BAL_4349312_04_001_EN.pdf

THE POWER BEHIND POWER. Operating instructions VACUTAP® VV®. On-load tap-changer 4349312/04 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. Infringement...

THE POWER BEHIND POWER. Operating instructions VACUTAP® VV®. On-load tap-changer 4349312/04 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 product is delivered in accordance with MR's technical specifications, which are based on information provided by the customer. The customer has a duty of care to ensure the compatibility of the specified product with the customer's planned scope of application. The original operating instructions were written in German. Table of contents 1 Introduction................................................. 4 7.2 Maintenance intervals................................................ 40 1.1 Manufacturer................................................................. 4 7.3 Changing the insulation fluid.................................... 42 1.2 Completeness............................................................... 4 7.3.1 Moving on-load tap-changer to 1.3 Safekeeping................................................................... 4 adjustment position...................................... 42 1.4 Notation conventions.................................................. 5 7.3.2 Removing horizontal drive shaft.................... 42 1.4.1 Hazard communication system....................... 5 7.3.3 Emptying the oil compartment and oil 1.4.2 Information system........................................... 5 conservator.................................................... 44 1.4.3 Instruction system............................................. 5 7.3.4 Filling the oil compartment and oil conservator with fresh insulating fluid........ 45 2 Safety........................................................... 7 7.3.5 Installing horizontal drive shaft...................... 47 2.1 Appropriate use............................................................. 7 7.3.6 Centering on-load tap-changer and 2.2 Inappropriate use......................................................... 8 motor-drive unit............................................ 48 2.3 Fundamental safety instructions................................ 8 7.4 Performing DC resistance measurement on 2.4 Personal protective equipment.................................. 9 transformer.............................................................. 49 2.5 Personnel qualification............................................... 10 8 Technical data........................................... 50 3 Product description.................................... 12 8.1 Technical data for on-load tap-changer................... 50 3.1 On-load tap-changer................................................... 12 8.1.1 On-load tap-changer properties..................... 50 3.1.1 Function description......................................... 12 8.1.2 Permissible ambient conditions...................... 51 3.1.2 Setup/models................................................... 13 8.1.3 Height of the oil conservator........................... 51 3.1.3 Nameplate and serial number........................ 14 8.1.4 Installation height above sea level................ 52 3.1.4 Protective devices........................................... 14 8.2 Technical data for protective relay RS...................... 53 3.2 Drive shaft................................................................... 20 8.3 Special models of protective relay RS...................... 55 3.2.1 Function description........................................ 20 8.3.1 Protective relay with CO change-over 3.2.2 Design/versions.............................................. 20 contact as tripping switch............................ 55 8.3.2 Protective relay with several dry-reed 4 Commissioning.......................................... 25 magnetic switches........................................ 55 4.1 Commissioning transformer at operating site........ 25 8.4 Technical data for pressure monitoring device...... 57 4.1.1 Filling the oil compartment of the on- 8.5 Limit values for dielectric strength and water load tap-changer with insulating fluid......... 25 content of insulating fluids..................................... 58 4.1.2 Bleeding on-load tap-changer head and suction pipe................................................... 27 9 Drawings................................................... 59 4.1.3 Checking motor-drive unit............................. 28 9.1 737774......................................................................... 60 4.1.4 Checking protective relay............................... 28 9.2 898863......................................................................... 61 4.1.5 Checking pressure monitoring device........... 29 9.3 737060......................................................................... 62 4.1.6 Commissioning the transformer................... 30 9.4 738902........................................................................ 63 9.5 739172......................................................................... 64 5 Operation.................................................... 31 9.6 898866........................................................................ 65 5.1 Operating the motor-drive unit with the hand 9.7 899110......................................................................... 66 crank.......................................................................... 31 9.8 899409........................................................................ 67 9.9 899083........................................................................ 68 6 Fault elimination......................................... 33 9.10 899051....................................................................... 69 6.1 Tripping the protective relay and re- 9.11 733469....................................................................... 70 commissioning the transformer............................ 35 9.12 892916........................................................................ 71 6.1.1 Flap valve in OPERATION position................ 35 6.1.2 Flap valve in OFF position............................... 36 Glossary........................................................ 72 6.1.3 Re-commissioning the transformer............... 36 6.2 Tripping the pressure monitoring device and putting the transformer back into operation........ 37 6.2.1 Sensor in the OPERATION position.............. 37 6.2.2 Sensor in the OFF position............................. 37 6.2.3 Re-commissioning the transformer.............. 38 7 Maintenance.............................................. 39 7.1 Inspection.................................................................... 