BAL_4349315_02_001_EN.pdf

On-load tap-changer VACUTAP® VR® Installation and commissioning instructions 4349315/02 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 wil...

On-load tap-changer VACUTAP® VR® Installation and commissioning instructions 4349315/02 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 Manufacturer....................................................................................................................................... 7 1.2 Completeness..................................................................................................................................... 7 1.3 Safekeeping........................................................................................................................................ 7 1.4 Notation conventions.......................................................................................................................... 7 1.4.1 Hazard communication system............................................................................................................................. 7 1.4.2 Information system................................................................................................................................................ 9 1.4.3 Instruction system................................................................................................................................................. 9 2 Safety................................................................................................................................. 11 2.1 Appropriate use................................................................................................................................ 11 2.2 Inappropriate use.............................................................................................................................. 12 2.3 Fundamental safety instructions....................................................................................................... 12 2.4 Personnel qualification...................................................................................................................... 14 2.5 Personal protective equipment......................................................................................................... 15 3 Product description.......................................................................................................... 16 3.1 Scope of delivery.............................................................................................................................. 16 3.2 On-load tap-changer......................................................................................................................... 16 3.2.1 Function description............................................................................................................................................ 16 3.2.2 Setup/models...................................................................................................................................................... 17 3.2.3 Nameplate and serial number............................................................................................................................. 22 3.2.4 Protective devices............................................................................................................................................... 22 3.3 Drive shaft......................................................................................................................................... 30 3.3.1 Function description............................................................................................................................................ 30 3.3.2 Design/versions................................................................................................................................................... 31 4 Packaging, transport and storage.................................................................................. 36 4.1 Packaging......................................................................................................................................... 36 4.1.1 Suitability............................................................................................................................................................. 36 4.1.2 Markings.............................................................................................................................................................. 37 4.2 Transportation, receipt and handling of shipments........................................................................... 38 4.3 Storage of shipments........................................................................................................................ 39 4.4 Unpacking shipments and checking for transportation damages..................................................... 40 Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 3  Table of contents 5 Mounting........................................................................................................................... 41 5.1 Preparatory work.............................................................................................................................. 41 5.1.1 Fitting mounting flange on transformer cover...................................................................................................... 41 5.1.2 Fitting stud bolts on mounting flange.................................................................................................................. 42 5.2 Installing the on-load tap-changer in the transformer (standard version)......................................... 43 5.2.1 Fastening on-load tap-changer to transformer cover.......................................................................................... 43 5.2.2 Connecting the tap winding and on-load tap-changer take-off lead.................................................................... 56 5.2.3 Performing transformer ratio test before drying.................................................................................................. 66 5.2.4 Performing DC resistance measurement on transformer.................................................................................... 67 5.2.5 Drying on-load tap-changer in autoclave............................................................................................................ 68 5.2.6 Drying on-load tap-changer in transformer tank.................................................................................................. 74 5.2.7 Filling the oil compartment of the on-load tap-changer with insulating fluid........................................................ 95 5.2.8 Performing transformer ratio test after drying..................................................................................................... 97 5.3 Installing on-load tap-changer in transformer (bell-type tank version).............................................. 98 5.3.1 Inserting on-load tap-changer into supporting structure...................................................................................... 98 5.3.2 Connecting the tap winding and on-load tap-changer take-off lead.................................................................. 108 5.3.3 Performing transformer ratio test before drying................................................................................................ 118 5.3.4 Performing DC resistance measurement on transformer.................................................................................. 119 5.3.5 Drying on-load tap-changer in autoclave.......................................................................................................... 120 5.3.6 Lifting top part of on-load tap-changer head off supporting flange (bottom part).............................................. 