VACUTAP® VR I On-Load Tap-Changer Maintenance Manual PDF

ON-LOAD TAP-CHANGER VACUTAP® VR I (without VR I 2602) MAINTENANCE MANUAL 2343791/02 EN © All rights reserved by Maschinenfabrik Reinhausen Dissemination and reproduction of this document and use and disclosure of its content are strictly prohibited unless expressly permitted. Infringements will re...

ON-LOAD TAP-CHANGER VACUTAP® VR I (without VR I 2602) MAINTENANCE MANUAL 2343791/02 EN © All rights reserved by Maschinenfabrik Reinhausen Dissemination and reproduction of this document and use and disclosure of its content are strictly prohibited unless expressly permitted. Infringements will result in liability for compensation. All rights reserved in the event of the granting of patents, utility models or designs. The product may have been altered since this document was published. We reserve the right to change the technical data, design and scope of supply. Generally the information provided and agreements made when processing the individual quotations and orders are binding. The original operating instructions were written in German. Table of contents Table of contents 1 Introduction......................................................................................................................... 7 1.1 Validity................................................................................................................................................. 7 1.2 Manufacturer....................................................................................................................................... 7 1.3 Completeness...................................................................................................................................... 7 1.4 Supporting documents......................................................................................................................... 7 1.5 Safekeeping......................................................................................................................................... 8 1.6 Notation conventions........................................................................................................................... 8 1.6.1 Abbreviations used................................................................................................................................................ 8 1.6.2 Symbols................................................................................................................................................................. 8 1.6.3 Hazard communication system........................................................................................................................... 10 1.6.4 Information system.............................................................................................................................................. 11 1.6.5 Instruction system............................................................................................................................................... 11 2 Safety................................................................................................................................. 13 2.1 General safety information................................................................................................................ 13 2.2 Appropriate use................................................................................................................................. 13 2.3 Inappropriate use............................................................................................................................... 13 2.4 Personnel qualification...................................................................................................................... 14 2.5 Operator's duty of care...................................................................................................................... 14 3 Monitoring during operation............................................................................................ 15 4 Product description.......................................................................................................... 16 4.1 Function description.......................................................................................................................... 16 4.2 Setup/models..................................................................................................................................... 16 4.3 Type designation............................................................................................................................... 16 5 Scope of maintenance, maintenance intervals, dielectric strength of diverter switch oil and DC resistance measurement............................................................................... 18 5.1 Scope of maintenance and maintenance intervals............................................................................ 18 5.2 Determining dielectric strength of diverter switch oil during operation.............................................. 18 5.3 Determining dielectric strength of diverter switch oil after maintenance............................................ 18 5.4 Measuring DC resistance on transformer.......................................................................................... 18 6 Preparatory work............................................................................................................... 20 6.1 Safety precautions............................................................................................................................. 20 Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 3  Table of contents 6.2 Providing auxiliary equipment............................................................................................................ 20 6.3 Moving on-load tap-changer to adjustment position.......................................................................... 21 7 Removing diverter switch insert...................................................................................... 22 7.1 Removing horizontal drive shaft........................................................................................................ 22 7.2 De-energizing auxiliary circuits.......................................................................................................... 24 7.3 Lowering oil level in diverter switch oil compartment......................................................................... 25 7.4 Removing on-load tap-changer head cover...................................................................................... 26 7.5 Removing tap position indicator (version without multiple coarse change-over selector)................. 27 7.6 Removing tap position indicator from multiple coarse change-over selector with more than 35 operating positions............................................................................................................................ 27 7.7 Removing the tap-change supervisory device................................................................................... 29 7.8 Removing the oil suction pipe............................................................................................................ 31 7.9 Lifting out diverter switch insert......................................................................................................... 32 8 Maintaining on-load tap-changer..................................................................................... 33 8.1 Cleaning and checking on-load tap-changer oil compartment and oil conservator........................... 33 8.2 Cleaning and inspecting diverter switch insert.................................................................................. 35 8.3 Inspecting coupling tube.................................................................................................................... 35 8.4 Checking transition resistors............................................................................................................. 