40 4349312/04 EN Table of contents 3  1 Introduction This technical file contains detailed descriptions for monitoring during opera- tion, fault elimination, and maintenance. It also includes safety instructions and general information about the product. Information about installation can be found in the installation and commission- ing instructions. This technical file is intended solely for specially trained and authorized person- nel. 1.1 Manufacturer Maschinenfabrik Reinhausen GmbH Falkensteinstraße 8 93059 Regensburg Deutschland +49 941 4090-0 [email protected] reinhausen.com MR Reinhausen customer portal: https://portal.reinhausen.com. Further information on the product and copies of this technical file are available 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 accessi- ble for future use at all times. 4 Introduction 4349312/04 EN  1.4 Notation conventions 1.4.1 Hazard communication system Warnings in this technical file are displayed as follows. 1.4.1.1 Warning relating to section Warnings relating to sections refer to entire chapters or sections, sub-sections 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 warnings apply to smaller units of information than the warnings relating to sections. Em- bedded warnings use the following format: DANGER! Instruction for avoiding a dangerous situation. 1.4.1.3 Signal words in warning notices Signal word Meaning 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 mi- nor or moderate injury. NOTICE Indicates measures to be taken to prevent damage to property. Table 1: Signal words 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. i 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: 4349312/04 EN Introduction 5  Aim of action Requirements (optional). Step 1 of 1. Result of step (optional). Result of action (optional). Multi-step instructions Instructions which consist of several process steps are structured as follows: Aim of action Requirements (optional). 1. Step 1. Result of step (optional). 2. Step 2. Result of step (optional). Result of action (optional). 6 Introduction 4349312/04 EN 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 product and other material assets due to the function may arise in the event of im- proper 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 envi- ronment. 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 acces- sories (drive, drive shaft, bevel gear, protective relay, etc.) must match if the on-load tap-changer and on-load tap-changer accessories are supplied 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. Exceeding the rated step voltage Uir by up to 10% for a short period is permitted as long as the rated step capacity PStN permissible for this step voltage is not ex- ceeded. 4349312/04 EN Safety 7  2.2 Inappropriate use Use is considered inappropriate if the product is used in a way other than as de- scribed 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 accordance 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 ma- chines. This applies to the affected transformer itself just as it does to trans- formers 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 adverse effects on the environment, those responsible for transport, installation, opera- tion, maintenance and disposal of the product or parts of the product must en- sure 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. 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 country. Working during operation The product may only be operated in a sound, operational condition. Otherwise 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 inter- vals described in this technical file. 8 Safety 4349312/04 EN  Explosion protection Highly flammable or explosive gases, vapors and dusts can cause serious explo- sions and fire. This increases the danger to life and limb. – Do not install, operate or perform maintenance work on the product in areas where a risk of explosion is present. Safety markings Warning signs and safety information plates are safety markings on the prod- uct. 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 installa- tion location. Auxiliary materials and operating materials Auxiliary materials and operating materials not approved by the manufacturer can lead to personal injury, damage to property and malfunctions of the prod- uct. – Only use insulating fluids [►Section 8.1.2, Page 51] approved by the manu- facturer. – Only use conductive and grounded hoses, pipes and pump equipment that are approved for flammable liquids. – 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 in- jury, material damage and operational faults. – Only modify the product after consultation with Maschinenfabrik Reinhausen 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 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. 4349312/04 EN Safety 9  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 slip- pery surfaces. Safety glasses To protect the eyes from flying parts and splashing liquids. Visor To protect the face from flying parts and splashing liquids 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 haz- ards. Table 2: Personal protective equipment 2.5 Personnel qualification The person responsible for assembly, commissioning, operation, maintenance and inspection must ensure that the personnel are sufficiently qualified. 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 applicable standards and regulations. The electrically skilled person is also proficient 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 acci- dent prevention. Electrically trained persons An electrically trained person receives instruction and guidance from an electri- cally skilled person in relation to the tasks undertaken and the potential dangers in the event of inappropriate handling as well as the protective devices and safety measures. The electrically trained person works exclusively under the guidance and supervision of an electrically skilled person. 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 improper han- dling. 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 de- partment, please ensure that the personnel who carry out the maintenance are trained and authorized by Maschinenfabrik Reinhausen GmbH to carry out the work. 10 Safety 4349312/04 EN Authorized personnel Authorized personnel are trained by Maschinenfabrik Reinhausen GmbH to carry out special maintenance. 