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5 br 155 M MASCHINENFABRIK REINHAUSEN ON-LOAD TAP CHANGER TYPE MD Inspection...

5 br 155 M MASCHINENFABRIK REINHAUSEN ON-LOAD TAP CHANGER TYPE MD Inspection Instructions Maschinenfabrik Reinhausen GmbH Postfach 12 03 60 * D-93025 Regensburg Phone +49-941-4090-0 « Telefax +49-941-4090-111 « Telex 65881  MASCHINENFABRIK M REINHAUSEN IA 110/01 en — 0196/1000 Maschinenfabrik Reinhausen GmbH Printed in Germany Postfach 12 03 60 D-93025 Regensburg Phone: +49-941-4090-0 Fax: +49-941-4090-111 Telex: 6 5 881 ON-LOAD TAP CHANGER TYPE M D Inspection Instructions No. 110/01 (additional Inspection Instructions No. 38/02 for on-load tap changer type M) ATTENTION: Contents The inspection work o n the diver- ter switch unit of column 2 (pole V) 01 =1 [1-1 3 Function principle of the on-load tap changer has t o b e carried out according t o Tap changer designation our Inspection Instructions No. 38. Two-column design of tap changer, components, tap change supervison control Inspection intervals Summary of inspection work Preparations........ccccvererersntrmsscrssnersenressesrssnsessasersasersssrassnssssansessansanerssns 7 241 Required tools and equipment 22 Safety precautions 23 Operating position Removal of the diverter SWItCh UNL........eeeeeeeveetreerrerieerirrerreereeresimresnssasens 8 Cleaning the oil compartment, the tap changer oil conservator and the diverter switch Unit........cooeeeiviorree creer ccna nr reece 9 Inspection of a two-pole diverter switch unit (poles W and U}), laminated Paper tYPe mcrae nneesane sees......ccorecirieeccniisine ats acne snasassanaseas 12 5.1 Withdrawal position 62 Measurement of the transition resistors Please note: 53 Separation of the diverter switches (pole W and pole U) 5.4 Cleaning of the insulating shaft Drawings and illustrations 5.5 Work on diverter switch pole W contained herein may differ in 5.5.1 Setting the mid-position detail from the tap changer 55.2 Removal of the contact shell 55.3 Removal of the arc chutes equipment delivered. 55.4 Cleaning the diverter switch They are for reference only and are 55.5 Determination of contact wear subject to change without notice. 55.6 Attachment of the contact shell 55.7 Detachment and reattachment of the resistor shell 55.8 Locking-in of the diverter switch 11001010 Contents Page 5.6 Work on diverter switch pole U 5.6.1 Setting the mid-position 5.6.2 Further steps to be carried out — Detachment of contact shell — Removal of arc chutes — Cleaning the diverter switch — Determination of contact wear — Attachment of the contact shell — Detachment and reattachment of the resistor shells — Locking-in of the diverter switch 5.7 Reassembly of the diverter switch unit Inspection of the two-pole diverter switch unit (pole W, U) in GFRP-design (since 1988) Withdrawal position Measurement of the transition resistors Separating the diverter switch unit (pole W and pole U) Removal of the upper supporting cylinder Work on diverter switch poles W and U Setting the mid-position Removal of the contact shell Removal of the arc chutes Cleaning of the diverter switch Determination of contact wear 6.5.6 Attachment of the contact shell 6.5.7 Detachment and reattachment of the resistor shell 6.5.8 Locking-in of the diverter switch 6.6 Assembly of the diverter switch unit Replacement of diverter switch contacts and flexible contac leads 71 Diverter switch contacts 72 Flexible contact leads Installation of the diverter switch unit Filling with oil 10. Further checks 10.1 Functional check of the tap change supervisory circuit 10.2 Drive shafts 10.3 Functional check of motor drive and tap changer 10.4 Monitoring equipment 10.5 Voltage regulator 11. Appendix 11.41 Coupling of the tap changer and the motor drive unit 11.2 Inspection tools 113 Lifting device 11.4 Spare parts list 11.5 Parts of diverter switch poles W and U 11.6 Adjusiment plans 110/01/01/0 1. GENERAL temporarily inserted in the circuit to The designation of a specific tap ensure no-break transfer of the changer model therefore incorporates 1.1 Function principle of the current. all these characteristics and permits on-load tap changer (fig. 1) easy and distinctive identification of 1.2 Designation of the on-load tap the tap changer. A tap change operation is initiated by changer (fig. 2) the tap selector which preselects the The basic connection diagram code desired tap on the transformer wind- Each tap changer type is available in in the model designation identifies: ing. different models. These models vary number of tap selector contacts, in their number of poles, max. rated number of operating positions, num- Then, the diverter switch unit transfers through-current, highest voltage for ber of mid-positions and type of the current from the tap in service to equipment Up, tap selector size and change-over selector. the preselected tap. During this quick basic connection diagram. change-over, ohmic resistors are Motor drive unit Tap selector Diverter switch unit Time i n seconds Circuit diagram A , B — main contacts a , b - main switching contacts a l , b 1 —- transition contacts Contact movement al bl al Fig. 1 Tap change operational sequence KHW 220-2 110/0101/0 Example in fig. 2: On-load tap changer type MD On-load tap changer 3-pole design, through-current 600 A, 600D-123/C - 10191W insulation to ground and between phases for Up, = 123 kV, tap selector size C, basic connection diagram 10191W, i.e. 1 0 contacts, 19 opera- ting positions with one midposition, Type Basic connection diagram change-over selector designed as reversing switch. Number of poles Tap selector size Max. rated through- 1.3 Two-column design of tap current in amperes Highes voltage for changer type M D and additional iden- tification of the equipment U,, The tap changer has a two-column model Insulation to ground construction (see fig. 3). Column 1 consists of a 2-pole diverter switch unit (poles W and U) and a single-pole Basic connection diagram tap selector (pole U). Column 2, 10 19 1 w however, consists of a single-pole diverter switch (pole V) and a two-pole tap selector (poles V and W). The diverter switch pole W of column Tap selector pitch Mid-position(s) Change-over selector 1 is connected to the tap selector of column 2 by tap selector leads. The two tap changer columns are 1 mechanically coupled by a horizontal 10 max. number of. 3 G w 12 operating positions Coarse tap Reversing drive shaft which runs between the 14 selector switch gear units on the tap changer heads -of columns 1 and 2. They are driven without with by a common motor drive unit. change-over selector The simultaneous operation of co- lumns 1 and 2 is monitored by a 10 09 19 suitable supervisory system which 12 1 23 switches off the motor drive imme- 14 13 27 16 15 31 diately in case of failure. 