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Questions and Answers
What is the recommended action when the tap changer has exceeded 800,000 switching operations?
What is the recommended action when the tap changer has exceeded 800,000 switching operations?
What is the suggested frequency for inspecting the MR oil filter unit?
What is the suggested frequency for inspecting the MR oil filter unit?
What is the consequence of not having inspections carried out by MR personnel?
What is the consequence of not having inspections carried out by MR personnel?
In which climate conditions is monitoring of insulating oils especially recommended?
In which climate conditions is monitoring of insulating oils especially recommended?
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What can potentially extend the inspection intervals of the MR oil filter unit?
What can potentially extend the inspection intervals of the MR oil filter unit?
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What is the immediate recommendation for operations exceeding 15,000 per year?
What is the immediate recommendation for operations exceeding 15,000 per year?
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Who should ideally carry out the inspections for the MR oil filter unit?
Who should ideally carry out the inspections for the MR oil filter unit?
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What type of filter insert is recommended for the stationary oil filter unit type 51?
What type of filter insert is recommended for the stationary oil filter unit type 51?
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What is the maximum torque specified for attaching the inner screening rings?
What is the maximum torque specified for attaching the inner screening rings?
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How many hexagon socket-head screws are used to attach each inner screening ring?
How many hexagon socket-head screws are used to attach each inner screening ring?
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What should be removed before cleaning the switching tube?
What should be removed before cleaning the switching tube?
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Which type of screws are used for fixing the bottom bearing?
Which type of screws are used for fixing the bottom bearing?
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What is the first step in the reinstallation of the inner screening rings?
What is the first step in the reinstallation of the inner screening rings?
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What must be done after unscrewing the fixing screws of the bottom bearing?
What must be done after unscrewing the fixing screws of the bottom bearing?
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What is necessary for working with tap changers of types V 111 350 Y or V 350 since 06/95?
What is necessary for working with tap changers of types V 111 350 Y or V 350 since 06/95?
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What should not be lost when removing the bottom bearing for certain tap changers?
What should not be lost when removing the bottom bearing for certain tap changers?
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What is the water content limit for transformer oil in the on-load tap changer type VI200Y?
What is the water content limit for transformer oil in the on-load tap changer type VI200Y?
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Which on-load tap changer type requires an inspection every 2 years?
Which on-load tap changer type requires an inspection every 2 years?
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What is the dielectric strength requirement for transformer oil in on-load tap changers?
What is the dielectric strength requirement for transformer oil in on-load tap changers?
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What is the maximum number of tap changer operations allowed without an MR oil filter unit for type VII500Y?
What is the maximum number of tap changer operations allowed without an MR oil filter unit for type VII500Y?
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What is the effect of disregarding the recommended inspection intervals?
What is the effect of disregarding the recommended inspection intervals?
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What is the recommended first inspection time frame for the on-load tap changer type VI350 Y?
What is the recommended first inspection time frame for the on-load tap changer type VI350 Y?
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Which method is used to measure water content in transformer oil?
Which method is used to measure water content in transformer oil?
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For the tap changer type VIII400Y, what is the maximum number of operations allowed with an MR oil filter unit?
For the tap changer type VIII400Y, what is the maximum number of operations allowed with an MR oil filter unit?
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What type of arrangement for an on-load tap changer allows for further inspections every 4 years without an MR oil filter unit?
What type of arrangement for an on-load tap changer allows for further inspections every 4 years without an MR oil filter unit?
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How often should type VII400D be inspected if it has an MR oil filter unit?
How often should type VII400D be inspected if it has an MR oil filter unit?
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What is the maximum torque specified for the M6 screws during the removal of the switching elements?
What is the maximum torque specified for the M6 screws during the removal of the switching elements?
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How many self-locking screws are used to secure each bottom bearing?
How many self-locking screws are used to secure each bottom bearing?
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During the assembly of the potential plate, what is the order of components to be installed?
During the assembly of the potential plate, what is the order of components to be installed?
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How are the screws securing the upper screening ring of the lower switching element described?