127 5.3.7 Attaching the bell-type tank and connecting the on-load tap-changer to the top part of the on-load tap-changer head.................................................................................................................................................................. 135 5.3.8 Drying on-load tap-changer in transformer tank................................................................................................ 147 5.3.9 Filling the oil compartment of the on-load tap-changer with insulating fluid...................................................... 168 5.3.10 Performing transformer ratio test after drying................................................................................................... 170 5.4 Fitting protective devices and drive components............................................................................ 171 5.4.1 Electrically connecting the temperature sensor................................................................................................ 171 5.4.2 Connecting the tap-change supervisory device................................................................................................ 171 5.4.3 Installing protective relay in piping and connecting........................................................................................... 171 5.4.4 Installing and connecting the pressure monitoring device................................................................................ 183 5.4.5 Fitting motor-drive unit...................................................................................................................................... 185 5.4.6 Fitting drive shaft............................................................................................................................................... 185 5.4.7 Centering on-load tap-changer and motor-drive unit........................................................................................ 244 5.4.8 Making the electrical connections for the motor-drive unit................................................................................ 244 4 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 Table of contents 6 Commissioning............................................................................................................... 245 6.1 Commissioning the on-load tap-changer at the transformer manufacturer's site........................... 245 6.1.1 Bleeding on-load tap-changer head and suction pipe....................................................................................... 246 6.1.2 Grounding the on-load tap-changer.................................................................................................................. 247 6.1.3 Checking motor-drive unit................................................................................................................................. 249 6.1.4 High-voltage tests on the transformer............................................................................................................... 249 6.2 Transporting transformer to the operating site................................................................................ 251 6.2.1 Transport with drive removed............................................................................................................................ 251 6.2.2 Transport with full transformer tank and without oil conservator....................................................................... 251 6.2.3 Transport with empty transformer tank............................................................................................................. 252 6.3 Commissioning transformer at operating site................................................................................. 253 6.3.1 Filling the oil compartment of the on-load tap-changer with insulating fluid...................................................... 253 6.3.2 Bleeding on-load tap-changer head and suction pipe....................................................................................... 255 6.3.3 Checking motor-drive unit................................................................................................................................. 256 6.3.4 Checking protective relay.................................................................................................................................. 257 6.3.5 Checking pressure monitoring device............................................................................................................... 258 6.3.6 Commissioning the transformer........................................................................................................................ 259 7 Fault elimination............................................................................................................. 260 7.1 Tripping the protective relay and re-commissioning the transformer.............................................. 262 7.1.1 Flap valve in OPERATION position.................................................................................................................. 263 7.1.2 Flap valve in OFF position................................................................................................................................ 263 7.1.3 Re-commissioning the transformer................................................................................................................... 263 7.2 Tripping the pressure monitoring device and putting the transformer back into operation............. 264 7.2.1 Sensor in the OPERATION position................................................................................................................. 264 7.2.2 Sensor in the OFF position............................................................................................................................... 265 7.2.3 Re-commissioning the transformer................................................................................................................... 265 8 Disposal........................................................................................................................... 266 9 Technical data................................................................................................................. 267 9.1 Technical data for on-load tap-changer.......................................................................................... 267 9.1.1 On-load tap-changer properties........................................................................................................................ 267 9.1.2 Permissible ambient conditions......................................................................................................................... 270 9.2 Technical data for protective relay.................................................................................................. 271 9.3 Special models of protective relay.................................................................................................. 273 9.3.1 Protective relay with CO change-over contact as tripping switch..................................................................... 273 9.3.2 Protective relay with several dry-reed magnetic switches................................................................................. 274 Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 5  Table of contents 9.4 Technical data for pressure monitoring device............................................................................... 275 9.5 Limit values for dielectric strength and water content of insulating fluids....................................... 276 10 Drawings......................................................................................................................... 277 10.1 899992............................................................................................................................................ 278 10.2 899898............................................................................................................................................ 279 10.3 899945............................................................................................................................................ 