Mechanical Engineering Basics

Questions and Answers

What happens when the push-button 'Off' is pressed?

The transformer is energized by the circuit breaker.

The transformer is disconnected from the circuit.

The protective device flap is opened. (correct)

The inspection windows are hidden from view.

What is the state of the protective device when the 'Operation' button is pressed?

The protective device is ready for service. (correct)

The transformer is fully de-energized.

The protective device is unresponsive.

The inspection windows are closed.

Which component must be properly connected to energize the transformer?

The protective device flap

The inspection windows

The push-button switch

The circuit breaker (correct)

What occurs during an inspection of the protective device?

The transformer is put back into service afterwards. Signup and view all the answers

What should be done after performing a test and inspection?

Tighten the fixing screws on the cover cap. Signup and view all the answers

What happens to the visibility of the inspection windows when the 'Operation' button is pressed?

They give a free view. Signup and view all the answers

What is indicated by the sloping position of the protective device flap?

The device is set for inspection. Signup and view all the answers

When should the transformer be inspected according to the given protocols?

After every test, before being put into service. Signup and view all the answers

What is the maximum admissible contact burning 'a' according to the specifications?

5 mm Signup and view all the answers

Which type of contact is specified as a 'fixed auxiliary contact'?

Contact 320 Signup and view all the answers

What material is specified for the contacts in the provided content?

E-Cu Signup and view all the answers

Which term best describes the configuration of the moving main contacts?

Movable Signup and view all the answers

Which of the following statements is true regarding 'fixed main contacts'?

They remain stationary. Signup and view all the answers

Which contact number is associated with moving main contacts?

322 Signup and view all the answers

What is the role of Contact 319 in the context of the content provided?

It functions as a fixed main contact. Signup and view all the answers

How many distinct types of contacts are mentioned in the content?

Three Signup and view all the answers

What is the first step in disassembling the diverter switch insert?

Remove bolts and washers from the tap changer head cover. Signup and view all the answers

Under what condition is it unnecessary to completely disassemble the diverter switch insert during a periodic inspection?

If the oil is not much contaminated. Signup and view all the answers

What precaution must be taken when putting down the supporting cylinder?

Take care not to damage the driving shaft. Signup and view all the answers

What is the minimum withdrawal height dependent on?

The voltage series. Signup and view all the answers

What should be done after removing the screws and nuts at the supporting flange?

Lift supporting cylinder vertically. Signup and view all the answers

Which component is removed last during the disassembly of the diverter switch insert?

Transfer resistors (315). Signup and view all the answers

What is the recommended action if further disassembly of the diverter switch is necessary?

Proceed as indicated in the instructions. Signup and view all the answers

Where is the guide pin located in relation to the supporting flange?

On the lower part of the supporting flange. Signup and view all the answers

What must be checked after tightening the supporting flange screws?

Whether all screw joints are tightened and locked Signup and view all the answers

What is the correct distance between the electrodes of the spark gap?

5 mm Signup and view all the answers

What is the first operational step after installing the diverter switch insert?

Filling the oil vessel with oil to the correct level Signup and view all the answers

In what manner should the diverter switch insert be introduced into its oil vessel?

Vertically and carefully Signup and view all the answers

What should be avoided to prevent damage to the system?

Performing trial switching operations without oil filling Signup and view all the answers

During the assembly of the diverter insert, what is the role of the four pressure springs?

To hold the diverter switch securely in place Signup and view all the answers

What should you do if necessary to engage the driving shaft?

Move the driving rod of the energy accumulator Signup and view all the answers

What must be observed regarding the non-interchangeable drive coupling before installing the diverter switch insert?

Its position must be noted Signup and view all the answers

What component is responsible for controlling the direction of oil flow in a transformer?

Diverter switch Signup and view all the answers

Which part of the tap changer is used to indicate the position of the operation?

Position indication disk Signup and view all the answers

What is the role of the safety diaphragm in a transformer?

To prevent overpressure and ensure safety Signup and view all the answers

Which component connects the diverter switch to the main contact system?

Sliding contact Signup and view all the answers

What part of the tap changer is primarily responsible for transforming electrical energy into mechanical movement?

Worm wheel with Geneva cam Signup and view all the answers

Which of the following components is essential for oil drainage in the transformer system?

Oil drain cock Signup and view all the answers

Which of these parts is crucial for the operational reliability of the diverter switch?

Detent pawl Signup and view all the answers

What function does the tapping selector provide in the transformer mechanism?