38 8.5 Replacing vacuum interrupters.......................................................................................................... 38 8.5.1 All types except VR I 1601/1801......................................................................................................................... 38 8.5.2 For VR I 1601/1801 only..................................................................................................................................... 38 8.6 Checking insulating shim................................................................................................................... 39 8.7 Replacing varistor connection leads.................................................................................................. 39 8.7.1 All types except VR I 1601/1801......................................................................................................................... 39 8.7.2 For VR I 1601/1801 only..................................................................................................................................... 39 8.8 Replacing diverter switch insert......................................................................................................... 39 8.9 Replacing fixed main contacts........................................................................................................... 40 8.9.1 All types except VR I 1601/1801......................................................................................................................... 40 8.9.2 For VR I 1601/1801 only..................................................................................................................................... 40 8.10 Maintaining tap selector..................................................................................................................... 40 8.11 Cleaning and inspecting protective relay RS..................................................................................... 40 9 Inserting diverter switch insert........................................................................................ 43 9.1 Inserting diverter switch insert........................................................................................................... 43 9.2 Inserting oil suction pipe.................................................................................................................... 46 4 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 Table of contents 9.3 Inserting the tap-change supervisory device..................................................................................... 47 9.4 Inserting the tap position indicator without multiple coarse change-over selector............................. 49 9.5 Inserting tap position indicator with multiple coarse change-over selector with more than 35 operating positions............................................................................................................................ 50 9.6 Filling oil and securing on-load tap-changer head cover................................................................... 51 9.7 Installing horizontal drive shaft.......................................................................................................... 55 9.8 Centering on-load tap-changer and motor-drive unit......................................................................... 57 10 Further checks.................................................................................................................. 65 10.1 Performing trial tap-change operations............................................................................................. 65 10.2 Checking field of rotation................................................................................................................... 65 10.3 Checking correct electric switch-off................................................................................................... 65 10.4 Checking mechanical and electric end stop of on-load tap-changer/off-circuit tap-changer and motor- drive unit............................................................................................................................................ 65 10.5 Checking protective relay RS 2001, 2001/V, 2001/H, 2001/E, 2001/5, 2001/R, 2003...................... 66 10.6 Checking protective relay RS 2004................................................................................................... 67 11 Commissioning the transformer...................................................................................... 69 12 Drawings............................................................................................................................ 70 12.1 Maintenance schedule - required tasks............................................................................................. 70 12.1.1 Maintenance schedule - required tasks, all types except VR I 1601/1801.......................................................... 70 12.1.2 Maintenance schedule - required tasks, VR I 1601/1801 only............................................................................ 71 12.2 Limit values for dielectric strength and water content of on-load tap-changer oil.............................. 71 12.3 Tap-change process.......................................................................................................................... 72 12.4 Switching sequence (728533)........................................................................................................... 73 12.5 VACUTAP® VRC/VRE, installation drawing (899992)...................................................................... 75 12.6 VACUTAP® VRD/VRF, selector size C/D, installation drawing (899898)......................................... 76 12.7 VACUTAP® VRF, selector size RC/RD/RDE, installation drawing (10018380)................................ 77 12.8 VACUTAP® VRG, installation drawing (899945).............................................................................. 78 12.9 VACUTAP® VR, adjustment positions (728557)............................................................................... 79 12.10 VACUTAP® VRC/VRE, adjustment plan without change-over selector (719853)............................ 80 12.11 VACUTAP® VRD/VRF, selector size C/D, adjustment plan without change-over selector (721089).... 82 12.12 VACUTAP® VRF, selector size RC/RD/RDE, adjustment plan without change-over selector (10016148)........................................................................................................................................ 84 12.13 VACUTAP® VRC I/VRE I, adjustment plan with reversing change-over selector connection (719851)........................................................................................................................................................... 85 Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 5  Table of contents 12.14 VACUTAP® VRD/VRF, selector size C/D, adjustment plan with change-over selector connection (721092)............................................................................................................................................ 86 12.15 VACUTAP® VRF, selector size RC/RD/RDE, adjustment plan with change-over selector connection (10016154)........................................................................................................................................ 87 12.16 VACUTAP® VRG, adjustment plan with reversing change-over selector connection (727074)....... 88 12.17 VACUTAP® VRC/VRE, adjustment plan with coarse tap selector connection (719852).................. 89 12.18 VACUTAP® VRC, adjustment plan with multiple coarse change-over selector for change-over selector division 10, 2-5 coarse tap connections (731412)............................................................... 