How are the screws securing the upper screening ring of the lower switching element described?
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What component is not specified to be removed with the main switching contact bearing support?
What component is not specified to be removed with the main switching contact bearing support?
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What should not be lost during the removal process of the switching elements?
What should not be lost during the removal process of the switching elements?
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Which screws are necessary to unlock and loosen at the main switching contact bearing support?
Which screws are necessary to unlock and loosen at the main switching contact bearing support?
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Which component has a cylindrical design and is specified by an M size?
Which component has a cylindrical design and is specified by an M size?
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What is the length in millimeters of the head screw specified as M6?
What is the length in millimeters of the head screw specified as M6?
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Which of the following parts is associated with pressure springs?
Which of the following parts is associated with pressure springs?
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What type of component does the term 'circlip' refer to?
What type of component does the term 'circlip' refer to?
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Which specification indicates a pitch design feature?
Which specification indicates a pitch design feature?
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Which on-load tap changer model is referenced in the content?
Which on-load tap changer model is referenced in the content?
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What is the designation of the pressure spring designed for the contact roller?
What is the designation of the pressure spring designed for the contact roller?
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Which is the correct part number for the lock nut specified for M6?
Which is the correct part number for the lock nut specified for M6?
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Which part is classified as a cable component in the content?
Which part is classified as a cable component in the content?
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Which part number corresponds to a lock nut for M5?
Which part number corresponds to a lock nut for M5?
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The gearing can be removed by lifting it out after loosening the guard plate.
The gearing can be removed by lifting it out after loosening the guard plate.
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The coupling piece to the upper gear unit has 8 screws M6 that need to be loosened.
The coupling piece to the upper gear unit has 8 screws M6 that need to be loosened.
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The drive shaft must always be completely removed to allow access to the gearing.
The drive shaft must always be completely removed to allow access to the gearing.
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It is important to count all small parts during the disassembly process to ensure that nothing is lost.
It is important to count all small parts during the disassembly process to ensure that nothing is lost.
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Two bolts M10 x 35/w.s.17 need to be unscrewed to remove the tap changer cover.
Two bolts M10 x 35/w.s.17 need to be unscrewed to remove the tap changer cover.
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The energy accumulator spring system requires replacement after every 100,000 operations.
The energy accumulator spring system requires replacement after every 100,000 operations.
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Spring washers must be taken care of not to lose during the removal of the gearing.
Spring washers must be taken care of not to lose during the removal of the gearing.
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The energy accumulator spring system is fixed to the tap changer cover by 5 screws M8.
The energy accumulator spring system is fixed to the tap changer cover by 5 screws M8.
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The lift height for the tap changer insert listed as Vil 500Y is 1750 mm.
The lift height for the tap changer insert listed as Vil 500Y is 1750 mm.
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The required oil capacity for the tap changer type Vii 350D is 145 litres.
The required oil capacity for the tap changer type Vii 350D is 145 litres.
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The inspection procedure necessitates cleaning both the oil conservator and the oil compartment of the tap changer.
The inspection procedure necessitates cleaning both the oil conservator and the oil compartment of the tap changer.
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Changing the switching oil is not required during a tap changer inspection.
Changing the switching oil is not required during a tap changer inspection.
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The tap changer model VI 200Y has an inspection frequency of every three years.
The tap changer model VI 200Y has an inspection frequency of every three years.
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Determining contact wear is included in the scope of work for the tap changer inspection.
Determining contact wear is included in the scope of work for the tap changer inspection.
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The oil compartment must have used oil emptied before the cleaning process begins.
The oil compartment must have used oil emptied before the cleaning process begins.
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Vil 200 has a lifting height of 800 mm without the operating key attached.
Vil 200 has a lifting height of 800 mm without the operating key attached.
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The maximum torque for fixing the bottom bearing is 9 Nm.
The maximum torque for fixing the bottom bearing is 9 Nm.
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After flushing the inside of the switching tube, a thorough visual check is required.
After flushing the inside of the switching tube, a thorough visual check is required.
