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On-LoadTap-Changer

VACUTAP® V V

Operating Instructions


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Contents

Contents

NOTE

The data in these Operating Instructions may differ from the data of the devices delivered.We reserve the right to make changes without notice.

1 General ..................................................................................................................................................... 5

1.1 Safety Instructions .......................................................................................................................... 51.2 Specified Application ....................................................................................................................... 5

2 Design / Types .......................................................................................................................................... 6

3 Shipment .................................................................................................................................................. 6

4 Installing the on-load tap-changer for cover mounting ......................................................................... 84.1 Mounting flange ............................................................................................................................... 84.2 Attaching the on-load tap-changer to the transformer tank ............................................................... 8

5 Installing the on-load tap-changer for bell-type transformer cover ....................................................... 10

5.1 Installing the on-load tap-changer in the supporting structure ........................................................... 105.2 Preparation ...................................................................................................................................... 115.3 Separating the top part of the on-load tap-changer head from the bottom part ................................. 115.4 Attaching the bell-type cover ........................................................................................................... 12

6 Connecting the tap winding and the tap changer take-off terminal ...................................................... 12

7 Transformer ratio test .............................................................................................................................. 13

8 Drying process and oil filling ................................................................................................................. 138.1 Drying process................................................................................................................................. 13

8.1.1 Vacuum-drying....................................................................................................................... 13

8.1.1.1 Vacuum-drying in the autoclave ................................................................................ 138.1.1.2 Vacuum-drying in the transformer tank ..................................................................... 13

8.1.2 Vapour-phase drying .............................................................................................................. 148.1.2.1 Vapour-phase drying in the autoclave ....................................................................... 148.1.2.2 Vapour-phase drying in the transformer tank ............................................................. 14

8.1.3 Operating the on-load tap-changer ......................................................................................... 148.2 Oil filling .......................................................................................................................................... 14

9 Pipe connections ..................................................................................................................................... 159.1 Pipe connection R for protective relay RS 2001 ............................................................................... 159.2 Pipe connections S and R (connection Q specially designed) to

tap changer interior .......................................................................................................................... 15

9.3 Pipe connection E2.......................................................................................................................... 15



10 Mounting the motor drive, bevel gear and drive shaft ........................................................................... 16

10.1 Mounting the motor drive unit........................................................................................................... 1610.2 Mounting the bevel gear................................................................................................................... 1610.3 Mounting the drive shaft (square tube) ............................................................................................. 16

11 Commissioning the on-load tap-changer at the transformer manufacturer's site ................................ 1711.1 Operational tests ............................................................................................................................. 1711.2 Complete oil filling ........................................................................................................................... 1711.3 Ground connections ......................................................................................................................... 1711.4 Electrical tests on the transformer ................................................................................................... 17

12 Transport to the operating site ................................................................................................................ 18

13 Commissioning at the operating site ..................................................................................................... 18

14 Monitoring during service ....................................................................................................................... 19

15 Failures ..................................................................................................................................................... 19

16 Inspections ............................................................................................................................................... 20

17 Appendix .................................................................................................................................................. 21

Contents



All personnel involved in installing, commissioning,

operating, maintenance or repair of the equipment must:

- be suitably qualified and- strictly observe these Operating Instructions.

Improper operation or misuse can lead to

- a reduction in the efficiency of the equipment,- damage to the equipment and property of the

user and- serious or fatal injury.

Safety instructions in this manual are presented inthree different forms to emphasize important information.

WARNING

This information indicates particular danger to lifeand health. Disregarding such a warning can lead toserious or fatal injury.

CAUTION

This information indicates particular danger to theequipment or other property of the user. Serious orfatal injury cannot be excluded.

NOTE

Notes give important information on specificsubjects.

1 General

1.1 Safety Instructions

1

General

1.2 Specified Application

CAUTION

The on-load tap-changer may only be used with thetransformer specified in the order.Installation, electrical connection and commissioningof the on-load tap-changer must only be carried outby qualified, skilled personnel and only in accord-ance with these Operating Instructions.

It is the responsibility of the user to ensure that theon-load tap-changer is used for the specified applica-tion only.

For safety reasons, any unauthorised work such asinstallation, alteration, electrical connection, com-missioning or modification to the on-load tap-changerequipment is forbidden without first consulting MR!

The trouble-free operation of the drive, on-load tap-changer and transformer may be put at risk.

WARNING

All relevant fire protection regulations must bestrictly observed.



Motor drive unit ED 100 S (approx. 80 kg), or

Motor drive unit ED 100 L (approx. 130 kg), fig. 2.