90 12.19 VACUTAP® VRC, adjustment plan with multiple coarse change-over selector for change-over selector division 12, 2-5 coarse tap connections (731411)............................................................... 91 12.20 VACUTAP® VRC, adjustment plan with multiple coarse change-over selector for change-over selector division 14, 2-5 coarse tap connections (731410)............................................................... 92 12.21 VACUTAP® VRC, adjustment plan with multiple coarse change-over selector for change-over selector division 16, 2-5 coarse tap connections (731000)............................................................... 93 12.22 VACUTAP® VRC, adjustment plan with multiple coarse change-over selector for change-over selector division 18, 2-5 coarse tap connections (730977)............................................................... 94 12.23 VACUTAP® VRD/VRF, selector size C/D, adjustment plan with coarse tap selector connection (721091)............................................................................................................................................ 95 12.24 VACUTAP® VRD/VRF, selector size RC/RD/RDE, adjustment plan with coarse tap selector connection (10016155)...................................................................................................................... 96 12.25 VACUTAP® VRG, adjustment plan with coarse tap selector connection (727075).......................... 97 12.26 Additional page VR for K applications............................................................................................... 98 12.27 Fax template...................................................................................................................................... 99 6 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 1 Introduction 1 Introduction This technical file contains detailed descriptions on the safe and proper maintenance of the product. It also includes safety instructions and general information about the prod- uct. This technical file is intended solely for specially trained and authorized per- sonnel. 1.1 Validity This technical file applies to all the VACUTAP® VR on-load tap-changers listed below, all of which can be supplied with and without change-over se- lector. ▪ Single-phase on-load tap-changer ▪ On-load tap-changer combination (special version for delta connection, known as the K application) 1.2 Manufacturer The product is manufactured by: Maschinenfabrik Reinhausen GmbH Falkensteinstraße 8 93059 Regensburg, Germany Tel.: (+49) 9 41/40 90-0 Fax: (+49) 9 41/40 90-7001 E-mail: [email protected] Further information on the product and copies of this technical file are avail- able from this address if required. 1.3 Completeness This technical file is incomplete without the supporting documentation. 1.4 Supporting documents The operating instructions for the following devices also apply in addition to this technical file: ▪ Drive shaft ▪ Protective relay RS ▪ TAPMOTION® ED motor-drive unit ▪ On-load tap-changer VACUTAP® VR I II III All documents form part of the scope of delivery. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 7  1 Introduction In addition, generally applicable legal and other binding regulations of Euro- pean and national law and the regulations for accident prevention and envi- ronmental protection in force in the country of use must be complied with. 1.5 Safekeeping Keep this technical file and all supporting documents ready at hand and ac- cessible for future use at all times. 1.6 Notation conventions This section contains an overview of the symbols and textual emphasis used. 1.6.1 Abbreviations used Abbrevia- Definition tion OI Operating instructions DS Diverter switch DSI Diverter switch insert MC Main contact MR Maschinenfabrik Reinhausen GmbH MSVa/MSVb Main switching contacts (vacuum interrupter), main path MDCa/MDCb Transfer contact, main path OLTC On-load tap-changer TCIS Tap-change indicator sections TDCa/TDCb Transfer contact, transition path TTVa/TTVb Main switching contact (vacuum interrupter), transition path Um Highest voltage for equipment (in kV) CS Change-over selector MM Maintenance manual ZnO Varistor Table 1: Abbreviations used 1.6.2 Symbols Symbol Meaning Wrench size Tightening torque 8 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 1 Introduction Symbol Meaning Number and type of fastening material used Fill with oil Cut open, cut through Clean Visual inspection Use your hand Adapter ring Apply a coat of paint Use a file Grease Coupling bolt Use a ruler Use a saw Hose clip Wire eyelet, safety wire Use a screwdriver Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 9  1 Introduction Symbol Meaning Apply adhesive Lock tab Table 2: Symbols 1.6.3 Hazard communication system Warnings in this technical file are displayed as follows. 1.6.3.1 Warning relating to section Warnings relating to sections refer to entire chapters or sections, sub-sec- tions or several paragraphs within this technical file. Warnings relating to sections use the following format: WARNING Type and source of danger! Consequences ► Action ► Action 1.6.3.2 Embedded warning information Embedded warnings refer to a particular part within a section. These warn- ings apply to smaller units of information than the warnings relating to sec- tions. Embedded warnings use the following format: DANGER! Instruction for avoiding a dangerous situation. 1.6.3.3 Signal words and pictograms The following signal words are used: Signal Meaning word DANGER Indicates a hazardous situation which, if not avoided, will result in death or serious injury. WARNING Indicates a hazardous situation which, if not avoided, could result in death or serious injury. CAUTION Indicates a hazardous situation which, if not avoided, could result in injury. 10 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 1 Introduction Signal Meaning word NOTICE Indicates measures to be taken to prevent damage to property. Table 3: Signal words in warning notices Pictograms warn of dangers: Pictogram Meaning Warning of a danger point Warning of dangerous electrical voltage Warning of combustible substances Warning of danger of tipping Table 4: Pictograms used in warning notices 1.6.4 Information system Information is designed to simplify and improve understanding of particular procedures. In this technical file it is laid out as follows: Important information. 1.6.5 Instruction system This technical file contains single-step and multi-step instructions. Single-step instructions Instructions which consist of only a single process step are structured as fol- lows: Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 11  1 Introduction Aim of action ü Requirements (optional). ► Step 1 of 1. ð Result of step (optional). ð Result of action (optional). Multi-step instructions Instructions which consist of several process steps are structured as follows: Aim of action ü Requirements (optional). 1. Step 1. ð Result of step (optional). 2. Step 2. ð Result of step (optional). ð Result of action (optional). 