TRANSPORTATION CHARGES ARE MARKED AS X

FOR RAISE AND LOWER

4

7

8

1110

2

5

TECHNICAL DATA

Rated voltage 66kV

Max.Rated through current 300A

Rated step voltage 1000V

Rated insulation level 140kV and 350kVp

Max no of tapping position 23 with linear arrangement

Tap changer

wt with oilNoof

positions

Current

in A

Tap

arrangementcycle WtofOil

17 300 Linear Uni directional pennant 1453kg 833kg

23 300 Linear Bi directional flag 2250kg 1500kg

ON LOAD GEARS

oltc-marketing@onloadgears.com

(REF NO:OLTC 04:2009)

432, 433, SIDCO Estate, Ambattur, Chennai-600 098

Tel: +91-44-4393 5800, 4393 5811.Fax +91-44-4393 5888

Emai l:

OUTLINE DIAGRAM

TYPE TESTAs per IEC 60214 and IS 8486 all type tests are successfully performed on this on load tap changer.