280 10.4 727042............................................................................................................................................ 281 10.5 899941............................................................................................................................................ 282 10.6 786919............................................................................................................................................ 283 10.7 786920............................................................................................................................................ 284 10.8 720781............................................................................................................................................ 285 10.9 720845............................................................................................................................................ 286 10.10 893899............................................................................................................................................ 287 10.11 895168............................................................................................................................................ 288 10.12 899648............................................................................................................................................ 289 10.13 728557............................................................................................................................................ 290 10.14 719853............................................................................................................................................ 291 10.15 721089............................................................................................................................................ 293 10.16 719850............................................................................................................................................ 295 10.17 719851............................................................................................................................................ 296 10.18 721092............................................................................................................................................ 297 10.19 727074............................................................................................................................................ 298 10.20 719852............................................................................................................................................ 299 10.21 731412............................................................................................................................................ 300 10.22 731411............................................................................................................................................ 301 10.23 731410............................................................................................................................................ 302 10.24 731000............................................................................................................................................ 303 10.25 730977............................................................................................................................................ 304 10.26 721091............................................................................................................................................ 305 10.27 727075............................................................................................................................................ 306 10.28 890183............................................................................................................................................ 307 10.29 890182............................................................................................................................................ 308 10.30 892916............................................................................................................................................ 309 6 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 1 Introduction 1 Introduction This technical file contains detailed descriptions of the safe and proper in- stallation, connection, and commissioning of the product. It also includes safety instructions and general information about the prod- uct. Information about operation can be found in the operating instructions. This technical file is intended solely for specially trained and authorized per- sonnel. 1.1 Manufacturer The product is manufactured by: Maschinenfabrik Reinhausen GmbH Falkensteinstraße 8 93059 Regensburg Tel.: (+49) 9 41/40 90-0 E-mail: [email protected] Further information on the product and copies of this technical file are avail- able from this address if required. 1.2 Completeness This technical file is incomplete without the supporting documents. The following documents are considered supporting documents: ▪ Unpacking instructions ▪ Supplement ▪ Routine test report ▪ Connection diagrams ▪ Dimensional drawings ▪ Order confirmation 1.3 Safekeeping Keep this technical file and all supporting documents ready at hand and ac- cessible for future use at all times. 1.4 Notation conventions 1.4.1 Hazard communication system Warnings in this technical file are displayed as follows. Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 7  1 Introduction 1.4.1.1 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 of danger! Source of the danger and outcome. ► Action ► Action 1.4.1.2 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. 1.4.1.3 Signal words and pictograms The following signal words are used: Signal word Definition 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 minor or moderate injury. NOTICE Indicates measures to be taken to prevent damage to property. Table 1: Signal words in warning notices 8 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 1 Introduction Pictograms warn of dangers: Pictogram Definition Warning of a danger point Warning of dangerous electrical voltage Warning of combustible substances Warning of danger of tipping Warning of danger of crushing Table 2: Pictograms used in warning notices 1.4.2 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. 1.4.3 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 GmbH 2021 4349315/02 EN VACUTAP® VR® 9  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). 10 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 2 Safety 2 Safety ▪ Read this technical file through to familiarize yourself with the product. ▪ This technical file is a part of the product. ▪ Read and observe the safety instructions provided in this chapter. ▪ Read and observe the warnings in this technical file in order to avoid func- tion-related dangers. ▪ The product is manufactured on the basis of state-of-the-art technology. Nevertheless, risks to life and limb for the user or impairment of the prod- uct and other material assets due to the function may arise in the event of improper use. 2.1 Appropriate use The product is an on-load tap-changer and adjusts the transmission ratio of transformers without interrupting the load flow. The product is designed solely for use in electrical energy systems and facilities. If used as intended and in compliance with the requirements and conditions specified 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 danger to people, property or the environment. This applies throughout the service life of the product, from delivery, installation and operation to removal and disposal. The following is considered appropriate use: ▪ Use the product only with the transformer/motor-drive unit specified in the order. ▪ The serial numbers of on-load tap-changer and on-load tap-changer ac- cessories (drive, drive shaft, bevel gear, protective relay, etc.) must match if the on-load tap-changer and on-load tap-changer accessories are sup- plied as a set for one order. ▪ You will find the standard valid for the product and the year of issue on the nameplate. ▪ Operate the product in accordance with this provided technical file, the agreed delivery conditions and technical data. ▪ Ensure that all necessary work is performed by qualified personnel only. ▪ Only use the equipment and special tools included in the scope of delivery for the intended purpose and in accordance with the specifications of this technical file. ▪ The on-load tap-changer is not intended to be used with an oil filter unit. Permitted electrical operating conditions In addition to the design data in accordance with the order confirmation, ob- serve the following limits for the through-current and the step voltage: In the standard version, the on-load tap-changer is designed for sinusoidal 50/60 Hz alternating current with a curve form symmetrical to the zero axis and can switch 2 times the rated through-current Ir at its rated step voltage Uir. Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 11  2 Safety Exceeding the rated step voltage Uir by up to 10% for a short period is per- mitted as long as the rated step capacity PStN permissible for this step volt- age is not exceeded. 2.2 Inappropriate use Use is considered inappropriate if the product is used in a way other than as described in the "Appropriate use" section. In addition, observe the following: Prohibited electrical operating conditions All operating conditions that do not comply with the design data in accor- dance with the order confirmation are prohibited. Prohibited operating conditions may arise due to short circuits as well as due to inrush current impulses when energizing transformers or other electrical machines. This applies to the affected transformer itself just as it does to transformers electrically connected in parallel or serially or other electrical machines. Higher voltages may occur due to transformer overexcitation following load shedding, for example. Operations outside of the permitted operating conditions can lead to injury to persons and damage to the product. ▪ Prevent any such operations outside of the permitted operating conditions by taking suitable measures. 2.3 Fundamental safety instructions 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: Personal protective equipment Loosely worn or unsuitable clothing increases the danger of becoming trapped or caught up in rotating parts and the danger of getting caught on protruding parts. This poses a danger to life and limb. ▪ Wear appropriate personal protective equipment such as a helmet, work gloves, etc. for the respective activity. ▪ Never wear damaged personal protective equipment. ▪ Never wear rings, necklaces, or other jewelry. ▪ If you have long hair, wear a hairnet. 12 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 2 Safety Work area Untidy and poorly lit work areas can lead to accidents. ▪ Keep the work area clean and tidy. ▪ Make sure that the work area is well lit. ▪ Observe the applicable laws for accident prevention in the relevant coun- try. Working during operation The product may only be operated in a sound, operational condition. Other- wise it poses a danger to life and limb. ▪ Regularly check the operational reliability of safety equipment. ▪ Comply with the inspection work, maintenance work and maintenance in- tervals described in this technical file. Explosion protection Highly flammable or explosive gases, vapors and dusts can cause serious explosions and fire. This increases the danger to life and limb. ▪ Do not install, operate or perform maintenance work on the product in ar- eas where a risk of explosion is present. Safety markings Warning signs and safety information plates are safety markings on the product. They are an important aspect of the safety concept. ▪ Observe all safety markings on the product. ▪ Make sure all safety markings on the product remain intact and legible. ▪ Replace safety markings that are damaged or missing. Ambient conditions To ensure reliable and safe operation, the product must only be operated under the ambient conditions specified in the technical data. ▪ Observe the specified operating conditions and requirements for the in- stallation location. Auxiliary materials and operating materials Auxiliary materials and operating materials not approved by the manufac- turer can lead to personal injury, damage to property and malfunctions of the product. ▪ Only use insulating fluids [►Section 9.1.2, Page 270] approved by the manufacturer. ▪ Only use conductive and grounded hoses, pipes and pump equipment that are approved for flammable liquids. Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 13  2 Safety ▪ Only use lubricants and auxiliary materials approved by the manufacturer. ▪ Contact the manufacturer. Modifications and conversions Unauthorized or inappropriate changes to the product may lead to personal injury, material damage and operational faults. ▪ Only modify the product after consultation with Maschinenfabrik Rein- hausen GmbH. Spare parts Spare parts not approved by Maschinenfabrik Reinhausen GmbH may lead to physical injury, damage to the product and malfunctions. ▪ Only use spare parts that have been approved by Maschinenfabrik Rein- hausen GmbH. ▪ Contact Maschinenfabrik Reinhausen GmbH. 2.4 Personnel qualification The person responsible for assembly, commissioning, operation, mainte- nance and inspection must ensure that the personnel are sufficiently quali- fied. Electrically skilled person The electrically skilled person has a technical qualification and therefore has the required knowledge and experience, and is also conversant with the ap- plicable standards and regulations. The electrically skilled person is also pro- ficient in the following: ▪ Can identify potential dangers independently and is able to avoid them. ▪ Is able to perform work on electrical systems. ▪ Is specially trained for the working environment in which (s)he works. ▪ Must satisfy the requirements of the applicable statutory regulations for accident prevention. Electrically trained persons An electrically trained person receives instruction and guidance from an electrically skilled person in relation to the tasks undertaken and the poten- tial dangers in the event of inappropriate handling as well as the protective devices and safety measures. The electrically trained person works exclu- sively under the guidance and supervision of an electrically skilled person. 14 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 2 Safety Operator The operator uses and operates the product in line with this technical file. The operating company provides the operator with instruction and training on the specific tasks and the associated potential dangers arising from im- proper handling. Technical Service We strongly recommend having maintenance, repairs and retrofitting carried out by our Technical Service department. This ensures that all work is per- formed correctly. If maintenance is not carried out by our Technical Service department, please ensure that the personnel who carry out the mainte- nance are trained and authorized by Maschinenfabrik Reinhausen GmbH to carry out the work. Authorized personnel Authorized personnel are trained by Maschinenfabrik Reinhausen GmbH to carry out special maintenance. 