18 17 35 The main components of each tap changer column are: 1 2 — tap changer head, EHF = — diverter switch unit, — diverter switch oil compartment, — tap selector. All tap changer parts subject to in- spection are clearly marked in colour in fig. 4. Please note: Inspection work o n t h e diverter switch unit of column 2 (pole V) has to be carried out according to our Inspection Instructions N o. 3 8. KHW 503-2 110/01/01/0  Components of the tap changer 13 Gasket 14 Position indicator 15 Inspection glass 16 Position indicator drive shaft 21 Tap changer head 22 Cover screw 23 Cover gasket 24 Tap changer cover 25 Upper gear unit with drive shaft 25a 26 Pipe connection R f i r protective relay 27 Pipe connection S fiir suction pipe 28 Pipe connection with terminals for tap change supervisory control 29a Bleeder valve on tap changer cover 29b Bleeder connection for transformer oil tank 29c Bleeder screw for suction pipe 31 Diverter switch oil compartment ( 3 t a = 2-pole, 31b = 1-pole) 32 Oil compartment bottom with tap selector supporting bolt 32a Supporting contact Oil compartment - terminal Terminal (35a, 35b, 3 5 ¢ for tap changer take-off leads) Suction pipe Tap selector suspension Tap selector gear Fine tap selector Change-over selector Tap selector terminal Tap selector connecting lead (48b for pole U, 48a for pole W, 48c for pole V) Diverter switch unit (51a for pole W , 51b for pole U, 51c for pole V) Support cylinder Support plate Fixing screw Lifting lug Transition resistors Screening rings (only if Ug, = 123 kV) Shaft for tap change supervisory control Column 1 Column 2 New designation: Column A Column B KHW 525-2 110/01/010 1.4 Inspection intervals inspection intervals to be extended. Continuous filtering also increases the IMPORTANT: The tap changing mechanical life of the tap changer by A WARNING: equipment must b e inspected at immediately removing most of the Disregard of the inspection regular intervals t o maintain a high abrasive particles responsible for intervals puts at risk the level of operating reliability. mechanical wear. trouble-free operation of the The inspection can be carried out by The insulating oils in the transformer tap changer and transformer. qualified, MR-trained personnel are to be monitored by the operator usually within one day, provided it has according to the relevant directions. been well prepared and organized. If inspections are not carried out by W e strongly recommend t o have M R personnel, w e request a report t o inspections carried out by our supplement our inspection data, so Technical Service. that, in case of need, recommendations This guarantees a professional per- for the next inspection can be given. formance of the inspection and en- sures the updating of specific com- ponents to the latest operational state. If the inspection is not carried out by MR personnel we recommend to ask The following standard values for oil testing according to CIGRE report 12-13 MR for all spare parts necessary for (1982) apply to transformer oil at service temperature: inspection. For this purpose please indicate the tap changer serial num- On-load tap changer water content*) Dielectric strength**) ber and the number of tap change operations. M III 350 D, M Ill 500 D (old) < 30 ppm > 40 kV/2.5 mm The numbers of tap change operations M i l 600 D determining the inspection intervals indicated in table I are figures based *} measured according to Karl-Fischer method based on IEC-Publication 814 on experience with use of usual oil **) measured according to DIN VDE 0370 Teil 1 qualities. The tap selector of the tap changer is basically maintenance-free. In particu- lar cases however, e.g if installed in On-load Transformer Number of tap change operations industrial transformers with a high tap changer rated current without MR oil filter with MR oil filter number of switching operations, our Technical Service should be contacted M I I 350 D bis 350 A 40 000 80 000 when about 1,000,000 switching operations have been reached. M Ill 500 D (old) bis 500 A 40 000 80 000 The diverter switch units of the tap M lll 600 D bis 600 A 40 000 80 000 changer must b e replaced after 800,000 switching operations at the Table! Inspection intervals latest. If the number of tap change operati- Independent of the number of tap change operations stated in table | a first ons per year is 15,000 or higher, we inspection has to be carried out after 20,000 tap change operations. recommend the use of our stationary Further inspections are necessary in intervals of 4 years. oil filter unit type 51 with a paper filter cartridge (see Operating Instructions No. 18). The use of an ail filter unit type 51 with a combined filter cartridge (paper filter filled with drying agent) is obligatory, if the highest voltage for equipment between phases exceeds 92 kV. Filtering of the switching oil allows the 110/01/01/0 1.5 Summary of inspection work 2. PREPARATIONS 2.2 Safety precautions The inspection covers the following steps: 2.1 Required tools and equipment: Removal and reinstallation of the — empty vessels for the dirty oil and A WARNING: diverter switch units new transformer oil for cleaning Make sure that the following Cleaning of the diverter switch oil and oil change safety precautions have been compartments and the diverter carried out b y the user of the switch units. In the course of the Column 1 Column 2 plant: inspection, the oil conservator for The transformer must b e dis- the tap changer has to be cleaned, kv 72,5 1 2 3 72,5 1 2 3 connected and secured against too. reclosing. All terminals must b e Lies | 230 270 130 1 5 0 grounded visibly (ground cables, Change of the switching oil ground switches). The working Check of diverter switch oil com- Table l i Oil filling quantity in litres area must b e clearly marked out. partment and diverter switch unit. Start with the inspection only Determination of contact wear an oil pump for the oil change after all these safety measures Measurement of transition brushes and absorbent non- have been carried out. resistors fuzzing rags Disregard endangers lives. Check of the tap change supervi- — awork table sory system, the protective relay, the drive shaft, the motor drive — alifting device: and, if present, of the oil filter unit a crane or an MR lifting device 2.3 Operating position and the voltage regulator. (see section 11.3), } The diverter switch unit can be re- max. weight of diverter switch unit: The diverter switch units should be moved in any operating position. Take max. 80 kg, the required with- exposed to air no longer than 10 note of the operating position when drawal force is max. 1300 N. hours at the most. withdrawing the unit. It is recommended, however, to with- The inspection work should not be Column 1 Column 2 draw the diverter switch unit in the interrupted. Cleanliness and care adjustment position which is marked should be observed. kV 725 123 72,5 123 by an arrow on the position indication dial of the motor drive (fig. 5). mm | 1500 1700 | 870 1000 A WARNING: Table l l l Withdrawal heights in mm The inspection must b e carried — inspection tools out b y qualified, skilled per- (see section 11.2) sonnel only. All instructions — spare pants stated i n the Inspection Instruc- (see section 11.4) tions manual must b e strictly observed. Please note: If any damage is detected during Lock tabs, self-locking nuts and inspection, immediately contact screws should never be used twice; MR for assistance. I n this case after removal they have to be replaced the tap changer must not b e put by new ones. into service. Do not alter o r modify the tap changer equipment without prior consultation with MR. Improperly performed o r in- complete inspection work can affect the trouble-free operation A WARNING: WARNING: Do not operate the motor drive of tap changer and transformer. Always use MR-authorized Under certain circumstances replacement parts. while the tap changer i s un- this can cause property damage Parts of other origin can affect coupled. To prevent electrical and/or personal injury. the trouble-free operation of operation the motor drive must tap changer and transformer. b e blocked b y tripping the motor protective switch. 