Resin Impregnated Paper Bushing,Type CORIP, Oil to AirPTAB-AOA834

Instructions for Installation, Maintenance and Storage34.5 kV & Higher

2 ABB

Unless otherwise specified dimensions given in this document are in millimeters with the corresponding inchdimensions given in parenthesis.

ABB 3

Scope

This leaflet contains general procedures and guidelinesto be followed from the time the bushings are receivedfrom the factory. These instructions do not purport tocover all possible contingencies, which may ariseduring installation, operation, maintenance, and alldetails and variations of this equipment. Beforeinstallation and energizing, please consult the outlinedrawing for specific information. For additionalinformation, contact your local ABB Inc.representative.

General Information

Type CORIP bushings are designed for oil filledtransformers and reactors and meet or exceed theapplicable requirements of the IEEE StandardsC57.19.00 – 1991 and C57.19.01 – 2000. TypeCORIP bushings are manufactured exclusively for ABBAlamo, TN by ABB’s bushing manufacturing facility(MICAFIL) in Zurich, Switzerland.

Type CORIP is a dry oil free capacitively gradedcondenser bushing. The condenser consists of anelectrical grade paper, wound over a central tube. Thecondenser is then vacuum heat dried andimpregnated with a special electrical grade epoxy. Theupper part of the condenser is enclosed in acomposite insulator, consisting of one-piece glassfiber reinforced epoxy impregnated tube with siliconeweathersheds to provide the necessary creepage andarcing distance. The corrosion resistant mountingflange and the top cap are an integral part of the upperinsulator and provide the mechanical strength.

The space between the condenser and the compositeinsulator is filled with a specially formulated gel, whichafter curing results in a hard rubber like consistency.The double O-ring seals at top and bottom ends alongwith composite insulator make the bushing designvirtually impervious to moisture from the outside.

The use of silicone composite insulator and absenceof oil, make the bushing virtually maintenance freeand less susceptible to vandalism, shipping, andhandling damage. See figures 1 and 2 for details.

Tools RequiredThe following tools/materials will be required forinstallation/removal of these bushings.

1. Retaining ring pliers for round wire retaining ring.Part # FACOM 411 A 17 *

2. Torque wrenches for 8 ft-lb (10 N-m) and 36 ft-lb(50 N-m)

3. Crowfoot wrench with 2-9/16 inch (65 mm)opening

4. Metric L wrench set5. Adjustable wrench up to 3 inch opening6. Silicone grease7. Petroleum jelly8. Nylon slings for lifting the bushing9. 10 - 12 Gage steel wire or a nylon rope suitable

for lifting at least 150 lbs.10. Eye bolt with M12 threads and with maximum

width of 1.25 inch

* Supplied with the bushing.

Safety InformationKeep this Instruction Leaflet available to thoseresponsible for installation, maintenance, andoperation of the bushing.

The installation, operation, and maintenance of abushing presents numerous potential unsafeconditions, including but not limited to the following:

• High pressures• Lethal Voltages• Moving machinery• Heavy components

Specialized procedures and instructions are requiredand must be adhered to when working on suchapparatus. Failure to follow instructions could resultin severe personal injury, death, and/or product orproperty damage.

Additionally, all applicable safety procedures such asOSHA requirements, regional and local safetyrequirements, safe working practices, and goodjudgment must be used by personnel when installing,operating, and/or maintaining such equipment.

Safety, as defined in this Instruction Leaflet, involvestwo conditions:

1. Personal injury or death2. Product or property damage (includes damage

to the bushing or other property, and reducedbushing life)

4 ABB

Figure 1. Type CORIP Bushing up to and including 69 kV

TOPTERMINAL

CAPNUT

TOPCAP

DRAWLEAD

CONNECTOR

SILICONECOMPOSITEINSULATOR

TAPTEST

MOUNTINGFLANGE

SPLITCONDUCTOR

CONDENSERCORE

BOTTOMTERMINAL

ABB 5

Figure 2. Type CORIP Bushing Above 69 kV

TOPTERMINAL

CAPNUT

DRAWLEAD

CONNECTOR

SILICONECOMPOSITEINSULATOR

VOLTAGETAP

MOUNTINGFLANGE

SPLITCONDUCTOR

CONDENSERCORE

TOPCAP

LOWEREND

SHIELD

BOTTOMTERMINAL

6 ABB

Safety notations are intended to alert personnel ofpossible personal injury, death or property damage.They have been inserted along with the instructionaltext and the steps in which the condition is cited.

