Vacuum interrupter/ operator

Close-latch lever

Closing-spring release cam

Normal operating position

 

Trip-pushrod cam

 

Trip-latch lever

Enclosure rear

Trip-free pushrod

Retaining rings

Trip-pushrod cam

Interlock levers

Spring-dump tube

Figure 35: CLOSED circuit-breaker interlock mechanism in stored-energy mechanism

The racking-cam profile on the racking mechanism allows the trip- free racking-interlock to be in the lowest position (reset) only when the circuit breaker is in the TEST or the CONNECT position. Thus, during racking, the trip-free interlock is held in an elevated condition except when the circuit breaker reaches the TEST or the CONNECT position. The circuit breaker can be closed only when the interlock plunger is down, and will trip if the plunger is moved up.

The operation of the trip-free racking-interlock may be seen in Figure 34: Interlock mechanisms on the type 38-3AH3 vacuum circuit breaker on page 37. As the interlock (6.0) rises, it moves a series of linkages, that cause a guided tube (4.0) to rise, and enter the operating-mechanism enclosure.

Figure 35: CLOSED circuit breaker interlock mechanism in stored- energy mechanism shows the operating mechanism detail components that establish a trip- free condition as the tube (4.0) rises. The rising tube raises a lever attached to the base of the operating-mechanism enclosure. This lever raises the trip-free pushrod.

The rising trip-free pushrod elevates the trip-free pushrod cam, that pushes the trip-free coupling lever (62.8.3) (refer to Figure 15: Stored- energy operating mechanism on page 20) toward the rear of the enclosure.

The movement of the trip-free coupling lever toward the rear of the enclosure is transmitted through the trip-free coupling link (62.8.2) to the spring-return latch (62.8.1). With the latch displaced from a normal reset position, the trip-free coupling rod (62.8) cannot apply closing effort to the jack shaft (63.0). Thus, upon release, the closing-spring energy will not be transmitted to the jack shaft.

C. Automatic closing-spring energy release

The automatic closing-spring energy-release (spring-dump) (refer to Figure 32: Circuit-breaker interlocks and ground disconnect on page 33) is a plunger with a roller on the lower end. The spring dump has a return spring that returns the spring dump to the reset or lowered position.

The plunger roller tracks the shape of the spring discharge cam on the racking mechanism in the switchgear (refer to Figure 33: Circuit-breaker compartment (MOC/ TOC switch cover removed for photo) on page 34).

38

Page 37 Page 39
Page 38
Image 38
Siemens 38-3AH3 38 kV instruction manual Automatic closing-spring energy release
Page 37 Page 39

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.
Top Page Image Contents