Drive shafts with coupling parts and bevel gear(max. approx. 20 kg), fig. 3.

Protective relay RS 2001 (3.5 kg), fig. 4.

The shipment should be checked against the consign-ment documents to ensure it is complete. The partsmust be stored in a dry place until assembly.

The on-load tap-changer must remain packed air-tight inthe protective wrapping and should only be removedshortly before installation.

3

Shipment

NOTE

In general, the drive shafts, the bevel gear and theprotective relay are packed with the on-load tap-changer.

WARNING

When carrying out any work on the on-load tap-changer, motor drive or components, ensure they arepositioned securely.Otherwise there is a danger that individual devicesmay tip over accidentally. This can result in seriousinjury and, in some cases, fatalities.

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A mounting flange is required for mounting the tap

changer head to the transformer cover. This mountingflange should be designed according to the sealingsurface of the tap changer head (see fig. 5 and fig. 6and appendix, drawing 898866).

We recommend using a stencil to position the studs(M12, max. length 45mm), see fig. 7 and appendix,drawing 893787. This stencil is supplied free of chargefor the initial installation of an on-load tap-changerVACUTAP ® VV, if desired.

4.2 Attaching the on-load tap-changer tothe transformer cover

Proceed as follows to attach the on-load tap-changer:

1. Remove the tap changer cover (fig. 8)

• Loosen the 24 bolts M10 x 35/w.s.17 andthe 24 locking washers.

• Remove the tap changer head paying attentionto the sealing (fig. 9).

2. Loosen the fixing screws in the top part of thehead (22 hexagonal screws M8/w.s.13, lockingwashers for securing, fig. 10).Keep the loose parts for reinstallation.

4 Installing the on-load tap-changer

for cover mounting 4.1 Mounting flange

4

Installing the on-load tap-changer for cover mounting

CAUTION

When attaching the on-load tap-changer, ensure thatthe lifting device uses 4 cables of equal length, atleast 1m (see appendix, drawing 898 866), otherwisethe equipment may be damaged.

CAUTION

Under all circumstances, avoid dropping parts into theoil compartment, as there is a risk that the on-loadtap-changer will be blocked.This could damage the on-load tap-changer and thetransformer.For this reason, check the quantities of small partswhen disassembling and reassembling to ensurethey are identical.

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4

Installing the on-load tap-changer for cover mounting

3. Separate the top part of the head from the

bottom part• Lift up the top part of the head. Take care not

to damage the O-ring gasket on the bottompart of the head (fig. 11).

4. Clean the sealing surface on the mounting flangeand on the tap changer head.

5. Place an oil-resistant gasket on the mountingflange.

6. Fix the top part of the head to the mounting

flange.

7. Check the position of the tap changer headwhen it is installed. The on-load tap-changer canbe turned towards the top part of the head insteps of 15 degrees.

8. Slowly lift the on-load tap-changer from under-neath towards the top part of the head using4 cables of equal length (min. 1m), (see appendix,drawing 898866). Pay attention to the centeringbolts.

9. Screw the top and bottom part of the headtogether;• 22 hexagonal screws M8/w.s.13

(tightening torque 20 Nm).

10. Fix the tap changer cover• 24 bolts M10 x 35/w.s.17,

24 locking washers (max. torque 35 Nm).

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5

Installing the on-load tap-changer for bell-type transformer cover

5 Installing the on-load tap-changerfor bell-type transformer cover

To install the on-load tap-changer in a transformer with abell-type cover, the on-load tap-changer must be moun-ted onto a supporting structure. For this purpose, the

bottom part of the tap changer head is designed as asupporting flange (see appendix, drawing 899110).

Firstly, lift the on-load tap-changer into the supportingstructure and connect it to the tap winding. The on-loadtap-changer must be attached to the supporting struc-ture in such a way so it cannot be displaced. The sup-porting flange is provided with drill holes, so it can befixed to the supporting structure easily. Placing spacerblocks between the supporting structure and the sup-porting flange temporarily may be of help. These are tobe removed before attaching the bell-type cover.

Once the bell-type cover is attached, lift the on-load tap-

changer with the lifting device (see appendix, drawing899110) and fix it to the bell-type cover together with thetop part of the head.

To attach the tap changer head to the bell-type cover,we recommend using a mounting flange as describedin section 4.1.

Lift the on-load tap-changer into the supporting structure.

Check the installation position of the tap changer and fixit securely.