11001010 3. REMOVAL OF THE DIVERTER SWITCH UNIT (fig. 6) Lowering the oil level: Close the stop valve between oil conservator and tap changer head. Lower the oil level in the tap changer head by opening the drain valve of the tap changer head and the bleeder valve on the tap changer cover (open screw cap M30/w.s.36, lift the valve tappet by means of a screw driver, fig. 7). AN ATTENTION: The switching oil o f the tap changer should always b e handled as a flammable liquid. Moreover, explo- sive gases can accumulate under the tap changer cover, i n the switching oil o r i n the o i l compart- ment. Therefore, strictly avoid open fire. Use only pumping equipment suitable for flammable liquids. If an oil filter unit is installed: Open the sample valve of the return pipe and take the oil filter unit into operation. Drain approx. 10 litres from the oil in the tap changer head until Fig.6 Tap changer head the support plate of the diverter switch unit is free of oil (check through the 1 — Drive shaft (square tube) inspection glass in the tap changer 2 — Coupling bracket with coupling bolt 3 — Upper gear unit cover). (centric arrangement) [S00 Uncoupling of the drive shaft at the Tap changer cover 1 upper gear unit: — Bleeder screw on the tap changer Loosen 6 screws M6/w.s.10 at the cover 6 — Pipe connection R for coupling bracket; take note of the protective relay RS 2001 coupling bolts, nuts and lock tabs. 7 — Pipe connection S for Normally, the square tube can be suction pipe moved to one side for clearance. If not, 8 — Connecting facility for tap change detach the other coupling bracket of supervisory circuit the gear unit from the square tube Position indication © | (fixing material as above) until the horizontal drive shaft can be com- pletely removed. Removal of the tap changer cover (fig. 8a): Unscrew the cover screws M10/w.s.17, take note of the spring washers. Lift off the cover and make sure not to damage the gasket. Note: In case of special design with eccentric arrangement of the upper gear unit (fig. 8b) these Inspection Instructions apply analogously. 110/01/01/0 Further dissassembly i n the follow- 4. CLEANING THE OIL COMPARTMENT, THE TAP CHANGER OIL ing order: CONSERVATOR AND THE DIVERTER SWITCH UNIT Remove the position indicator dial (fig. 9). Take off the clip from the shaft end. The coupling pin allows Oil compartment, o i l conservator: reinstallation of the position indicator Pump out the oil from the diverter switch oil compartment. Open the stop dial in its correct position only. valve between tap changer head and tap changer oil conservator and drain the oil until clean oil flows. If necessary, flush the oil conservator with new transformer oil. A ATTENTION: The tap change supervisory circuit i s active. Before starting with the inspection this circuit has to b e disconnected and secured against reclosure. Disregard endangers lives. Withdraw 4 (or 6) leads for the super- visory circuit (fig. 10). Take note of the marks o n the tap changer head and o n the support plate. They must coincide i n the adjustment position (key of the diverter switch drive shaft has to match the triangle mark on the sup- port plate). Loosen the fixing screws of the support plate. Standard design: 4 screws M8 x 20/w.s. 13, fig. 10. Special design for installation into a bell-type tank: 5 studs M8 with nuts (w.s. 13), fig. 11 and 12. A ATTENTION: The nuts o f the studs located i n the red-marked area of the tap changer head must not b e loosened. Otherwise the tap changer may fall into the transformer tank and cause serious damage to parts of the tap changer and transformer. In both cases take care not to lose the spring washers. Now, carefully lift out the diverter switch (fig. 13) unit by using the lifting lugs. Place it on a flat and clean surface. 110/01001/0 9 Drain the diverter switch oil compart- ment completely.Flush it thoroughly with transformer oil and drain again until it is absolutely empty (fig.14). Remove the suction pipe (fig. 15) and thoroughly flush with transformer oil inside and outside. Then reinstall the suction pipe. To make sure that n o parts fall into the oil compartment until installation of the diverter switch unit, close the tap changer head with the cover using all cover screws M10/w.s.17. Fig. 14 Tap changer head open, inside view of the diverter switch oil compartment A ATTENTION: 1 — suction pipe U s e o n l y n e w transformer oil 2 — drive shaft for position indication when cleaning the diverter 3 — gearing for position indication switch oil compartment, the 4 — coupling for tap selector drive suction pipe and the diverter 5 — kerosene drain screw switch unit. Other liquids (e.g. 6 — oil compartment terminals organic solvents, cleaning petrol) are not suitable. The use of other cleaning agents may put at risk the trouble-free operation of tap changer and transformer. When having cleaned the insulating parts check that they are free of deposits and damage (e.g. creeping paths). Fig. 16 (Poles W, U), 1 7 (Pole V) Diverter switch unit 1 — support plate 2 — support cylinder 3 — spring energy accumulator 4 — diverter switch 10 110/01/01/0  On-load tap changer Motor drive On-load tap changer Motor drive rf = = Ir Tr 3 | Pimbleli-ese | i if =f,= iifsssle ke seg] | pbb bebloe| Ree] 1 1 1 3 I ade | 52897 , K21] k2] Ki ) K21C3 01 xaCIK2 Loto ===. Fig. 18a: from 01/1991 until 05/1994 Fig. 18b: since 06/1994 1 ~ column 1 1 — column Qi — motor protective switch 2 — column 2 2 — column 2 S15 — cam-operated contact K1,K2 — motor contactors K1, K2 — motor contactors S28 — safety switch K30 — time delay relay (release delayed), K3 — brake contactor signalling contact sefting: at 5,5 s: running time =1,0's, K21 — auxiliary contactor (manual operation) at2,75 s: running time = 0 , 5 s LS ~ transformer $80, S81 — monitoring contacts circuit-breaker $90, S91 — monitoring contacts Basic connection diagrams for the tap change supervisory circuit 31205 TS/31500 Diverter switch poles W , UandV: Column 1 (pole W, U), fig. 1 6 Column 2 (pole V), fig. 1 7 Preparatory cleaning Visually check the outside of the diverter switch unit. Clean the diverter switch unit by flushing it with new transformer oil. Thorough cleaning of the diverter switch unit will be carried out after removal of the contact shells and resistor shells. Moreover, the circuit as per fig. 18b i s in case of circuit as per fig. 18b: Further important inspection work on provided with a connection for tripping e.g. between terminals 1-6 and the diverter switch unit of column 2 the transformer circuit breakers. 2-5. (pole V) has to be performed accord- ing to our Inspection Instructions No. The signalling contacts are closed in ® operate the diverter switch with the 38 (sections 5, 6 and 7). the respective diverter switch position. operating key (see section 11.2) to If the diverter switches show different the other position, see fig. 20. Check of the signalling contacts positions, the tap change supervisory The signalling contacts, as stated for the supervisory circuit circuit immediately stops the motor under point 1, must now be open. Reed contacts are provided for the drive. The signalling contacts of each ® In this position, however, current supervisory control of the diverter column are connected to a 4-pole or continuity must be as follows: switch units of columns 1 and 2. 