1. DANGER – immediate hazard that will result insevere personal injury, death, or propertydamage.

2. WARNING – hazard or unsafe practice, whichcould result in severe personal injury, death, orproperty damage.

3. CAUTION – hazard or unsafe practice, whichcould result in minor personal injury, or propertydamage.

Shipping MethodsCondenser bushings are generally shipped from thefactory in horizontal wooden crates. The lower andthe upper ends of the bushings are protected againsthumidity with plastic bags and drying cartridges. Whenthe bushing is shipped from the transformer factoryto the end user, it should be protected against humiditywith plastic bags and silica gel and repacked in theoriginal crate. It is necessary to insure the quality ofpacking and sealing to prevent damage to thebushing.

CAUTIONFAILURE TO FOLLOW THESE GUIDELINES MAYRESULT IN DAMAGE TO THE BUSHINGS ANDCAUSE AN ELECTRICAL FAILURE. FAILURE TOFOLLOW THESE GUIDELINES WILL ALSOCANCEL THE WARRANTY ON THE BUSHING.

Receiving

When a bushing is received, it should be examinedfor damage incurred during shipment. If damage orrough handling is evident, file a claim with thetransportation company, and notify your ABB Inc.representative immediately.

Storing

Type CORIP bushings can be stored outside in theiroriginal shipping crate for a maximum of 6 months.The crate should be covered with a double plasticsheets to prevent moisture / water damage. Forextreme temperature conditions it is recommendedthe bushing be stored indoors.

For indoor storage, the bushings can be stored intheir original crates. If the bushing is taken out of thecrate, it can be stored indoor (at about 75º F) on arack for long period of time. The lower end of the

bushing should be protected against humidity withplastic and silica gel bags.

The bushing should be checked regularly to makesure there is no evidence of moisture in the plasticbag. If at any time, the indicator patch on the dryingcartridge (supplied from the factory) or the silica gelbag shows pink color, or if condensation is observed,clean and dry the bushing with lint free cloth and resealwith new plastic and silica gel bags.

If the bushing is removed from the crate, it should beprotected/sealed against humidity with plastic andsilica gel bags and repacked in the original crate.

Type CORIP should never be stored or handled in away that might damage the silicone weather shedsinsulator or the condenser.

CAUTION

FAILURE TO FOLLOW THESE GUIDELINES MAYRESULT IN DAMAGE TO THE BUSHINGS ANDCAUSE AN ELECTRICAL FAILURE. FAILURE TOFOLLOW THESE GUIDELINES WILL ALSOCANCEL THE WARRANTY ON THE BUSHING.

Handling

Before lifting the bushing, remove any clamps ormounting flange bolts holding the bushing to the crate.

Small bushings can be taken out of the crate by hand.Larger and heavier types should be lifted by crane asshown in figure 3. Use two independent crane hookswith nylon slings to adjust the angle of orientation andfacilitate mounting of the bushing. Use nylon slings toprevent any damage to the silicone insulator.

Type CORIP should never be handled in a way thatmight damage the silicone weathersheds insulator orthe condenser.

WARNING

FAILURE TO FOLLOW THESE GUIDELINES WILLRESULT IN DAMAGE TO THE BUSHINGS ANDCAUSE AN ELECTRICAL FAILURE. IN ADDITION,FAILURE TO FOLLOW THESE GUIDELINESCOULD RESULT IN SEVERE PERSONAL INJURY,DEATH OR PROPERTY DAMAGE.

ABB 7

NYLONSLINGS

NYLONSLINGS

SPREADERBAR

NYLONSLINGS

NYLONSLINGS LIFTING

BOLT

CHOKERROPE

Figure 3. Bushing Handling Methods

8 ABB

Installation And MountingPrior to installation, make sure the bushing is at theenvironmental temperature to avoid any condensationon the bushing surface.

Clean and dry the bushing with a clean lint free clothto remove any dust or contamination. Clean the insideof the tube to remove any contamination that mayhave entered the tube during storage or shipping. TypeCORIP bushings are of dry, oil free design and can bemounted at any angle from 0° to 90° from the vertical.

It is recommended to use flat gasket between thebushing mounting flange and the transformer.

We recommend that capacitance and power factormeasurements be made before installation andenergizing in accordance with the “ Bushing Test andVoltage Tap” sections of this instruction leaflet.

The bushing central tube must be full of oil beforeenergizing. See section on “ENERGIZING” foradditional information.

CAUTION

FAILURE TO FOLLOW THESE GUIDELINES WILLRESULT IN DAMAGE TO THE BUSHING AND INELECTRICAL FAILURE OF THE BUSHING ANDOR THE TRANSFORMER.

Painting

No painting is required on the top end external parts.However, if the environmental conditions make itnecessary, such parts can be painted with a suitablepaint as long as the insulator and the top terminal areproperly masked/protected.

Bolting

Tighten the mounting bolts a fraction of a turn at atime, working in a criss-cross pattern until all boltsare uniformly tight. Tighten sufficiently to seal thebushing to the apparatus. Normally, the torque valueslisted below will provide adequate gasket compressionfor sealing.