4349312/04 EN Safety 11  3 Product description 3.1 On-load tap-changer 3.1.1 Function description On-load tap-changers are used to adjust the transmission ratio of transformers without interrupting the load flow. This makes it possible to compensate for as- pects such as fluctuations in voltage occurring in the power transmission 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 regula- tor) changes the operating position of the on-load tap-changer, and the trans- former's transmission ratio is adapted to the prevailing operating requirements as a result. Figure 1: System overview of on-load tap-changer, transformer 1 Transformer tank 6 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 12 Product description 4349312/04 EN 3.1.2 Setup/models The following drawing shows the main components of the on-load tap-changer. You will find a detailed drawing of the on-load tap-changer in the "Drawings [►Section 9, Page 59]" section. Figure 2: On-load tap-changer 1 Upper gear unit 2 On-load tap-changer head 3 Supporting flange 4 Connection contact 5 Oil compartment 6 Change-over selector 7 Pipe bend 8 Rupture disk 3.1.2.1 Pipe connections The on-load tap-changer head features 4 pipe connections for different pur- poses. Depending on the order, some or all of these pipe connections are fitted with pipe bends ex factory. All pipe bends can be freely swiveled once the pressure ring is loosened. Figure 3: Pipe connections with pipe bends Pipe connection Q The pipe connection Q is closed with a blank cover. 4349312/04 EN Product description 13  The functions of the R and Q pipe connections can be interchanged. i 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 suction pipe, the on-load tap-changer can be completely emptied via pipe connection 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 con- nected to a collective pipe for the Buchholz relay, if necessary. This pipe con- nection serves an additional purpose, namely to equalize the pressure between the transformer tank and the oil compartment of the on-load tap-changer, which is necessary for drying, filling and transporting the transformer. 3.1.3 Nameplate and serial number The nameplate is on the on-load tap-changer head cover. Figure 4: Nameplate with serial number 3.1.4 Protective devices The on-load tap-changer is equipped with the following protective devices. 3.1.4.1 Protective relay 3.1.4.1.1 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 mag- netic switch is thereby actuated, the circuit breakers are tripped, and the trans- former is de-energized. 14 Product description 4349312/04 EN  The protective relay is a component of an on-load tap-changer filled with insu- lating 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 i overload will not cause the protective relay to trip. The protective relay responds to flow, not to gas accumulated in the pro- i tective relay. It is not necessary to bleed the protective relay when filling the transformer with insulating fluid. Gas accumulation in the protective re- lay is normal. 3.1.4.1.2 Design/versions Front view Figure 5: Protective relay RS 2001 1 Inspection window 2 Pressure equalization element Rear view Figure 6: Protective relay RS 2001 1 Dummy plug 2 Nameplate The protective relay RS 2001/R has an extra inspection window on the rear. i 4349312/04 EN Product description 15  View from above Figure 7: 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 i place of the cable gland. 3.1.4.1.3 Nameplate The nameplate is on the back of the protective relay. Figure 8: Nameplate 16 Product description 4349312/04 EN  3.1.4.2 Pressure monitoring device DW 3.1.4.2.1 Function description The DW 2000 pressure monitoring device protects the on-load tap-changer from impermissible pressure increases, contributing to the safety of the trans- former. 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 assembly is mechanically linked to the sensor on the snap-action switch. 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 protec- tion system and comes as standard. Additional use of a pressure monitoring device also requires installation of i 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 i overload do not cause the pressure-operated relay to trip. The pressure-operated relay responds to a pressure change and not to gas i accumulation under the pressure-operated relay. Gas accumulation under the pressure-operated relay is normal. 3.1.4.2.2 Design/versions There are two variants of the pressure monitoring device: – DW 2000 for vertical installation – DW 2000 for horizontal installation 4349312/04 EN Product description 17  The housing and the cover cap of the pressure monitoring device consist of lightweight, corrosion-resistant metal. Figure 9: Snap-action switch and pressure measuring element 1 Snap-action switch 2 Pressure measuring element Figure 10: Pressure monitoring device with cover cap and ventilation 1 Ventilation 2 Cover cap 18 Product description 4349312/04 EN 3.1.4.3 Rupture disk The rupture disk is a pressure relief device without signaling contact in accor- dance 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. 3.1.4.4 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 com- partment of the on-load tap-changer. The on-load tap-changer therefore meets the requirements of IEC 60214-1 re- garding pressure relief devices. 3.1.4.5 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 di- verter switch. 3.1.4.6 Temperature monitoring The temperature monitoring system monitors the temperature of the insulating fluid in the oil compartment of the on-load tap-changer. 4349312/04 EN Product description 19  3.2 Drive shaft 3.2.1 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. 3.2.2 Design/versions The drive shaft consists of a square tube and is coupled at each end by two cou- pling brackets and one coupling bolt to the driving or driven shaft end of the de- vice to be connected. Figure 11: 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 20 Product description 4349312/04 EN 3.2.2.1 Drive shaft without cardan joint and without insulator Figure 12: Drive shaft without cardan joint and without insulator (= standard version) Configuration V 1 min Intermediate bearing Middle of hand crank – middle of bevel 536 mm When the maximum value of gear (maximum permissible axial offset 2472 mm is exceeded, it is 2°) necessary to use an interme- diate bearing. V 1 ≤ 2472 mm (without in- termediate bearing) V 1 > 2472 mm (with inter- mediate bearing) 4349312/04 EN Product description 21  3.2.2.2 Drive shaft without cardan joint and with insulator Figure 13: Drive shaft without cardan joint and with insulator (= special model) Configuration V 1 min Intermediate bearing Middle of hand crank – middle of bevel 706 mm When the maximum value of gear (maximum permissible axial offset 2472 mm is exceeded, it is 2°) necessary to use an interme- diate bearing. V 1 ≤ 2472 mm (without in- termediate bearing) V 1 > 2472 mm (with inter- mediate bearing) 22 Product description 4349312/04 EN 3.2.2.3 Drive shaft with cardan joints, without insulator Figure 14: Drive shaft with cardan joints, without insulator (= special model) Configuration V 1 min [mm] Intermediate bearing for [mm] Middle of hand crank – middle of bevel 798 V 1 > 2564 gear (maximum permissible axial offset 20°) 4349312/04 EN Product description 23  3.2.2.4 Drive shaft with cardan joints, with insulator Figure 15: Drive shaft with cardan joints, with insulator (= special model) Configuration V 1 min [mm] Intermediate bearing for [mm] Middle of hand crank – middle of bevel 978 V 1 > 2772 gear (maximum permissible axial offset 20°) 24 Product description 4349312/04 EN  4 Commissioning 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 surfaces or sparks (e.g. caused by the build-up of static charge) in the transformer's immediate surroundings during commissioning 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 substances. WARNING Danger of explosion! Overloading the on-load tap-changer can lead to explosion and thus to death or serious injury. Ensure that the on-load tap-changer is not overloaded. Ensure use of the on-load tap-changer in accordance with section "Appro- priate use". Prevent operations outside of the permitted operating conditions by taking suitable measures. 