6-pole support plate, respectively, in case of circuit as per fig. 18a where they can be checked for con- Fig. 18 a: 1 N/O contact and 1 N/C between terminals 1-2, ductive continuity. contact. in case of circuit as per fig. 18b Fig. 18b: 2 Reed contacts connected Check a s follows: between terminals 3-6 and 4-5. in series and inserted into the @ test continuity to determine the @ Return the diverter switch to its corresponding control circuit of the closed condition of the signalling original position. The signalling associated motor drive. contacts (see fig. 19). contacts as stated under point 2 In case of circuit as per fig. 18a: must now be open. e.g. between terminals 3-4, or 110/01/010 11 5. INSPECTION OF A TWO- POLE DIVERTER SWITCH UNIT (POLES W, U), LAMINATED PAPER TYPE The diverter switch unit comprises two fully insulated diverter switches, each consisting of a spring energy accumulator, a contact system sector and two resistor shells. 5.1 Withdrawal position Before starting the inspection, take note of the switched position (= with- drawal position) of the diverter switches. Note the position of the trip lever of the spring energy accumulator (fig. 21), in order to regain this po- sition after reassembly of the diverter switch unit. 5.2 Measurement of the transition resistors (fig. 22). Measure the value of each transition resistor. T h e values are between 0.3 and 30 ohms. Measure between the main switching and the transition contacts on top and bottom of the contact shell (see fig. 22) starting from that side where the contacts are open. Before measuring on the opposite side set the diverter switch to the other positi- on by means of the operating key. Perform measurement as described above. Compare the measured values with the values given on the rating plate. A + 10% percent deviation is permis- sible. Perform a control measurement of the 2 x 1 0 0 kiloohms tie-in resistors at pole W as illustrated in fig. 22. 0,3...30Q 110/01/01/0 12 5.3 Separation of the diverter switches (pole W and pole U) Suspend the diverter switch to a lifting device by means of the lifting lugs at the support plate. Lift slightly to apply some tension to secure the unit against tilting. Loosen 8 screws M8 x 35/w.s. 13 on the laminated paper shells at the bottom of pole W (fig. 23). Each screw is provided with 1 lock nut, 1 washer and 3 dished washers. For every two screws one laminated shim is provided on the inside.Note their position for later reinstallation. Lift off diverter switch pole W. From now, all further steps of the in- spection are first carried out at pole W and then at pole U (fig. 24). 5.4 Cleaning the inside of the insulating shafts With older tap changer models the insulating shafts (1 supervisory con- trol and 2 diverter switch insulating shafts) have a tubular design (see fig. 25a). The inside of these tubular insulating shafts needs to be cleanded. To get access to the inside of these insulating shafts remove the top part of diverter switch pole W, : Z Ir Na = — ARN ~Lim A) 3% J Fig 25a: since 1979. Fig. 25b: since 1981 Designs of the diverter switch inslulating shaft 110/01/01/0 13 Proceed as follows: Punch-through the dowel pin on the insulating shaft for the tap change supervisory system (bottom), see fig. 26. Loosen, at each support bar (bottom), 2 screws M8 x 40/w.s. 13 with lock nuts and dished washers (see also fig. 29). Operate the spring energy accumu- lator to one side for clearance when removing or inserting screws. JAN ATTENTION: Strictly avoid dropping any parts into t h e diverter switch. Otherwise there i s the risk that the diverter switch blocks a n d the tap changer and transformer are damaged. Therefore, make s u r e t h a t t h e number of small parts i s complete when disassembling and reinstalling. Count them t o be sure. Clean the inside of the insulating — Place the support bars onto the shafts carefully with a suitable brush spring energy accumulator housing and flush it with transformer oil. Check A ATTENTION: so that the insulating shaft of the the inside visually. tap change supervisory system Check that the inner and outer can be inserted into the lower part Reassembly is carried out analogous- surfaces of the insulating shaft of t h e coupling. Make sure that the ly to removal. are absolutely clean and free triangle marks on the support plate Please observe: of damage (e.g. creeping (fig. 27) and on the spring energy paths). accumulator housing (fig. 28) When mounting the diverter Installation o f a damaged insu- switch insulating shaft t o t h e match properly. lating shaft can cause severe Insert screws and dished washers drive shaft, the shaft key must damage to the on-load tap point towards the eccentric. as shown in fig. 29 with a changer and the transformer. tightening torque of 22 Nm. 110/01/01/0 14 5.5 Work on diverter switch pole W 5.5.1 Setting the mid-position Before starting the following steps, the diverter switch has to be set to its mid- position where the transition resistors are closed. Unlock the spring energy accumula- tor and turn the drive shaft with the operating key until wind-up and cocking sledge have reached a stable position just about in the middle (fig. 30, 31, 32). 5.5.2 Removal of the contact shell Loosen the 6 hexagon socket screws M6 x 10/w.s. 4 for the transition resistor connection (fig. 33). Unlock and loosen 1 screw M8 x 25/ w.s. 13 on the left and on the right of the contact shell (fig. 34). Each screw has 1 washer and dished washer. Note correct installation position. Unlock and loosen 8 screws M6 x 20/ w.s. 10, (fig. 35). Take off the contact shell (fig. 36). 5.5.3 Removal of the arc chutes Withdraw the arch chutes to the front. On-load tap changer M Ill 350 D: see fig. 37. On-load tap changer M [ l l 500 D (old version) and M lll 600 D (fig. 38): The two outer arc chutes have split side walls and must be refitted in exactly their original position. 5.5.4 Cleaning the diverter switch Clean the diverter switch between Thoroughly clean the contact shell, all disassembling and reassembling the arc chutes and the movable contact contact shell. Proceed in the same system with a brush and clean way with the transition resistor shells transformer oil. The resistor shells later on. which will. be removed later on must also be cleaned. Take special care when cleaning the insulating parts. Rinse all parts carefully with transformer oil and dry with a rag. 110/01/010 5.5.5 Determination of contact wear The admissible wear of the diverter switch contacts is determined by two criteria: a) by the volume of the contact (see fig. 39). The max. admissible contact wear o n the individual f) 2Pa% contact is 4 mm. * *,x >. I T L U U R R YSCSTTCTeSe ey 55 5 %30! &35 x "o%e%s Po’ NAR a R R X X H I R I H KS C ( RR beseteleteletelolol! 50% 5555 2,CQ The contacts need to be replaced RRRR R x x 4% & 5 5 %5 5 bo 32 302 O T A a tL I I L KRIRRKS when this value has been reached or 0,S be! XS oC2 eo, TS is expected to be reached before the SS35C deeseeseteretels next inspection. CRXRNR thd a%"sta! oole’s%tets! S ER W1ET I ITITITIHII LITI I A A I F T T LLOLR b) by the kinematically correct tap osOo 2525 Co %®. RR change operations sequence (see oR o 5S pS 5 els, X 2% section 1.1) of main contact (A, B), ¥e%a%ata%! 