Physical inspections

Installation checks and functional tests

Figure 4: Manual charging of the closing springs

The suggested procedure to engage the racking mechanism is as follows:

1.The circuit breaker must be OPEN. (The racking shroud cannot be moved if the circuit breaker is CLOSED.)

2.Hold the socket-end of the crank in one hand and the crank handle in the other hand.

3.Place the socket over the end of the racking-mechanism shaft. Align the socket with the shoulder on the racking-mechanism shaft.

Note: If the socket is not aligned, the socket will not be able to engage the shoulder of the racking-mechanism shaft.

4.Once alignment is achieved, firmly push the crank and socket assembly toward the racking mechanism.

5.When properly engaged, the crank should remain connected to the racking mechanism. If the crank does not remain in position, adjust the spring plungers clockwise one-half turn. This will increase the contact pressure of the spring plunger.

6.To remove the crank, pull the assembly off of the racking-mechanism shaft.

Note: If the effort to rack the circuit breaker increases considerably during racking, or if turning of the racking crank requires excessive force, stop racking immediately. Do not try to force the racking crank to rotate, or parts of the circuit breaker or racking mechanism could be damaged. Determine the source of the problem and correct it before continuing with racking.

1.Verify the rating of the circuit breaker is compatible with both the system and the switchgear.

2.Perform a visual-damage check. Clean the circuit breaker of all dust, dirt and foreign material.

Manual-spring charging check

1.Insert the manual-spring charging crank into the manual-charge handle socket as shown in Figure 4. Turn the crank clockwise (about 48 revolutions) until the spring condition indicator shows the closing spring is CHARGED.

2.Repeat the spring discharge check.

3.Verify the springs are DISCHARGED and the circuit-breaker primary contacts are OPEN by indicator positions.

As-found and vacuum-integrity check tests

Perform and record the results of both the as-found insulation test and the vacuum- integrity check (dielectric) test. Procedures for these tests are described in the Maintenance section of this instruction manual pages 40-52.

Automatic spring-charging check

Refer to the specific wiring information and rating label for your circuit breaker to determine the voltage required and where the control-voltage signal should be applied. Usually, spring-charging power is connected to secondary-disconnect fingers SD16 and SD15, closing control power to SD13 and SD15 and tripping power to SD1 and SD2.

When control power is connected to the type 38-3AH3 vacuum circuit breaker, the closing springs should automatically charge, if the racking crank is not engaged.

38-3AH3 38 kV specifications

The Siemens 38-3AH3 is a high-voltage circuit breaker designed for medium voltage applications, particularly in substations and industrial environments. This device operates at a voltage level of 38 kV, showcasing Siemens' commitment to innovation and reliability in electrical engineering.

One of the main features of the Siemens 38-3AH3 is its advanced interruption technology, which employs the proven hybrid design combining both gas-insulated and air-insulated technologies. This hybrid approach not only enhances the breaker's performance and reliability but also minimizes its footprint, making it an ideal choice for space-constrained environments.

The Siemens 38-3AH3 uses vacuum interruption technology, allowing for efficient switching with minimal wear and tear. The vacuum interrupters are highly reliable and provide excellent performance under various operating conditions. This technology ensures that the circuit breaker can handle short circuits and overloads effectively, thus protecting the entire electrical system.

Additionally, the Siemens 38-3AH3 incorporates intelligent monitoring systems. These digital technologies provide real-time data on breaker status, operational performance, and maintenance needs. This predictive maintenance capability helps operators to identify potential issues before they develop into significant problems, ultimately leading to reduced downtime and maintenance costs.

Another notable characteristic of the Siemens 38-3AH3 is its high insulation strength. Thanks to its robust design and development, this circuit breaker can withstand adverse environmental conditions, making it suitable for use in diverse geographical locations and climates. Its components are designed to resist contamination and corrosion, ensuring long-term reliability.

The Siemens 38-3AH3 also offers enhanced safety features. It includes protective relays and automatic fault detection systems that isolate faults quickly, preventing damage to downstream equipment. Furthermore, the design allows for easy maintenance, with components that are accessible without the need for extensive disassembly.

In summary, the Siemens 38-3AH3 38 kV circuit breaker is a leading solution in high-voltage protection and control, characterized by its advanced interruption technology, integrated monitoring systems, high insulation strength, and user-friendly maintenance features. Its innovative design and engineering make it a trusted choice for utilities and industrial facilities aiming to enhance the reliability and safety of their electrical systems.