Bolt Size TorqueInch – Thread ft–– lb (N-m)

1/2 - 13 25 (34)5/8 - 13 30 (41)

WARNING

BEFORE APPLYING VACUUM TO THETRANSFORMER, BE CERTAIN THERE ISSUFFICIENT SLACK IN THE CONNECTIONS TOTHE BUSHING TO ALLOW FOR BUSHINGMOVEMENT CAUSED BY FLEXING OF THETRANSFORMER COVER AND/OR WALLS.FAILURE TO RELIEVE THIS STRESS AT THEBUSHING CONNECTIONS MAY RESULT INDAMAGE TO THE BUSHING AND ITS SEALSAND CAUSE ELECTRICAL FAILURE OF THEBUSHING AND/OR THE TRANSFORMER.

Connections

Internal Electrical Connections

The method used in making connections between abushing and the apparatus on which it is mountedwill depend upon the type of connection used in theapparatus.

Draw Lead Connected Bushings

Bushings with 400 and 800A ratings are designedwith a hollow central tube through which a flexibledraw lead cable can be pulled. The cable is considereda component of the apparatus on which the bushingis mounted and is not supplied with the bushing.

In order to withstand the transient voltages betweenthe cable and the central tube, the draw lead cablemust be insulated with radial paper insulation of about1 mm thick. Do not use more than 1 mm thickinsulation, as it will affect the thermal performance ofthe bushing.

The draw lead bushing is supplied with a draw leadconnector. Refer to figure 4 for connector details. Theconnector is supplied with an adapter that can bebrazed to the transformer cable or the lead. In orderto prevent any damage to the draw lead connectorO-rings, this adapter must be unbolted from the drawlead connector before brazing the cable.

CAUTION

FAILURE TO FOLLOW THESE GUIDELINES WILLRESULT IN DAMAGE TO THE BUSHING ANDCAUSE ELECTRICAL FAILURE OF THEBUSHING AND/OR THE TRANSFORMER.

For crimped type connector, please contact yourABB Inc. representative.

ABB 9

Fig

ure

4. D

raw

Lea

d C

onn

ecto

r D

etai

ls

327

[12.

87]

169

[6.6

5]B

RA

ZEA

BLE

AD

AP

TER

HLJ

5893

53

150

[5.9

1]

42 [1

.65]

57.2

[2.2

5]81

[3.1

9]

222

[8.7

4]

30 [1

.18]

DR

AW

LE

AD

CO

NN

EC

TOR

HLJ

5866

43 b

40 [1

.57]

6.35

[0.2

5]

3XM

6TH

RE

AD

ED

HO

LE

40 [1

.57]

52.5

[2.0

7]

1.50

” -

12U

NF

- 2A

10 ABB

To remove the draw lead connector from the bushing,refer to figure 5 and follow the steps outlined below.

1. Unscrew and remove the cap nut.2. Unscrew and remove the relief vent plug from the

top of the draw lead connector.3. Firmly, screw in an eyebolt (with M12 threads) into

top of the draw lead connector.4. Pull (while twisting) the draw lead connector up

along with the tightening sleeve with the help ofthe eyebolt.

5. Remove the retaining ring with retaining ring pliers.Make sure the O-ring is not damaged during thisoperation.

6. Apply silicone grease on the exposed O-ring onthe draw lead connector.

7. Pull up (while twisting) and slide off the tighteningsleeve from the draw lead connector. Make surethe inside sealing surface on the tightening sleeveare not damaged during this process.

8. Save these parts for later assembly.

WARNING

USE PROPER RETAINING RING PLIERS FORREMOVING THE RETAINING RING FROM THEGROOVE. DO NOT USE SCREW DRIVER OR ANYOTHER KIND OF TOOL, AS THIS WILL DAMAGETHE O RING SEALING SURFACE. FAILURE TOFOLLOW THESE GUIDELINES WILL RESULT INDAMAGE TO THE BUSHING AND CAUSEELECTRICAL FAILURE OF THE BUSHING AND/OR THE TRANSFORMER.

To assemble the draw lead and mount the bushing,refer to figure 5 and follow the steps outlined below:

1. Unbolt the brazeable adapter from the draw leadconnector. See figure 4 for details.

2. Braze the transformer cable to the brazeableadapter.

3. Clean the bolting current carrying contactsurfaces with a suitable abrasive pad and applypetroleum jelly.

4. Bolt the draw lead connector to the brazedadapter using the hardware supplied with theconnector as shown in figure 4.

5. Tighten the bolts with 7-8 ft-lb (10 N-m) torque.6. Pass a wire or a rope through the bushing central

tube.7. Tie the lower end of the wire to an eyebolt (with

M12 threads) that is screwed into the draw leadconnector attached to the transformer cable.

8. Apply silicone grease on draw lead connector,tightening sleeve, and the top cap O-rings.

9. Slide the tightening sleeve, retaining ring, and thecap nut over the wire at the upper end.

10. Lower the bushing into the opening in thetransformer cover, simultaneously pulling thewire and the transformer cable/lead through thecentral tube.

