EKTO 72.5 – 550 kVRIP Transformer Oil Bushing

RIP condenser bushing type EKTO

DesignIntended for the direct connection of power transformers

to oil filled cable boxes, the type EKTO has an insulating

body of resin impregnated paper (RIP). The condenser core

is made of special paper epoxy resin vacuum-impregnated

paper. Conductive layers made of aluminium foil are inserted

between these paper layers for grading the electric field.

Thanks to their good conductivity, optimum voltage distribution

is guaranteed even in case of rapid voltage changes.

The insulating body is fixed to the one-piece flange. A system

of multiple-sealing made of oil-resistant O-ring seals is employed

between the insulating body and the bushing flange.

All bushings have a test tap connecting lead at the flange.

The test tap is led through as insulated wire and screwed to

the flange plate for grounding. Upon customer request this

wire can be led through an external test tap fixed to

the transformer tank (see drawing “external test tap”).

The bushings have two M12 earthing holes and threaded lifting

holes on the pitch circle diameter of the transformer side flange

plate as a standard.

All bushings can be provided with a detachable cable or conductor

bolt. The connecting surfaces on the conductor bolt can be designed

as round or flat terminal connection. The central bore of the bushing

can be vented via the vent screw at the front of the cable or conduc-

tor bolt. C.t. accommodations in steps of 100 mm up to 500 mm

are available.

Standards and customized modifcations All bushings are designed to comply with IEC Standard 60137 and

tested accordingly. Bushings that comply with IEEE Standard or other

national regulations are available on request.

The types specifed in this brochure represent standard versions.

Modifcations are possible, but may result in changes of price and

delivery times and must therefore be specifically requested.

The technical designs of these bushing types are documented in

comprehensive delivery specifications.

External test tap Option: EKTO with double flange

2 | 3

As an option the bushing can be equipped with a double flange.

This flange has an additional pitch circle diameter on the cable side.

A

C.T.

60°

Insulating electrode with bayonet from HSP

Test voltage [kV]EK1

(Ø 200 x 200)EK2

(Ø 250 x 250)Minimum distance

Um AC1min A [mm] A [mm] A [mm]

72,5 155 130 150 110

100 205 150 160 130

123 255 170 180 160

145 305 200 210 185

170 355 290 250 210

245 505 420 400 330

300 505 420 400 330

362 560 – 450 340

420 695 – 675 410

550 750 – 850 500

550 870 – ■ 550

■ Additional barriers required

Recommended installation of screen electrodes

Type series EKTO – Details and dimensions

Screen electrodesCable side shield electrodes can be supplied on request. Two op-

tions are available: cast resin electrode or PU-coated aluminium

shield, according to the illustration “Cable side connection with

cast resin electrode or PU-coated aluminium shield”.

Cast resin electrodes are made of a metal mesh casted in resin.

They can be stored outside and absorption of atmospheric moisture

is minimized. These electrodes can be shifted over the bushing

body to enable easy installation of the connection to the cable

pot-head. The other option is an electrode made of aluminium

with 125 µm polyurethane coating. Bushings with a voltage

up to 245 kV are equipped with an integrated shield electrode

on the transformer side.

Bushings of the type shown in the illustration “Outlet end at

transformer with cast resin electrode” must be shielded with an

electrode. The dimensions given in the table above refer to elec-

trodes (EK1, EK2) made of insulating material that can be detached

via a bayonet connection. They can be moved upwards as well as

downwards and thus allow possible installation of a junction point

for the current conductor.

The required distance to ground “A” in each case is contained in

the table above. Additional insulating measures or larger distances

may be necessary because of the constraints when installing in the

transformer. The bushing can also be operated with electrodes and

barrier systems not manufactured by HSP. The distance must not be

less than the “Minimum distance A” given in the above table.