4.1 Commissioning transformer at operating site 4.1.1 Filling the oil compartment of the on-load tap-changer with insulating fluid NOTICE Damage to the on-load tap-changer! Unsuitable insulating fluids cause damage to the on-load tap-changer. Only use insulating fluids [►Section 8.1.2, Page 51] approved by the man- ufacturer. 1. NOTICE! Check whether the on-load tap-changer head cover has a flange for attaching a pressure relief device. If it does, operation without a pressure relief device is not permitted and may result in damage to the on-load tap- changer. Fit a pressure relief device which is approved for this on-load tap-changer on the on-load tap-changer head. 4349312/04 EN Commissioning 25  2. Establish a connecting lead between pipe connection E2 and one of the pipe connections R, S or Q to ensure equal pressure in the oil compartment and transformer during evacuation. Figure 16: Connecting lead 3. Fill on-load tap-changer with new insulating fluid using one of the two free pipe connections of the on-load tap-changer head. Figure 17: Pipe connections S and R 4. Take an insulating fluid sample from the oil compartment. 5. Record the temperature of the sample immediately after the sample is taken. 6. Determine dielectric strength and water content at a sample temperature of 20 °C ± 5 °C. The dielectric strength and water content must comply with the limit values specified in the technical data. 26 Commissioning 4349312/04 EN  4.1.2 Bleeding on-load tap-changer head and suction pipe 4.1.2.1 Bleeding on-load tap-changer head 1. Open all forward and return valves in the pipe system. 2. Remove screw cap on air-vent valve E1 on the on-load tap-changer head cover. Figure 18: Air-vent valve E1 3. Use screwdriver to lift valve tappet on air-vent valve E1 and bleed on-load tap-changer head. Figure 19: Valve tappet 4. Seal air-vent valve E1 with screw cap (tightening torque 10 Nm). 4.1.2.2 Bleeding suction pipe on pipe connection S 1. Remove screw cap from pipe connection S. Figure 20: Pipe connection S 2. Open vent screw and bleed piping. 3. Close vent screw. 4349312/04 EN Commissioning 27  4. Seal vent screw with screw cap. 4.1.3 Checking motor-drive unit NOTICE Damage to the on-load tap-changer / de-energized tap-changer! Damage to the on-load tap-changer / de-energized tap-changer due to actua- tion of the on-load tap-changer / de-energized tap-changer without insulating fluid. Ensure that the selector / de-energized tap changer is fully immersed in in- sulating fluid and that the oil compartment of the on-load tap-changer is completely filled with insulating fluid. NOTICE Damage to the on-load tap-changer and motor-drive unit! Damage to on-load tap-changer and motor-drive unit due to incorrect use of position transmitter equipment. Only circuits stated in the chapter Technical data for position transmitter equipment may be connected to the position transmitter module connec- tions. The switchover point of the position transmitter equipment in the motor- drive unit is not the same as the switchover point of the diverter switch op- eration. This depends on the type of diverter switch. This fact should be noted when project planning the locking circuits between the motor-drive unit and external equipment (e.g. transformer circuit breaker). Prior to commissioning the transformer, check whether the motor-drive unit and on-load tap-changer are correctly coupled and that the motor-drive unit functions correctly. Tests on the motor-drive unit 1. Perform function checks as described in relevant MR operating instructions for motor-drive unit. 2. NOTICE! An incorrectly coupled motor-drive unit will lead to damage to the on-load tap-changer. Undertake trial tap-change operations across the entire range of settings. Ensure that in each operating position, the tap position in- dicators of motor-drive unit and on-load tap-changer (inspection window in the on-load tap-changer head) match. Dielectric tests on transformer wiring Note information relating to dielectric tests on transformer wiring in relevant MR operating instructions for motor-drive unit. 4.1.4 Checking protective relay 4.1.4.1 Checking protective relay (RS 2001, 2001/V, 2001/H, 2001/E, 2001/5, 2001/R, 2001/T, 2003) Check that the protective relay is functioning correctly before commissioning the transformer: 1. Ground the transformer on the high-voltage side and low-voltage side. En- sure that the grounding for work connection on the transformer is not re- moved during testing. 2. Ensure that the transformer remains de-energized during testing. 3. Deactivate the automatic fire extinguishing device. 4. Loosen the three screws on the terminal box cover and lift off the terminal box cover. 28 Commissioning 4349312/04 EN  5. Remove the slotted head screw for potential tie-in and remove the terminal box cover with wire. 6. Press OFF test button. 7. Leave the transformer's danger zone. 8. Ensure that the transformer's circuit breaker cannot be closed. Passive protection test 9. Press OPERATION test button. 10. Leave the transformer's danger zone. 11. Close the transformer's circuit breaker with isolating switches open and the transformer grounded on all sides. 12. Press OFF test button. 13. Ensure that the transformer's circuit breaker is open. Active protection test. 14. Press OPERATION test button to reset the protective relay. 15. Position the wire for the terminal box cover and affix using the slotted head screw. 16. Attach the terminal box cover and secure with screws. 4.1.4.2 Checking protective relay (RS 2004) Check that the protective relay is functioning correctly before commissioning the transformer: 1. Ensure that the flap valve is in the OPERATION position. 2. Leave the transformer's danger zone. 3. Close the transformer's circuit breaker with isolating switches open and the transformer grounded on all sides. 4. Press OFF test button. 5. Ensure that the transformer's circuit breaker is open. Active protection test 4.1.5 Checking pressure monitoring device 1. Ground the transformer on the high-voltage side and low-voltage side. En- sure that the grounding for work connection on the transformer is not re- moved during testing. 2. Ensure that the transformer remains de-energized during testing. 3. Deactivate the automatic fire extinguishing device. 