By using the temporary spacer blocks between thesupporting structure and the supporting flange, the on-load tap-changer is at the correct final installation heightafter the bell-type cover is attached. This means theleads to be connected to the on-load tap-changer arecorrectly dimensioned in length.

Connect the tap winding and the tap changer leadaccording to section 6.

CAUTION

When attaching the on-load tap-changer, ensure thatthe lifting device uses 4 cables of equal length, atleast 1m (see appendix, drawing 899110), otherwisethe equipment may be damaged.

5.1 Installing the on-load tap-changer inthe supporting structure

The transformer ratio test and drying process are to becarried out according to sections 7 and 8.

CAUTION

Make sure that the connected leads do not exert anyforce on the on-load tap-changer.In addition, there should be sufficient slack so that

the on-load tap-changer can be raised to its finalinstallation position after the bell-type cover isattached.

NOTE

Due to the supporting structure, the diverter switchwith an external change-over selector is limited in itsinstallation position. The supporting structure and thechange-over selector including the activation levermust not collide (see appendix, drawing 899409).

NOTE

The on-load tap-changer must be suspended exactlyvertical in the supporting structure.The on-load tap changer must be installed, so itcannot be lifted by more than 5-20 mm after the bell-type cover is attached.



5

Installing the on-load tap-changer for bell-type transformer cover

5.2 Preparation

Before attaching the bell-type cover, the top part of the

head must be separated from the bottom part of thehead (see 5.3).

Make sure the on-load tap-changer is in the adjustmentposition. This position is given in the connection diagramsupplied with the on-load tap-changer.

Proceed as follows to attach the on-load tap-changer:

1. Remove tap changer cover (fig. 8)

• loosen the 24 bolts M10 x 35/w.s.17 and the 24 locking washers.

• lift off the tap changer cover. Take care notto damage the sealing (fig. 9).

2. Loosen the fixing screws in the top part of thehead (22 hexagonal screws M8/w.s.13,locking washers for securing, fig. 10).Keep the loose parts for reinstallation.

3. Separate the top part of the head from the bottompart;

– Lift up the top part of the head from thebottom part.Take care not to damage theO-ring gasket on the bottom part of the head(fig. 11).

CAUTION

Under all circumstances, avoid dropping parts intothe oil compartment, as there is a risk that the on-loadtap-changer will block.This could damage the on-load tap-changer and thetransformer.For this reason, check the quantities of small partswhen disassembling and reassembling to ensurethey are identical.

5.3 Separating the top part of the on-load

tap-changer head from the bottom part

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5 Installing the on-load tap-changer for bell-type transformer cover

6 Connecting the tap winding and the tap changer take-off terminal

The tap winding and the tap changer take-off terminal

must be connected according to the connection diagramsupplied with the tap changer equipment.

If connection leads have to cross the open surface of

the oil compartment, there must be a clearance of atleast 50 mm between the lead and the surface.

The designation of the tap changer connecting termi-nals are shown in the connection diagram. They are pro-vided with vertical drill holes, 11mm diameter for M10bolts (see appendix, drawing 898864).

6 Connecting the tap winding and the

tap changer take-off terminal

CAUTION

Make sure that all connections are correctly andsecurely made. The connection leads must beconnected without exerting force on the on-load tap-changer.

CAUTION

The connecting terminals must not be adjusted

unsymmetrically as this will jeopardise the functioningof the on-load tap-changer.

1. Before attaching the bell-type cover, clean the

sealing surface of the bottom part of the head.Remove the spacer blocks (see section 5.1).

2. Lift the bell-type cover over the active part of thetransformer and attach it.

3. Before mounting the tap changer head clean thesealing surfaces on the mounting flange of thetransformer. Place an oil-resistant gasket on themounting flange.

Depending on the height adjustment, there must be aclearance of 5 - 20 mm between the top part of thehead and the bottom par t. The position of the fixing

holes in the top part of the head must align with theposition of the threaded holes in the bottom part ofthe head. The on-load tap-changer can be turnedtowards the top part of the tap changer head in stepsof 15 degrees.

4. Fix the top part of the head to the mountingflange.

5. Check the position of the tap changer head whenit is installed. The on-load tap-changer can beturned towards the top part of the head in steps of15 degrees.

6. Slowly lift the on-load tap-changer from under-neath towards the top part of the head using4 cables of equal length (min. 1 m). Using thelifting device, lift the on-load tap-changer to aposition (see appendix, drawing 899110) so thatthe bottom part of the head is aligned with the toppart of the head and the connection screws of thetop part and bottom part of the head (22 hexago-nal screws M8/w.s.13 and locking washers forsafety) can be screwed in. Pay attention to thecentering bolts.