11. Mount the bushing on the transformer tankusing the appropriate hardware.

12. Firmly, press (while twisting) and slide thetightening sleeve down over the draw leadconnector while holding the draw leadconnector in place. Make sure the tighteningsleeve is inserted into the gap between the topcap and the draw lead connector and theshoulder in the tightening sleeve sits on top ofthe top cap. Also make sure the retaining ringgroove is visible above the tightening sleeve.

13. Expand the retaining ring with the retaining ringpliers and secure the retaining ring into theretaining ring groove (closest to the tighteningsleeve) in the draw lead connector.

14. Press down (while twisting) the draw leadconnector until the retaining ring sits on top ofthe tightening sleeve. Make sure the retainingring is in the groove.

15. Screw the cap nut on to the top cap andtighten it in place with 36-37 ft-lb (50 N-m)torque.

16. Unscrew and remove the eyebolt from the drawlead connector.

17. Replace and tighten the relief vent plug.

WARNING

USE RETAINING RING PLIERS FORASSEMBLING THE RETAINING RING INTO THEGROOVE. DO NOT USE SCREW DRIVER OR ANYOTHER KIND OF TOOL, AS THIS WILL DAMAGETHE O RING SEALING SURFACE. FAILURE TOFOLLOW THESE GUIDELINES WILL RESULT INDAMAGE TO THE BUSHING AND CAUSEELECTRICAL FAILURE OF THE BUSHING AND/OR THE TRANSFORMER.

Split Conductor Bushings

Bushings rated 1200 A are designed with aremovable split conductor that carries the current.The split conductor is supplied with the bushing.Refer to figure 6 for split conductor details

To remove the split conductor from the bushing,refer to figure 5 and follow the steps outlined below:

1. Mount the bushing upright on a stand or hangfrom a crane hook.

2. Remove the lower end shield (if provided) byunscrewing the set screws provided on the sideof the shield as shown in figure 7.

3. Unscrew and remove the cap nut.

ABB 11

“R” THD SIZE“A” THD LGTH

65.0 [2.56]“R” THD SIZE“A” THD LGTH

LOWERSPLIT

CONDUCTOR

LOWERSPLIT

CONDUCTOR

C B

Figure 6. Split Conductor Details

CAPNUT

RETAININGRING

TIGHTNINGSLEEVE

EYEBOLT

RELIEF VENTPLUG

DRAWLEADCONNECTOR/SPLIT

CONDUCTOR

RETAINING RINGGROOVES

TOPCAP

Figure 5. Draw Lead Connector Assembly

UPPERSPLIT

CONDUCTOR

M12

“R” THD SIZE“A” THD LGTH

UPPERSPLIT

CONDUCTOR

M12

38.8 [1.53]

M6 BOLT/WASHERSTAINLESS STEEL

M6 BOLT/WASHERSTAINLESS STEEL

65.0 [2.56]

C B

40.0 [1.57]

40.0 [1.57]

177.5 [6.92]

38.8 [1.53]

FIG. B

FIG. A

GNITAR #ELYTS #NOITPO #.GIF "B" "C" EZISDHT"R" HTGLDHT"A"

Vk5.43 AAC-210430CCZI XXHSFS A ]17.03[087 ]53.52[446 A2-FNU21-5.1 ]52.2[2.75

Vk96 AAC-210960CCZI XXHSFS A ]96.63[239 ]61.73[449 A2-FNU21-5.1 ]52.2[2.75

Vk831 AAC-210831CCZI XXBBFS B ]29.94[8621 ]49.06[8451 A2-FNU21-5.1 ]52.2[2.75

12 ABB

4. Remove the retaining ring with retaining ring plierswhile holding the split conductor at the bottom.

5. Apply silicone grease on the exposed O ring onthe split conductor.

6. Slowly pull (while twisting) the split conductordownwards from the bottom end. Make sure thegasket-sealing surface on the inside of thetightening sleeve is not damaged while removingthe split conductor.

7. Pull up (while twisting) and slide off the tighteningsleeve from the top cap.

8. Save these parts for later assembly.

WARNING

USE RETAINING RING PLIERS FOR REMOVINGTHE RETAINING RING FROM THE GROOVE. DONOT USE SCREW DRIVER OR ANY OTHER KINDOF TOOL, AS THIS WILL DAMAGE THE O RINGSEALING SURFACE. FAILURE TO FOLLOWTHESE GUIDELINES WILL RESULT IN DAMAGETO THE BUSHING AND CAUSE ELECTRICALFAILURE OF THE BUSHING AND/OR THETRANSFORMER.