12 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 2 Safety 2 Safety 2.1 General safety information This technical file contains detailed descriptions on the safe and proper maintenance of the product. ▪ Read this technical file through carefully to familiarize yourself with the product. ▪ Particular attention should be paid to the information given in this chap- ter. 2.2 Appropriate use The product and associated equipment and special tools supplied with it comply with the relevant legislation, regulations and standards, particularly health and safety requirements, applicable at the time of delivery. If used as intended and in compliance with the specified requirements and conditions in this technical file as well as the warning notices in this technical file and attached to the product, then the product does not present any haz- ards to people, property or the environment. This applies throughout the product's entire life, from delivery through installation and operation to disas- sembly and disposal. The operational quality assurance system ensures a consistently high quality standard, particularly in regard to the observance of health and safety re- quirements. The following is considered appropriate use ▪ The product must be maintained in accordance with this technical file ▪ The equipment and special tools supplied must be used solely for the in- tended purpose and in accordance with the specifications of this techni- cal file ▪ The product must be used only with the transformer specified in the or- der 2.3 Inappropriate use Use is considered to be inappropriate if the product is used other than as de- scribed in the Appropriate use section. Please also note the following: ▪ Risk of explosion and fire from highly flammable or explosive gases, va- pors, or dusts. Do not operate product in areas at risk of explosion. ▪ Unauthorized or inappropriate changes to the product may lead to per- sonal injury, material damage, and operational faults. Only modify prod- uct following discussion with Maschinenfabrik Reinhausen GmbH. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 13  2 Safety 2.4 Personnel qualification The product is designed solely for use in electrical energy systems and facili- ties operated by appropriately trained staff. This staff comprises people who are familiar with the installation, assembly, commissioning and operation of such products. 2.5 Operator's duty of care To prevent accidents, disruptions and damage as well as unacceptable ad- verse effects on the environment, those responsible for transport, installa- tion, operation, maintenance and disposal of the product or parts of the prod- uct must ensure the following: ▪ All warning and hazard notices are complied with. ▪ Personnel are instructed regularly in all relevant aspects of operational safety, the operating instructions and particularly the safety instructions contained therein. ▪ Regulations and operating instructions for safe working as well as the relevant instructions for staff procedures in the case of accidents and fires are kept on hand at all times and are displayed in the workplace where applicable. ▪ The product is only used when in a sound operational condition and safety equipment in particular is checked regularly for operational relia- bility. ▪ Only replacement parts, lubricants and auxiliary materials which are au- thorized by the manufacturer are used. ▪ The specified operating conditions and requirements of the installation location are complied with. ▪ All necessary devices and personal protective equipment for the specific activity are made available. ▪ The prescribed maintenance intervals and the relevant regulations are complied with. ▪ Maintenance of the product may only be carried out by qualified and trained personnel in accordance with this technical file. ▪ Be sure to contact MR immediately in the event of damage during on- load tap-changer maintenance work. ▪ The operator must ensure appropriate use of the product. 14 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 3 Monitoring during operation 3 Monitoring during operation Monitoring the on-load tap-changer and motor-drive unit is limited to occa- sional visual checks of on-load tap-changer head, protective relay and mo- tor-drive unit. For efficiency reasons these visual checks can be combined with the usual checks on the transformer. Pay particular attention to the following: ▪ Oil impermeability at the sealing points of the on-load tap-changer head, protective relay and connected pipes ▪ Gaskets of the protective housing of the motor-drive unit ▪ Correct functioning of the installed electrical heater in the protective housing of the motor-drive unit ▪ Protective relay function test in accordance with respective operating in- structions ▪ Perfect condition of the silica gel breather for the on-load tap-changer oil conservator The insulating oils in the transformer, including the on-load tap-changer, are to be monitored by the operator following the appropriate rules and regula- tions. 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 in accordance with IEC 60214-1): every 7 years ▪ For on-load tap-changers used at points other than the neutral point of windings (class 2 in accordance with IEC 60214-1): every 2 years To do so, proceed as follows: 1. Take oil sample from diverter switch oil compartment. 2. Record temperature of oil sample just after sample is taken. 3. Determine dielectric strength and water content at a diverter switch oil temperature of 20 °C ± 5 °C. The dielectric strength and water content must comply with the limit values provided in the appendix [► 71]. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 15  4 Product description 4 Product description This chapter contains an overview of the design and function of the product. 4.1 Function description On-load tap-changers are used to adjust the desired tap of a tap winding un- der load. During the tap change operation the fine tap selector first selects the desired tap of the tap winding. The diverter switch insert then switches from the cur- rent-carrying tap to the preselected tap. During this tap change operation one tapping step of the tap winding is briefly bridged with an ohmic resistor so that the diverter switch operation can be carried out without any interrup- tion in current. The tap-change process for one step is shown in the appendix [► 72]. 4.2 Setup/models The on-load tap-changer consists of the on-load tap-changer head, diverter switch oil compartment with built-in diverter switch insert and the tap selector mounted below (also available with change-over selector on request). The standard model is available with on-load tap-changers without change- over selector up to a maximum of 18 operating positions and with change- over selector with up to a maximum of 35 operating positions. The design and designation of the most important on-load tap changer com- ponents are shown in the installation drawings in the appendix [► 75]. 4.3 Type designation The on-load tap-changers are available in several models. The type desig- nation of the on-load tap-changer therefore depends on the model hence ensuring an unmistakable and non-interchangeable on-load tap- changer designation. Example: VACUTAP® VRF I 1301 Y - 72,5/C – 10 19 1 G VACUTAP® VRF On-load tap-changer type I Number of phases 1301 Maximum rated through current (in A) Y Neutral point application 72.5 Highest voltage for equipment Um (in kV) C Tap selector size 10 Pitch of tap selector 16 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 4 Product description 19 Number of maximum operating po- sitions 1 Number of mid-positions G Change-over selector as coarse change-over selector Table 5: Type designation Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 17  5 Scope of maintenance, maintenance intervals, dielectric strength of diverter switch oil and DC resistance measurement 5 Scope of maintenance, maintenance intervals, dielectric strength of diverter switch oil and DC resistance measurement We generally recommend having maintenance carried out by our Technical Service. If this route is taken, in addition to the correct performance of all work, certain components will be upgraded to the latest state of technology and manufacturing status. The maintenance can usually be carried out by qualified and MR-trained per- sonnel within one day per on-load tap-changer pole, provided it is well pre- pared and organized. If maintenance is not carried out by our Technical Service department, please ensure that the personnel who carry out the maintenance are trained by MR or are otherwise suitably qualified to carry out the work. In such cas- es, we would ask you to forward to us a report on the maintenance per- formed so we can update our maintenance files. You can use the fax tem- plate in the appendix for the report. For inquiries about spare parts, please provide the serial number (see name plate on on-load tap-changer head cover) and the number of tap-change op- erations (see operations counter on motor-drive unit). 