7. Screw the top part of the head and the bottom

part together:• 22 hexagonal screws M8/w.s.13

(20 Nm tightening torque)

8. Fix the tap changer head

• 24 bolts M10 x 35/w.s.17,• 24 locking washers (max. torque 35 Nm)

5.4 Attaching the bell-type cover

CAUTION

Under no circumstances should the on-load tap-changer be lifted up with the fixing screws as this candamage the top part of the head.



Drying:

Vacuum-dry the on-load tap-changer at a max. temper-ature of 110 °C. The duration of the drying processdepends on that of the transformer.

8.1.1.2 Vacuum-drying in the transformer tank

The tap changer cover is vacuum-proof.

To ensure the interior of the oil compartment and thebuilt-in tap changer insert is sufficiently dried, a shortconnecting pipe with a nominal width of 25mm must beinserted between the transformer tank and a connecting

flange on the tap changer head which leads directly tothe interior of the oil compartment.

The connecting pipe should be fitted on the tap changerhead between the connections E2 and Q or E2 and R(for the position of the connections see fig. 14 andsection 9).

Details on the procedure, temperature and duration ofthe drying process are described in section 8.1.1.1.

Transformer Ratio Test 7

Drying Process and Oil Filling 8

7 Transformer Ratio Test

NOTE

If the transformer is to be dried in its own tank, theinterior of the on-load tap-changer must be connectedto the vacuum by a connecting pipe, as the tapchanger cover remains closed for the entire dryingprocess.

It is recommended that a transformer ratio test be

carried out before the transformer undergoes drying.

To operate the drive shaft of the tap changer head, apipe (nominal width 25mm) with screwed-in couplingbolts (diameter 12mm) and a hand wheel or hand crankcan be used.

16.5 drive shaft revolutions are required for one tapchange operation. You should be able to hear theswitching action of the on-load tap-changer clearly.

When operating the change-over selector (adjustmentposition ± 1 tap position), noticeable by the increasedexpenditure of force, the tap change operation alreadyunderway must always be completed without chang-ing the rotation direction.

Keep the number of tap change operations without oilto a minimum.

The end positions, which are given in the connectiondiagram supplied with the equipment (position designa-tion), must never be overrun. To ensure this, alwayscheck the operating position reached through the in-spection window on the tap changer head (fig. 12).

After the transformer ratio test, the on-load tap-changermust be operated back to the adjustment position (seeconnection diagram supplied with the on-load tap-

changer).

8 Drying Process and Oil Filling

8.1 Drying Process

A precondition of MR's guaranteed dielectric values ofthe on-load tap-changer is that a minimum drying pro-cess must be carried out according to the instructionsbelow (either 8.1.1 or 8.1.2).

8.1.1 Vacuum-drying

8.1.1.1 Vacuum-drying in the autoclave

Heating:Heat the on-load tap-changer in air at atmosphericpressure, increasing the temperature by approx. 20 °C/hup to a max. temperature of 110 °C.Pre-drying:Pre-dry the on-load tap-changer in circulating air at amax. temperature of 110°C for 10 hours.

NOTE

Before drying the transformer in the autoclave, the on-load tap-changer cover must be removed and storedoutside the autoclave.

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8

Drying Process and Oil Filling

Before the drying process, the kerosene drain plug in the

oil compartment bottom must be opened to drain thecondensate.

The kerosene drain plug screw can be opened fromoutside (w.s.24) or from the inside (hexagonal recessscrew w.s.8), (see fig. 13). The plug cannot be lost as itis attached. It must be closed again after the dryingprocess (max. torque 39 Nm).

8.1.2.1Vapour-phase drying in the autoclave

Heating:Supply kerosene vapour at a temperature of approx.90°C. Keep this temperature constant for approx. 3-4

hours.Drying:Increase the kerosene vapour temperature applied tothe on-load tap changer by approx.10 °C/h to the desiredfinal temperature which should not exceed 125 °C.The duration of the drying process depends on that ofthe transformer.Check that the kerosene drain plug is closed after thedrying procedure.

8.1.2 Vapour-phase drying

CAUTION

Ensure the kerosene drain plug is securely closedafter the drying process to avoid oil from the oilcompartment getting into the oil chamber of thetransformer tank.

