Maintenance

Removal from switchgear

Prior to performing any inspection or maintenance checks or tests, the circuit breaker must be removed from the switchgear. The "Installation checks and initial functional tests" section (refer to page 8) describes the removal procedure in detail. The principal steps are repeated here for information and guidance, but without the details of the preceding section.

1.The first step is to de-energize the circuit breaker. Figure 36: Trip-control pushbutton (lower button) illustrates the location of the trip control on the circuit-breaker operator panel. Depressing the trip pushbutton opens the circuit breaker prior to removal from the switchgear.

2.The second step in the removal procedure is to de-energize control power to the circuit breaker. Open the control-power disconnect device.

3.Rack the circuit breaker to the DISCONNECT position.

4.Perform the spring discharge check. This is done by first depressing the red trip pushbutton. Second, depress the black close pushbutton. Third, depress the red trip pushbutton again, and observe the spring condition indicator. It should read DISCHARGED.

5.Remove the circuit breaker from the switchgear. Refer to page 10 of "Installation checks and initial functional tests" section of this instruction manual for special instructions and precautions regarding removal of a circuit breaker not at floor level.

6.The circuit breaker can be located either on the floor or on a pallet. Each circuit breaker has four wheels and handles to allow one person to maneuver the unit on a level surface without assistance.

Checks of the primary power path

The primary power path consists of three vacuum interrupters and three upper- and three lower-primary disconnects. These components are checked for cleanliness and condition. The vacuum interrupters are also checked for vacuum integrity.

Some test engineers prefer to perform the contact-erosion check during the manual- spring charging check of the operator, since charging of the springs is necessary to place the contacts in the CLOSED position.

Also, the vacuum-integrity check is usually performed in conjunction with the high- potential test.

These instructions follow the recommendation these tests (contact- erosion/manual-spring charging check and vacuum integrity/high-potential tests) should be combined as described.

Cleanliness check

Figure 37: Type 38-3AH3 vacuum circuit breaker showing vacuum interrupters and primary disconnects (outer phase barrier removed) is a side view of the type 38- 3AH3 vacuum circuit breaker with the outer-insulating barriers removed to show the vacuum interrupter and the upper- and lower-primary disconnects.

All of these components must be cleaned and free of dirt or any foreign objects. Use a dry lint-free cloth. For stubborn dirt, use a clean cloth saturated with isopropyl alcohol (except on a vacuum interrupter).

For stubborn dirt on a vacuum interrupter, use a cloth and warm water and a small amount of mild liquid-household detergent as a cleaning agent. Dry thoroughly using a dry lint-free cloth.

Figure 36: Trip-control pushbutton (lower button)

Figure 37: Type 38-3AH3 vacuum circuit breaker showing vacuum interrupters and primary disconnects (outer-phase barrier removed)

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Siemens 38-3AH3 38 kV instruction manual Removal from switchgear, Checks of the primary power path, Cleanliness check
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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.
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