4. Remove the cover cap. 5. Activate the sensor on the snap-action switch. Sensor is in the OFF position. 6. Leave the transformer's danger zone. 7. Ensure that the transformer's circuit breaker cannot be closed. Passive protection test 8. Activate the sensor on the snap-action switch. Sensor is in the OPERATION position. 9. Leave the transformer's danger zone. 10. Close the transformer's circuit breaker with isolating switches open and the transformer grounded on all sides. 11. Activate the sensor on the snap-action switch. Sensor is in the OFF position. 12. Ensure that the transformer's circuit breaker is open. Active protection test. 13. Activate the sensor on the snap-action switch to reset the pressure moni- toring device. Sensor is in the OPERATION position. 14. Secure the cover cap. 4349312/04 EN Commissioning 29  4.1.6 Commissioning the transformer The signaling contact for falling below the minimum insulating fluid fill level in the on-load tap-changer's oil conservator is looped into the tripping circuit of the circuit breaker. The protective relay and additional protective devices are looped into the cir- cuit breaker's tripping circuit. The motor-drive unit and all protective devices are functioning correctly and are ready for use. The oil compartment of the on-load tap-changer is completely filled with in- sulation fluid. All stop-cocks between on-load tap-changer and oil conservator of the on- load tap-changer are open. 1. Switch on transformer. 2. NOTICE! Inrush current impulses can be significantly greater than the trans- former rated current and may lead to current paths with asymmetrical or non-sinusoidal curve shapes and, as a result, overload the on-load tap- changer during the diverter switch operation. Only perform tap-change oper- ations - whether under no load or under load conditions - once the inrush current impulse has subsided. 30 Commissioning 4349312/04 EN  5 Operation 5.1 Operating the motor-drive unit with the hand crank WARNING Danger of explosion! Unauthorized operation of the motor-drive unit with the hand crank may re- sult in death or serious injury. Never operate the motor-drive unit electrically or with the hand crank be- fore the transformer has been disconnected if you think there may be a fault in the transformer or on-load tap-changer / de-energized tap-changer. Never use the hand crank to complete a tap-change operation that has be- gun electrically, but has not been ended completely. If the hand crank is difficult to move, you must stop using it. When operating the motor-drive unit with the hand crank, never reverse the direction of rotation. If there is any doubt about the on-load tap-changer / de-energized tap- changer being in proper working condition or about the cause of a fault in the motor-drive unit, contact the Technical Service department of Maschi- nenfabrik Reinhausen GmbH immediately. To operate the motor-drive unit manually, only use the hand crank mounted in the motor-drive unit. For information about fault rectification, refer to the "Fault elimination" chapter. Normal operation During normal operation, there is no need to operate the unit with the hand crank. The hand crank is mainly required during installation and for tests in the transformer plant. Use of the hand crank for operating the motor-drive unit is permitted if the transformer is disconnected, e.g. for maintenance tasks, if there is no de- tectable fault on the transformer or on-load tap-changer / de-energized tap- changer and the previous tap-change operation has been completed correctly. Emergency operation exception An operation is considered an emergency operation if a tap-change operation is absolutely necessary when a transformer is energized, despite a fault in the mo- tor-drive unit. In this case, be sure to observe the warnings listed above. Operating the motor-drive unit with the hand crank To carry out a tap-change operation with the hand crank, proceed as follows: 1. Open the door of the protective housing for the motor-drive unit. 2. Switch off motor protective switch Q1 (position 0). 3. Insert the hand crank mounted in the motor-drive unit into the hand crank aperture in the upper cover plate. The built-in hand crank interlock switch interrupts the motor circuit at two poles. The control circuit will not be interrupted. 4. NOTICE! Damage to the on-load tap-changer due to tap-change operation not being completed correctly. Turn the hand crank in one direction until the pointer has fully circled the tap-change indicator once and is again in the mid- position of the area marked in gray on the tap-change indicator. The tap-change operation is complete. 4349312/04 EN Operation 31  5. Remove the hand crank and return it to the mounting bracket. 6. Switch on motor protective switch Q1 (position I). 7. Close the door of the protective housing for the motor-drive unit. 32 Operation 4349312/04 EN  6 Fault elimination WARNING Danger of explosion! Explosive gases under the on-load tap-changer head cover can deflagrate or explode and result in severe injury or death. Ensure that there are no ignition sources such as open 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 de- vice, pressure relief device, pressure monitoring device) before removing the on-load tap-changer head cover. Do not operate any electrical devices during the work (e.g. risk of sparks from impact wrench). NOTICE Damage to the on-load tap-changer and transformer! If the protective relay or other protective devices trip, this can indicate dam- age to the on-load tap-changer and transformer. The transformer must not be energized without being inspected first. Check on-load tap-changer and transformer when protective relay or other protective devices have been tripped. Do not use the equipment again until you are sure there is no damage to the on-load tap-changer or transformer. NOTICE Damage to motor-drive unit! Damage to the motor-drive unit due to condensate in protective housing of motor-drive unit. Always keep protective housing of the motor-drive unit tightly closed. In the event of operation interruptions of more than 2 weeks, connect and operate the heater in the motor-drive unit. If this is not possible, e.g. during transportation, place a sufficient amount of desiccant in the protective housing. The table below is intended to assist with detecting and, where possible, reme- dying faults. For more information, please consult the operating instructions for the protec- tive relay or the relevant protective device. In the event of faults on the on-load tap-changer and motor-drive unit which cannot be easily corrected on site, or if the protective relay or additional protec- tive devices have been tripped, please inform your authorized MR representa- tive, the transformer manufacturer or contact MR directly. Maschinenfabrik Reinhausen GmbH Technical Service Postfach 12 03 60 93025 Regensburg Germany Phone: +49 94140 90-0 4349312/04 EN Fault