CAUTION

The oil compartment and its associated oil conser-

vator must only be filled with new insulating oil fortransformers according to IEC 60296 (Specificationfor unused mineral insulating oils for transformers andswitchgear) and IEC 60422 (Supervision and main-tenance guide for mineral insulating oils in electricalequipment). For dielectric strength limit values seesection 16, table 1. The use of any other oils may putthe trouble-free operation of the on-load tap-changerand the transformer at risk.

8.1.2.2 Vapour-phase drying in thetransformer tank

For vapour-phase drying in the transformer tank, the

tap changer insert must be removed to unscrew thekerosene drain plug from inside the oil compartment(fig. 13). Please contact MR for specific instructions onremoving and re-installing the tap changer insert.

8.1.3 Operating the on-load tap-changer

8.2 Oil Filling

Close the tap changer head by lowering the cover.Tighten all 24 bolts M10/ w.s.17 on the cover uniformly(max. torque 35 Nm).

Under vacuum, fill the on-load tap-changer and trans-

former simultaneously with new transformer oil.To fill with oil, use the connection S or R on the tapchanger head. To apply a vacuum to the transformerand oil compartment simultaneously, install a connec-tion pipe between the connection E2 and R or S.

NOTE

Before drying the transformer in the autoclave, the tapchanger cover must be removed and stored outsidethe autoclave.

CAUTION

Do not operate the on-load tap-changer after dryingwithout a complete oil filling of the oil compartment,

as bearings and gaskets will be damaged.The external change-over selector must also bewetted with oil after the kerosene drying, whenswitching occurs.

164M01313



There are 2 pipe connections provided on the tap chan-

ger head for different purposes.All pipe connections can swivel freely by loosening thethrust collar (4 bolts M10/w.s.17), see fig.14 andappendix, drawing 898863.

9.1 Pipe connection R for theprotective relay RS 2001

Install the protective relay RS 2001 (see appendix,drawing 899084) according to our OperatingInstructions no. 59.

9.2 Pipe connections S and R

(Connection Q as special design)Connection to tap changer interior

To lower the oil level during inspections (approx. 7 l), apipe connection should be fitted to one of the freeconnections R, S or Q which ends at the side of thetransformer tank at operating height for a drainage tap.

9.3 Connection E2

This connection is closed by a dummy plug. It leadsinto the oil chamber of the transformer, directly underthe tap changer head. When necessary, it can beconnected to a collective pipe for the Buchholz-relay.

9 Pipe Connections

9

Pipe Connections

NOTE

The stamped serial number must match the serialnumber of the on-load tap-changer.The protective relay must be installed as close aspossible to the tap changer head in a horizontalposition.

The arrow on the installed protective relay must pointto the oil conservator.

The pipe leading to the oil conservator must have aninclination of at least 2 %.Ensure that the maximum space between the trans-former cover and the top edge of the tap changer oilconservator does not exceed 5 m.

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10.3 Mounting the drive shaft (square tube)

The drive shaft must be mounted according to ourOperating Instructions no.42.

The drive shaft is the mechanical connection betweenthe motor drive unit and the tap changer head.

The bevel gear is responsible for changing the directionfrom vertical to horizontal. Accordingly, the vertical driveshaft must be installed between the motor drive unit andthe bevel gear, and the horizontal drive shaft betweenthe bevel gear and the tap changer head.

10

Mounting the Motor Drive Unit, Bevel Gear and Drive Shaft

10.2 Mounting the bevel gear

The bevel gear is attached to a support on the trans-former cover with 2 screws (drill holes 18mm, seeappendix, drawing 892916).

10 Mounting the Motor Drive Unit,

Bevel Gear and Drive Shaft

NOTE

The serial number of the motor drive unit mustmatch that of the on-load tap-changer (name plate).

The motor drive unit must be in the same operatingposition as the on-load tap-changer when coupling.The adjustment position is given in the connectiondiagram supplied with the on-load tap-changer.

The motor drive unit must be mounted at the providedplace on the transformer tank in a vertical positionand protected against transformer vibrations.

Detailed mounting instructions can be found in our

Operating Instructions no. 138 for the Motor DriveUnit ED.

10.1 Mounting the motor drive unit(see appendix, drawing 898801).

The drive shaft is designed as a square tube and is

connected on both ends to the end of the drive shaft ordriven shaft of the respective unit by two couplingbrackets and one coupling bolt.

Square tubes, coupling brackets, coupling bolts andscrews are corrosion-resistant. We therefore recommend

that the exterior coating applied to the transformer tank

is not applied to these parts.

The guard plate, which serves as a foot step protectionfor the horizontal drive shaft over the transformer cover,and the square tubes are supplied in oversized lengths(various standard lengths). These parts must be cut tothe required size before mounting.