4

Typenreihe EKTO – Maßbild

L8 L9

L7 L7

L8

L7

ø D10

ø D9

ø D10 ø D10

ø D9

α

ø D4

ø D3

Connecting lead

z x α

øi

90°

S

4

ø i

ø d1

ø d2

ø D

2

ø D

w

Connecting leadCable side Transformer side

ø D

5

ø D

1

ø d

L3

S

E

I1

I23690

L2 L1

L

Type series EKTO – Dimensional drawing

EK1 EK2

D9 mm 160 180

D10 mm 200 250

L7 mm 200 250

L8 mm 130 160

Connection transformer side

Dimensions of the cast resin electrodes

EK1 EK2 Aluminium shield

D9 mm 160 180 –

D10 mm 200 250 220

L7 mm 200 250 240

L8 mm 119 159 –

L9 mm – – 135

Dimensions of the cast resin electrodes / PU-coated aluminium shield

Outlet end at transformer with cast resin electrode

Cable side connection with cast resin electrode or PU-coated aluminium shield

Electrical values/dimensions

325/

73-0

325/

73-A

325/

73-B

550/

123-

0

550/

123-

A

550/

123-

B

650/

145-

A

650/

145-

B

750/

170-

A

750/

170-

B

1050

/24

5-A

1050

/24

5-B

1050

/30

0-A

1050

/30

0-B

1175

/36

2-A

1175

/36

2-B

1425

/42

0-A

1425

/42

0-B

1550

/42

0-A

1550

/42

0-B

1675

/55

0-B

Description

Technical data

Highest voltage for equipment: Um kV 72,5 72,5 72,5 123 123 123 145 145 170 170 245 245 300 300 362 362 420 420 420 420 550

Max. service voltage: line-ground kV 42 42 42 71 71 71 84 84 98 98 142 142 173 173 210 210 242 242 242 242 318

Rated lightning impulse withstand voltage: 1.2/50 µs kV 325 325 325 550 550 550 650 650 750 750 1050 1050 1050 1050 1175 1175 1425 1425 1550 1550 1675

Rated switching impulse withstand voltage: 250/2500 µs kV – – – – – – – – – – 850 850 850 850 950 950 1050 1050 1175 1175 1175

Rated current and maximum service current: Cable bolt Ir ; Imax A 630 800 1250 630 800 1250 800 1250 800 1250 800 1250 800 1250 800 1250 800 1250 800 1250 1250

Rated current and maximum Detachable conductor bolt Ir ; Imax

A 1250 2000 2500 1250 1600 2500 1600 2000 1600 2000 1250 2000 1250 2000 1250 2000 1250 1600 1250 1600 1600

Routine Test voltage levels

Power frequency withstand voltage dry: Up 50 Hz, 1 min kV 155 155 155 255 255 255 305 305 355 355 505 505 505 505 560 560 695 695 750 750 750

Maximum value of partial discharge pC 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Partial discharge extinction voltage kV ≥ 94 ≥ 94 ≥ 94 ≥ 160 ≥ 160 ≥ 160 ≥ 188 ≥ 188 ≥ 221 ≥ 221 ≥ 318 ≥ 318 ≥ 390 ≥ 390 ≥ 470 ≥ 470 ≥ 546 ≥ 546 ≥ 546 ≥ 546 ≥ 714

Lightning impulse test voltage (BIL): 1.2/50 µs pos./neg. kV – / – – / – – / – – / – – / – – / – – / – – / – – / – – / – – / 1050 – / 1050 – / 1050 – / 1050 – / 1175 – / 1175 – / 1425 – / 1425 – / 1550 – / 1550 – / 1675

Chopped lightning impulse test voltage: time to sparkover 2…6 µs pos./neg. kV – / – – / – – / – – / – – / – – / – – / – – / – – / – – / – – / 1155 – / 1155 – / 1155 – / 1155 – / 1293 – / 1293 – / 1568 – / 1568 – / 1705 – / 1705 – / 1843