0%0X Petsts main switching contact (a, b ) and QE transition contact (a1, b1). The correct switching sequence of the diverter switch can only be ensured, if the differences in contact wear bet- AN ween main switching and transition Ann contacts do not exceed certain limits. Unfavourable operating conditions may cause increased contact wear at the transition contacts. J A WARNING: Continued operation of the Fig. 39 diverter switch unit with greatly Max. admissible contact wear of differing contact layer thick- stationary and movable ontacts ness can lead to severe da- | X—y=4mm, mage of tap changer a n d condition when new: x = 8 + 0.3 m m transformer. x = 8 + 0. 3 mm y = 4 m m The max. permissible difference in thickness of contact layers between main switching and transition contacts KHW 524-2 is 2.5... 2.6 mm. If this difference has been reached or is expected to b e reached before the next inspection, the contacts must be replaced or matched to the other contact by interchanging or milling. Measure the thickness of the contact layers on the stationary and the movable main switching and transition contacts with a vernier gauge. Note the results. Determine the contact wear of each contact b y comparing the difference between the condition of a new contact and the measured value. 16 110/01/01/0 5.5.6 Attachment of the contact shell The reattachment of the contact shell is carried out step-by-step in the reverse order to its removal. The diverter switch must be set to its mid- position (see section 5.5.1). For the ease of installation insert a chucking wedge (see section 11.2) between the epoxy segment and the take-off con- tact carriers to hold back the movable contact system of the diverter switch and to compensate for its contact pressure (fig. 40, 41). Make sure that all arc chutes are seated properly. Each contact shell is fixed by: 8 screws M6 x 20/w.s.10, max. torque 5 Nm, lock tabs, 2 screws M8 x 25/w.s.13, max. torque 22 Nm (fig. 42). Each provided with 1 washer, 1 dis- hed washer and a lock tab. Do not yet insert the screws for the resistor leads. After having tightened the screws, withdraw the chucking wedge upwardly (fig. 43). 5.5.7 Detachment and reattachment of the resistor shell Loosen 1 hexagon sockket screw M6 x10/w.s.4 for the potential connec- tion beneath the slide contact (fig. 44). Unlock and loosen 2 screws M 8 x 25/ w.s. 13, fig. 45. Each screw has 1 washer and 1 dis- hed washer. Note correct installation position. Unlock and loosen 4 screws M6 x 20/ w.s. 10, fig. 46. Take off the resistor shell. Clean the resistor shell and the transition resistor (also refer to section 5.5.4). Reattach the resistor shell. Make sure that the resistor leads are properly seated in the contact shell. 110/01/01/0 17 Attachment: 4 screws M6 x 20/w.s.10, max. torque 5 Nm, lock tabs; 2 screws M8 x 25/w.s. 13, max. torque 22 Nm, each screw provided with 1 washer, 1 dished washer and lock tab. Potential connection: 1 hexagon socket screw M6 x 10/w.s. 4, max. torque 5 Nm, secure by centre punch. Proceed likewise with the other resistor shell. After reinstallation of t h e two resistor shells insert the screws of the resistor connections on the contact shell by using: 6 hexagon socket screws M 6 x 10/w.s. 4, max. torque 5 Nm. Secure by centre punch (fig. 47). 5.5.8 Locking-in the diverter switch After reassembly lock-in the spring energy accumulator in any operating position of the diverter switch. Insert a screw driver between wind-up and cocking sledge and turn the eccentric, using the operating key (fig. 48), until the pawl locks in (fig. 49, 50). Check the mechanical function by operating the diverter switch several times between the two positions. 5.6 Work on diverter switch pole U (fig. 51) 5.6.1 Setting the mid-position Unlock the spring energy accumulator as described in section 5.5.1 and turn the eccentric, using the flat end of the operating key, until the spring energy accumulator is in the mid-position (fig. 52, 53). 110/01/01/0 18 5.6.2 Further steps to be carried out as described for pole W - Detachment of contact shell (fig. 54, 55, 56) —- Removal of arc chutes (fig. 57) - Cleaning the diverter switch - Determination of contact wear - Attachment of the contact shell (fig. 58, 59, 60, 61) 110/01/01/0 19 —- Detachment and reattachment of the resistor shells (fig. 62, 63, 64) - Locking-in the diverter switch (fig. 65) Check the mechanical function by operating the diverter switch several times between the two positons. 5.7 Reassembly of the diverter switch unit Set the two diverter switches to the same position before reassembly (pole W: fig. 66, pole U: fig. 67). 20 110/01/01/0 Place the lower insulating shaft on the diverter switch pole U (fig. 68). The shaft key on top must point to the eccentric. Lift diverter switch pole W over pole U and engage the lower insulating shaft. Connect the two diverter switches by screws, i.e. the 3 laminated paper shells of pole W with the spring ener- g y accumulator of pole U. Attachment by 8 screws M8 x 35/w.s. 1 3 with lock nuts, max. torque 2 2 Nm, each screw provided with 1 washer and 3 dished washers. Place the laminated shims as shown in fig. 69. After reassembly carry out some test operations. Set the withdrawal posi- tion (see section 5.1). The diverter switch unit is now ready for installa- tion (fig. 70). Fig. 69 Attachment of the laminated paper shells of diverter switch pole W Parts: 056 452 spacer, laminated paper 056 514 lock tab 450 090 hex. head screw M 8 x 2 8 450 388 hex. head screw M 8 x 3 5 451 326 washer 452 357 dished washer 453 978 lock nut M 8 110/01/010 21 6. INSPECTION OF THE TWO- POLE DIVERTER SWITCH UNIT (POLE W, U) IN GFRP DESIGN The diverter switch unit comprises two fully insulated diverter switches, each consisting of a spring energy accumu- lator, a contact system sector and two resistor shells. 6.1 Withdrawal position Before starting with the inspection, note the present position of the diverter switch unit (= withdrawal position). Note the position of the trip lever of the spring energy accumulator (fig. 71), so that the diverter switch insert can be set to its original position when reassembling. 6.2 Measurement of the transition resistors (fig. 72) Measure the value of each transition resistor. The values are between 0.3 and 30 ohms. Perform measurement always at the open side of the diverter switch sector between the stationary main switching and transition contacts on the top and - at the bottom. Before measuring the other side, the diverter switch has to be switched to the opposite position by means of the operating key (see section 11.2). Measurement is then carried out as described above. Compare the measured values with the values given on the rating plate. A deviation of +10% is permissible. 0,3...30Q 0,3...30Q Perform a control measurement of the 2 x 100 kiloohms tie-in resistors at pole W as depicted in fig. 72. @ 0,3...30Q 0,3...30Q 22 11001010 6.3 Separating the diverter switch unit (pole W and pole U) Separate the diverter switch unit from A ATTENTION: the screw connection between the Visually check the surfaces of lower supporting cylinder and the support cylinder and insulating spring energy accumulator housing of shaft. Make sure that they are pole U. This screw connection is simi- absolutely clean and free of lar to the one between the upper damage (e.g creeping paths). supporting cylinder and pole W (see Installation o f adamaged section 6.4: 8 screws M8 x 20 with support cylinder o r insulating lock nuts and washers). shaft can cause severe damage t o the on-load tap changer and the transformer. 