5.1 Scope of maintenance and maintenance intervals Please refer to the maintenance schedule in the appendix for the scope of maintenance and maintenance intervals. 5.2 Determining dielectric strength of diverter switch oil during operation Check the dielectric strength of the diverter switch oil in the diverter switch oil compartment. The dielectric strength and water content must comply with the limit values provided in the appendix [► 71]. 5.3 Determining dielectric strength of diverter switch oil after maintenance Check the dielectric strength of the diverter switch oil added after mainte- nance. The dielectric strength and water content must comply with the limit values provided in the appendix [► 71]. 5.4 Measuring DC resistance on transformer Note the measurement scenarios listed below and the associated maximum measured currents when measuring DC resistance on the transformer. 18 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 5 Scope of maintenance, maintenance intervals, dielectric strength of diverter switch oil and DC resistance measurement The measurement DC current is normally restricted to 10 % of the rated cur- rent of the measured transformer winding in order to prevent the winding from overheating. Measure the DC resistance in various on-load tap-changer operating posi- tions. You need to distinguish here as to whether the measured current is in- terrupted when changing operating position or not. Status of oil com- Without interruption With interruption partment in measured current (measured current = 0 A before change in operating position) Oil compartment emp- Maximum 10 A DC Maximum 50 A DC ty Oil compartment filled Maximum 50 A DC Maximum 50 A DC with insulating oil Table 6: Maximum permitted measured currents when measuring DC resistance on transformer Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 19  6 Preparatory work 6 Preparatory work Perform the following work before starting maintenance. 6.1 Safety precautions WARNING Danger of death and severe injury! An energized transformer and energized on-load tap-changer components could cause death or serious injuries during maintenance work! ► Adherence to the following safety precautions is mandatory. 1. Switch off transformer on high and low-voltage side. 2. Lock transformer to prevent unintentional restart. 3. Make sure everything is de-energized. 4. Visibly connect all transformer terminals to ground (grounding leads, grounding disconnectors) and short circuit them. 5. Cover or cordon off adjacent energized parts. 6.2 Providing auxiliary equipment Provide the following auxiliary equipment for on-load tap-changer mainte- nance: ▪ Oil pump for performing an oil change ▪ Brush and highly-absorbent, lint-free cleaning rags ▪ Working table ▪ Oil sump ▪ Tool ▪ Clean empty barrels and transformer oil for cleaning and oil change in accordance with following table (the oil quantity depends on the on-load tap-changer type and its rated voltage Um). OLTC variant Highest voltage for equipment Um [kV] 72.5 123 170 245 300 362* VRC 155 175 190 210 235 VRD, VRE, VRF, VRG 175 195 210 230 255 280 * for VRF/VRG only Table 7: Oil quantity for oil change (stated in liters) ▪ Crane or MR lifting device (maximum weight of diverter switch insert 120 kg) OLTC variant Highest voltage for equipment Um [kV] 72.5 123 170 245 300 362* VRC 1120 1250 1350 1450 1580 20 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 6 Preparatory work VRD, VRE, VRF, VRG 1250 1380 1480 1580 1710 1840 * for VRF/VRG only Table 8: The withdrawal height of the diverter switch insert during maintenance (stat- ed in millimeters) 6.3 Moving on-load tap-changer to adjustment position 1. Write down the current operating position of the on-load tap-changer. 2. Operate on-load tap-changer to adjustment position. The adjustment po- sition is indicated in the on-load tap-changer connection diagram. Figure 1: Adjustment position Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 21  7 Removing diverter switch insert 7 Removing diverter switch insert WARNING Danger of explosion! Explosive gases under the on-load tap-changer head cover, in the pipework system, in the oil conservator or at the dehydrating breather opening can deflagrate or explode and result in severe injury or death! ► Ensure that there are no ignition sources such as naked flames, hot surfaces or sparks (e.g. caused by the build-up of static charge) in the immediate surroundings and that none occur. ► De-energize all auxiliary circuits, for example tap-change supervisory device, pressure relief device, pressure monitoring device, before re- moving the on-load tap-changer head cover. ► Do not operate any electrical devices (e.g. impact wrench, risk of sparks) during the work. ► Only use conductive and grounded hoses, pipes, and pump equipment that are approved for flammable liquids. Proceed as follows to remove the diverter switch insert. 7.1 Removing horizontal drive shaft NOTICE Damage to the on-load tap-changer and transformer! Damage to on-load tap-changer and transformer if motor-drive unit is oper- ated when not coupled! ► Never operate the motor-drive unit if the horizontal drive shaft has been removed. ► As a precaution, block the motor-drive unit against electrical operation by actuating the motor protective switch (see operating instructions for "Tapmotion® ED"). 22 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 7 Removing diverter switch insert 1. Loosen hose clips on protective cover of horizontal drive shaft, remove protective cover. Figure 2: Removing protective cover Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 23  7 Removing diverter switch insert 2. Depending on version, loosen 4 or 6 screws on coupling brackets to up- per gear unit and bevel gear. Figure 3: Loosening coupling brackets 3. Remove horizontal drive shaft. Be sure not to lose the coupling bolts. Figure 4: Removing drive shaft 7.2 De-energizing auxiliary circuits De-energize all auxiliary circuits (for example tap-change supervisory device, pressure relief device, pressure monitoring device) before removing the on- load tap-changer head cover. 1. De-energize auxiliary circuits. 2. Make sure everything is de-energized. 24 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 7 Removing diverter switch insert 7.3 Lowering oil level in diverter switch oil compartment Before removing the on-load tap-changer head cover, the oil level in the diverter switch oil compartment must be lowered. 1. Remove screw cap on air-vent valve E1 on on-load tap-changer head cover. Figure 5: Screw cap 2. Use screwdriver to lift valve tappet on air-vent valve E1 until oil starts to come out. Figure 6: Valve tappet 3. Close stop-cock between oil conservator and on-load tap-changer. 4. Place a bucket (10 l) under the drain valve of the on-load tap-changer to collect the drained oil. 5. Open drain valve. 6. Use screwdriver to lift valve tappet on air-vent valve E1. ð The oil level falls automatically. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 25  7 Removing diverter switch insert Figure 7: Valve tappet 7. Once approx. 10 l of oil has been drained, close drain valve and seal air-vent valve E1 with screw cap. 7.4 Removing on-load tap-changer head cover NOTICE Damage to the on-load tap-changer! Small parts in the oil compartment may block the diverter switch insert, thereby damaging the on-load tap-changer! ► Ensure that parts do not fall into the oil compartment. ► Check that you have the same number of small parts when removing and installing. 1. De-energize all auxiliary circuits, for example tap-change supervisory devices, pressure relief devices, pressure monitoring devices. 2. Make sure everything is de-energized. 