Type Test voltage levels

Lightning impulse test voltage (BIL): 1.2/50 µs pos./neg. kV 325/ 325 325/ 325 325/ 325 550/ 605 550/ 605 550/ 605 650/ 715 650/ 715 750/ 825 750/ 825 1050/1155 1050/1155 1050/1155 1050/1155 1175/1293 1175/1293 1425/1568 1425/1568 1550/1705 1550/1705 1675/1843

Chopped lightning impulse test voltage: time to sparkover 2…6 µs pos./neg. kV – / – – / – – / – – / 666 – / 666 – / 666 – / 787 – / 787 – / 908 – / 908 – / 1271 – / 1271 – / 1271 – / 1271 – / 1422 – / 1422 – / 1724 – / 1724 – / 1876 – / 1876 – / 20 27

Switching impulse test voltage dry (SIL): 250/2500 µs pos./neg. kV – / – – / – – / – – / – – / – – / – – / – – / – – / – – / – 850/935 850/935 850/935 850/935 950/1045 950/1045 1050/1155 1050/1155 1175/1293 1175/1293 1175/1293

Dimensions

L1 mm 260 260 260 340 340 340 390 390 450 450 620 620 620 620 690 690 790 790 840 840 990

L2 mm 387 387 387 512 512 512 567 567 607 607 782 812 802 832 882 882 1002 1002 1042 1042 1212

L3 mm 120 120 120 120 120 120 120 120 120 120 120 150 120 150 150 150 150 150 150 150 150

Dw mm 90 120 120 120 142 162 142 162 162 182 200 220 200 220 220 240 290 290 290 290 334

D1 mm 90 90 120 90 90 120 90 120 90 120 90 120 90 120 90 120 90 120 90 120 120

D2 mm 90 100 120 80 100 120 100 120 100 120 120 140 140 140 140 140 140 140 140 140 140

D3 mm 250 250 250 290 290 290 290 290 290 290 350 400 350 400 400 450 450 450 450 450 550

D4 mm 290 290 290 335 335 335 335 335 335 335 400 450 400 450 450 500 500 500 500 500 600

D5 mm 125 163 163 163 185 205 185 205 205 225 245 265 245 265 265 285 335 335 335 335 379

l1 mm – 90 – 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90

d1 mm 31 48 68 31 48 68 48 68 48 68 48 68 48 68 48 68 48 68 48 68 68

l2 mm 52 52 52 52 52 52 52 52 52 52 52 52 – – – – – – – – –

d2 mm 45 65 85 45 65 85 65 85 65 85 65 85 – – – – – – – – –

s mm 15 15 15 20 20 20 20 20 20 20 20 25 20 25 25 25 25 25 25 25 30

i mm 15 15 15 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 25

z 8 8 8 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 16

α ° 45 45 45 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 22,5

d mm Type-0 M24x1,5; Type-A Ø30 up to 1250 A, Ø40 > 1250 A; Type-B Ø30 up to 1250 A, Ø42 > 1250 A

C.T. accommodation length E mm 0 0 0 0 0 0 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

Total length L mm 647 647 647 852 852 852 1057 1057 1157 1157 1502 1532 1522 1552 1672 1672 1892 1892 1982 1982 2302

C.T. accommodation length E mm 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300

Total length L mm 947 947 947 1152 1152 1152 1257 1257 1357 1357 1702 1732 1722 1752 1872 1872 2092 2092 2182 2182 2502

C.T. accommodation length E mm 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600

Total length L mm 1247 1247 1247 1452 1452 1452 1557 1557 1657 1657 2002 2032 2022 2052 2172 2172 2392 2392 2482 2482 2802

Bushing type EKTO

Detailed drawings for the dimensions of the table see flap left

5 |6 | 7

325/

73-0

325/

73-A

325/

73-B

550/

123-

0

550/

123-

A

550/

123-

B

650/

145-

A

650/

145-

B

750/

170-

A

750/

170-

B

1050

/24

5-A

1050

/24

5-B

1050

/30

0-A

1050

/30

0-B

1175

/36

2-A

1175

/36

2-B

1425

/42

0-A

1425

/42

0-B

1550

/42

0-A

1550

/42

0-B

1675

/55

0-B

Description

Technical data

Highest voltage for equipment: Um kV 72,5 72,5 72,5 123 123 123 145 145 170 170 245 245 300 300 362 362 420 420 420 420 550