6.4 Removal of the upper supporting cylinder Before removing the upper supporting cylinder, dismount the link for the tap change supervisory control system (fig. 74) which is fixed to the cocking slide by 2 studs M 5 with lock nuts. The supporting cylinder i s screwed to the lugs of the spring energy accul- mulator housing. Loosen the 8 screws M8 x 20 (w.s. 13) with lock nuts and washers (fig. 75). A WARNING: Strictly avoid dropping any parts into the diverter switch unit. Otherwise there i s the risk that the diverter switch blocks and the tap changer and transformer are damaged. Therefore, make sure that the number of small parts i s com- plete when disassembling and reinstalling. Count them t o b e sure. Take off the supporting cylinder (fig. 76). Lift off the insulating shaft (fig. 77). Clean the supporting cylinder inside and outside with a brush and trans- former oil. Rinse with transformer oil and wipe dry with a rag. Clean the insulating shaft in the same way. 110/01/01/0 23 6.5 Work on diverter switch poles W a n d U 6.5.1 Setting the mid-position Before carrying out the next steps, set the diverter switch to the mid-position. For this purpose disengage the spring energy accumulator a n d turn t h e eccentric, using the flat end of the operating key, until the cocking and the wind-up sledge of the spring energy accumulator have reached a stable mid-position (fig. 78, 79). 6.5.2 Removal of the contact shell Loosen the 6 self-locking hexagon socket screws M6 x 10/w.s. 4 for resistor connection (fig. 80). Unlock and loosen one screw M8 x 25/w.s. 13, on the right and the left of the contact shell (fig. 81). Each screw has 1 washer and 1 dished washer. Note the correct installation position. Unlock a n d loosen 8 screws M 6 x 20/ w.s. 10, f i g. 82. Take off the contact shell (fig. 83). 6.5.3 Removal of the arc chutes Withdraw the arc chutes towards the front. On-load tap changer M Ill 350 D: see fig. 84. On-load tap changer M Ill 500 D (old version) and M Ill 600 D (fig. 85): The two outer arc chutes have split sidewalls and must be refitted in exactly their original position. 110/01/01/0 24 6.5.4 Cleaning of the diverter switch The contact shell, all arc chutes and the movable contact system have to be thoroughly cleaned with a brush and transformer oil. Likewise clean 2MN vw) the resistor shells when dismounting 02, NN them lateron. s e r 2 ANAAWANRANNRANUAARNY All insulating parts should be cleaned SS 51 with special care. Flush all parts with lNE Stl !. C1} HRN transformer oil and wipe them dry with arag. Clean the diverter switch after the contact shell has been dismounted and before it is installed again. N CCH NE P B SoOsSeAyA 2 R5S5K %] Proceed in the same way when dis- NE N Y T xr} mounting and reinstalling the resistor ANAT N A N N Y H shells. 6.5.5 Determination of contact wear The admissible contact wear on the diverter switch contacts is determined 5, [> », XDL R by two criteria: b> of BR 2 THEIR a) by the volume of the contact (see fig. 86). The max. admissible contact wear on the individual contact is 4 mm. The contact has to be replaced when this value has been reached or is expected to be reached before the next inspection. b) by the kinematically correct tap Fig. 86 change operation sequence (see Max. permissible contact wear of section 1.1) of main contact (A, B), stationary and movable contacts main switching contact (a, b) and ) X—y=4mm, transition contact (a1, b1). condition when new x = 8 + 0.3 mm The correct switching sequence of the x = 8 2 0. 3 m m y=24mm diverter switch can only be ensured, if the differences in contact wear bet- ween main switching and transition contacts do not exceed certain limits. Unfavourable operating conditions KHW 524-2 may cause increased contact wear at the transition contacts. The max. permissible difference in Measure the thickness of the contact thickness of contact layers between layers on the stationary and the main switching and transition contacts movable main switching and transition is 2.5... 2.6 mm. If this difference has contacts with a vernier gauge. Note A WARNING: been reached or is expected to be the results. Determine the contact Continued operation of the diverter reached before the next inspection, wear of each contact by comparing switch unit with greatly differing the contacts must be replaced or the difference between the condition contact layer thickness can lead to matched to the other contacts by of a new contact and the measured severe damage o f tap changer and interchanging or milling. value. transformer. 110/01/010 25 6.5.6 Attachment of the contact shell The reattachment of the contact shell is carried out step-by-step in the reverse order to its removal. For the ease of installation insert a chucking wedge between the epoxy segment and the take-off contact carrier to hold back the movable contact system of the diverter switch and to compensate for its contact pressure (fig. 87, 88). Make sure that all arc chutes are seated properly. Each contact shell is fixed by: 8 screws M 6 x 20/w.s. 10, max. torque 5 N m , lock tabs and 2 screws M8x25/ w.s 13, each provided with 1 washer, 1 dished washer and a lock tab, max. torque 22 Nm (fig. 89). Do not yet insert the screws for the resistor leads. After having tightened the screws, withdraw the chucking wedge upwardly (fig. 90). 6.5.7 Detachment and reattachment of t h e resistor shell Loosen 1 hexagon socket screw M6 x 10 (self-locking, w.s. 4) for the poten- tial connection beneath the slide con- tact (fig. 91). Unlock and loosen 2 screws M 8 x 25/ w.s. 13 (fig. 92). Each screw has 1 washer and 1 dished washer. Note correct installation position. Unlock and loosen 4 screws M6 x 20/ w.s. 10 (fig. 93). Take off the resistor shell (fig. 94). Clean the resistor shell and the tran- sition resistor (also refer to section 6.5.4). Reattach the resistor shell. Make sure that the resistor leads are properly seated in the contact shell. 26 110/01/01/0 Attachment: 4 screws M6 x 20/w.s. 10, max. torque 5 Nm, lock tabs. 2 screws M 8 x 25, w.s. 13, max. tor- que 22 Nm, each screw has 1 washer, 1 dished washer and lock tab. Potential connection: 1 hexagon socket screw M6 x 10 (self-locking, w.s. 4), max. torque 5 Nm. Proceed likewise with the other resis- tor shell. After reinstallation of the two resistor shells attach the screws of the resistor leads on the contact shell by using: 6 hexagon socket screws (w.s. 4, self- locking), max. torque 5 Nm (fig. 95). Please note: — Put the diverter switch insulating 6.5.8 Locking-in the diverter switch shaft onto the eccentric. The After reassembly lock-in the spring shaft key must point to the energy accumulator in any operating eccentric. position of the diverter switch. — Put the supporting cylinder onto Insert a screw driver between wind-up the spring accumulator housing. and cocking sledge and turn the Make sure that the triangle eccentric, using the flat end of the marks of the supporting plate operating key (fig. 96), until the pawl (fig. 97) and of the lug at the locks in. spring energy accumulator housing coincide (fig. 98), so Check the mechanical function by that the shaft for the tap change operating the diverter switch several supervisory system can be times between the two positions. inserted i n the bottom