Selects the tapping points for voltage adjustment Signup and view all the answers

Which component’s function is to connect various amount of electrical resistance in the diverter switch?

Transfer resistors Signup and view all the answers

What is the role of the inspection window in transformer maintenance?

To inspect the tap changer operation Signup and view all the answers

The diverter switch insert can be withdrawn with the tap changer in any position.

True Signup and view all the answers

Inspection work should be performed during wet weather to ensure thorough cleaning.

False Signup and view all the answers

The maximum exposure time of insulating parts to the atmosphere during inspection is about 5 hours.

False Signup and view all the answers

The load transfer time of the diverter switch takes about 0.017 - 0.027 seconds.

False Signup and view all the answers

The inspection instructions emphasize that the tap selector requires regular wear checks.

False Signup and view all the answers

Appropriate cleanliness and carefulness are not crucial during the inspection procedures.

False Signup and view all the answers

The tap changer is comprised of three main components including the diverter switch insert and transfer capacitors.

False Signup and view all the answers

The procedure for inspecting the diverter switch includes withdrawing, cleaning, checking, and reassembling.

True Signup and view all the answers

The diverter switch has a separate oil compartment, while the tap selector is placed in the diverter switch's oil vessel.

False Signup and view all the answers

Oil must be drained from the tap changer head before venting the screw.

True Signup and view all the answers

The components of the tap changer include a tap selector with a pre-selector and a high-speed diverter switch.

True Signup and view all the answers

Shutting off all cocks is necessary before performing an inspection of the tap changer.

True Signup and view all the answers

The inspection procedures specify to expose insulating parts for a minimum of 12 hours.

False Signup and view all the answers

The main function of the diverter switch is to manage the transfer of load via inductive capacitors.

False Signup and view all the answers

Inspection intervals for the diverter switch are determined based on historical switching operations and service duration.

True Signup and view all the answers

The first step in the inspection of the diverter switch is to check the wear of its contacts.

False Signup and view all the answers

During a periodic inspection, it is necessary to completely disassemble the diverter switch insert if the oil is slightly contaminated.

False Signup and view all the answers

The minimum withdrawal height for a component is solely dependent on the temperature of the surrounding environment.

False Signup and view all the answers

Supporting cylinder (307) should be lifted vertically along with the diverter insert head (301) during disassembly.

True Signup and view all the answers

To prevent damage, it is important to be cautious when putting down the driving shaft (308).

True Signup and view all the answers

Lock washers are used exclusively for securing the supporting flange without any relation to screws during assembly.

False Signup and view all the answers

Resistor connecting bolts (316) are removed before lifting the transfer resistors (315) vertically.

True Signup and view all the answers

The supporting flange (309) is designed with a guide pin to facilitate the proper alignment during assembly.

True Signup and view all the answers

The removal of nuts (117) and compression springs (118) is the first step in the disassembly of the diverter switch insert.

False Signup and view all the answers

The transformer must be inspected every 3 years according to standard protocol.

False Signup and view all the answers

The safety diaphragm in a transformer is responsible for controlling oil flow direction.

False Signup and view all the answers

The component known as fixed main contacts can be replaced without disassembling the entire device.

False Signup and view all the answers

During the operation of a diverter switch, the guide pin should be outside of the supporting flange.

False Signup and view all the answers

The non-interchangeable drive coupling is crucial for the safe operation of the transformer.

True Signup and view all the answers

The distance between the spark gap electrodes is fixed at 1 centimeter.

False Signup and view all the answers

An inspection window allows for visual checks without needing to disconnect any components.

True Signup and view all the answers

After tightening the supporting flange screws, no further checks are necessary.

False Signup and view all the answers

The tap changer's primary role is to switch electrical resistance amounts.

True Signup and view all the answers

The divergent switch insert should be introduced into its oil vessel with a tilt of 45 degrees.

False Signup and view all the answers

The tap changer head is equipped with a driving shaft with a worm.

True Signup and view all the answers

The oil vessel bottom is responsible for oil separation.

False Signup and view all the answers

The diverter switch insert contains energy accumulator devices for suspension systems.

True Signup and view all the answers

Safety diaphragms are only used in conjunction with oil separator components.

False Signup and view all the answers

A venting screw is crucial for maintaining pressure within the transformer system.

True Signup and view all the answers

The contact bridge in the tap selector is located above the insulating bars.

False Signup and view all the answers

Cage rings are critical for the structural integrity of the tap selector mechanism.

True Signup and view all the answers

Resistance connecting screws are utilized exclusively for the diverter switch output terminal.