2.5 Personal protective equipment Personal protective equipment must be worn during work to minimize risks to health. ▪ Always wear the personal protective equipment required for the job at hand. ▪ Never wear damaged personal protective equipment. ▪ Observe information about personal protective equipment provided in the work area. Protective clothing Close-fitting work clothing with a low tearing strength, with tight sleeves and with no protruding parts. It mainly serves to protect the wearer against being caught by moving machine parts. Safety shoes To protect against falling heavy objects and slipping on slippery surfaces. Safety glasses To protect the eyes from flying parts and splashing liq- uids. Visor To protect the face from flying parts and splashing liq- uids or other dangerous substances. Hard hat To protect against falling and flying parts and materials. Hearing protection To protect against hearing damage. Protective gloves To protect against mechanical, thermal, and electrical hazards. Table 3: Personal protective equipment Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 15  3 Product description 3 Product description 3.1 Scope of delivery The product is packaged with protection against moisture and is usually de- livered as follows: ▪ Diverter switch (oil compartment with diverter switch insert) ▪ Selector ▪ Motor-drive unit ▪ Drive shaft with coupling parts and bevel gear ▪ Protective devices ▪ Technical files Please refer to the delivery slip for full details of the scope of delivery. On-load tap-changers can also be provided as an on-load tap-changer set with a common motor-drive unit. Note the following information: ▪ Check the shipment for completeness on the basis of the shipping docu- ments. ▪ Store the parts in a dry place until installation ▪ The product must remain in its airtight, protective wrapping and may only be removed immediately before installation You will find more information in the "Packaging, transport, and stor- age" [►Section 4, Page 36] chapter. 3.2 On-load tap-changer 3.2.1 Function description On-load tap-changers are used to adjust the transmission ratio of transform- ers without interrupting the load flow. This makes it possible to compensate for aspects such as fluctuations in voltage occurring in the power transmis- sion grid. For this purpose, on-load tap-changers are fitted in transformers and connected to the active part of the transformer. A motor-drive unit which receives a control impulse (e.g. from a voltage reg- ulator) changes the operating position of the on-load tap-changer, as a result of which the transformer's transmission ratio is adapted to the prevailing op- erating requirements. 16 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 3 Product description Figure 1: System overview of on-load tap-changer, transformer 1 Transformer tank 6 Upper gear unit 2 Motor-drive unit 7 On-load tap-changer 3 Vertical drive shaft 8 Protective relay 4 Bevel gear 9 Oil conservator 5 Horizontal drive shaft 10 Active part of the transformer 3.2.2 Setup/models The following drawing shows the main components of the on-load tap- changer. Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 17  3 Product description You will find a detailed drawing of the on-load tap-changer in the "Drawings [►Section 10, Page 277]" section. Figure 2: VACUTAP® VRC/VRE 1 On-load tap-changer head 3 Tap selector 2 Oil compartment 4 Change-over selector 18 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 3 Product description Figure 3: VACUTAP® VRD/VRF 1 On-load tap-changer head 3 Tap selector 2 Oil compartment 4 Change-over selector Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 19  3 Product description Figure 4: VACUTAP® VRG 1 On-load tap-changer head 3 Tap selector 2 Oil compartment 4 Change-over selector 3.2.2.1 Pipe connections The on-load tap-changer head features 4 pipe connections for different pur- poses. 20 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 3 Product description Depending on the order, some or all of these pipe connections are fitted with pipe bends ex factory. All pipe bends without terminal box for the tap-change supervisory control can be freely swiveled once the pressure ring is loos- ened. Figure 5: Pipe connections with pipe bends Pipe connection Q The pipe connection Q is closed with a blank cover. If the on-load tap- changer is equipped with a tap-change supervisory device, the connection cables for the tap-change supervisory device are fed through the pipe con- nection. The functions of the R and Q pipe connections can be interchanged. Pipe connection S The pipe bend on pipe connection S features a vent screw and can be con- nected to a pipe that ends with a drain valve on the side of the transformer tank at operating height. If the on-load tap-changer is fitted with an oil suc- tion pipe, the on-load tap-changer can be completely emptied via pipe con- nection S. Pipe connection R Pipe connection R is intended for attachment of the protective relay and con- nection of the on-load tap-changer oil conservator and can be interchanged with pipe connection Q. Pipe connection E2 Pipe connection E2 is sealed off with a blank cover. It leads into the oil tank of the transformer, directly under the on-load tap-changer head and can be connected to a collective pipe for the Buchholz relay, if necessary. This pipe connection serves a further purpose, namely to equalize the pressure be- Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 21  3 Product description tween the transformer tank and oil compartment of the on-load tap-changer, which is necessary for drying, filling with insulating fluid and transportation of the transformer. 3.2.3 Nameplate and serial number The nameplate with serial number is on the on-load tap-changer head cover. Figure 6: Nameplate 3.2.4 Protective devices The on-load tap-changer is equipped with the following protective devices. 3.2.4.1 Protective relay 3.2.4.1.1 Function description The protective relay is looped into the circuit breaker tripping circuit. It is tripped when the specified speed of flow from the on-load tap-changer head to the oil conservator is exceeded due to a fault. The flowing insulating fluid actuates the flap valve which tips over into position OFF. The contact in the dry-reed magnetic switch is thereby actuated, the circuit breakers are tripped, and the transformer is de-energized. The protective relay is a component of an on-load tap-changer filled with in- sulating fluid and its properties conform to the respective applicable version of IEC publication 60214-1. Diverter switch operations at rated switching capacity or at permissible over- load will not cause the protective relay to trip. The protective relay responds to flow, not to gas accumulated in the protec- tive relay. It is not necessary to bleed the protective relay when filling the transformer with insulating fluid. Gas accumulation in the protective relay is normal. 22 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 3 Product description 3.2.4.1.2 Design/versions Front view Figure 7: Protective relay RS 2001 1 Inspection window 2 Pressure equalization element Rear view Figure 8: Protective relay RS 2001 1 Dummy plug 2 Nameplate The protective relay RS 2001/R has an extra inspection window on the rear. Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 23  3 Product description View from above Figure 9: Protective relay RS 2001 1 Gasket 2 Potential tie-in 3 Terminal box cover 4 Slotted head screw for potential tie-in 5 OPERATION (reset) test button 6 Slotted head screw for protective cover 7 OFF (test tripping) test button 8 Cable gland 9 Protective cover 10 Dummy plug 11 Connection terminal 12 Pressure equalization element 13 Cylinder head screw for protective conductor connection The protective relays RS 2003 and RS 2004 have a 1/2"-14NPT adapter in place of the cable gland. 24 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 3 Product description 3.2.4.1.3 Nameplate The nameplate is on the back of the protective relay. Figure 10: Nameplate 3.2.4.1.4 Safety markings The following safety markings are used on the product: Figure 11: Safety markings overview 1 Protective conductor connection 2 Warning of dangerous electrical voltage 3 Read the documentation 3.2.4.2 Pressure monitoring device DW 3.2.4.2.1 Function description The DW 2000 pressure monitoring device protects the on-load tap-changer from impermissible pressure increases, contributing to the safety of the transformer. The pressure monitoring device is installed on the outside of the on-load tap-changer and is tripped by impermissible static and dynamic pressures in the on-load tap-changer oil compartment. The pressure monitoring device uses a concept where a corrugated tube acts as a barometer together with a spring providing counter force. This as- sembly is mechanically linked to the sensor on the snap-action switch. Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 25  3 Product description The pressure increase activates the sensor on the snap-action switch, which flips into the OFF position. This triggers the circuit breaker and de-energizes the transformer. The sensor on the snap-action switch has to be reset to the initial position by hand after tripping. Low-energy interference does not cause the pressure monitoring device to trip since the required tripping pressure is not reached. The tripping pressure is set at the factory and prevented from being changed. The pressure monitoring device responds to large pressure increases faster than the protective relay. The protective relay is part of the standard MR pro- tection system and comes as standard. Additional use of a pressure monitoring device also requires installation of the provided protective relay. The features and characteristics of the pressure monitoring device comply with the respective applicable version of IEC publication 60214-1. Diverter switch operations at the rated switching capacity or permitted over- load do not cause the pressure-operated relay to trip. The pressure-operated relay responds to a pressure change and not to gas accumulation under the pressure-operated relay. Gas accumulation under the pressure-operated relay is normal. 3.2.4.2.2 Design/versions There are two variants of the pressure monitoring device: ▪ DW 2000 for vertical installation ▪ DW 2000 for horizontal installation 26 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 3 Product description The housing and the cover cap of the pressure monitoring device consist of lightweight, corrosion-resistant metal. Figure 12: Snap-action switch and pressure measuring element 1 Snap-action switch 2 Pressure measuring element Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 27  3 Product description Figure 13: Pressure monitoring device with cover cap and ventilation 1 Ventilation 2 Cover cap 3.2.4.3 Rupture disk The rupture disk is a pressure relief device without signaling contact in ac- cordance with IEC 60214-1 and is located in the on-load tap-changer head cover. The rupture disk responds to a defined overpressure in the oil compartment of the on-load tap-changer. 3.2.4.4 Pressure relief device MPreC® On request, MR will supply a pre-fitted MPreC® pressure relief device in place of the rupture disk. This device responds to a defined overpressure in the oil compartment of the on-load tap-changer. The on-load tap-changer therefore meets the requirements of IEC 60214-1 regarding pressure relief devices. 3.2.4.5 Tap-change supervisory device The tap-change supervisory device monitors both the drive shaft between on-load tap-changer(s) and motor-drive unit and the correct switching of the diverter switch. 28 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 3 Product description 3.2.4.6 Temperature monitoring The temperature monitoring system monitors the temperature of the insulat- ing fluid in the oil compartment of the on-load tap-changer. Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 29  3 Product description 3.3 Drive shaft 3.3.1 Function description The drive shaft is the mechanical connection between the drive and the on- load tap-changer/de-energized tap-changer. The bevel gear changes the direction from vertical to horizontal. Accordingly, the vertical drive shaft has to be mounted between drive and bevel gear, and the horizontal drive shaft between bevel gear and on-load tap-changer or de-energized tap-changer. 30 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 3 Product description 3.3.2 Design/versions The drive shaft consists of a square tube and is coupled at each end by two coupling brackets and one coupling bolt to the driving or driven shaft end of the device to be connected. Figure 14: Components of the drive shaft 1 Bevel gear 2 Hose clip 3 Telescopic protective tube 4 Coupling bracket 5 Square tube 6 Coupling bolt 7 Adapter ring 8 Protective cover Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 31  3 Product description 3.3.2.1 Drive shaft without cardan joint and without insulator Figure 15: Drive shaft without cardan joint and without insulator (= standard version) Configuration V 1 min Intermediate bearing Middle of hand crank – middle of 536 mm When the maximum value bevel gear (maximum permissible of 2472 mm is exceeded, it axial offset 2°) is necessary to use an in- termediate bearing. V 1 ≤ 2472 mm (without in- termediate bearing) V 1 > 2472 mm (with inter- mediate bearing) 32 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 3 Product description 3.3.2.2 Drive shaft without cardan joint and with insulator Figure 16: Drive shaft without cardan joint and with insulator (= special model) Configuration V 1 min Intermediate bearing Middle of hand crank – middle of 706 mm When the maximum value bevel gear (maximum permissible of 2472 mm is exceeded, it axial offset 2°) is necessary to use an in- termediate bearing. V 1 ≤ 2472 mm (without in- termediate bearing) V 1 > 2472 mm (with inter- mediate bearing) Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 33  3 Product description 3.3.2.3 Drive shaft with cardan joints, without insulator Figure 17: Drive shaft with cardan joints, without insulator (= special model) Configuration V 1 min [mm] Intermediate bearing for [mm] Middle of hand crank – middle of 798 V 1 > 2564 bevel gear (maximum permissible axial offset 20°) 34 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 3 Product description 3.3.2.4 Drive shaft with cardan joints, with insulator Figure 18: Drive shaft with cardan joints, with insulator (= special model) Configuration V 1 min [mm] Intermediate bearing for [mm] Middle of hand crank – middle of 978 V 1 > 2772 bevel gear (maximum permissible axial offset 20°) Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 35  4 Packaging, transport and storage 4 Packaging, transport and storage 4.1 Packaging The products are sometimes supplied with sealed packaging and sometimes in a dry state, depending on requirements. Sealed packaging surrounds the packaged goods with plastic foil on all sides. Products that have also been dried are identified by a yellow label on the sealed packaging. In the dry state, delivery is also possible in a transport container. The information in the following sections should be applied as appropriate. 4.1.1 Suitability NOTICE Property damage due to incorrectly stacked crates! Stacking the crates incorrectly can lead to damage to the packaged goods. ► The outer marking on the packaging states if, for example, the on-load tap-changer or selector has been packed upright. Never stack these crates. ► General rule: Do not stack crates above a height of 1.5 m. ► For other crates: Only stack up to 2 equally sized crates on top of one an- other. The packaging is suitable to ensure undamaged and fully functional means of transportation in compliance with local transportation laws and regula- tions. The packaged goods are packed in a sturdy crate. This crate ensures that, when in the intended transportation position, the packaged goods are stabi- lized to prevent impermissible changes in position, and that none of the parts touch the loading surface of the means of transport or touch the ground after unloading. Sealed packaging surrounds the packaged goods with plastic foil on all sides. The packaged goods are protected from humidity using a desiccant. The plastic foil was bonded after the desiccant is added. 