elimination 33  Fax: +49 9 41 40 90-7001 E-mail: [email protected] Internet: www.reinhausen.com Fault description Action Tripping of protective relay See "Tripping the protective relay and re-commissioning the transformer" Also contact MR. Tripping of pressure relief device (e.g. MPreC®) On-load tap-changer and transformer must be checked. De- pending on the cause of tripping, take measurements / carry out checks on the transformer. Contact MR to check the on-load tap-changer. Tripping of pressure monitoring device (e.g. DW 2000) See "Tripping the pressure monitoring device and putting the transformer back into operation" Also contact MR. Activation of tap-change supervisory device The motor-drive unit can no longer be electrically actuated once the tap-change supervisory device has been activated. Manual operation of the motor-drive unit via the hand crank when the transformer is switched on is prohibited. On-load tap-changer and transformer must be checked. De- pending on the cause of tripping, take measurements / carry out checks on the transformer. Contact MR to check the on-load tap-changer. Activation of rupture disk in on-load tap-changer head cover On-load tap-changer and transformer must be checked. De- pending on the cause of tripping, take measurements / carry out checks on the transformer. Contact MR to check the on-load tap-changer. Tripping of motor protective switch in motor-drive unit See chapter "Fault elimination" in the operating instructions of the motor-drive unit Tripping of signaling contact that indicates that the fill level of Check pipe system (pipes etc.) and on-load tap-changer head the insulating fluid has fallen below the minimum in the on-load for leaks. Check the fill level and the quality of the insulating tap-changer oil conservator fluid in the oil compartment in accordance with the operating instructions for the on-load tap-changer. If the fill level has fallen below the limit values, also contact MR. On-load tap-changer not changing tap position (sluggishness, Contact MR. Raise keys / Lower keys not working, no audible diverter switch action) No change in voltage on the transformer despite change in po- Contact MR. sition on motor-drive unit Tap position indicator on motor-drive unit and on-load tap- Contact MR. changer different Noises on drive shaft or motor-drive unit when changing tap po- Ensure proper mounting of the drive shaft in accordance with sition its operating instructions. Check that hose clips and protective covers are seated correctly. Contact MR in the event of noise from the motor-drive unit. Red message on monitoring unit If possible read out database and send to MR along with error code. Warning or tripping of Buchholz relay on transformer Notify transformer manufacturer. Deviation from desired value when measuring winding resis- Contact transformer manufacturer and, if necessary, MR, and tance of transformer provide measured values. 34 Fault elimination 4349312/04 EN Fault description Action Deviation from desired value during dissolved gas analysis Contact transformer manufacturer and, if necessary, MR, and (transformer oil) provide measured values. Deviation from desired value during transformer ratio test Contact transformer manufacturer and, if necessary, MR, and provide measured values. Deviation from limit value for insulating fluids Carry out insulating fluid change, check oil conservator breather of on-load tap-changer. Table 3: Fault elimination 6.1 Tripping the protective relay and re-commis- sioning the transformer WARNING Danger of explosion! Explosive gases in the protective relay can deflagrate or explode and result in severe injury or death. Wait 15 minutes after switching off the transformer before beginning fur- ther work on the protective relay so that the gases can dissipate. Ensure that there are no ignition sources such as naked flames, hot sur- faces or sparks (e.g. caused by the build-up of static charge) in the immedi- ate surroundings and that none occur. De-energize all auxiliary circuits before beginning work. Do not operate any electrical devices during the work (e.g. risk of sparks from impact wrench). WARNING Danger of death or severe injury! Danger of severe injury or death if on-load tap-changer and transformer are insufficiently tested. Be sure to contact Maschinenfabrik Reinhausen to check on-load tap- changer and transformer if the protective relay has tripped. Only use the equipment again when you are sure there is no damage to the on-load tap-changer or transformer. When the circuit breakers have been tripped by the protective relay, proceed as follows: 1. Establish time of tripping. 2. Determine operating position of on-load tap-changer. 3. As a precaution, block the motor-drive unit by tripping the motor protective switch to prevent the on-load tap-changer from being actuated by remote control. 4. Check the on-load tap-changer head cover. If insulating fluid is leaking, close the oil conservator stop valve immediately. 5. Check whether the flap valve of the protective relay is in the OFF or OPERA- TION position. 6.1.1 Flap valve in OPERATION position If the flap valve is in the OPERATION position, there may be a fault in the trip- ping circuit. Check the tripping circuit in this case. If you are not able to clarify why the protective relay tripped, be sure to contact Maschinenfabrik Rein- hausen to check the on-load tap-changer. 4349312/04 EN Fault elimination 35  6.1.2 Flap valve in OFF position Note that protective relay RS 2004 features an automatic reset mechanism i which means that the flap valve does not remain in the OFF position after tripping. If the protective relay RS 2004 has not tripped due to an error in the tripping circuit, also proceed as described below for RS 2004. If the flap valve is in the OFF position, proceed as follows: 1. Ensure that the transformer is not started up under any circumstances. 2. Contact and inform Maschinenfabrik Reinhausen of the following: Serial number of protective relay and on-load tap-changer What was the load of the transformer at the instant of tripping? Was the on-load tap-changer moved immediately before or during trip- ping? Did any other protective devices of the transformer respond at the instant of tripping? Were switching operations in the network being carried out at the instant of tripping? Were overvoltages registered at the instant of tripping? 3. Take further action in agreement with Maschinenfabrik Reinhausen. 6.1.3 Re-commissioning the transformer Once the reason for the protective relay tripping has been established and remedied, you can re-commission the transformer: 1. Check the protective relay [►Section 4.1.4.1, Page 28]. 2. Commission the transformer. 