On-load tap-changer VACUTAP® VV Maintenance Manual WA 241/05 PDF

www.reinhausen.com On-load tap-changer VACUTAP® VV Maintenance Manual WA 241/05  NOTE The product may have been modified after this document went to press. We expressly reserve the right to make changes to the technical...

www.reinhausen.com On-load tap-changer VACUTAP® VV Maintenance Manual WA 241/05  NOTE The product may have been modified after this document went to press. We expressly reserve the right to make changes to the technical data, the design or the scope of delivery. In general, the information provided and the arrangements agreed to during processing of the relevant offers and orders are binding.  Table of contents Table of contents 1 Safety...................................................................................................................................... 5 1.1 Safety instructions.................................................................................................................... 5 1.2 Specific safety instructions....................................................................................................... 5 2 Safety regulations.................................................................................................................... 6 3 Design/Types........................................................................................................................... 7 3.1 On-load tap-changer type designation..................................................................................... 7 3.2 Function principle of the on-load tap-changer.......................................................................... 8 3.3 Assemblies and subassemblies of the on-load tap-changer – valid for deliveries up to  July 2006.................................................................................................................................. 9 3.4 Assemblies and subassemblies of the on-load tap-changer – valid for deliveries as of  July 2006.................................................................................................................................. 10 3.5 Monitoring during operation...................................................................................................... 11 3.6 Maintenance intervals............................................................................................................... 12 3.7 Scope of maintenance.............................................................................................................. 13 3.8 Measuring DC resistance on transformer................................................................................. 14 4 Preparatory tasks.................................................................................................................... 15 4.1 Auxiliary equipment.................................................................................................................. 15 4.2 Safety precautions.................................................................................................................... 16 4.3 Operating position.................................................................................................................... 17 5 Removing the on-load tap-changer insert............................................................................... 18 5.1 Lowering the oil level................................................................................................................ 18 5.2 Uncoupling the horizontal drive shaft....................................................................................... 20 5.3 Removing the on-load tap-changer cover................................................................................ 20 5.4 Checking the index mark of the adjustment position................................................................ 20 5.5 Pumping off the oil.................................................................................................................... 20 5.6 Unscrewing screw coupling on design type with suction pipe.................................................. 21 5.7 Detaching the gearing of the on-load tap-changer insert......................................................... 21 5.8 Lifting out the gearing............................................................................................................... 22 5.9 Lifting out the on-load tap-changer insert................................................................................. 23 6 Cleaning and inspection work.................................................................................................. 25 6.1 Cleaning the oil compartment................................................................................................... 25 6.2 Inspecting the oil compartment................................................................................................. 25 6.2.1 Fixed contacts............................................................................................................. 25 6.2.2 Current take-off ring.................................................................................................... 25 6.2.3 Temporary covering of on-load tap-changer oil compartment..................................... 25 6.3 Cleaning the on-load tap-changer insert.................................................................................. 25 6.4 Inspecting the on-load tap-changer insert................................................................................ 