To assemble the split conductor and mount thebushing on the transformer refer to figure 5, 6 & 7and follow the steps outlined below:

1. Slide the lower end shield (applicable to bushingsabove 69 kV only) over the transformer cable/lead.See figure 7 for shield details.

2. Attach the lower half of the split conductor to thetransformer cable/lead by using the appropriateconnector/hardware.

3. Attach the shield (applicable to bushings above69 kV only) to the lower terminal by using thehardware supplied with the bushing. Make surethe set screws in the in the shield are aligned withthe fixing holes in the bottom terminals. See figure7 for shield details.

4. Clean the split conductor bolting current carryingcontact surfaces with a suitable abrasive pad andapply petroleum jelly.

5. Bolt the two halves of the split conductor usingthe hardware supplied with the bushing. Refer tofigure 6.

6. Tighten the bolts with 7-8 ft-lb (48 N-m) torque.7. Pass a wire or a rope through the bushing central

tube.8. Tie the lower end of the wire to an eyebolt (with

M12 threads) that is screwed into the uppersplit conductor.

9. Apply silicone grease on the split conductor,tightening sleeve, and top cap O-rings.

10. Slide the tightening sleeve, retaining ring, and thecap nut over the wire at the upper end.

11. Lower the bushing into the opening in thetransformer cover, simultaneously pulling the wireand the split conductor through the central tube.

12. Mount the bushing on the transformer tank usingthe appropriate hardware.

13. Firmly, press (while twisting) and slide thetightening sleeve down over the split conductor(while holding the split conductor in place). Makesure the tightening sleeve is inserted into the gapbetween the top cap and the split conductor andthe shoulder in the tightening sleeve sits on topof the top cap. Also make sure a retaining ringgroove is visible above the tightening sleeve.

14. Expand the retaining ring with the retaining ringpliers and secure the retaining ring into the groovein the split conductor.

15. Press down (while twisting) the split conductoruntil the retaining ring sits on top of the tighteningsleeve. Make sure the retaining ring is in thegroove.

16. Screw the cap nut on to the top cap and firmlytighten it in place with 36-37 ft-lb (50 N-m) torque.

17. Unscrew and remove the eyebolt from the splitconductor.

18. Replace and tighten the relief vent plug.

WARNING

USE RETAINING RING PLIERS FORASSEMBLING THE RETAINING RING INTO THEGROOVE. DO NOT USE SCREW DRIVER OR ANYOTHER KIND OF TOOL, AS THIS WILL DAMAGETHE O RING SEALING SURFACE. FAILURE TOFOLLOW THESE GUIDELINES WILL RESULT INDAMAGE TO THE BUSHING AND CAUSEELECTRICAL FAILURE OF THE BUSHING AND/OR THE TRANSFORMER.

External Electrical Connections

The upper part of the draw lead connector and thesplit conductor are threaded to serve as the topterminal for making connections with the externallines/cables.

The external line connections to the bushing must besufficiently slack or flexible to avoid putting anymechanical strain on the bushing parts.

ABB 13

LOCKINGSET SCREW

LOCKINGSET SCREW

79.4 [3.13]

44.45 [1.75]

76.2 [3.00]

177.8 [7.00]

140.0 [5.51]

177.8 [7.0]

BOTTOMTERMINAL

LOWEREND

SHIELD

19.05TK.[.75]

44.45 [1.75]

[0.563]4 TOTAL

15.9 [0.63]

Figure 7. Lower End Shield and Terminal For 138 kV Bushing

14 ABB

If the complete split conductor bushing is to beremoved from the transformer, disconnect thetransformer cable/lead from the bottom terminal andremove the bushing. For bushings above 69 kV, it maybe necessary to disconnect the lower end shield fromthe bottom terminal before disconnecting thetransformer cable from the terminal. Refer to figure 2& 7 for shield and terminal details.

Bushing Tap

Test Tap

Bushings with rated voltage up to and including 69kV are provided with a test tap. This tap is connectedto the outermost foil electrode of the condenser. Undernormal operation, this tap is automatically groundedthrough an internal spring in the tap housing.

If the test tap is used in conjunction with a monitoringdevice, the voltage between the tap and groundshould be limited to 300 V. See figures 1 and 8 fordetails.

The test tap can be used for checking the power factorand capacitance of the bushing insulation. For makingthese measurements the tap electrode must beungrounded. This is done by inserting a 4 mm pinadapter (supplied with the bushing) into the test tapreceptacle as shown in figure 8A. Insert a standardbanana plug in the pin adapter to make the connectionto test set.

After the power factor measurement is completed,remove the test adapter/connection and close thehousing by replacing the tap cover. Make sure thecover is tight.

For making a connection to a monitoring device aspecial coupler kit is required to make the connectionto a shielded cable. Refer to figure 8A and contactyour ABB Inc. representative for ordering this kit.