bearing. — Install the link for driving the tap change supervisory system at 6.6 Assembly of the diverter switch the cocking slide of the spring unit energy accumulator (fig. 99). Diverter switch pole W : Attachment by: 2 lock nuts M5/ w.s. 8, max. torque 5 Nm. Remount the supporting cylinder with supporting plate (reverse to removal, see section 6.3). Attachment: by 8 screws M8 x 20/ w.s.13, each provided with 2 washers and lock nut, max. torque 22 Nm. 110/01/010 27  Diverter switch pole U Place the lower insulating shaft on the eccentric. (fig. 100). Set the diverter switch pole W to the same position as pole U (fig. 101). Lift pole W over pole U and screw the lower supporting cylinder of pole W to the lugs provided at the spring energy accumulator housing of pole U. Attachment by: 8 screws M8 x 20/w.s. 13, each provided with 2 washers and lock nut, max. torque 22 Nm, Check that the resistor leads of diver- ter switch pole W (between contact shell and resistor shells) have sufficient clearance to the upper screen ring of the diverter switch insulating shaft. Switch the diverter switch unit re- peatedly in both directions by using - the operating key. Set to the withdrawal position (see section 6.1 and fig. 102). The diverter switch unit is now ready for installation. 7. REPLACEMENT OF DIVERTER SWITCH CONTACTS AND FLEXIBLE CONTACT LEADS 7.1 Diverter switch contacts The diverter switch includes 2 main switching contacts (a, b) and 2 transitions contacts ( a l , b1). Each switching and transition contact is Stationary contacts provided as movable and stationary (see fig. 103 and 104) contact. Each contact is divided in two contact tips. When replacing the Each contact tip is fixed by a hexagon contact tips for the stationary and the socket screw M6 x16/w.s. 4, max. movable contact system (each torque 9 Nm, secured by a centre contact tip is fixed by just one screw punch at the groove of the screw M6) please note in detail: head. 28 11001010 Movable contacts (see fig. 105, 106, 107) Each contact tip is fixed by a hexagon socket screw M6x16/w.s.10, 2 dished washers, max. torque 9 Nm, secured b y a lock tab. Furthermore, please note: On-load tap changer M ll1 350 D Before dismounting the movable con- tacts, loosen the flexible contact leads on top and bottom (see section 7.2). JAN NOTE: For through-currents of more than 200 A, tungsten-copper material i s used for the contact tips of the transition contacts (a1, b 1 MR part no. 009 859). These contact tips must not b e used for the switching contacts (a, b) because this would affect the continuous current carrying capacity of the diverter switch. The different contact tips are identi- fied by the following MR part numbers: contact 200 A a,b 0 5 1 783 0 5 1 783 0 1 7 355% al, bl 0 5 1 783 009 859 Note: " Only in case of fumace/electrolysis transformers Industrial transformers with high switching frequency (e.g. electric furnaces) are equipped with special contact tips. For replacement please enquire. On-load tap changers 7.2 Flexible contact leads Flexible contact leads provided with a M Ill 500 D (old version), M Ill 600 D protective hose have to b e replaced The flexible contact leads connect the main switching and transition contacts after 250,000 switching operations. Before dismounting the movable contacts, remove the flexible contact of the movable contact system with leads on top (see section 7.2). the slide contact of the tap changer take-off terminal. The flexible contact The different contact tips are identified leads are attached to the contact sys- by the following MR part numbers: tem by self-locking screw connections (fig. 108, 109). contact 500 A , 600 A Independent of the replacement of the diverter switch contacts, the flexible a,b 009 859 contact leads have to be replaced by n e w ones after 150,000 switching al, bi 009 8 5 9 operations. 110/01/010 29 Please note: On-load tap changer Méx 18L M6x 16 M Ill 3 5 0D (Bild 110) ey dl The flexible contact leads for the main l i switching and transitions contacts are joined at the connection point of the take-off terminal. a al bi b Two flexible contact leads each (on fr \) (f top and bottom), attached to the 093326 | f 4- Hd 1 ] 093 326 take-off ermineoys. 10, self-locking M6 x 18L M6 x 16 M6 x 28 M6 x 16 M6 x 18L nut and washer, max. torque 9 Nm. (7 \) ( ( Attachment to the main switching 012770 | f ( ] 012 801 contact (double contact braid) and LL transition contact: M6 x 18L MS x 22 M6 x 18L each by 1 screw M6 x 18L/w.s.10, ~ oon hm nut and washer, max. 012 801 (( (f ) 012 770 ’ 1] 4 flexible contact leads (in the M6 x 18L MS x 22 M6 x 18L middle) Attachment to the switching contact: N) (( each by 1 screw M6 x 18L/w.s. 10, - 093326 f 4- pl If J ] 093 326 with self-locking nut and washer, max. torque9 Nm. 9 Mox16L M6x16 M6x28 M 6x 16 M 6x 16L Attachment to the take-off terminal: Atac by 1 screw M5 v i a 8. with Fig. 110 Flexible contact leads for M Ill 350D self-locking nut and washer, max. C N 650.4 oben (schematic illustration) torque 5 Nm. : On-load tap changers M Ill 500 D (old version), M Ill 600 D (fig. 111) Two flexible contact leads for main switching and transition contact (on a ai | bi b top only); 083 325 { ll | 1 093 325 The flexible contact leads of the main = = nt = - switching contact and the correspon- M6x 16 M6x 16 M6 x 28 M6x 16 M6x 16 ding transition contact are joined at | the take-off terminal. Attachment to the main switching and transition contact: Fig. 111 Flexible contact leads for M i l l 500 D (old version), M Ill 600D each by 1 screw M6 x 16/w.s. 10, with (schematic illustration) self-locking nut and screw, max. torque 9 Nm. K I O04 unten Attachment to the take-off contact: Take notice of the triangle marks in 1 screw M6 x 25, w.s/10, self-locking the tap changer head (see section 3). nut and washer, max. torque 9 Nm. When placing the diverter switch unit it may be necessary to turn the insu- lation shaft of the diverter switch slightly until the coupling engages. 8. INSTALLATION OF THE Make sure that the marks on the DIVERTER SWITCH UNIT bearing plate of diverter switch unit and tap changer head match properly Take off the tap changer cover. (fig. 112). Lift the diverter switch insert overthe Attach the diverter switch unit with the open tap changer head and lower it fixing screws of the supporting plate. slowly and carefully into the oil compartment. 