36 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 4 Packaging, transport and storage 4.1.2 Markings The packaging bears a signature with instructions for safe transport and cor- rect storage. The following symbols apply to the shipment of non-hazardous goods. Adherence to these symbols is mandatory. Protect against Top Fragile Attach lifting Center of mass moisture gear here Table 4: Shipping pictograms Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 37  4 Packaging, transport and storage 4.2 Transportation, receipt and handling of shipments WARNING Danger of death or severe injury! Danger of death or serious injuries due to tipping or falling load. ► Only transport the crate when closed. ► Do not remove the securing material used in the crate during transport. ► If the product is delivered on a pallet, secure it sufficiently. ► Only trained and authorized persons may select the sling gear and se- cure the load. ► Do not walk under the suspended load. ► Use means of transport and lifting gear with a sufficient carrying capacity in accordance with the weight stated on the delivery slip. In addition to oscillation stress, jolts must also be expected during trans- portation. In order to prevent possible damage, avoid dropping, tipping, knocking over and colliding with the product. If a crate tips over, falls from a certain height (e.g. when slings tear) or is subject to an unbroken fall, damage must be expected regardless of the weight. Every delivered shipment must be checked for the following by the recipient before acceptance (acknowledgment of receipt): ▪ Completeness based on the delivery slip ▪ External damage of any type The checks must take place after unloading when the crate or transport con- tainer can be accessed from all sides. Visible damage If external transport damage is found upon receipt of the shipment, proceed as follows: ▪ Immediately record the identified transport damage in the shipping docu- ments and have this countersigned by the carrier. ▪ In the event of severe damage, total loss or high damage costs, immedi- ately notify the manufacturer and the relevant insurance company. ▪ After identifying damage, do not modify the condition of the shipment fur- ther and retain the packaging material until an inspection decision has been made by the transport company or the insurance company. ▪ Record the details of the damage immediately on site together with the carrier involved. This is essential for any claim for damages. ▪ Photograph damage to packaging and packaged goods. This also applies to signs of corrosion on the packaged goods due to moisture inside the packaging (rain, snow, condensation). ▪ NOTICE! Damage to packaged goods due to damaged sealed packag- ing. If the product is delivered in sealed packaging, check the sealed packaging immediately. If the sealed packaging is damaged, do not under 38 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 4 Packaging, transport and storage any circumstances install or commission the packaged goods. Either re- dry the dried packaged goods as per the operating instructions, or contact the manufacturer to agree on how to proceed. ▪ Identify the damaged parts. Hidden damage When damages are not determined until unpacking after receipt of the ship- ment (hidden damage), proceed as follows: ▪ Make the party responsible for the damage liable as soon as possible by telephone and in writing, and prepare a damage report. ▪ Observe the time periods applicable to such actions in the respective country. Inquire about these in good time. With hidden damage, it is very hard to make the transportation company (or other responsible party) liable. Any insurance claims for such damages can only be successful if relevant provisions are expressly included in the insur- ance terms and conditions. 4.3 Storage of shipments Packaged goods dried by Maschinenfabrik Reinhausen Upon receipt of the shipment, immediately remove the packaged goods dried by Maschinenfabrik Reinhausen from the sealed packaging and store air-tight in dry insulating fluid until used if the packaged goods were not sup- plied in insulating fluid. Non-dried packaged goods Non-dried packaged goods but with a functional sealed packaging can be stored outdoors when the following conditions are complied with. When selecting and setting up the storage location, ensure the following: ▪ Protect stored goods against moisture (flooding, water from melting snow and ice), dirt, pests such as rats, mice, termites and so on, and against unauthorized access. ▪ Store the crates on timber beams and planks as a protection against ris- ing damp and for better ventilation. ▪ Ensure sufficient carrying capacity of the ground. ▪ Keep entrance paths free. ▪ Check stored goods at regular intervals. Also take appropriate action after storms, heavy rain or snow and so on. Protect the packaging foil from direct sunlight so that it does not disintegrate under the influence of UV rays, which would cause the packaging to lose its sealing function. Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 39  4 Packaging, transport and storage If the product is installed more than 6 months after delivery, suitable mea- sures must be taken without delay. The following measures can be used: ▪ Correctly regenerate the drying agent and restore the sealed packaging. ▪ Unpack the packed goods and store in a suitable storage space (well ven- tilated, as dust-free as possible, humidity < 50% where possible). 4.4 Unpacking shipments and checking for transportation damages ▪ NOTICE! Damage to packaged goods due to ineffectively sealed packag- ing. Transport the packaged crate to the place where the packaged goods are to be installed. Do not open the sealed packaging until just before in- stallation. ▪ WARNING! Serious injuries and damage to the packaged goods due to the packaged goods tipping out. Place the packaged goods in an up- right crate and protect it from tipping out. ▪ Unpack the packaged goods and check the condition. ▪ Check the completeness of the accessories kit using the delivery slip. 40 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 5 Mounting 5 Mounting WARNING Risk of crushing! When the on-load tap-changer undertakes a tap-change operation, compo- nents – some of which are freely accessible – move on the selector, change-over selector, and potential connection unit. Reaching into the se- lector, change-over selector, or potential connection unit during a tap- change operation may result in serious injuries. ► Keep at a safe distance of at least 1 m during tap-change operations. ► Do not reach into the selector, change-over selector, or potential connec- tion unit during tap-change operations. ► Do not switch the on-load tap-changer during work on the selector, change-over selector, or potential connection unit. 5.1 Preparatory work Perform the work stated below before installing the on-load tap-changer in the transformer. 5.1.1 Fitting mounting flange on transformer cover A mounting flange is required for fitting the on-load tap-changer head on the transformer cover. This can be supplied as an option or can be produced by the customer. Mounting flanges made by the customer must comply with the installation drawings in the appendix. ► NOTICE! Fit mounting flange on transformer cover (pressure tight).En- sure that the sealing face makes complete contact and is not damaged. Figure 19: Mounting flange Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 41  5 Mounting 5.1.2 Fitting stud bolts on mounting flange To attach the stud bolts to the mounting flange, use a tracing template. This can be provided upon request free of charge for the initial installation of the on-load tap-changer. 1. Place tracing template on mounting flange and use the four markings to align. 2. Fit stud bolts on mounting flange. Figure 20: Tracing template, stud bolts 42 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 5 Mounting 5.2 Installing the on-load tap-changer in the transformer (standard version) 5.2.1 Fastening on-load tap-changer to transformer cover 5.2.1.1 Fastening oil compartment on transformer cover 1. CAUTION! An unstably positioned oil compartment may tip over, re- sulting in injuries or property damage. Place the oil compartment on a level surface and secure it against tipping. 2. Remove red-colored packaging material and transport material from oil compartment. 