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Dished washers are used with M5 screws for fixing screening rings.
Dished washers are used with M5 screws for fixing screening rings.
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A brush of 140 mm diameter can be used to remove carbon deposits from the switching tube surface.
A brush of 140 mm diameter can be used to remove carbon deposits from the switching tube surface.
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The maximum torque for self-locking screws securing the inner screening rings is 10 Nm.
The maximum torque for self-locking screws securing the inner screening rings is 10 Nm.
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The removal order of the inner screening rings does not need to be noted.
The removal order of the inner screening rings does not need to be noted.
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New screws must be used for reassembly of the hexagon socket-head screws after removal.
New screws must be used for reassembly of the hexagon socket-head screws after removal.
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Flushing with transformer oil is recommended to prepare the inside of the switching tube for assembly.
Flushing with transformer oil is recommended to prepare the inside of the switching tube for assembly.
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The complete set of contact rollers should be replaced only if the minimum contact roller diameter has been reached during inspection.
The complete set of contact rollers should be replaced only if the minimum contact roller diameter has been reached during inspection.
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Checking the spring movement of the contact rollers is only necessary for the main contact.
Checking the spring movement of the contact rollers is only necessary for the main contact.
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Inspection of the contact rollers should be performed after every 100,000 switching operations.
Inspection of the contact rollers should be performed after every 100,000 switching operations.
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The contact rollers are to be inspected for smooth spring operation as part of regular maintenance.
The contact rollers are to be inspected for smooth spring operation as part of regular maintenance.
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The minimum contact diameter for the complete switching contact V 350 is 22.0 mm.
The minimum contact diameter for the complete switching contact V 350 is 22.0 mm.
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Replacement of contact rollers should be done in isolation, without considering other switching elements.
Replacement of contact rollers should be done in isolation, without considering other switching elements.
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Inspection of the spring movement of contact rollers is unnecessary if they appear visually intact.
Inspection of the spring movement of contact rollers is unnecessary if they appear visually intact.
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The torque specified for securing self-locking hexagon socket-head screws M6 is 10 Nm.
The torque specified for securing self-locking hexagon socket-head screws M6 is 10 Nm.
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The contact diameter for the complete transition contact Vv 200 on the left is indicated as 20.0 mm.
The contact diameter for the complete transition contact Vv 200 on the left is indicated as 20.0 mm.
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The maximum number of contacts in the circle for the complete switching contact of type V 500 is 14.
The maximum number of contacts in the circle for the complete switching contact of type V 500 is 14.
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The contact diameter of the complete switching contact for type V 1350 is 22.0 mm.
The contact diameter of the complete switching contact for type V 1350 is 22.0 mm.
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The diameter values for contact rollers are only specified when the contact is replaced.
The diameter values for contact rollers are only specified when the contact is replaced.
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The complete transition contact for type V 350 has a contact code of 086 063.
The complete transition contact for type V 350 has a contact code of 086 063.
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The contact diameter for the complete switching contact V 500 is 220 mm.
The contact diameter for the complete switching contact V 500 is 220 mm.
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A torque of 5 Nm is sufficient to secure the M6 screws of the contact roller bearing plates.
A torque of 5 Nm is sufficient to secure the M6 screws of the contact roller bearing plates.
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Self-locking hexagon socket-head screws M6 are used at the contact roller bearing bushings.
Self-locking hexagon socket-head screws M6 are used at the contact roller bearing bushings.
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Study Notes
Maintenance and Inspection of Oil Filter Units and Tap Changers
- Regular maintenance of MR oil filter units is essential for maintaining high operating reliability.
- Tap changer inserts and gearings need replacement after 800,000 switching operations.
- Qualified personnel should perform inspections, ideally within one day, if well-prepared.
- Use of stationary oil filter unit type 51 with a paper filter is recommended if operations exceed 15,000 per year.
- Insulating oils in transformers should be monitored per manufacturer guidelines to maintain dielectric properties.
- In humid, tropical climates, combined filter inserts are advised to avoid dielectric property degradation.