25 6.5 Adjusting the contact stroke of the vacuum interrupter............................................................ 26 6.5.1 Checking the guide rollers and control rollers............................................................. 26 6.5.2 Checking the transition resistors................................................................................. 26 6.6 Replacement of switching elements......................................................................................... 26 6.7 Replacement of energy accumulator springs – only valid for deliveries up to July 2006.......... 26 7 Inserting the on-load tap-changer insert.................................................................................. 27 Wartungsanleitung WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. 241/05 EN ©Maschinenfabrik Reinhausen GmbH 2010 3  Table of contents 8 Required oil fill......................................................................................................................... 31 9 Further checks......................................................................................................................... 32 9.1 Drive shafts............................................................................................................................... 32 9.2 Function check of the motor-drive unit and on-load tap-changer............................................. 32 9.3 RS 2001 protective relay (see operating instructions no. 59)................................................... 33 10 Appendix.................................................................................................................................. 34 10.1 Coupling on-load tap-changer and motor-drive unit................................................................. 34 10.2 Adjustment plans...................................................................................................................... 36 10.3 On-load tap-changer VACUTAP® VV, adjustment plan for design types without change-over selector..................................................................................................................................... 36 10.4 On-load tap-changer VACUTAP® VV – adjustment plan for design types without change-over selector (899027)...................................................................................................................... 37 10.5 On-load tap-changer VACUTAP® VV – adjustment plan for design types with change-over  selector (899026)...................................................................................................................... 38 10.6 On-load tap-changer VACUTAP® VV – tap-changer supervisory control device (733469)...... 39 10.7 On-load tap-changer VACUTAP® VV – mounting rod (726415).............................................. 40 10.8 On-load tap-changer VACUTAP® VV – bracket (726416)........................................................ 41 10.9 On-load tap-changer VACUTAP® VV – socket wrench for gearing (726417).......................... 42 10.10 On-load tap-changer VACUTAP® VV – tools for installation and maintenance (726418)........ 43 10.11 Lifting device for mounting on transformer cover (898853)...................................................... 44 10.12 Lifting device for mounting on on-load tap-changer head (898854)......................................... 45 10.13 On-load tap-changer VACUTAP® VV – withdrawing and inserting the switching column,  mounting drawing (899765)...................................................................................................... 46 Wartungsanleitung WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 4 241/05 EN  1 Safety 1 Safety 1.1 Safety instructions 1.2 Specific safety instructions The following safety instructions relating to the operation Special safety labels are used to warn of specific haz- of the VACUTAP® VV are used in this document. ards, such as electric shock: These instructions must always be observed. DANGER! DANGER! Refers to an imminent danger that will result in death or severe Danger of electric shock! injury if not avoided. Refers to an imminent danger due to electricity that will result in death or severe injury if not avoided. WARNING! The following specific safety instructions are used in this Refers to a potentially dangerous document: situation that may result in death or severe injury if not avoided. CAUTION! Refers to a potentially dangerous Risk of electric Danger of Fire hazard! situation shock! tipping! that may result in slight injury or material damage if not avoided. ATTENTION! Refers to a potentially harmful sit- uation that may result in damage of the product itself or of adjacent objects if not avoided. NOTE! Contains important information and special notes. Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 5  2 Safety regulations 2 Safety regulations In order to avoid accidents, malfunctions and damages Observe the characteristic data! as well as undesired effects on the environment, the The service life of the device can be reduced by un- party responsible for transportation and installation, suitable ambient conditions and incorrect mounting. operation and maintenance as well as for the disposal of Ensure compliance with the specified operating the product or parts of the product must ensure the conditions, installation site requirements and mainte- following: nance specifications. Ensure you have the devices and protective equip- Always observe all warning and hazard notices. ment required! Failure to follow the safety instructions may lead to Make sure that the devices and precautions required accidents and severe personal injury to you or your for safe work and the personal protective equipment colleagues. required for certain jobs are available and put to use. Read the operating instructions before commission- Observe the specified maintenance cycles! ing the equipment! Ensure that only replacement parts, lubricants and Read the operating instructions before switching on auxiliary materials which are authorized by the the VACUTAP® VV. As operator, you are responsible manufacturer are used. for ensuring that all personnel of the device have fully understood the operating and safety instruc- tions. Train your staff! Train your staff in regard to the general and special safety instructions and accident prevention regula- tions both prior to commencing activities with the product as well as regularly thereafter and following any special situations. Only allow suitably qualified personnel to work with the VACUTAP® VV! The VACUTAP® VV is exclusively designed for use in electrical power technology systems and facilities in which trained specialists perform the required work. Specialists are those persons who are familiar with the setup, installation, commissioning and oper- ation of such products. Make sure that all information is available to the staff! Ensure that regulations and operating instructions for safe working as well as the relevant instructions for staff procedures in the case of accidents and fires can be read at all times and are displayed in the work- place where applicable. Do not make any changes in the device! Do not make any changes in the device without con- sulting with Maschinenfabrik Reinhausen. Inappropri- ate changes can lead to personal injury, material damage and operational faults. Maschinenfabrik Reinhausen does not accept liability for damage from unauthorized or inappropriate changes to the device. Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 6 241/05 EN  3 Design/Types 3 Design/Types 3.1 On-load tap-changer type designation Each on-load tap-changer type is available in a variety of On-load tap-changer Laststufenschalter versions to accommodate various different max. rated VV III 400 -- 76 -- 10 19 1 W through-currents or with insulation between the phases and to ground according to Um and the basic connection diagram. For this reason, the on-load tap-changer designation is Typ Type made in accordance with the above characteristics, BasicGconnection rundschaltdiagram bild hence ensuring an unmistakable and non-interchange- able on-load tap-changer designation. Polzahl Number of poles Highest Höchstevoltage Spannuforng The designation of the basic connection diagram con- Max. M ax. rated Bemessungs- through-current equipment für BetriebU sm in kV m ittel D urchgangs- in A Um in kV tained therein illustrates the on-load tap-changer’s con- strom in A tact circle pitch, the number of operating positions, the Neutral point connection Sternpunktschaltung Y Y number of mid-positions, and the type of change-over selector. Dreieckschaltung oder Delta connection Anordnung im or winding arrangement Example in Figure 1. Wicklungszug Basic connection diagram 10 19 1 W, i.e. contact circle BasicGrundschaltbild connection diagram pitch of 10, 19 operating positions, including 1 mid-posi- 10 19 1 W tion, use of the change-over selector as reversing change-over selector. Contact circle pitch Kontaktkreisteilung Mid-position(s) Mittelstellungen(en) Change-over selector Vorwähler 0 1 10 Max.max. operating 3 G W 12 positions Betriebsstellungen Coarse tap Grobstufen- Reversing Wender- selector schaltung change-over schaltung connection selector connection without change-over with change-over ohne Vorwähler mit Vorwähler selector selector 1 0 19 1 2 23 Figure Bild 1 1 Designation code Bezeichnung von of on-load tap-changer design Laststufenschalterausführung 1 and basic und connection diagram Grundschaltbild Figure 1 Designation of on-load tap-changer design and basic connection diagram Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 7  3 Design/Types 3.2 Function principle of the on-load tap-changer The on-load tap-changer VACUTAP® VV functions both On-load tap-changers serve to adjust the desired tap of as a diverter switch and a tap selector. a tap winding under load. If required, the on-load tap-changer is equipped with a During tap-change operations from the current-carrying change-over selector. Change-over selector operations tap to the next, one tapping step of the tap winding is are performed prior to tap-change operations. briefly shunted out with an ohmic resistor to maintain As an option, the on-load tap-changer is also supplied diverter switch operation without current interruptions. with an oil suction pipe. Figure 2 Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 8 241/05 EN  3 Design/Types 3.3 Assemblies and subassemblies of the on-load tap-changer – valid for deliveries up to July 2006 On-load tap-changer head Oil compartment On-load tap-changer insert Gear unit Switching element only with 145 kV 11 On-load tap-changer head – bot- On-load tap- not present tom part 12 On-load tap-changer head – top in case of changer insert neutral point part connection 13 On-load tap-changer head – cover 14 Top gear unit with drive shaft Change-over selector 14a 15 M12 ground connection not present 16 Inspection window for tap position indicator in case of neutral point 21 Gear unit supporting plate connection 22 Cogwheel with coupling 23 Geneva wheel 24 Geneva gearing 25 Cam disc E1 Bleeding device for on-load tap-changer E2 Bleeding device for the transformer space under- On-load tap- neath the head outside of the oil compartment changer head 31 Pipe connection E2 (optional) Transition resistor 32 Pipe connection R for protective relay 33 Pipe connection S 34 Pipe connection Q (optional) 41 Take-off contact 42 Fine tap selector connection contact 43 Oil compartment bottom with Kerosene drain plug 43a 44 On-load tap-changer – oil compartment 51 Change-over selector tube 52 Change-over selector connection contact.