110/01/01/0 30 Standard design: ®@ Provisionally couple the column nearest to the bevel gear with the 4 screws M 8 x 20, w.s.13. A ATTENTION: motor drive. Special design for installation into a bell-type tank: 5 nuts M8/w.s.13. Make sure that the suction pi- Make sure that positions coincide p e has been vented completely. and that coupling is symmetrical Both types secured by spring The insulation capability of the (see section 10.3). washers, max. torque 2 2 Nm. tap changer to ground i s other- ® Move the coupled column by one Reinstall the position indication dial wise significantly impaired. step by means of the motor drive. (provide the shaft end with a clip). @ After the motor drive has stopped Connect the leads for the tap change make sure that it cannot b e started supervisory control. Pay attention to again by pressing the push button. In case of tap changers equipped with the lead colours. a stationary oil filter unit: put the oil ® Return the coupled column to its fitter unit into service a n d vent. original position by operating the Fill the oil conservator with new oil up motor drive manually. The ope- 9. FILLING WITH OIL to the original level. rating positions of the two columns are now identical again. ® Couple the second column with the first one. A ATTENTION: FAN NOTE: Make sure that their operating The diverter switch oil com- After oil filling, the transformer positions coincide and coupling is partment and the associated oil must remain deenergized for at symmetrical (see section 10.3). conservator must b e filled only least 1 hour. @ Press the push button of the motor with new mineral insulating oil drive to operate both columns by for transformers according to one step. Dismount the drive shaft IEC 296 (1982). The use of other between the two columns again. oil puts at risk the trouble-free operation of tap changer and Return the column, which is still 10. FURTHER CHECKS coupled to the motor drive, to its transformer. original position. W h e n t h e motor drive has stopped, make sure that A ATTENTION: it cannot be started again by Fill the diverter switch oil compartment actuating the push button. with new oil up to the level of the T h e transformer m u s t n o t b e supporting plate. Close the tap reconnected before the checks © Return the coupled column to the changer head by the cover and make according to sections 10.1... 10.4 same position of the uncoupled sure that the gasket fits properly; if have been carried out. column by turning the hand crank. necessary replace the gasket ring. Remount the drive shaft. When fixing the tap changer cover Make sure that the operating please note: positions coincide and that 10.1 Functional check of the tap Use 24 screws M10/w.s. 17, max. change supervisory control coupling is symmetrical (see tightening torque 34 Nm, secure by circuit section 10.3). spring washers. ®© Operate both columns by the Check the function of the tap change Open the stop valve between the supervisory circuit (= monitoring the motor drive into the adjustment protective relay and the oil conser- coincidence of positions at the diverter position of the tap changer. vator. Vent the tap changer head by switches of columns 1 and 2) in con- the bleeding valve located on the tap junction with the motor drive. changer cover (remove screw cap 10.2 Drive shafts Keep the motor drive ready for electric M30/w.s. 36, lift the valve tappet with operation. Couple the horizontal drive shaft to a screw driver). Vent the suction pipe (screw cap M16/w.s. 22, slotted Proceed a s follows: the upper gear unit and the bevel gear bleeder screw M6, max. tightening (6 screws M6/w.s. 10, max. torque 9 @® Motor drive, column 1 and column torque 2 Nm). N m , lock tabs). 2 must be in the same operating position. 110/01/01/0 31 Attach the horizontal drive shaft 10.4 Monitoring equipment between the tap changer heads of columns 1 and 2. A ATTENTION: 10.4.1 Tap change supervisory circuit Check both the horizontal and the After a response of the protecti- (also refer to section 4) vertical drive shaft, especially the ve relay, d o not reset until the coupling locations. If necessary, If there is a failure in the simultaneous tap changer a n d t h e motor drive grease the coupling bolts a n d O-rings operation between column 1 and co- have been checked. For this (e.g. with SHELL 6432). Adjust the lumn 2, the supervisory circuit en- p u r p o s e withdraw t h e diverter axial clearance to 3 m m. sures that the motor drive will be switch unit. Proceed i n detail stopped. according to our Operating In- In the case of special designs check struction N o. 5 9 f o r t h e protec- the bellows and the grease supply of Please note: tive relay RS 2001. the ball joints. The motor drive must be sure to stop Before returning to operation, Check the upper gear unit on the tap after a response of the supervisory make sure that the cause of the changer cover and the bevel gear control circuit. It must not b e oper- trouble has been corrected and (add grease, if necessary). ated, neither electrically n o t manu- that tap changer and transformer ally, a s long as the transformer is are free of damage. energized. 10.3 Functional check of motor drive Put the transformer into service again Reconnection o f t h e transformer and tap changer only after the cause of the failure has without prior checking is inad- been found and remedied. m i s s i b l e a n d c a n lead t o severe Check symmetrical coupling of the damage of tap changer and motor drive in relation to the tap transformer. changer. —— Please note: 10.4.2 Protective relay RS 2001 The diverter switches of columns 1 In case of a response of the protective In case of major faults with tap chan- and 2 should switch over a s simul- relay, the transformer must be ger or motor drive which cannot be taneously as possible (permissible immediately switched off by the circuit easily overcome on the spot and in difference is about 1 hand crank re- breakers. The functional testing of the case of a response of the protective volution of the motor drive). The lag of protective relay must, therefore, in- relay, please contact the authorized the motor drive must b e the same i n clude checking the proper function of M R representative, t h e transformer both directions (adjust, if necessary, the circuit breakers. manufacturer or directly see section 11.1). Make sure that the transformer can- Maschinenfabrik Reinhausen G m b H Perform test operations over the entire not be energized during the testing Technical Service setting range. procedure and that its ground Postfach 1 2 0 3 6 0 C h e c k coincidence o f position connections cannot b e removed. D-93025 Regensburg indications of the tap changer (tap Furthermore, be sure that any fire- Phone: +49-941-4090-0 changer heads of columns 1 and 2) extinguishing equipment that may be Fax: +49-941-4090-501 and the motor drive i n all operating triggered in connection with a res- Telex: 65881 positions. ponse of the protective relay, will not Cables: oltc reinhausen come into operation. Proceed a s follows: 10.5 Voltage regulator A ATTENTION: @® Close the circuit breakers with the (see Operating Instructions Misalignment between tap isolating switches open and the No. 66 for voltage regulator c h a n g e r a n d motor drive unit transformer terminals grounded. MK 20 or Operating Instruc- exists, if tap changer and motor tions No. 114 for MK30) ®@ Open the hood for access to the drive show different operating test buttons (3 screws M6, w.s. positions. If the tap changer is controlled by an 1 0 ). Press test button »OFF«. The automatic voltage regulator: Misalignment of coupling can circuit breakers must open. lead t o severe damage of tap Check the settings of voltage level, @ If the protective relay is in position changer and transformer, if sensitivity (bandwidth) and delay time »OFF«, it must be impossible to operation is continued. according to the Operating Instruc- close the circuit breakers. tions i n order to avoid unnecessary Check the electrical a n d the Check this. tap changer operations. mechanical end position limitation of @ Reset the protective relay to the motor drive (see Operating position »IN SERVICE« and lock Instructions No. 40 for motor drive the hood (3 screws M 6 , max. MA 7). torque 5 Nm). 32 110/01/01/0 11. APPENDIX Coupling of the tap changer and the motor drive unit (also refer to Operating Instructions 10 15 No. 40 for motor drive MA 7) I