WARNING

DO NOT OPERATE THE BUSHING WITH THETAP COVER REMOVED, AS IT WILL RESULT INCORROSION OF THE GROUND CONTACTAND DAMAGE TO THE BUSHING AND CAUSEAN ELECTRICAL FAILURE OF THE BUSHINGAND OR THE TRANSFORMER.

THE VOLTAGE ON THE TEST TAP MUST NOTEXCEED 1 kV WHEN MEASURING POWERFACTOR AND CAPACITANCE. FAILURE TOFOLLOW THESE GUIDELINES MAY RESULT INSEVERE PERSONAL INJURY, DEATH ORPROPERTY DAMAGE.

Terminal connections, lines should be of uniform crosssection and ample size so that at a distance of 3 ft (1m) from the bushing, the temperature rise aboveambient air does not exceed 30o C at the rated current.The use of even more generously sized connectors isrecommended to minimize bushing overheatingduring possible overloads.

CAUTION

ONLY USE TERMINAL CONNECTORS RATED TOCARRY THE BUSHING CURRENT. TERMINALCONNECTORS INTENDED TO CARRY ONERATING OFTEN FIT ON BUSHINGS OF HIGHERRATINGS. USE OF UNDER RATED TERMINALCONNECTORS WILL RESULT IN OVERHEATINGAND SHORTEN THE LIFE OF THE BUSHING.FAILURE TO FOLLOW THESE GUIDELINES MAYRESULT IN DAMAGE TO THE BUSHINGS ANDCAUSE AN ELECTRICAL FAILURE OF THEBUSHING AND/OR THE TRANSFORMER.

INSTRUCTIONS FOR REMOVAL OF BUSHINGFROM THE TRANSFORMER

To remove the bushing from the transformer, refer tofigure 5 and follow the steps outlined below.

1. Unscrew and remove the cap nut.2. Unscrew and remove the relief vent plug and

screw in an eyebolt (with M12 threads) into topof the draw lead connector or the split conductor.

3. Attach a wire or a rope to the eyebolt to hold thedraw lead/split conductor in position during thebushing removal process.

4. Remove the retaining ring with retaining ring plierswhile holding the draw lead connector or the splitconductor in place.

8. Unbolt and slowly lift the bushing with a cranewhile pressing down the draw lead connector orsplit conductor. Make sure the draw leadconnector or split conductor is sliding downthrough the tightening sleeve while the bushingis being lifted. If not, then check for anyinterference between the tightening sleeve andthe draw lead connector/split conductor. Makesure the gasket-sealing surface on the inside ofthe tightening sleeve is not damaged during thisprocess.

5. Pull (while twisting) and slide off the tighteningsleeve from the top cap.

6. For split conductor bushing, unbolt and removethe upper split conductor.

7. Attach the draw lead cable or the lower half ofthe split conductor to the transformer for shippingpurpose.

8. Save the parts for later assembly.

ABB 15

Figure 8. Test Tap

Figure 8A. Test Tap Adapters

GROUNDINGSPRING

GASKET

TEST TAPCOVER

MOUNTINGFLANGE

DO NOT USESCREW DRIVER

PIN ADAPTERART NO 10 06 46

COUPLER KITHLJ429983 d

EXTERNALCABLE

CONNECTION

4 [0.16]

45 [1.77]

55 [2.15]

16 ABB

Voltage Tap

Bushings, rated above 69 kV are provided with aType A (Normally grounded) voltage tap as per Figure1 of the IEEE Standard C57.19.01 - 2000. This tap isconnected to one of the inner foil electrode of thecondenser. Under normal operation, this tap isgrounded by means of the spring clip in the tap cover.

If the voltage tap is used in conjunction with apotential/monitoring device, the voltage between thetap and ground should be limited to 6 kV. See figures2 and 9 for details. A potential device connection cablecan be used to connect to the bushing. Please contactyour ABB Inc. representative for ordering this kit.

When using the bushing with a potential device,remove the fill plug on top of the tap housing and fillthe chamber with clean dry transformer oil. While filling,leave an expansion space of approximately onequarter of an inch at the top of the chamber. Coat thethreads of the fill plug with a suitable sealer and replacethe plug in the fill hole.

The voltage tap can be used for checking the powerfactor and capacitance of the bushing insulation. Aconnection to tap connector can be made by using asuitable connector.

After the power factor measurement is completed andthere is no connection to the potential device, removethe test connection and close the housing by replacingthe tap cover. Make sure the cover is tight.

WARNING

DO NOT APPLY VOLTAGE TO THE BUSHINGWITH THE VOLTAGE TAP COVER REMOVED,EXCEPT WHEN USING THE BUSHING WITH APOTENTIAL DEVICE OR WHEN MEASURINGPOWER FACTOR. IF THE TAP IS NOTGROUNDED, THE VOLTAGE MAY EXCEED THEINSULATION STRENGTH, RESULTING INDAMAGE TO THE BUSHING AND CAUSE ANELECTRICAL FAILURE OF THE BUSHING ANDOR THE TRANSFORMER.