+. 53 Change-over selector connection contact.0. Gear unit Oil compartment 54 Change-over selector connection contact.-. 61 Switching element 62 STC contacts 63 TTS contacts 64 MTS contacts 65 Vacuum interrupter 71 Transition resistor Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 9  3 Design/Types 3.4 Assemblies and subassemblies of the on-load tap-changer – valid for deliveries as of July 2006 On-load tap-changer head Oil compartment On-load tap-changer insert Gear unit Switching element 11 On-load tap-changer  only with 145 kV head – bottom part 12 On-load tap-changer  head – top part 13 On-load tap-changer  head – cover On-load tap- 14 Top gear unit with drive  not present shaft 14a in case of changer insert 15 M12 ground connection neutral point connection 16 Inspection window for tap position indicator 21 Gear unit supporting plate Change-over selector 22 Cogwheel with coupling 23 Geneva wheel not present in case of 24 Geneva gearing - neutral point 25 Cam disc connection E1 Bleeding device for on-load tap-changer E2 Bleeding device for transformer space underneath the head outside of the oil compartment 31 Pipe connection E2 (optional) On-load tap-changer 32 Pipe connection R for protective relay 33 Pipe connection S head 34 Pipe connection Q (optional) Transition resistor 41 Take-off contact 42 Fine tap selector connection contact 43 Oil compartment bottom with Kerosene drain plug 43a 44 On-load tap-changer – oil compartment 51 Change-over selector tube 52 Change-over selector connection contact.+. 53 Change-over selector connection Gear unit contact.0. 54 Change-over selector connection Oil compartment contact.-. 61 Switching element 62 STC contacts 63 TTS contacts 64 MTS contacts 65 Vacuum interrupter 71 Transition resistor Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 10 241/05 EN  3 Design/Types 3.5 Monitoring during operation Pay particular attention to the following: Oil impermeability of the sealed areas of the on-load tap-changer head, protective relay, and connected WARNING! pipes, sealings of the protective housing of the motor-drive Danger of death and severe unit, injury. Danger of death and severe injury correct functioning of the installed electrical heater in from explosive gases under the the protective housing of the motor-drive unit, on-load tap-changer cover, in the perfect condition of the silica gel breather for the on- pipework system, in the oil con- load tap-changer oil conservator, servator or at the dehydrating breather opening. function test of the protective relay in accordance with Ensure that there are no naked respective operating instructions. flames, hot surfaces or sparks The insulating oils in the transformer are to be monitored (e.g. caused by static charging) in by the operator (see also section 3.6). the immediate surroundings and that they cannot arise. The oil quality of the on-load tap-changer oil should be checked at regular intervals: For on-load tap-changers used on the neutral point of windings (class 1 according to IEC 60214-1): every NOTE! 5 years Damage to the on-load tap- For on-load tap-changers used at points other than changer due to insufficient oil in the neutral point of windings (class 2 according to the oil conservator of the on-load IEC 60214-1): every 2 years. tap-changer. Operation of the on-load tap- changer with too little oil in the on- load tap-changer's oil conservator may cause damage to the on-load tap-changer. Make sure that the contact which signals instances when levels falls below the minimum oil level in the on-load tap-changer's oil conser- vator was looped through to the tripping circuit of the circuit breaker and that the circuit breaker will immediately de-ener- gize the transformer when the oil has fallen below this minimum oil level in the oil conservator. Monitoring the on-load tap-changer and motor-drive unit is limited to occasional visual checks of on-load tap- changer head, protective relay and motor-drive unit. For efficiency reasons these visual checks can be combined with the usual control inspections on the transformer. Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 11  3 Design/Types 3.6 Maintenance intervals Maintenance intervals valid for deliveries until July 2006: Maintenance must be scheduled after every 150,000 tap-change operations. NOTE! The switching elements of the on-load tap-changer insert have to be replaced after every 450,000 tap- The tap-changing equipment must change operations. be maintained at regular intervals The on-load tap-changer insert and gearing mecha- to maintain a high level of opera- nism have to be replaced after every 900,000 tap- tional safety. The maintenance change operations. can be carried out by qualified and The change-over selector of the on-load tap-changer MR-trained personnel usually has to be inspected after 2,100,000 tap-change oper- within one day, provided it is well ations (counter reading of the motor-drive unit). prepared and organized. We generally recommend having maintenance carried out by our Maintenance intervals