Before coupling the upper gear unit of the tap changerhead, operate the on-load tap-changer to the exactadjustment position (including idling) as follows:

Loosen the screws on the tap changer cover (24 boltsM10/w.s. 17, locking washers), raise the tap changercover at least 15 mm so that the upper gear unit dis-engages. Support the tap changer cover using suitablepieces of wood or similar.

Turn the upper gear unit of the tap changer cover in thedesired direction so the drive shaft can be properlycoupled.

Check the position of the driven shaft on the output side

of the gear unit below the tap changer cover and turn thedrive shaft manually until the driven shaft engages intothe coupling of the gear unit.

Remove the supporting pieces of wood and fix the tapchanger cover again, 24 bolts M10/w.s. 17, max. torque35 Nm, locking washers for securing.

Finally, check the idling torque of the motor drive unitagainst the diverter switch operation of the tap changeraccording to our Operating Instructions no. 138 for themotor drive unit ED.

NOTE

When installing the drive shaft, make sure that theshaft ends to be connected are exactly aligned andthe coupling bolts are greased.

NOTE

The stamped serial number must match that of the on-load tap-changer.

The horizontal drive shaft must align with the shaftend of the on-load tap-changer head.

By loosening the thrust collar (6 screws M8/w.s. 13)the upper gear unit can swivel freely. After mounting,tighten the thrust collar, (max. torque 20 Nm).

The bolts are to be secured.

The above instructions also apply to bevel gears ofspecial designs and to intermediate bearings of thevertical and horizontal drive shafts.



11

Commissioning the on-load tap-changer at the transformer manufacturer's site

11 Commissioning the OLTC at thetransformer manufacturer's site

11.1 Operational tests

Before voltage is applied to the transformer, test tap

change operations must be performed to check themechanical function of the on-load tap-changer and themotor drive.

These tap change operations are to be performed overthe entire operating range.

Make sure that the position indicators of the motor driveand the on-load tap-changer (inspection glass on the tapchanger head) have the same reading in everyoperating position.

Check that the automatic switch-off is working in bothend positions and check the function of the electrical

and mechanical end position limits (see OperatingInstructions no. 138 for the motor drive ED).

11.2 Complete oil filling

Fill the on-load tap-changer with transformer oil via theoil conservator and bleed as follows:

• bleed the oil chamber of the tap changer head usingthe bleeder valve in the tap changer cover (E1):

Open the screw cap M30/w.s. 36, max. torque

10 Nm (fig. 15), lift the valve tappet using ascrewdriver.

• the elbow connection with bleeder screw:screw cap M16/w.s. 22, max. torque 9 Nm, bleederscrew M6 with slotted head, max. torque 2 Nm(fig. 16).

11.3 Ground Connections

Connect the ground screw of the tap changer head to

the transformer cover (1 screw M12 with nuts (w.s. 19),max. torque 60 Nm, fig. 17).

Connect the ground screws (M12/w.s. 19,max. torque 60 Nm) of the motor drive protectivehousing to the transformer tank.

The electrical tests required for the final inspection of

the transformer can be performed after the afore-mentioned work has been completed.

11.4 Electrical tests on the transformer

CAUTION

If the position indicators on the on-load tap-changerand the motor drive read different operating positions,there is a coupling fault.Operating the equipment with incorrect coupling willresult in damage to the on-load tap-changer and to thetransformer.The transformer may not be put into operation.

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Before commissioning the transformer, a function test

must be carried out on the on-load tap-changer andmotor drive unit according to section 11.1. The functionof the protective relay should also be checked at thispoint.

As a control test, trigger the connected circuit breakerby activating the test button "OFF" of the protectiverelay. Make sure that closing of the circuit breakers isonly possible again after the protective relay has beenbrought to the "IN SERVICE" position by pressing theother test button.

After energizing the transformer, tap change operationsunder load can be performed.

13 Commissioning at the operating site

NOTE

The protective relay must be inserted into the trippingcircuit of the circuit breakers so the transformer isimmediately shut down by the circuit breakers when

the protective relay is triggered (see OperatingInstructions no. 59 for the protective relay RS 2001).

CAUTION

Check that all stop valves between the oil conser-vator and the tap changer are open.

CAUTION

The relevant safety regulations must be observedhere.

11 Transport to the operating site

12 Commissioning at the operating site

If the motor drive unit has to be dismounted for the trans-

port of the transformer to the operating site, operate it tothe adjustment position and then uncouple it.