3. Make sure that inspection window is sealed off with cover. 4. Loosen screws with locking elements on on-load tap-changer head cov- er. Figure 8: On-load tap-changer head cover 26 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 7 Removing diverter switch insert 5. Remove on-load tap-changer head cover. Figure 9: On-load tap-changer head cover 6. Remove the remaining oil from the oil compartment via the pipe connec- tion S. 7.5 Removing tap position indicator (version without multiple coarse change-over selector) ► Pull the spring clip off the shaft end and remove the tap position indica- tor disc. Figure 10: Tap position indicator disk 7.6 Removing tap position indicator from multiple coarse change-over selector with more than 35 operating positions 1. Ensure that the red marks on the panel, tap position indicator disk and cover disk produce a continuous red line. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 27  7 Removing diverter switch insert 2. Remove countersunk head screw. Figure 11: Countersunk head screw 3. Lever cover disk off underlying disk with flat screwdriver and pull out po- sition-indication disk from between panel and bracket. Figure 12: Cover disk and position-indication disk 4. Remove hexagon screws and associated lock tab. Figure 13: Lock tab 28 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 7 Removing diverter switch insert 5. Pull panel and bracket up and off indicator drive shaft. Figure 14: Panel 7.7 Removing the tap-change supervisory device NOTICE Damage to the on-load tap-changer and transformer! Removing the tap-change monitoring unit without due care may damage it, thereby resulting in damage to the on-load tap-changer and transformer! ► Disconnect tap-change monitoring unit with care in order not to damage or rip out the connecting leads. 1. Take the tap-change supervisory device plug connector out of the mounting bracket and disconnect it. Figure 15: Plug connector Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 29  7 Removing diverter switch insert 2. Remove nuts and locking elements (3 or 4 depending on model) on the mounting plate. Figure 16: Mounting plate 3. Remove tap-change supervisory device with mounting plate and drive shaft. Figure 17: Tap-change supervisory device with mounting plate and drive shaft 30 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 7 Removing diverter switch insert 4. Swivel the lead of the tap-change supervisory device out of the on-load tap-changer head in direction indicated by the arrow until the cable will not be damaged when the on-load tap-changer insert is pulled out. Swiveling out the lead of the tap-change supervisory device 7.8 Removing the oil suction pipe 1. Remove cable ties from the oil suction pipe. Figure 18: Cable tie 2. Pull oil suction pipe out of on-load tap-changer head. Figure 19: Oil suction pipe Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 31  7 Removing diverter switch insert 7.9 Lifting out diverter switch insert 1. By turning the coupling tube on the upper screening ring, align it in such a manner that the triangular marks on the on-load tap-changer head and those on the coupling tube match up. Figure 20: Aligning the coupling tube 2. Insert the lifting gear in the eyebolts of the coupling tube and position vertically above the diverter switch insert. 3. Lift the diverter switch insert slowly and vertically out of oil compartment. Figure 21: Diverter switch insert 4. CAUTION! Place the diverter switch insert on a level surface and se- cure it against tipping. An unstably positioned diverter switch insert may tip, resulting in injuries and damage. 5. NOTICE! Neither operate the diverter switch insert while removed nor change the position of the tap selector coupling.Otherwise, the diverter switch insert may be damaged when being reinstalled. 32 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 8 Maintaining on-load tap-changer 8 Maintaining on-load tap-changer The on-load tap-changer must be maintained after every 300,000 switching operations. Proceed as follows to do this: NOTICE Damage to the on-load tap-changer and transformer! Damage to the on-load tap-changer and transformer from used fixtures and gaskets! ► Only use lock tabs, lock disks, lock nuts and the on-load tap-changer head cover o-ring once and replace once removed. ► Only use self-locking screws with thread coating with micro-encapsulat- ed adhesives once and replace once removed. Note expiry date of new parts. ► Ensure that screw connection points and elements are free of oil and grease. 8.1 Cleaning and checking on-load tap-changer oil compartment and oil conservator Cleaning diverter oil compartment and oil conservator WARNING Danger of explosion! Explosive gases in the oil compartment of the on-load tap-changer, trans- former, pipework system, oil conservator and at the dehydrating breather opening can deflagrate or explode and result in severe injury or death! ► Ensure that there are no ignition sources such as naked flame, hot sur- faces or sparks (e.g. caused by the build-up of static charge) in the transformer's immediate surroundings and that none occur. ► Do not operate any electrical devices (e.g. risk of sparks from impact wrench). ► Only use conductive and grounded hoses, pipes, and pump equipment that are approved for flammable liquids. Proceed as follows to clean the oil compartment and oil conservator: 1. Open stop valve located between on-load tap-changer head and on- load tap-changer oil conservator. ð The oil from the oil conservator flows into the on-load tap-changer oil compartment. 2. NOTICE! Unsuitable cleaning agents may cause damage to the on-load tap-changer. Only rinse on-load tap-changer oil conservator with new transformer oil. 3. Use an oil pump to pump all the oil out of the oil compartment. 4. Make sure the oil compartment is completely drained. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 33  8 Maintaining on-load tap-changer 5. NOTICE! Unsuitable cleaning agents may cause damage to the on-load tap-changer. Clean oil compartment and on-load tap-changer oil conser- vator using only new transformer oil and absorbent, lint-free cleaning cloths. Avoid damaging the inner surface of the oil compartment and the contacts fitted there. 6. Check the oil conservator breather of on-load tap-changer and replace the drying agent if necessary. Checking oil compartment Proceed as follows to check the oil compartment: 1. Check fixed oil compartment contacts and inside of oil compartment us- ing a mirror and lamp. The silver coating on the contacts must not be discolored. Figure 22: Oil compartment contacts 2. Under adequate lighting, inspect the inside of the oil compartment for mechanical or electrical damage (creepage paths, signs of discharge). 3. Document any defects with a camera. 4. After the inspection, cover oil compartment with the on-load tap-changer head cover. If you are unsure, please contact the MR Technical Service department for advice. In such cases photographs of the affected areas are helpful. 34 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 8 Maintaining on-load tap-changer 8.2 Cleaning and inspecting diverter switch insert 1. NOTICE! Unsuitable cleaning agents may cause damage to the diverter switch insert. Thoroughly clean diverter switch insert using only new transformer oil. 2. Perform thorough visual inspection of the diverter switch insert. 3. Under adequate lighting, inspect diverter switch insert for mechanical or electrical damage (creepage paths, signs of discharge). 8.3 Inspecting coupling tube Inspecting the coupling tube requires removing the coupling tube from the diverter switch insert. Proceed as follows. 