THE VOLTAGE ON THE TAP MUST NOT EXCEED5 kV WHEN MEASURING POWER FACTOR ANDCAPACITANCE. FAILURE TO FOLLOW THESEGUIDELINES MAY RESULT IN SEVEREPERSONAL INJURY, DEATH OR PROPERTYDAMAGE.

Energizing

Before energizing, make sure the bushing is clean andundamaged and has good dielectric insulation.

For satisfactory operation of the bushing it is essentialthat the air in the central tube is vented out and thetube is full of oil. The air in the central tube can bevented by loosening the relief vent plug (located ontop of the top terminal) with a hexagonal “L” wrench.After venting the air, make sure the plug is tightenedfor proper sealing.

If the transformer is filled under vacuum with bushingsmounted then venting of the air is not necessary.

CAUTION

FAILURE TO FOLLOW THESE GUIDELINES WILLRESULT IN ELECTRICAL FAILURE OF THEBUSHING AND OR THE TRANSFORMER.

Interchangeability

An outstanding feature of CORIP bushings is that a400/800 A draw lead bushing can be converted to a1200 A split conductor bushing or vice versa bychanging the draw lead/ split conductor parts. Partscan be retrieved from bushings being replaced orordered from the factory. Refer to section on“ORDERING ACCESSORIES” for additional details.

Nameplate Data

Nameplate data is especially important in answeringquestions about bushings. All requests will beexpedited if the factory is furnished with serial number,style number and option number, and the year ofmanufacture stamped on the bushing nameplate. ITIS ABSOLUTELY NECESSARY FOR THE FACTORYTO HAVE AT LEAST THE SERIAL NUMBER.

The style number and option number identifies thebushing by type and rating. When corresponding withthe factory, provide the complete nameplateinformation. All bushings of the same style and optionnumber are completely interchangeable.

Ordering Accessories

When ordering accessories for conversion of abushing, give the following information:1. Style number and option number of the bushing

being converted2. Type of the apparatus on which the bushing will

be used3. Current rating of the bushing as it will be used

ABB 17

SILICON COMPOSITEINSULATOR

VOLTAGE TAPINSULATOR

PLUG

GASKET

VOLTAGE TAPCOVER

GROUNDINGSPRING

MOUNTINGFLANGE

Figure 9. Voltage Tap

18 ABB

MaintenanceThe use of silicone composite insulator and absenceof oil, make the bushing virtually maintenance freeand less susceptible to vandalism, shipping, andhandling damage.

Under normal circumstances, the silicone compositeinsulator does not require any cleaning. Bushingsexposed to excessive amounts of air bornecontaminants should be checked periodically andcleaned if necessary. Wiping with a wet cloth shouldbe sufficient to clean the surface. If necessary, a mild5 % detergent water solution may be used to removeexcessive contamination but the insulator must berinsed with clean water to remove any soap residue.DO NOT USE SOLVENTS ON POLYMERSINSULATORS, AS THEY MAY DAMAGE THEMATERIAL.

In-service insulators may be pressure water washedby trained operators using approved methods. Careshould be taken so as not to damage the insulatorwith high-pressure water.

CAUTION

FAILURE TO FOLLOW THESE GUIDELINESWILL RESULT IN DAMAGE TO THE BUSHINGAND IN ELECTRICAL FAILURE OF THEBUSHING AND OR THE TRANSFORMER.

Due to inconvenience and possible serviceinterruptions resulting from bushing outages, manyusers have programs for Planned PreventativeMaintenance. We endorse such programs andrecommend:

1. Measurement of power factor and capacitance at the time of installation and repeating the measurements annually.

Field measurements can differ from measurementsmade under controlled conditions in the factory.Therefore, the power factor and capacitance shouldbe measured before and after installation. The installedtest values should be used as a benchmark tocompare with future measurements. Contact yourABB Inc. representative for corrective actionprocedures if:

• The power factor doubles the originalinstallation value; or

• The capacitance increases to 110 % of the originalinstallation value

The following guidelines may be used to minimize theeffect of contamination and high humidity during

power factor and capacitance measurements in thefield.

• Clean and dry the bushing thoroughly to removeany contaminants that may have deposited duringshipping or storage.

• Clean and dry the tap insulator to remove anycontamination or condensation.

• Avoid making power factor measurements inwooden crates to minimize the effect of surfaceleakage current due to moist wood.

• Provide sufficient clearance between the bushingsand other objects to minimize the effect of straycapacitance.

• For information on ground connections and otherguidelines, please refer to test equipmentmanufacturer’s Instruction Manual.