3. Clean sealing surfaces on mounting flange and on-load tap-changer head, place oil-resistant gasket on mounting flange. Figure 21: Sealing surfaces, gasket Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 43  5 Mounting 4. NOTICE! Lowering the oil compartment without due care can result in the oil compartment colliding with the transformer cover and becoming dam- aged. Lift the oil compartment by hooking up the on-load tap-changer head and carefully lower it vertically into the opening of the transformer cover. Figure 22: Oil compartment 5. Check that the on-load tap-changer head is mounted in the position speci- fied by the design. 44 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 5 Mounting 6. Screw the on-load tap-changer head to the mounting flange. Figure 23: On-load tap-changer head with mounting flange 7. Remove the blocking device from the coupling of the oil compartment base. Figure 24: VACUTAP® VRC/VRE, blocking strip Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 45  5 Mounting Figure 25: VACUTAP® VRD/VRF, blocking plate and shackle Figure 26: VACUTAP® VRG, blocking plate and shackle 46 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 5 Mounting 5.2.1.2 Securing tap selector on oil compartment of the on-load tap-changer VRC/VRE 1. CAUTION! An unstably positioned selector may tip, resulting in in- juries or property damage. Place the selector on a level surface and se- cure it against tipping. 2. Remove red-colored packaging material and transport material from the selector. Only remove the red protective cap on the 0-bar of the change- over selector (if present) after fixing the selector to the oil compartment. 3. Remove plastic bag with fastening materials from the selector and keep it ready. Figure 27: Plastic bag with fastening materials 4. Remove the blocking strip from the selector coupling. Once the blocking strip is removed, the selector coupling may no longer be turned. Figure 28: Selector coupling with blocking strip Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 47  5 Mounting 5. Place the selector on the lifting device. The weight of the selector is a maximum of 165 kg (multiple coarse change-over selector max. 280 kg). 6. NOTICE! Lifting the selector without due care can result in the selector and oil compartment colliding and becoming damaged. Carefully lift the selector below the oil compartment, ensuring that the tap-selector con- necting leads and potential connection unit (if installed) are free when lift- ing the selector onto the oil compartment, and that they do not touch the compartment. 7. Align the position of both coupling parts and attachment points on the oil compartment and the selector with one another. The correct position of the two coupling parts is shown in the adjustment plans supplied. 8. Screw selector onto oil compartment. Figure 29: Selector with oil compartment 48 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 5 Mounting 9. NOTICE! Incorrect tightening torques and unsecured screw connections can lead to damage to the on-load tap-changer. Screw the tap-selector connecting leads to connecting piece with care. Comply with the specified tightening torque, secure screw connections and snap the screening caps in place over the screw heads. Figure 30: Tap-selector connecting leads Figure 31: Tap-selector connecting leads 10. Remove the red protective cap on the 0-bar of the change-over selector (if present). 5.2.1.3 Securing tap selector on oil compartment of the on-load tap-changer VRD/VRF 1. CAUTION! An unstably positioned selector may tip, resulting in in- juries and property damage. Place the selector on a level surface and se- cure it against tipping. 2. Remove red-colored packaging material and transport material from the selector. Only remove the red supports and set-down cylinder (if present), however, after fixing the selector to the oil compartment. Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 49  5 Mounting 3. Remove plastic bag with fastening materials from the selector and keep it ready. Figure 32: Plastic bag with fastening materials 4. Remove the blocking strip from the selector coupling. Once the blocking strip is removed, the selector coupling may no longer be turned. Figure 33: Blocking strip 5. Place the selector on the lifting device. The weight of the selector is a maximum of 270 kg. 50 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 5 Mounting 6. Remove the ring nuts from the selector. Figure 34: Ring nut 7. NOTICE! Lifting the selector without due care can result in the selector and oil compartment colliding and becoming damaged. Carefully lift the selector below the oil compartment, ensuring that the tap-selector con- necting leads and potential connection unit (if installed) are free when lift- ing the selector onto the oil compartment, and that they do not touch the compartment. 8. Align the position of both coupling parts and attachment points on the oil compartment and the selector with one another. The correct position of the two coupling parts is shown in the adjustment plans supplied. 9. Screw selector onto oil compartment. Figure 35: Selector with oil compartment Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 51  5 Mounting 10. NOTICE! Incorrect tightening torques and unsecured screw connections can lead to damage to the on-load tap-changer. Screw the tap-selector connecting leads to connecting piece with care. Comply with the speci- fied tightening torque, secure screw connections and snap the screening caps in place over the screw heads. Figure 36: Tap-selector connecting leads Figure 37: Tap-selector connecting leads 11. Remove the support and support ring on the underside of the change- over selector. 5.2.1.4 Securing tap selector on oil compartment of the on-load tap-changer VRG 1. CAUTION! An unstably positioned selector may tip, resulting in in- juries and property damage. Place the selector on a level surface and se- cure it against tipping. 2. Remove red-colored packaging material and transport material from the selector. 52 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 5 Mounting 3. Remove plastic bag with fastening materials from the selector and keep it ready. Figure 38: Plastic bag with fastening materials 4. Remove the blocking strip from the selector coupling. Once the blocking strip is removed, the selector coupling may no longer be turned. Figure 39: Blocking strip 5. Place the selector on the lifting device. The weight of the selector is a maximum of 465 kg. Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 53  5 Mounting 6. Remove the ring nuts from the selector. Figure 40: Ring nut 7. NOTICE! Lifting the selector without due care can result in the selector and oil compartment colliding and becoming damaged. Carefully lift the selector below the oil compartment, ensuring that the tap-selector con- necting leads and potential connection unit (if installed) are free when lift- ing the selector onto the oil compartment, and that they do not touch the compartment. 8. Align the position of both coupling parts and attachment points on the oil compartment and the selector with one another. The correct position of the two coupling parts is shown in the adjustment plans supplied. 9. Screw selector onto oil compartment. Figure 41: Selector with oil compartment 54 VACUTAP® VR® 4349315/02 EN Maschinenfabrik Reinhausen GmbH 2021 5 Mounting 10. NOTICE! Incorrect tightening torques and unsecured screw connections can lead to damage to the on-load tap-changer. Screw the tap-selector connecting leads to connecting piece with care. Comply with the speci- fied tightening torque, secure screw connections and snap the screening caps in place over the screw heads. Figure 42: Tap-selector connecting leads Figure 43: Tap-selector connecting leads Maschinenfabrik Reinhausen GmbH 2021 4349315/02 EN VACUTAP® VR® 55  5 Mounting 5.2.2 Connecting the tap winding and on-load tap-changer take-off lead NOTICE Damage to the on-load tap-changer! Connecting leads that place mechanical strain on the on-load ta