36 Fault elimination 4349312/04 EN  6.2 Tripping the pressure monitoring device and putting the transformer back into operation WARNING Danger of death or severe injury! Danger of severe injury or death if on-load tap-changer and transformer are insufficiently tested. Be sure to contact Maschinenfabrik Reinhausen to check on-load tap- changer and transformer after the pressure monitoring device has been tripped. Only use the equipment again when you are sure there is no damage to the on-load tap-changer or transformer. If the circuit breaker is tripped by the pressure monitoring device, proceed as follows: 1. Establish time of tripping. 2. Determine operating position of on-load tap-changer. 3. As a precaution, block the motor-drive unit by tripping the motor protective switch to prevent the on-load tap-changer from being actuated by remote control. 4. Check the on-load tap-changer head cover. If insulating fluid is leaking, close the oil conservator stop valve immediately. 5. Check whether the pressure monitoring device sensor is in the OFF position or OPERATION position. 6.2.1 Sensor in the OPERATION position If the sensor is in the OPERATION position, there may be an error in the tripping circuit. Check the tripping circuit in this case. If you are not able to clarify why the pressure monitoring device tripped, be sure to contact Maschinenfabrik Reinhausen to check the on-load tap-changer. 6.2.2 Sensor in the OFF position Proceed as follows if the sensor is in the OFF position. 1. Ensure that the transformer is not started up under any circumstances. 2. Contact and inform Maschinenfabrik Reinhausen of the following: What was the load of the transformer at the instant of tripping? Was there a tap-change operation on the on-load tap-changer immedi- ately before or during the tripping? Did any other protective devices of the transformer respond at the instant of tripping? Were switching operations in the network being carried out at the instant of tripping? Were overvoltages registered at the instant of tripping? How high is the static pressure on the pressure relief device (height differ- ence between the oil level in the on-load tap-changer oil conservator and the pressure relief device)? 3. Take further action in agreement with Maschinenfabrik Reinhausen. 4349312/04 EN Fault elimination 37  6.2.3 Re-commissioning the transformer You can re-commission the transformer once the cause for tripping the pres- sure monitoring device has been determined and resolved: 1. Ensure that the sensor on the snap-action switch is in the OPERATION posi- tion. 2. Commission the transformer. 38 Fault elimination 4349312/04 EN  7 Maintenance DANGER Electric shock! An energized transformer could cause death or serious injuries. Switch off transformer on high and low-voltage side. Lock transformer to prevent unintentional restart. Ensure that everything is de-energized. Visibly connect all transformer terminals to ground (grounding leads, grounding disconnectors) and short circuit them. Cover or cordon off adjacent energized parts. DANGER Electric shock! Working on the on-load tap-changer when on-load tap-changer components are energized can lead to death or serious injuries. De-energize all auxiliary circuits, such as the tap-change supervisory device, pressure relief device, pressure monitoring device. Make sure that everything is de-energized. WARNING Danger of explosion! Explosive gases in the oil compartment of the on-load tap-changer, trans- former, pipe 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 flames, hot sur- faces or sparks (e.g. caused by the build-up of static charge) in the trans- former'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. NOTICE Damage to motor-drive unit! Damage to the motor-drive unit due to condensate in protective housing of motor-drive unit. Always keep protective housing of the motor-drive unit tightly closed. In the event of operation interruptions of more than 2 weeks, connect and operate the heater in the motor-drive unit. If this is not possible, e.g. during transportation, place a sufficient amount of desiccant in the protective housing. 4349312/04 EN Maintenance 39  7.1 Inspection Monitoring the on-load tap-changer and motor-drive unit/control cabinet is lim- ited to occasional visual checks and monitoring the quality of the insulating fluid. For efficiency reasons these visual inspections can be combined with the usual checks on the transformer. Interval Action Annually Check the door seal, cable bushings, and ventilation of the motor- drive unit/control cabinet housing. Annually Check the sealing points of the on-load tap-changer head, the pro- tective relay, and the connected pipes. Annually Check the correct function of the installed electrical heater in the motor-drive unit/control cabinet housing. Annually Check the correct function of the protective relay [►Section 4.1.4, Page 28]. Annually Check the perfect condition of the breather (silica gel) for the on- load tap-changer oil conservator. Every 2 years Check the quality of the insulating fluid of on-load tap-changers that are installed in positions other than the neutral point of wind- ings (Class 2 in accordance with ICE 60214-1). 1. Take a sample of insulating fluid from the oil compartment. 2. Record the temperature of the sample (insulating fluid) immedi- ately after the sample is taken. 3. Determine the dielectric strength and water content at an insu- lating fluid temperature of 20°C ±5°C. The dielectric strength and water content must comply with the limit values specified in the technical data. 4. If the limit values are not complied with, change the insulating fluid in accordance with the "Changing the insulating fluid" sec- tion. Every 7 years Check the quality of the insulating fluid of on-load tap-changers that are installed at the neutral point of windings (Class 1 in accor- dance with IEC 60214-1). 1. Take a sample of insulating fluid from the oil compartment. 2. Record the temperature of the sample (insulating fluid) immedi- ately after the sample is taken. 3. Determine the dielectric strength and water content at an insu- lating fluid temperature of 20°C ±5°C. The dielectric strength and water content must comply with the limit values specified in the technical data. 4. If the limit values are not complied with, change the insulating fluid in accordance with the "Changing the insulating fluid" sec- tion. Table 4: Inspection plan 7.2 Maintenance intervals Maintenance intervals without MR monitoring system 40 Maintenance 4349312/04 EN WARNING Danger of explosion! If pending maintenance work is not carried out immediately, this may lead to death or serious injury as a result of a progressive short circuit, for example. Adherence to the following maintenance intervals is mandatory. If you are operating the on-load tap-changer without an MR monitoring system, the following maintenance intervals shall apply. Interval Action after every 300,000 switching operations Maintenance of the on-load tap-changer. (motor-drive unit counter reading) Contact Maschinenfabrik Reinhausen GmbH Technical Service [►Section 6, Page 33] for this. After 600,000 