2. Examination of top terminals for loose externalconnection and overheating.

For satisfactory operation of a bushing, it is importantthat the top terminal external connections are tight atall times. If the connection is loose, overheating ofthe current carrying joint can take place and result indamaged terminal joint. This type of overheating candeteriorate the top end gasket seals and allow ingressof moisture.

Visually examine the bushings or do infrared scan andlook for discolored top terminal, external terminalconnector or bolts. Look for steam rising from theterminal/connector.

If the above examination indicates overheating,remove the transformer from service and check thepower factor and capacitance. Refer to guidelines onpower factor and capacitance measurements.

Check the top end parts and the connection betweenbushing top terminal and the external connector. Ifany sign of overheating is present, the bushing shouldbe taken out of service as the overheating may haveaffected the top end sealing gaskets.

If the external connector cannot be removed, it hasmost likely suffered overheating damage at thethreaded joint. Remove the bushing from service.

If the top end parts do not show any sign ofoverheating or damage and the power factor andcapacitance values are acceptable, then reinstallthe external connector by following the instructionsin the section on “Connections”. FOR SPECIFICRECOMMENDATIONS PLEASE CONTACT ABBInc.

ABB 19

CAUTION

FAILURE TO FOLLOW THESE GUIDELINESWILL RESULT IN DAMAGE TO THE BUSHINGAND IN ELECTRICAL FAILURE OF THEBUSHING AND OR THE TRANSFORMER.

Field Repairs

Any repairs of Type CORIP Bushings should bedone in the factory because of danger of damageto the bushing insulation.

Any damage to the bushing which might makerepair either desirable or necessary, should bereported to the factory. DO NOT ATTEMPT TOREPAIR A TYPE “ CORIP” BUSHING WITHOUTSPECIFIC RECOMMENDATIONS FROM ABB Inc.

CAUTION

FAILURE TO FOLLOW THESE GUIDELINESWILL RESULT IN ELECTRICAL FAILURE OFTHE BUSHING AND OR THE TRANSFORMER.

ABB Inc.1128 S. Cavalier DriveAlamo, TN 38001, USATelephone: 731-696-5561Fax: 731-696-5269www.abb.com

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DISCLAIMER OF WARRANTIESAND LIMITATION OF LIABILITY

THERE ARE NO UNDERSTANDINGS, AGREEMENTS,REPRESENTATIONS OR WARRANTIES, EXPRESSEDOR IMPLIED, INCLUDING WARRANTIES OFMERCHANTABILITY OR FITNESS FOR A PARTICULARPURPOSE OTHER THAN THOSE SPECIFICALLY SETOUT BY AN EXISTING CONTRACT BETWEEN THEPARTIES. ANY SUCH CONTRACT STATES THE ENTIREOBLIGATION OF SELLER. THE CONTENTS OF THISDOCUMENT SHALL NOT BECOME PART OF ORMODIFY ANY PRIOR OR EXISTING AGREEMENT,COMMITMENT OR RELATIONSHIP.

THE INFORMATION, RECOMMENDATIONS, DESCRIP-TION AND SAFETY NOTATIONS IN THIS DOCUMENTARE BASED ON OUR EXPERIENCE AND JUDGEMENTWITH RESPECT TO BUSHINGS. THIS INFORMATIONSHOULD NOT BE CONSIDERED TO BE ALL INCLUSIVEOR COVERING ALL CONTINGENCIES. IF FURTHER INFORMATION IS REQUIRED, ABB INC. SHOULD BECONSULTED.

NO WARRANTIES, EXPRESSED OR IMPLIED,INCLUDING WARRANTIES OF FITNESS FOR APARTICULAR PURPOSE OR MERCHANTABILITY, ORWARRANTIES ARISING FROM COURSE OF DEALINGOR USAGE OF TRADE, ARE MADE REGARDING THEINFORMATION, RECOMMENDATIONS, DESCRIP-TIONS, AND SAFETY NOTATIONS CONTAINEDHEREIN. IN NO EVENT WILL ABB INC. BE RESPON-SIBLE TO THE USER IN CONTRACT, IN TORT(INCLUDING NEGLIGENCE), STRICT LIABILITY OROTHERWISE FOR ANY SPECIAL, INDIRECT, INCIDEN-TAL, OR CONSEQUENTIAL DAMAGE OR LOSS WHAT-SOEVER INCLUDING BUT NOT LIMITED TO DAMAGETO OR LOSS OR USE OF EQUIPMENT, PLANT ORPOWER SYSTEM, COST OF CAPITAL, LOSS OF PROF-ITS OR REVENUES, COST OF REPLACEMENT POWER,ADDITIONAL EXPENSES IN THE USE OF EXISTINGPOWER FACILITIES, OR CLAIMS AGAINST THE USERBY ITS CUSTOMERS RESULTING FROM THE USE OFTHE INFORMATION, RECOMMENDATIONS, DESCRIP-TION, AND SAFETY NOTATIONS CONTAINED HEREIN.