valid for deliveries as of Technical Service. July 2006: This guarantees professional per- Maintenance must be scheduled after every 300,000 formance of the maintenance work tap-change operations. and ensures the updating of spe- The switching elements of the on-load tap-changer cific components to the latest insert have to be replaced after every 600,000 tap- operational state. change operations. If the maintenance is not carried The on-load tap-changer insert and gearing mecha- out by MR personnel, we recom- nism have to be replaced after every 1,200,000 tap- mend that you request the change operations. replacement parts required for the The change-over selector of the on-load tap-changer maintenance preparation (please has to be inspected after 2,100,000 tap-change oper- quote the on-load tap-changer ations (counter reading of the motor-drive unit). serial number and the number of tap-change operations). ATTENTION! Monitoring of the on-load tap-changer oil – the dielectric Damage to the on-load tap- strength is the decisive criteria – should be combined changer and transformer! with the usual inspection of the transformer oil. Disregard of the maintenance When replacing the breather system (silica gel) of the intervals puts at a risk the trouble- on-load tap-changer oil conservator, be sure to test the free operation of on-load tap- dielectric strength of the on-load tap-changer oil as a changer and transformer. precautionary measure. The insulating oils in the transformer and the breather The temperature of the on-load tap-changer oil should systems are to be monitored by the operator in accor- be logged during sampling. The temperature of the on- dance with the appropriate rules and regulations. load tap-changer oil should be recorded when establish- If the maintenance is not carried out by MR personnel, ing the dielectric strength (Ud) and water content (H2O). we request a report to supplement our maintenance The limit values specified in Table 1 are valid for oil tem- files. peratures of 20 °C ± 5 °C. Ud (kV/2.5 mm) H2O (ppm) During operation 30 (minimum) 30 (maximum) Table 1 Limit values for on-load tap-changer oil (dielectric strength Ud measured in accor- dance with IEC 60156) Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 12 241/05 EN  3 Design/Types 3.7 Scope of maintenance The maintenance work involves the following tasks: DANGER! Withdrawing and reinserting the on-load tap-changer Risk of injury or death! insert. The maintenance work must only Cleaning the on-load tap-changer oil compartment be carried out by qualified, skilled and on-load tap-changer insert. Be sure to clean the personnel. on-load tap-changer oil conservator during on-load All maintenance instructions must tap-changer maintenance. be strictly observed. Check the on-load tap-changer oil. Be sure to immediately notify MR of any damages noted during the Check the on-load tap-changer oil compartment and on-load tap-changer mainte- on-load tap-changer insert. nance work. If damage is found, Check and adjustment of the vacuum interrupter the on-load tap-changer must not stroke. be started up. Measure the transition resistors. Any alterations or modifications to Check the protective relay, drive shaft and motor- the on-load tap-changer equip- drive unit. ment may only be carried out fol- lowing instructions from MR. Be sure to limit exposure of the on-load tap-changer Improper or incomplete execution insert and oil compartment interior to atmospheric of the maintenance work may humidity to no more than ten hours. jeopardize the trouble-free opera- Swift performance of all related works is of the essence, tion of the on-load tap-changer as are cleanliness and carefulness. and transformer, which may lead to serious injuries or death. Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 13  3 Design/Types 3.8 Measuring DC resistance on transformer Note the measurement scenarios listed below and the associated maximum measured currents when measur- ing DC resistance on the transformer. DC resistance measurement in various DC resistance measurement in various on-load tap-changer operating posi- on-load tap-changer operating posi- tions without interrupting measured tions interrupting measured current current when changing operating when changing operating position (the position measured current must be 0 A when changing operating position) Diverter switch oil compartment empty max. 10 A DC* max. 50 A DC* Diverter switch oil compartment filled max. 50 A DC* max. 50 A DC* with insulating oil * The measured DC current is normally restricted to 10 % of the rated current of the measured transformer winding in order to prevent the winding from heating excessively. Table 2 Maximum permitted measured currents when measuring DC resistance on transformer Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 14 241/05 EN  4 Preparatory tasks 4 Preparatory tasks 4.1 Auxiliary equipment The required withdrawal height depends on the design of The following auxiliary equipment is required for carrying the on-load tap-changer. The withdrawal height (see fig. out maintenance work: below) corresponds to the clearance between the cover flange and the lifting device of the on-load tap-changer Clean and empty barrels plus new or treated transformer insert, while the mounting rod is inserted. oil for cleaning purposes and for performing an oil change, if necessary. Additional slings, which may be necessary for affixing the on-load tap-changer insert, have to be considered VV III-145 kV approx. 325 liters separately. VV III-76 kV approx. 