switching operations (motor- Replacement of switching elements of di- drive unit counter reading) verter switch insert. Contact Maschinenfab- rik Reinhausen GmbH Technical Service [►Section 6, Page 33] for this. after 1.2 million switching operations (mo- Replacement of diverter switch insert and tor-drive unit counter reading) gearbox. Contact Maschinenfabrik Rein- hausen GmbH Technical Service [►Section 6, Page 33] for this. after 2.1 million switching operations (mo- Maintenance of the change-over selector. tor-drive unit counter reading) Contact Maschinenfabrik Reinhausen GmbH Technical Service [►Section 6, Page 33] for this. after 4 million switching operations (motor- Replacement of the on-load tap-changer. drive unit counter reading) Contact Maschinenfabrik Reinhausen GmbH in this regard. Table 5: Maintenance plan without MR monitoring system A label on the inside of the door of the TAPMOTION® ED motor-drive unit also specifies the relevant maintenance interval. Figure 21: Label showing maintenance intervals 4349312/04 EN Maintenance 41  Maintenance intervals with MR monitoring system WARNING Danger of explosion! If pending maintenance work is not carried out immediately, this may lead to death or serious injury as a result of a progressive short circuit, for example. Contact the Maschinenfabrik Reinhausen GmbH Technical Service depart- ment as soon as the MR monitoring system issues a maintenance warning. In the event of failure or shutdown of the MR monitoring system, observe the maintenance intervals as specified in the maintenance plan without the MR monitoring system. If you are operating the on-load tap-changer with an MR monitoring system, the maintenance intervals displayed by the MR monitoring system shall apply. More information can be found in the operating instructions for the MR monitoring system. 7.3 Changing the insulation fluid 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 all small parts are accounted for. Change the insulating fluid in the on-load tap-changer oil compartment and oil conservator if the dielectric strength and water content are not in compliance with the limit values specified in the technical data. 7.3.1 Moving on-load tap-changer to adjustment position 1. Make a note of the current operating position of the on-load tap-changer. 2. Move the on-load tap-changer to the adjustment position. The adjustment position is indicated in the on-load tap-changer connection diagram included in delivery. 7.3.2 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 re- moved. As a precaution, block the motor-drive unit against electrical operation by actuating the motor protective switch (see operating instructions for "Tap- motion® ED"). 42 Maintenance 4349312/04 EN 1. Loosen hose clips on protective cover of horizontal drive shaft, remove pro- tective cover. Figure 22: Removing protective cover 2. Depending on version, loosen 4 or 6 screws on coupling brackets to upper gear unit and bevel gear. Figure 23: Loosening coupling brackets 4349312/04 EN Maintenance 43  3. Remove horizontal drive shaft. Be sure not to lose the coupling bolts. Figure 24: Removing drive shaft 7.3.3 Emptying the oil compartment and oil conservator 1. Ensure that the stop-cock between oil conservator and on-load tap-changer is open. 2. Remove the screw cap on air-vent valve E1 on the on-load tap-changer head cover. 3. Use a screwdriver to lift the valve tappet on air-vent valve E1. The gas under the on-load tap-changer head cover will escape. In this situ- ation, ensure sufficient ventilation. 4. Once the gas has been discharged and insulating fluid is flowing out of the air-vent valve, close the air-vent valve. 5. Close the stop-cock between the oil conservator and on-load tap-changer. 6. Open air-vent valve E1 again and extract approximately 5–10 liters of insulat- ing fluid via the pipe connection S until the area under the on-load tap- changer head cover is free of insulating fluid. 7. Remove the screws and washers from the on-load tap-changer head cover. Figure 25: On-load tap-changer head cover 8. Remove on-load tap-changer head cover. Figure 26: On-load tap-changer head cover 44 Maintenance 4349312/04 EN  9. Extract insulating fluid via pipe connection S. 10. Open the stop-cock between oil conservator and on-load tap-changer. The insulating fluid flows out of the oil conservator into the oil compart- ment. 11. Extract insulating fluid via pipe connection S. 7.3.4 Filling the oil compartment and oil conservator with fresh in- sulating fluid NOTICE Damage to the on-load tap-changer! Unsuitable insulating fluids cause damage to the on-load tap-changer. Only use insulating fluids [►Section 8.1.2, Page 51] approved by the man- ufacturer. Ensure that the new insulating fluid has the same chemical, mechanical, thermal and electrical properties. Otherwise, contact Maschinenfabrik Rein- hausen GmbH's Technical Service department. 1. Fill the oil compartment of the on-load tap-changer with fresh insulating fluid via the pipe connection S up to the level of the upper edge of the coupling shaft. 2. Insert the new o-ring untwisted in the on-load tap-changer head cover. 3. Place on-load tap-changer head cover on on-load tap-changer head and se- cure. Figure 27: On-load tap-changer head cover 4. Fill the oil conservator with fresh insulating fluid. 5. Vent the on-load tap-changer head via air-vent valve E1 on the on-load tap- changer head cover. To do this, remove screw cap and lift valve tappet with a screwdriver. 6. Seal air-vent valve E1 with screw cap (tightening torque 10 Nm). 4349312/04 EN Maintenance 45  7. Remove screw cap from pipe connection S. Figure 28: Pipe connection S 8. Open vent screw and bleed piping. 9. Close vent screw. 10. Seal vent screw with screw cap. 11. Check the level in the oil conservator and top up with insulating fluid if nec- essary. 12. Re-vent the on-load tap-changer head via air-vent valve E1 and the pipe con- nection S via the vent screw. 13. Flush the oil suction pipe and take an insulating fluid sample from the oil compartment via pipe connection S. 14. Record the temperature of the sample immediately after the sample is taken. 15. Determine dielectric strength and water content at a sample temperature of 20 °C ± 5 °C. The dielectric strength and water content must comply with the limit values specified in the technical data (after maintenance). 46 Maintenance 4349312/04 EN 7.3.5 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 operating in- structions for details. Figure 29: Securing drive shaft 2. Use hose clips to secure protective cover to horizontal drive shaft. Figure 30: Securing protective cover 3. For special design types featuring cardan shafts, be sure to check the expan- sion bellows and the lubricant reservoir of the cardan shafts. 4349312/04 EN Maintenance 47  You will find a detailed description of how to fit the drive shaft in the MR operat- ing instructions "Drive shaft".