Max. service voltage: line-ground kV 42 42 42 71 71 71 84 84 98 98 142 142 173 173 210 210 242 242 242 242 318

Rated lightning impulse withstand voltage: 1.2/50 µs kV 325 325 325 550 550 550 650 650 750 750 1050 1050 1050 1050 1175 1175 1425 1425 1550 1550 1675

Rated switching impulse withstand voltage: 250/2500 µs kV – – – – – – – – – – 850 850 850 850 950 950 1050 1050 1175 1175 1175

Rated current and maximum service current: Cable bolt Ir ; Imax A 630 800 1250 630 800 1250 800 1250 800 1250 800 1250 800 1250 800 1250 800 1250 800 1250 1250

Rated current and maximum Detachable conductor bolt Ir ; Imax

A 1250 2000 2500 1250 1600 2500 1600 2000 1600 2000 1250 2000 1250 2000 1250 2000 1250 1600 1250 1600 1600

Routine Test voltage levels

Power frequency withstand voltage dry: Up 50 Hz, 1 min kV 155 155 155 255 255 255 305 305 355 355 505 505 505 505 560 560 695 695 750 750 750

Maximum value of partial discharge pC 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Partial discharge extinction voltage kV ≥ 94 ≥ 94 ≥ 94 ≥ 160 ≥ 160 ≥ 160 ≥ 188 ≥ 188 ≥ 221 ≥ 221 ≥ 318 ≥ 318 ≥ 390 ≥ 390 ≥ 470 ≥ 470 ≥ 546 ≥ 546 ≥ 546 ≥ 546 ≥ 714

Lightning impulse test voltage (BIL): 1.2/50 µs pos./neg. kV – / – – / – – / – – / – – / – – / – – / – – / – – / – – / – – / 1050 – / 1050 – / 1050 – / 1050 – / 1175 – / 1175 – / 1425 – / 1425 – / 1550 – / 1550 – / 1675

Chopped lightning impulse test voltage: time to sparkover 2…6 µs pos./neg. kV – / – – / – – / – – / – – / – – / – – / – – / – – / – – / – – / 1155 – / 1155 – / 1155 – / 1155 – / 1293 – / 1293 – / 1568 – / 1568 – / 1705 – / 1705 – / 1843

Type Test voltage levels

Lightning impulse test voltage (BIL): 1.2/50 µs pos./neg. kV 325/ 325 325/ 325 325/ 325 550/ 605 550/ 605 550/ 605 650/ 715 650/ 715 750/ 825 750/ 825 1050/1155 1050/1155 1050/1155 1050/1155 1175/1293 1175/1293 1425/1568 1425/1568 1550/1705 1550/1705 1675/1843

Chopped lightning impulse test voltage: time to sparkover 2…6 µs pos./neg. kV – / – – / – – / – – / 666 – / 666 – / 666 – / 787 – / 787 – / 908 – / 908 – / 1271 – / 1271 – / 1271 – / 1271 – / 1422 – / 1422 – / 1724 – / 1724 – / 1876 – / 1876 – / 20 27

Switching impulse test voltage dry (SIL): 250/2500 µs pos./neg. kV – / – – / – – / – – / – – / – – / – – / – – / – – / – – / – 850/935 850/935 850/935 850/935 950/1045 950/1045 1050/1155 1050/1155 1175/1293 1175/1293 1175/1293

Dimensions

L1 mm 260 260 260 340 340 340 390 390 450 450 620 620 620 620 690 690 790 790 840 840 990

L2 mm 387 387 387 512 512 512 567 567 607 607 782 812 802 832 882 882 1002 1002 1042 1042 1212