False Signup and view all the answers

Flexible contact leads ensure proper connectivity in both main and auxiliary contacts.

True Signup and view all the answers

The Geneva drive is a mechanical component used in the tap selector driving shafts.

True Signup and view all the answers

Study Notes

Disassembly of Diverter Switch Insert

Remove bolts (109) and washers (110) to unscrew the assembly.
Detach the tap changer head cover (106) and gasket (108).
Eliminate nuts (117) and compression springs (118).
Lift the diverter switch insert vertically using supporting lugs (302).
Total weight of assembly is approximately 100 kg.
Minimum withdrawal height depends on series voltage; refer to the specifics on page 5.

Periodical Inspection Protocol

During inspections, if diverter switch oil is clean, full disassembly is unnecessary.
Often sufficient to clean the contact shell for wear assessment.
If further disassembly is required, follow detailed steps:
- Unscrew screws with lock washers and nuts (310) at the supporting flange (309).
- Carefully lift supporting cylinder (307) along with diverter insert head (301).

Safety and Handling Precautions

Ensure not to damage the driving shaft (308) when lowering the supporting cylinder.
Remove resistor connecting bolts (316) and lock washers, then withdraw transfer resistors (315) vertically.
Slide guide pin 'M' into the designated hole on supporting cylinder flange (309) for alignment.
The driving rod of the energy accumulator may need adjustment to engage the driving shaft (308).

Assembly Completion Steps

After aligning supports, screws (310) and lock washers on supporting flange (309) need tightening.
Verify that all screw joints are secure.
Spark gap electrode distance should be checked; standard is 5 mm.
Correct positioning of the non-interchangeable drive coupling (303) is critical for correct assembly.

Oil Filling and Testing

Fill the diverter switch oil vessel up to the insert head (301) before final assembly.
Conduct several manual trial switching operations to ensure functionality.
Avoid trial operations without adequate oil filling to prevent damage.

Protective Device Inspection

Activation of the "Off" push-button opens the protective device flap, while the "Operation" button initiates the operational state, closing the flap.
Proper connections must be confirmed to de-energize the transformer via the circuit breaker.

Component Listing

Contact materials used in components (322, 323) are primarily E-Cu to enhance conductivity.
Maximum contact burning limit (a) is set at 5 mm.
System includes a comprehensive component list (e.g., Groups 100, 200, 300, 400, 500) detailing parts like tap changers, diverter switches, and selector drives.

Tap Changer Components

Three main components: tap changer head with diverter switch oil vessel, diverter switch insert with diverter switch and transfer resistors, tap selector with preselector.
Load transfer from the current tap to the preselected next tap is executed by a high-speed diverter switch using ohmic transfer resistors.
Load transfer time for the diverter switch is between 0.027 and 0.037 seconds.
Diverter switch has a separate oil vessel; the tap selector operates in transformer oil.

Inspection Guidelines

Strict adherence to published inspection instructions is vital for reliability.
Inspection intervals depend on the number of switching operations and duration of service.
Inspection is limited to the diverter switch as the tap selector does not experience wear.
Procedures for inspection include cleaning insulating parts and checking contact wear.
Immediate reporting to representatives is required for any faults affecting functionality.

Diverter Switch Maintenance Procedures

Withdrawal of the diverter switch insert can be done with the tap changer in any position by following a series of steps involving shut-off cocks and oil drainage.
Ensure peak cleanliness and carefulness during inspections and maintenance operations.
Withdrawal of the diverter switch insert involves lifting vertically and requires a minimum height dependent on series voltage.

Disassembly of Diverter Switch Insert

Periodic inspection may not require complete disassembly if the oil is minimally contaminated; cleaning a contact shell may suffice.
Further disassembly requires removal of screws, bolts, and support cylinders, ensuring not to damage the driving shaft.
Transfer resistors must be withdrawn vertical by unscrewing connecting bolts.

Grouping of Components

Group 100: Tap changer head components including mounting flange, driving shaft, and oil shut-off cock.
Group 200: Diverter switch oil separation components such as oil drain cock and oil vessel components.
Group 300: Diverter switch insert components including contact shells, driving shaft, and transfer resistors.
Group 400: Tap selector components including Geneva drive and driving shafts.
Group 500: Preselector components involving preselector driving mechanisms and switching contacts.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on removing and handling various mechanical components such as bolts, washers, and diverter switches. This quiz covers essential processes and techniques in mechanical engineering relevant to component assembly and disassembly. Perfect for students and professionals alike who want to refresh their understanding of mechanical operations.