Oil Testing and Monitoring
- Key water content thresholds for transformer oil testing:
- V III 200 Y, V I N 350 Y, V I I I 500 Y: < 40 ppm
- V I I 200 D, V I N 350 D, V I I I 500 D: < 30 ppm
- Required dielectric strength for transformer oils:
- V III 200 Y, V I N 350 Y, V I I I 500 Y: > 30 kV/2.5 mm
- V I I 200 D, V I N 350 D, V I I I 500 D: > 40 kV/2.5 mm
Inspection Intervals
- Inspection intervals based on tap changer type and operation levels:
- For types V I I 200 Y, V I I 350 Y, V I I 500 Y:
- First inspection: 6-7 years
- Further inspections: 6-7 years (with/without MR oil filter unit)
- For other types (e.g., V I I I 200 D, V I I I 250 D, etc.):
- First inspection: 2 years
- Further inspections: 4 years (without MR oil filter unit), 6-7 years (with MR oil filter unit)
- For types V I I 200 Y, V I I 350 Y, V I I 500 Y:
Assembly Procedures
- Detailed steps for reinstallation of inner screening rings include:
- Provisional fixing of inner screening rings with screws.
- Securely attaching rings with hexagon socket-head screws and dished washers.
- Disassembly steps vary by tap changer type but generally involve loosening multiple screws and numbering switching elements for reassembly.
Risk and Compliance
- Ignoring inspection intervals can jeopardize the trouble-free operation of the system.
- Proper documentation and reporting are required if non-MR personnel conduct inspections.
Parts and Specifications
- List of parts for tap changers is provided, including specific screw types and sizes required during reinstallation.
- Emphasis on securing components properly to ensure functionality and safety.
Key Caution
- Strict adherence to maintenance routines and documentation is critical to operational integrity and safety.
Inspection Preparation
- Inspection includes tap changer insert removal and reinstallation, cleaning of oil compartments, and oil changes.
- Requires auxiliary equipment for performing inspections.
Required Tools and Equipment
- Empty vessels for used oil and new transformer oil.
- Various dimensions of equipment, e.g., V i 200 (800/950 mm) and V i l l 500D (2000/2200 mm).
Oil and Contact Checks
- Switching oil must be changed during inspections.
- Check the tap changer oil compartment and tap changer insert for quality and wear.
- Determine contact wear to assess maintenance needs.
Removal Procedures
- Remove guard plate and loosen various screws without losing spring washers.
- Avoid dropping parts into the oil compartment as it may damage the transformer.
- Count and retain all small parts, including bolts, nuts, and lock tabs during disassembly.
Energy Accumulator and Gearing
- Energy accumulator spring system must be handled carefully to avoid damage.
- The switching tube contains grooves for washer placement; removing washers is crucial for maintenance.
Cleaning Protocols
- Switch tube cleaned by thorough flushing with transformer oil; debris removal is essential.
- Ensure proper reinstallation of parts to maintain insulating properties.
Contact Roller Maintenance
- Inspect smooth operation of contact roller springs; check all contact types.
- Replacement is required when roller diameter falls below minimum thresholds.
Contact Specifications
- Specifications for contact sizes include:
- V 350 complete switching contact: new diameter 22.0 mm, minimum 17.0 mm.
- V 200 complete transition contact: new diameter 22.0 mm, minimum 16.0 mm.
- V 500 complete switching contact: new diameter 22.0 mm, minimum 17.0 mm.
Torque and Security Checks
- Check secure fit of screws M6 at 8 Nm torque for contact roller bearing.
- During inspections of specific tap changer types, ensure proper torque procedure adherence.
Safety Notes
- Pay attention to the installation order of the potential plate and internal components.
- Use new self-locking screws for reassembly to ensure component integrity.
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Description
Test your knowledge on the maintenance of MR oil filters and the importance of regular inspections. This quiz covers the operating instructions related to tap changers and filtering of switching oil. Ideal for professionals looking to ensure reliability in operations.