1. Remove the 6 screws holding the lower shielding ring. Figure 23: Screws on the lower shielding ring Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 35  8 Maintaining on-load tap-changer 2. Lift the lower shielding ring and remove the 6 drive sleeves using pliers. Figure 24: Drive sleeves on the lower shielding ring 3. Pull out the coupling tube. 4. Clean the coupling tube with transformer oil. Note the oil quality limit val- ues. 5. Perform thorough visual inspection of the inside and outside of the cou- pling tube. Check for mechanical or electrical damage (leakage paths, discharge marks). The coupling tube is refitted following the instructions for removal but in re- verse order. 36 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 8 Maintaining on-load tap-changer When refitting, ensure alignment of the red adjustment mark (at top of cou- pling tube) and the adjustment mark on the diverter switch insert (energy ac- cumulator, see appendix [► 79]). Figure 25: Adjustment marks In order to ensure that the adjustment marks are positioned correctly, when assembling the coupling tube, the parts must be positioned as they were be- fore being disassembled. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 37  8 Maintaining on-load tap-changer 8.4 Checking transition resistors ► Check the transition resistors visually for unusual appearances. Figure 26: Transition resistors 8.5 Replacing vacuum interrupters 8.5.1 All types except VR I 1601/1801 Replace the vacuum interrupters and the prefitted supporting structure after 600,000 tap change operations. Please contact MR Technical Service. 8.5.2 For VR I 1601/1801 only Replace the vacuum interrupters and the prefitted supporting structure after 300,000 tap change operations. Please contact MR Technical Service. 38 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 8 Maintaining on-load tap-changer 8.6 Checking insulating shim ► Before refitting the diverter switch insert in the oil compartment, ensure that all six insulating shims are in the energy accumulator carrier. Figure 27: Insulating shims 8.7 Replacing varistor connection leads 8.7.1 All types except VR I 1601/1801 Replace the two varistor connection leads and their fasteners after 600,000 tap change operations. Please contact MR Technical Service. 8.7.2 For VR I 1601/1801 only Replace the two varistor connection leads and their fasteners after 300,000 tap change operations. Please contact MR Technical Service. 8.8 Replacing diverter switch insert Replace the complete diverter switch insert after 1.2 million switching opera- tions. Please contact MR Technical Service. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 39  8 Maintaining on-load tap-changer 8.9 Replacing fixed main contacts 8.9.1 All types except VR I 1601/1801 Replace the fixed main contacts (MC) in full after 1.2 million tap change op- erations. Please contact MR Technical Service. 8.9.2 For VR I 1601/1801 only Replace the fixed main contacts (MC) in full after 300,000 tap change opera- tions. Please contact MR Technical Service. 8.10 Maintaining tap selector The tap selector must be maintained after 1.2 million tap change operations. Please contact MR Technical Service. 8.11 Cleaning and inspecting protective relay RS Proceed as follows to clean and inspect the protective relay: 1. Loosen screws on cover and take off cover. Figure 28: Cover with hexagon socket screws 40 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 8 Maintaining on-load tap-changer Figure 29: Cover with hexagonal head screws 2. Clean protective relay with a brush and new insulating oil. 3. Use spring balance to measure retaining force of flap valve. The retain- ing force must be between 2.0...2.2 N. Contact the Technical Service at Maschinenfabrik Reinhausen GmbH if the above value is not observed. Figure 30: Flap valve 4. Visually inspect dry-reed magnetic switches. Ensure that dry-reed mag- netic switches are intact and sealed. 5. Replace seal in cover. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 41  8 Maintaining on-load tap-changer 6. Fit cover and screw down. Figure 31: Cover with hexagon socket screws Figure 32: Cover with hexagonal head screws 42 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 9 Inserting diverter switch insert 9 Inserting diverter switch insert Proceed as follows to insert the diverter switch insert: NOTICE Damage to the on-load tap-changer and transformer! Damage to the on-load tap-changer and transformer from used fixtures and gaskets! ► Only use lock tabs, lock disks, lock nuts and the on-load tap-changer head cover o-ring once and replace once removed. ► Only use self-locking screws with thread coating with micro-encapsulat- ed adhesives once and replace once removed. Note expiry date of new parts. ► Ensure that screw connection points and elements are free of oil and grease. 9.1 Inserting diverter switch insert 1. To fit the diverter switch insert, ensure that the selector coupling is in the adjustment position. Figure 33: Adjustment marks in oil compartment base VACUTAP® VRC/VRE Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 43  9 Inserting diverter switch insert Figure 34: Adjustment marks in oil compartment base VACUTAP® VRD/VRF Figure 35: Adjustment marks in oil compartment base VACUTAP® VRG 2. Ensure that the diverter switch insert's energy accumulator is inter- locked (the energy accumulator's eccentric disk is at its dead center, see "Adjustment plan" for tap-changer variant used in the appendix). 3. Attach lifting gear to diverter switch insert and position diverter switch in- sert over oil compartment. NOTICE Damage to the on-load tap-changer and transformer! Damage to on-load tap-changer and transformer due to diverter switch in- serts being confused in K applications (on-load tap-changer set comprising a VACUTAP® VR I and VACUTAP® VR II). ► When using the diverter switch insert, note the red markings on the coupling flange and on the on-load tap-changer head: VACUTAP® VR I: 1 marking VACUTAP® VR II: 2 markings 44 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 9 Inserting diverter switch insert 4. Align diverter switch insert such that the red markings at the top of the coupling flange and on the on-load tap-changer head are opposite one another. 5. Slowly lower diverter switch insert until it hits the oil compartment base. Figure 36: Aligning diverter switch insert 6. Carefully press until energy accumulator carrier is in position. The shape of the selector coupling ensures that coupling with the oil compartment base is only possible in the correct position. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 45  9 Inserting diverter switch insert 7. Check the distance between the upper edge of the diverter switch insert coupling tube and the head flange. The distance is 10 ± 2 mm (cover mounting and bell-type tank mounting). Figure 37: Distance between the upper edge of the coupling tube and head flange 9.2 Inserting oil suction pipe NOTICE Damage to the on-load tap-changer! Damage to the on-load tap-changer and oil suction pipe due to incorrect or- der of installation. ► Strictly adhere to the order of installation. Make sure to always install the diverter switch insert before inserting the oil suction pipe into the oil compartment. 