Follow the instructions in section 10.1 and 10.3 in orderto re-install the motor drive unit.

This pipe should be connected on the tap changer headbetween the connections E2 and one of the free

connections R, S or Q.

It is sufficient to lower the oil level by approx. 7 litresfor short standing periods, 2-4 weeks, without an oilconservator.

If the transformer is completely emptied of oil, the tapchanger insulating oil must also be completely drained.

The interior of the oil compartment is to be conserved inthe same way as the transformer (e.g. by filling withnitrogen).

For longer standing periods, the motor drive unitheating must be connected and operated.

12 Transport to the operating site

CAUTION

Do not operate the motor drive unit while it is notcoupled to the on-load tap changer.

NOTE

If the transformer is filled with oil, but is stored ortransported without an oil conservator, a pipe mustbe connected between the interior of the tap changeroil compartment and the transformer oil chamber toequalize the static pressure.



16 Inspections

Limit values for the exchange or treatment of the tap changer oil:

Table I

*) measured according to IEC 60156

The temperature of the oil sample at the time of measuring the dielectric strength should be noted.The given values for dielectric strength are valid for oil temperatures of 20 ± 5 °C.

On-load tap-changer Dielectric Strength*)

V V III 250 Y, V V III 400 Y, V V III 600 Y 30 kV/2.5 mm (minimum)

V V III 250 D, V V III 400 D, V V III 600 D 40 kV/2.5 mm (minimum)

V V I 250, V V I 400, V V I 600 40 kV/2.5 mm (minimum)

CAUTION

The oil compartment and its associated oil conser-vator must only be filled with new insulating oil for

transformers according to IEC 60296 (Specificationfor unused mineral insulating oils for transformers andswitchgear) and IEC 60422 (Supervision and main-tenance guide for mineral insulating oils in electricalequipment). For dielectric strength limit values seetable 1. The use of any other oils may put the trouble-free operation of the tap changer and the transformerat risk.

16

Inspections

Inspection intervals:

An inspection should be carried out after every 15years or 150,000 tap change operations, whichever isreached first.

The scope and type of inspections are specified in thecorresponding Inspection Instructions from MR.

If the appropriate preparations are made, a properinspection can be carried out within a day.

WARNING

Disregarding the inspection intervals or incomplete / improper inspections can lead to severe damage onthe on-load tap-changer and the transformer.

The on-load tap-changer VACUTAP ® VV with VACUTAP ® -vacuum switching technology has considerably longerinspection intervals when compared to conventional tapchangers with oil switching technology, which drama-tically lowers operating and maintenance costs.This means that properly conducted inspections areeven more important. For this reason we emphaticallyrecommend that our Technical Service Department carry

out each inspection. As well as guaranteeing that allwork is properly carried out, specific components arealso retro-fitted to the latest standard of technology.

If an inspection is not carried out by our Technical

Service department, please ensure that the personnelwho carry out the inspection are trained by MR or areotherwise suitably qualified to carry out the work. Insuch a case, we would ask you to forward us a reporton the inspection performed, to complete our inspectionrecords. For inquires about spare parts we ask you toinform us about the serial number (see the name plateon the motor drive unit) and the number of switchingoperations.

In addition to the inspection intervals mentioned above,the diverter switch unit and the complete gearingmechanism must be replaced after 800,000 tap change

operations.

In addition, the limit values in Table I below should beconsidered when exchanging or preparing the diverterswitch oil.



17

Appendix

On-load tap-changer VACUTAP ® V V8988635E

Drawing of tap changer head

31 Tap changer head - bottom part

32 Tap changer head - top part

33 Pipe connection E2 (option)

34 Pipe connection R for protective relay

35 Pipe connection S

36 Pipe connection Q (option)

37 Upper gear unit with drive shaft 37a

38 Tap changer head cover

39 Earth connection M12

E1 Bleeding facility for tap changer

E2 Bleeding facility for space under the

head outside the oil compartment

R Pipe connection for protective relay

Q Pipe connection (optional)

