Vacuum interrupter/ operator

The spring-dump cam raises the spring-dump interlock upon insertion of the circuit breaker into the compartment, or upon withdrawal from the compartment. The interlock is raised at about the time the front wheels pass over the cubicle sill.

It allows the spring-dump interlock to be in the reset (lowest) position at all other times.

The operation of the spring-dump interlock may be seen in Figure 34: Interlock mechanisms on the type 38-3AH3 vacuum circuit breaker on page 37. As the interlock rises (5.0), it causes the 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 spring- dump condition as the tube rises. The rising tube raises a lever attached to the base of the operating-mechanism enclosure. This lever raises the trip-free pushrod, that elevates the closing- spring release cam. The closing- spring release cam moves the closing-spring latch, that causes the closing springs to discharge.

However, the trip-free interlock is raised, so that the operating mechanism is held trip-free (refer to "Trip-free interlock" on page 33). Thus, the energy in the closing springs is released (spring-dump), without movement of the jack shaft or the vacuum-interrupter contacts.

D. Trip-free interlock position - mechanical interlock

In order to prevent the motor- charging circuit from "making and breaking" as the circuit breaker and cubicle secondary disconnects make or break physical contact, an electrical switch is provided. This switch is mounted in the line of action taken by the trip-free interlock plunger that follows the racking-mechanism cam and is elevated at all times while the circuit breaker is in the drawout compartment except when in the TEST or CONNECT positions.

A striker plate, integral with the trip- free interlock plunger, engages and operates (opens) the switch when the plunger is in an elevated position blocking spring-charging motor operation. The switch is closed when the circuit breaker occupies the TEST or CONNECT position, allowing the charging motor to operate automatically.

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Siemens 38-3AH3 38 kV instruction manual Trip-free interlock position mechanical interlock
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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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