265 liters On-load tap-changer VV III VV I VV III-40 kV approx. 240 liters Rated voltage UM 40 and 76 kV 76 kV VV I-145 kV approx. 120 liters Withdrawal height 1910 mm 920 mm VV I-76 kV approx. 100 liters Mounting rod length 1937 mm Oil pump for performing an oil change Rated voltage UM 145 kV 145 kV Highly-absorbent, lint-free cleaning rags Withdrawal height 2310 mm 1070 mm Working table Mounting rod length 2327 mm Lifting device: Crane or MR lifting device (refer to appendix,) weight Table 3 of the on-load tap-changer insert: max. 50 kg Maintenance tools (refer to appendix, section 10.10) Spare parts Be sure to contact the Technical Service department of MR for spare parts in good time before your scheduled maintenance date, indicating the serial number and cur- rent number of tap-change operations. NOTE! Locking pins/screws, gaskets (i.e.on-load tap-changer cover O- ring) etc. cannot be used more than once and have to be replaced after being disassembled. ATTENTION! Damage to the on-load tap- changer and transformer! Use only original MR spare parts. Spare parts of different origin may jeopardize the trouble-free opera- tion of the on-load tap-changer and transformer. Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 15  4 Preparatory tasks 4.2 Safety precautions DANGER! Risk of injury or death! Make sure that the following safety precautions have been car- ried out by the operator of the plant: The transformer is disconnected on all sides and all poles and is Withdrawal secured against reconnection to height the system. All terminals must be visibly short-circuited and grounded (including all star point bushings). Demarcate the working area. Do not start the maintenance work until completion of the above safety measures. Disregarding these safety measures may lead to serious injuries or death. Figure 3 Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 16 241/05 EN  4 Preparatory tasks 4.3 Operating position To withdraw the on-load tap-changer insert, it must be in the adjustment position. The adjustment position is indi- cated by the arrow on the tap position indicator disc of the motor-drive unit (see fig. below). Write down the current operating position of the on-load tap-changer. Figure 4 ATTENTION! Damage to the on-load tap- changer and motor-drive unit! Never operate the motor-drive unit while the on-load tap-changer is not coupled! As a precautionary measure, block the motor-drive unit for elec- trical operation by tripping the motor protective switch. Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 17  5 Removing the on-load tap-changer insert 5 Removing the on-load tap-changer insert 5.1 Lowering the oil level WARNING! NOTE! If the on-load tap-changer does Danger of death and severe not have an oil suction pipe, use a injury. hose or plastic pipe to extract the Danger of death and severe injury oil. from explosive gases under the on-load tap-changer cover, in the pipework system. De-energize all auxiliary circuits (e.g. tap-change supervisory con- trol, pressure relief valve, pres- sure-operated relays) before ATTENTION! removing the on-load tap-changer cover. Damages to the insulating mate- Do not operate any electric rial! devices (e.g. impact wrench, risk Take precautions to avoid scratch- of sparks) during the work. ing the insulating material. Only use conductive and grounded hoses, pipes and pump equipment that are approved for flammable liquids. 1) De-energize all auxiliary circuits (e.g. tap-change su- pervisory control, pressure relief valve, pressure-op- erated relays). 2) If the stop-cock (slide valve) between the oil conser- vator and diverter switch oil compartment is open, open the air-vent valve on the on-load tap-changer head by removing M30/wrench 36 screw cap and lift- ing valve tappet with a screwdriver (see no. 5 in Fig- ure 5). 3) Drain off the gas from under the on-load tap-changer cover. Ensure sufficient fresh air (e.g. in transformer cells and work tents). 4) Once the gas has been drained off and the oil is flow- ing out of the air-vent valve, close this valve and close the stop-cock between the oil conservator and divert- er switch oil compartment. 5) Place a bucket at the drain valve to catch the drained oil. Open air-vent valve again and drain off around 5– 10 liters of oil via the drain pipe until the area under the on-load tap-changer cover is free of oil. Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 18 241/05 EN  5 Removing the on-load tap-changer insert ATTENTION! Damage to the on-load tap- changer and motor-drive unit! The switching oil of the on-load tap-changer must be treated as a flammable liquid at all times. Therefore, strictly avoid open fire. Use only pumping equipment approved for flammable liquids. Never allow parts to fall into the oil compartment. Otherwise there is a risk of the on- load tap-changer blocking. This may damage the on-load tap- changer and transformer. Therefore check the number of small parts when disassembling and reassembling to ensure they are identical. 1 2 1 - Guard plate for horizontal drive shaft 2 - Gear unit 3 - On-load tap-changer cover 4 - Inspection window cover 5 - Air-vent valve 7 6 - Pipe connection for RS 2001 protective relay 7 - Pipe connection with vent screw 4 6 5 3 Figure 5 Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 19  5 Removing the on-load tap-changer insert 5.2 Uncoupling the horizontal drive shaft 1) Unfasten the hose clamps fastened to the guard plate Plastic pipe, outer diameter: max. 30 mm of the horizontal drive shaft. Sectional plane A-A 2) Remove the guard plate. Min. length = h + 50 mm 3) Unfasten all 4 M6/wrench 10 screws at the coupling bracket for the upper part of the gear unit, always carefully watching out for the coupling bolt and screws. 