S Pipe connection

Connecting flange for

R, Q and S O-ring

44,2 – 5,7

Connections can rotate 360°

only with 145 kV



17

Appendix


Installation drawing

The connection diagram is binding

for the designation of the

connecting terminals and phases

only with 145 kV

11 Change-over selector pipe

12 Change-over selector terminal "+"

13 Change-over selector terminal "0"

14 Change-over selector terminal "–"

21 Take-off contact22 Fine tap selector terminal

23 Oil compartment bottom with kerosene drain plug 23 a

24 Tap changer oil compartment

31 Tap changer head - bottom part

32 Tap changer head - top part

33 Pipe connection E2 (optional)

34 Pipe connection R for protective relay

35 Pipe connection S

36 Pipe connection Q (optional)

37 Upper gear unit with drive shaft

38 Tap changer head cover

12 – Detail X

13 – Detail X

14 – Detail X

Detail Z

is not present for

neutral connection

Detail Y

X

Change-over selector

connecting terminal

Y

Fine tap selector connecting terminal

Potential W (n-1) provide sufficient clearance

on transformer tank

Z

Take-off contactZ

Y

X

is not present for

neutral connection



17

Appendix


Drilling stencil for the tap changer head

3 mm thick

Marks pounded



17

Appendix


Assembly drawing

Centering bolts 3x

O-ring

Transformer cover

Width of gasket 43

only with 145 kV

Attention!

Make sure that hooksand gear parts

do not collide!

Lifting device optional

712645:



17

Appendix


Mounting of the bell-type cover

Centering bolts 3x O-ring

Transformer cover

Width of gasket 43

Supporting flange

Only with 145 kV

Support on the transformer


712645:

Attention!Make sure that hooksand gear parts

do not collide !



17

Appendix


Position of the OLTC for bell-type tank installation

Swivelling range

Support on

transformer

Support on

transformer

Support on

transformerEnsure free movement of

change-over selector lever

Swivelling range

only with 145 kV




Transport instructions

Remove pieces of wood

in direction of arrow!

Do not damage

the grading rings!

Turn tap-changer

until change-over

selector is on top


712 645:

Remove thered-marked

eyebolts before

commissioning!

17

Appendix

Lift here



17

Appendix


Switching sequence

Switching sequence, 10-pitch

MTS Tap selector contacts, main path

MSV Main switching contacts (vacuum interrupter), main path

TTS Tap selector contacts, transition path

TTV Transition contacts (vacuum interrupter), transition path

STC Sliding take-off contacts

R Transition resistor

IC Circulating current



17

Appendix

Inspectionwindow

Identification plate

GasketGasket

Cable glandPG 16

Test Buttons

IN SERVICE OFF(reset) (test tripping)

The arrow must always point towards the oil pipe leading tothe oil conservator of the transformer.

Plan view of test buttons(cover removed)

1)NO - normally open, NC - normally closed, CO - change-over contact

The protective relay is to be connected in such a way that if it is energized, the transformer is switched off immediately by its associated circuitbreakers.

S t a n d a r d

S p e c i a l D e s i g n w i t h s u r c h a r g e

0.65 - NO1 1.2 - NO A

3.0 - NO4.8 - NO

0.65 - NC2 1.2 - NC B

3.0 - NC4.8 - NC

0.65 - CO3 1.2 - CO C

3.0 - CO4.8 - CO

0.65 - 2NO4 1.2 - 2NO 2 A

3.0 - 2NO4.8 - 2NO

0.65 - 2NC5 1.2 - 2NC 2 B

3.0 - 2NC4.8 - 2NC

0.65 - NO + NC6 1.2 - NO + NC 1 A & 1 B

3.0 -NO + NC4.8 -NO + NC

Variant Key

Variants Terminal ArrangementRelay Designation1) Reed Switch

Contact Positions

IN SERVICE OFF

Design

Protective relay RS 20018990840E

(STANDARD)

Metal blind screw PG 16



17

Appendix

Motor drive unit ED-S8988012E

Protective housing

Vertical guard plate

with spacing ringHand crank

Wall of transformer tank

Shim

Attachment of the housing

approx. 690 if opened 130°

approx. 864 if opened 180°

The cover can be opened to the left or right

depending on the location of the hinge pins.

Location of fixing holes on protective housing (rear view) Entry in protective housing for cables

(bottom view)

1 1 8 9 *

4 5 4 *

* for designs with

intermediate gear

3 dummy plates for packing glands

special design for OLTC monitoring



17

Appendix

Bevel gear CD 64008929166E

Dimension Drawing

e 1 = 2 0 5 f o r s t a n d a r d d e s i g

n

e 2 = 2 1 5 f o r d e s i g n w i t h b a l l j o i n t



© Maschinenfabrik Reinhausen GmbH 2001Postfach 12 03 6093025 RegensburgGermanyTelephone: (+49) 9 41 / 40 90-0Fax: (+49) 9 41 / 40 90-111

Email: [email protected]: http://www.reinhausen.com

vv oltc operating

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