L3 mm 120 120 120 120 120 120 120 120 120 120 120 150 120 150 150 150 150 150 150 150 150

Dw mm 90 120 120 120 142 162 142 162 162 182 200 220 200 220 220 240 290 290 290 290 334

D1 mm 90 90 120 90 90 120 90 120 90 120 90 120 90 120 90 120 90 120 90 120 120

D2 mm 90 100 120 80 100 120 100 120 100 120 120 140 140 140 140 140 140 140 140 140 140

D3 mm 250 250 250 290 290 290 290 290 290 290 350 400 350 400 400 450 450 450 450 450 550

D4 mm 290 290 290 335 335 335 335 335 335 335 400 450 400 450 450 500 500 500 500 500 600

D5 mm 125 163 163 163 185 205 185 205 205 225 245 265 245 265 265 285 335 335 335 335 379

l1 mm – 90 – 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90

d1 mm 31 48 68 31 48 68 48 68 48 68 48 68 48 68 48 68 48 68 48 68 68

l2 mm 52 52 52 52 52 52 52 52 52 52 52 52 – – – – – – – – –

d2 mm 45 65 85 45 65 85 65 85 65 85 65 85 – – – – – – – – –

s mm 15 15 15 20 20 20 20 20 20 20 20 25 20 25 25 25 25 25 25 25 30

i mm 15 15 15 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 25

z 8 8 8 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 16

α ° 45 45 45 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 22,5

d mm Type-0 M24x1,5; Type-A Ø30 up to 1250 A, Ø40 > 1250 A; Type-B Ø30 up to 1250 A, Ø42 > 1250 A

C.T. accommodation length E mm 0 0 0 0 0 0 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

Total length L mm 647 647 647 852 852 852 1057 1057 1157 1157 1502 1532 1522 1552 1672 1672 1892 1892 1982 1982 2302

C.T. accommodation length E mm 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300

Total length L mm 947 947 947 1152 1152 1152 1257 1257 1357 1357 1702 1732 1722 1752 1872 1872 2092 2092 2182 2182 2502

C.T. accommodation length E mm 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600 600

Total length L mm 1247 1247 1247 1452 1452 1452 1557 1557 1657 1657 2002 2032 2022 2052 2172 2172 2392 2392 2482 2482 2802

References

HSP bushings throughout the worldThe proverbial quality and reliability of HSP products has led

to our condenser bushings being used in the leading energy

projects worldwide.

800 kV bushing on a single-phase

transformer in China

420 kV bushing on a step-up transformer

for a power plant in Germany

420 kV outdoor bushing at a GIS substation

in Germany

8 | 9

1 42 3

250 kV direct current bushing on a converter transformer

in China

The HSP product range:We cover all requirements of modern high-voltage technology

up to the ultra-high operating voltages with our products and

services. Our product portfolio is enhanced with tailored services

for our own products as well as those from other manufacturers.

1 Transformer bushings2 Switchgear bushings3 Generator bushings4 HVDC bushings

In addition to standardized products, we also offer individual

special products for our customers that we manufacture with

state-of-the-art production processes. These are usually developed

by us in-house and tested in our fully equipped, internationally

accredited test bay.

www.hspkoeln.de

Published and copyright © 2015:

HSP Hochspannungsgeräte GmbH Camp-Spich-Str. 18 53842 Troisdorf-Spich Germany

Phone: +49 (0) 22 41/25 26-0 Fax: +49 (0) 22 41/25 26-116

E-mail: contact@hspkoeln.de

Pub. EKTO 72.5 – 550 kV04/15-500 TH 102-140723All rights reserved. Brands and trademarks used in this document are the property of HSP Hochspannungsgeräte GmbH.

Subject to change without prior notice. The information in this document contains general descriptions of the technical options which are not necessarily available in every single case. The required features must therefore be defined in each individual case when concluding the contract.

Printed in Germany on elementary chlorine free paper.