Installation checks and functional tests

Note: Secondary-disconnect terminals are numbered 1-16, from right to left.

The automatic spring-charging features of the circuit breaker must be checked. Control power is required for automatic spring-charging to take place.

1.Open control-power circuit by opening the control-power disconnect device.

2.Install the circuit-breaker end of the split-plug jumper (if furnished) to the circuit breaker as shown in Figure 5: Split-plug jumper connected to circuit breaker. The split-plug jumper is secured over the circuit-breaker secondary contacts with thumb screws.

3.Install the switchgear end of the split- plug jumper to the secondary- disconnect block inside the switchgear cubicle as shown in Figure 6: Split-plug jumper connected to switchgear. The jumper slides into place and interconnects all control power and signal leads (for example, electrical trip and close contacts) between the switchgear and the circuit breaker.

4.Energize (close) the control-power circuit disconnect.

5.Use the close and trip controls (refer to Figure 1: Type 38-3AH3 vacuum circuit breaker front panel controls on page 8) to first close and then open the circuit-breaker contacts. Verify the contact positions visually by observing the OPEN/CLOSED indicator on the circuit breaker.

6.De-energize control power by repeating Step 1. Disconnect the split- plug jumper from the switchgear before disconnecting the circuit- breaker end.

7.Perform the spring discharge check again. Verify the closing springs are DISCHARGED and the primary contacts of the type 38-3AH3 vacuum circuit breaker are OPEN.

Final mechanical inspections without control power

1.Make a final mechanical inspection of the circuit breaker. Verify the contacts are in the OPEN position, and the closing springs are DISCHARGED.

2.Check the upper- and lower-primary studs and contact fingers shown in Figure 7: Circuit breaker primary disconnect. Verify mechanical condition of finger springs and the disconnect studs, check for loose hardware, damaged or missing primary-disconnect contact fingers and damaged disconnect studs.

3.Coat movable primary-contact fingers (refer to Figure 7: Circuit breaker primary disconnect) and the secondary-disconnect contacts (refer to Figure 23: Construction of secondary shunt release (shown charged) on page 30) with a light film of Siemens contact lubricant number 15-172-791-233.

4.The type 38-3AH3 vacuum circuit breaker is ready for installation into its assigned cubicle of the metal-clad switchgear. Refer to removal procedures and install the circuit breaker into the switchgear.

5.Refer to the switchgear instruction manual for functional tests of an installed circuit breaker.

Figure 5: Split-plug jumper connected to circuit breaker

Figure 6: Split-plug jumper connected to switchgear

Figure 7: Circuit breaker primary disconnects

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Siemens 38-3AH3 38 kV Final mechanical inspections without control power, Split-plug jumper connected to circuit breaker
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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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