4) Remove the coupling part at the bevel gear from the square tube to allow complete removal of the horizon- tal drive shaft. 5.3 Removing the on-load tap-changer cover h (see related dimensional drawing) Unfasten the 24 M10x35/wrench 17 screws, carefully watching out for the 24 locking washers and the on-load tap-changer head cover gasket. 5.4 Checking the index mark of the adjustment position See appendix, 10.2 adjustment plans; for design type with tap-change supervisory control also see drawing 733469. 5.5 Pumping off the oil If design type has an oil suction pipe, the oil can be pumped off via pipe connection "S“. If design type does not have an oil suction pipe, it is pumped off via a plastic pipe (see Figure 6). Figure 6 Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 20 241/05 EN  5 Removing the on-load tap-changer insert 5.6 Unscrewing screw coupling on design type with suction pipe 1) Unscrew the screw coupling of the R3/4" suction tube (wrench 27, wrench 39). 2) Handle the gasket with care. 1 Figure 8 Design type up until July 2006 1 Figure 7 5.7 Detaching the gearing of the on-load tap- changer insert The gearing is fastened by means of 4 M8 screws. When unfastening these screws, use a socket wrench (wrench Figure 8a Design type as of July 2006 13, minimum length 15 cm) to reach the screws (see Fig- ure 8 and figure 8a). NOTE! The retaining brackets of the gear- ing have been riveted since April 2001. If the retaining brackets are not riv- eted, they must be removed before lifting out the gear unit and stored in a safe place. Take care to avoid parts falling into the oil compartment. Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 21  5 Removing the on-load tap-changer insert 5.8 Lifting out the gearing Pivot the gearing towards the driving toothed wheel (see. no. 1 in Figure 8 and Figure 8a) while lifting it up. When lifting out the gearing, the switching elements may move away from the current take-off rings and the posi- tion of the column in the oil compartment may then no longer be perfectly vertical. The gearing must be removed by hand, see Figure 9 and Figure 10. Figure 9 Lifting out the gearing with riveted retaining brackets Figure 10 Lifting out the gearing if retaining brackets are not riveted Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 22 241/05 EN  5 Removing the on-load tap-changer insert 5.9 Lifting out the on-load tap-changer insert The oil suction pipe must first be removed if one is fitted. ATTENTION! Damage to the on-load tap- Pulling oil suction pipe up and out changer! The on-load tap-changer insert may only be lifted out as described below. 4) Using the T handle, gently pre-stress the mounting rod in a clockwise direction and, using an appropriate lifting device, carefully lift out the on-load tap-changer insert 5 to 10 mm max. (Figure 13). Pre-stressing the mounting rod will cause the insert to pivot out from the center as soon as the insert leaves the guiding mechanism in the bottom bearing. 5) The contacts of the bottom phase will be exposed in the process. Remove the T-handle from the mounting rod and keep on carefully pulling the on-load tap- changer insert out from the oil compartment. Take care not to damage the contacts, control rollers, and screening rings. Figure 11 Special comment on on-load tap-changer design types featuring a change-over selector: Using a M8x16 hexagon head screw, fasten the lifting The process of lifting out the on-load tap-changer insert bracket (maintenance tool) to the coupling flange of the is simplified by turning it approx. 45 degrees while lifting on-load tap-changer insert (Figure 12 and drawing it (see Figure 14). This creates more clearance between 899765 in the appendix). the movable contacts and the change-over selector Use a mounting rod for withdrawing the on-load tap- lever. changer insert. The required rod length can be taken On-load tap-changer design types without a change- from Table 2. over selector do not require such a 45 degree rotation. The following steps are needed to pull out the on-load tap-changer insert: Mounting rod 1) Insert the mounting rod through the on-load tap- changer insert and push it all the way to the bottom of the oil compartment. 2) Now turn the mounting rod until the guide pin at the bottom end of the mounting rod engages in the bot- tom bearing. The bottom bearing features two guide notches. 3) The triangular mark of the mounting rod must be aligned with the switching elements. If not, lift up the mounting rod, turn it 180 degrees and put it in again. The guide pin is not properly engaged if the mounting Lifting bracket rod can still be freely rotated! Figure 12 Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 23  5 Removing the on-load tap-changer insert 5 to 10 mm T-handle Figure 13 45° Figure 14 Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 24 241/05 EN  6 Cleaning and inspection work 6 Cleaning and inspection work For cleaning purposes you will need a small amount of 6.2 Inspecting the oil compartment transformer oil and rags. The rags should be made of a lint-free cotton material. Be sure to keep a camera handy 6.2.1 Fixed contacts to document your findings, if required. All fixed contacts should be inspected individually, using a lamp and mirror. The fixed contacts should be silvery mat in appearance. Special attention must be paid to ATTENTION! leakage