1. Insert oil suction pipe into on-load tap-changer head. Figure 38: Inserting oil suction pipe 46 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 9 Inserting diverter switch insert 2. Fasten oil suction pipe on retaining bracket with cable tie. Figure 39: Fastening the oil suction pipe 9.3 Inserting the tap-change supervisory device 1. Insert tap-change supervisory device with mounting plate and drive shaft. Figure 40: Mounting plate with drive shaft Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 47  9 Inserting diverter switch insert 2. Check that drive shaft feather key is seated correctly in the groove. Figure 41: Feather key and groove 3. Secure mounting plate (3 or 4 nuts and locking elements depending on model). Figure 42: Mounting plate 4. Connect plug connector outside its bracket. Figure 43: Plug connector 48 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 9 Inserting diverter switch insert 5. Insert plug connector into the bracket. Figure 44: Plug connector in bracket 9.4 Inserting the tap position indicator without multiple coarse change-over selector Due to the coupling pin, the tap position indicator disc can only be installed when in the correct position. ► Place tap position indicator disk on indicator drive shaft, slide spring clip on to shaft end. Figure 45: Tap position indicator disk Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 49  9 Inserting diverter switch insert 9.5 Inserting tap position indicator with multiple coarse change-over selector with more than 35 operating positions 1. Place panel with bracket on indicator drive shaft and fasten with hexa- gon screws and associated lock tab. Figure 46: Fitting panel 2. Insert position-indication disk horizontally between panel and bracket and fit cover disk. Align tap position indicator disc and cover disk to pro- duce a continuous red line. Figure 47: Inserting position-indication disk 50 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 9 Inserting diverter switch insert 3. Secure cover disk with countersunk head screw. The countersunk head screw must be suitable for center-punching. Figure 48: Fastening cover disk 4. Secure countersunk head screw by center-punching. 9.6 Filling oil and securing on-load tap-changer head cover 1. NOTICE! Fill diverter switch oil compartment with insulating oil to upper edge of coupling shaft. Ensure that dielectric strength and water content of insulating oil comply with the limit values provided in the appendix [► 71]. Otherwise damage to the on-load tap-changer and transform- er may result. 2. NOTICE! Insert new o-ring in on-load tap-changer head cover. Take care not to damage the o-ring. A damaged o-ring will cause oil to es- cape from the diverter switch oil compartment, resulting in on-load tap- changer damage. Also ensure that the sealing surfaces are clean. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 51  9 Inserting diverter switch insert 3. Place on-load tap-changer head cover on on-load tap-changer head. Ensure that the red triangular marks on the on-load tap-changer head and the on-load tap-changer head cover match up. Figure 49: On-load tap-changer head cover 4. Screw down on-load tap-changer head cover onto the on-load tap- changer head. Figure 50: On-load tap-changer head cover 5. Open stop-cock between protective relay and oil conservator. 6. Fill oil conservator with insulating oil. 52 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 9 Inserting diverter switch insert 7. Vent on-load tap-changer head on air-vent valve E1 of on-load tap- changer head cover. To do this, remove screw cap and lift valve tappet with a screwdriver. Figure 51: Screw cap Figure 52: Valve tappet 8. Seal air-vent valve E1 with screw cap (tightening torque 10 Nm). Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 53  9 Inserting diverter switch insert 9. Vent pipe connection S on on-load tap-changer head. To do this, open pipe connection's screw cap and vent screw. Close screw cap again af- ter venting. Figure 53: Pipe connection S 10. Take oil sample from diverter switch oil compartment. 11. Record temperature of oil sample just after sample is taken. 12. Determine dielectric strength and water content at a diverter switch oil temperature of 20 °C ± 5 °C. The dielectric strength and water content must comply with the limit values provided in the appendix [► 71]. 54 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 9 Inserting diverter switch insert 9.7 Installing horizontal drive shaft 1. Secure horizontal drive shaft between upper gear unit and bevel gear with coupling brackets and 4 or 6 screws. Refer to the drive shaft oper- ating instructions for details. Figure 54: Securing drive shaft 2. Use hose clips to secure protective cover to horizontal drive shaft. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 55  9 Inserting diverter switch insert Figure 55: Securing protective cover 3. For special design types featuring cardan shafts, be sure to check the expansion bellows and the lubricant reservoir of the cardan shafts. You will find a detailed description of how to fit the drive shaft in the MR op- erating instructions "Drive shaft". 56 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 9 Inserting diverter switch insert 9.8 Centering on-load tap-changer and motor-drive unit WARNING Danger of death or severe injury! Danger of death or severe injury due to motor-drive unit starting up by acci- dent and due to electric voltage! ► Before starting any coupling work make sure that the motor protective switch is tripped. ► Carry out any adjustment work in manual mode only. ► When manually operating the motor-drive unit only use the hand crank provided for this purpose. ► Note that the hand crank safety switch causes a 2-pole disconnection of the motor circuit but that the control circuit is not interrupted. NOTICE Damage to property! The on-load tap-changer will be damaged by incorrectly centering the mo- tor-drive unit. ► Do not perform more than 250 tap-change operations on the on-load tap-changer. If more than 250 tap-change operations are performed, completely fill oil compartment with insulating oil and lubricate sliding surfaces of contacts on selector and selector gear with insulating oil. The following steps for centering on-load tap-changer and motor-drive unit do not apply to the DEETAP® DU and COMTAP® ARS. The process for centering motor-drive unit and DEETAP® DU or COMTAP® ARS is descri- bed in the relevant operating instructions. One on-load tap-change operation is represented by one rotation of the tap- change indicator. This indicator is divided into 33 tap-change indicator sec- tions each of which corresponds to one hand crank revolution in the stan- dard motor-drive unit design. The time of the switchover depends on the on- load tap-changer/de-energized tap-changer type, but is always 2 tap-change indicator sections before the area marked in gray on the tap-change indica- tor at the latest. Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 57  9 Inserting diverter switch insert To center the on-load tap-changer and motor-drive unit, proceed as follows. 1. NOTICE! Move on-load tap-changer/de-energized tap-changer and the motor-drive unit into adjustment position before commencing any adjust- ment work. Ensure that tap position indicators for the motor-drive unit and on-load tap-changer/de-energized tap-changer match. Otherwise damage to the on-load tap-changer and transformer may result. Figure 56: Adjustment position 58 VACUTAP® VR I (without VR I 2602) 2343791/02 EN Maschinenfabrik Reinhausen 2017 9 Inserting diverter switch insert 2. Attach the hand crank in the motor-drive unit to the shaft end located in the upper cover plate. This activates a hand crank interlock switch which disconnects the motor circuit at 2 poles. Figure 57: Hand crank 3. Turn the hand crank clockwise until the diverter switch operation begins. When turning the hand crank, observe the tap-change indicator which mechanically reflects the progress of the tap-change operation. Figure 58: Turning the hand crank until the diverter switch operation begins Maschinenfabrik Reinhausen 2017 2343791/02 EN VACUTAP® VR I (without VR I 2602) 59  9 Inserting diverter switch insert 4. Once the diverter switch operation begins, turn the hand crank in the same direction while counting the sections required for the pointer to reach the mid-position of the area marked in gray on the tap-change in- dicator. Note the number counted (value A) and the direction of rotation (example: A=2). Figure 59: Counting the tap changes needed to reach the mid-position 5. If value A is greater than 8 tap-change indicator sections, the tap- change operation has been completed correctly. If value A is less than 8 tap-change indicator sections, turn another 8-A tap-change indicator sections in the same direction (example: 8-2=6) to complete the tap- change operation. Then turn in the opposite direc