lines on the surface of the oil compartment. Malfunction of on-load tap- In case of uncertainty please contact the MR Technical changer and transformer! Service department for advice. Photos will be very help- The oil compartment and on-load ful in such cases. tap-changer insert may only be 6.2.2 Current take-off ring cleaned with transformer oil. Other cleaning agents (e.g. The current take-off ring should also have a silvery mat organic solvents, naphtha) are appearance. Discuss any abnormalities found with MR’s entirely unsuitable and may put Technical Service department. the trouble-free operation of on- Then proceed to check the surface of the oil compart- load tap-changer and transformer ment for leakage lines. This concerns particularly the at risk. clearances between fixed contacts and current take-off rings, the phase distances, and the distance to ground. 6.2.3 Temporary covering of on-load tap-changer oil NOTE! compartment After having checked the oil compartment, cover the oil After the cleaning, carefully compartment using the on-load tap-changer head cover. inspect all voltage-stressed insu- lating material surfaces of the fol- 6.3 Cleaning the on-load tap-changer insert lowing components for The on-load tap-changer insert should be flushed both mechanical or electrical damage on the outside and the inside. (discharge tracking): Flush all switching elements, transition resistor, and the The inside of the oil compart- switching column with transformer oil. ment (using a mirror) Be sure to rinse all the cleaned areas with transformer The inside and outside of the oil. on-load tap-changer insert. Be sure to replace all damaged 6.4 Inspecting the on-load tap-changer insert insulating parts Special attention must be paid to leakage lines inside as the continued operation with and outside the on-load tap-changer insert. damaged parts may damage the For this the inside of the on-load tap-changer insert on-load tap-changer and trans- should be illuminated with a light. former. Inspecting the exterior of the switching column does not require disassembly of the screening rings. 6.1 Cleaning the oil compartment Open the stop valve located between the on-load tap- changer head and the on-load tap-changer oil conserva- tor. Rinse the on-load tap-changer oil conservator and oil compartment with transformer oil. Make sure the oil compartment is completely drained. Check the dehydrating breather and replace the silica gel if necessary. Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 241/05 EN 25  6 Cleaning and inspection work 6.5 Adjusting the contact stroke of the vacuum These inspections have to be performed on all switching interrupter elements. For adjustment of the contact stroke a special tool is needed. Please contact the MR Technical Service 6.6 Replacement of switching elements department. The switching elements (see Figure 15) delivered up to July 2006 have to be replaced after every 450,000 tap- 6.5.1 Checking the guide rollers and control rollers change operations. All equipment delivered after July The guide rollers and control rollers should be visually 2006 needs replacing after every 600,000 tap-change checked for cracks and other abnormalities (see Fig- operations. Please contact the MR Technical Service ure 15). department for advice. 6.5.2 Checking the transition resistors 6.7 Replacement of energy accumulator springs – The transition resistors should be visually checked for only valid for deliveries up to July 2006 unusual appearances. The energy accumulator springs have to be replaced after every 150,000 tap-change operations. In this con- Use a multimeter to check the resistance values nection the switching time of the on-load tap-changer is between the TTS contact fingers and STC contact fin- to be checked and – if need be – has to be set. Special gers (take-off contact) (see Figure 15). The value should tools and devices are required for this work. Please con- be within ± 10 % of the value given on the name plate. tact the MR Technical Service department for advice. Contact rollers Guide rollers   Figure 15 Maintenance Manual WA 241/05 EN VACUTAP® VV Copying and distribution of this document and the utilization and communication of its contents are strictly prohibited unless expressly authorized. Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a patent, utility model or ornamental design registration. ©Maschinenfabrik Reinhausen GmbH 2010 26 241/05 EN  7 Inserting the on-load tap-changer insert 7 Inserting the on-load tap-changer insert To reassemble the on-load tap-changer insert you will need a mounting rod as indicated under Table 2 plus additional accessories. Insert the mounting rod in the bottom bearing of the oil compartment. The bottom bearing features two guide notches. The guide pin located at the bottom end of the mounting rod has to engage in the on-load tap-changer type- specific guide notch in the bottom bearing. 0 Be sure to insert the mounting rod in such a way as X to align the mounting rod’s red triangular marking as follows: for design types with change-over selector: towards the "0" mark (Figure 16/ Figure 17) for design types without change-over selector: towards the "X" mark (Figure 16) Figure 16 ATTENTION! Malfunction of on-load tap- changer and transformer! The on-load tap-changer insert may only be inserted as described below. Pivot the mounting rod in a clockwise direction. Plug the conical top onto the upper end of the mounting rod. The conical top prevents the on-load tap-changer insert from sliding down to the edge of the mountin