Maintenance

Figure 45: Contact-resistance test of the primary contacts

Continuous

Contact

current

resistance

rating (A)

(micro-ohms)

1,200

35

 

 

2,000

30

 

 

3,000

30

 

 

Table 4: Maximum contact resistance

7.Connect all points of the secondary disconnect with a shorting wire. Connect the shorting wire to the high- potential lead of the high-voltage tester and ground the circuit-breaker housing. Starting with zero volts, gradually increase the test voltage to 1,500 volts rms, 60 Hz. Maintain test voltage for one minute.

8.If no disruptive discharge occurs, the secondary-control insulation level is satisfactory.

9.Disconnect the shorting wire and re- attach the leads to the spring-charging motor.

10.Perform contact-resistance tests of the primary contacts (refer to Figure 45: Contact-resistance test of the primary contacts). Contact resistance should not exceed the values listed in Table 4: Maximum contact resistance.

Inspection and cleaning of circuit- breaker insulation

1.Perform the spring discharge check on the circuit breaker after all control power is removed. The spring discharge check consists of:

A.Depressing the red trip pushbutton

B.Depressing the black close pushbutton, and

C.Depressing again the red trip pushbutton.

All of these controls are on the circuit breaker front panel. Visually verify the DISCHARGE condition of the springs.

2.Remove phase barriers as shown in Figure 7: Circuit breaker primary disconnects on page 13.

3.Clean barriers and post insulators using a clean cloth dipped in isopropyl alcohol.

4.Replace all barriers. Check all visible fasteners again for condition and tightness.

Note: Do not use any cleaning compounds containing chlorinated hydrocarbons such as trichlorethylene, perchlorethylene or carbon tetrachloride. These compounds will damage the phenylene ether copolymer material used in the barriers and other insulation on the circuit breaker.

Functional tests

Refer to the "Installation checks and functional tests" section of this instruction manual on pages 8 to 13. Functional tests consist of performing at least three manual spring-charging checks and three automatic spring-charging checks. After these tests are complete, and the springs fully discharged, all fasteners and connections are checked again for tightness and condition before re-installing the circuit breaker into the metal-clad switchgear.

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Siemens 38-3AH3 38 kV Continuous Contact, Rating a, Inspection and cleaning of circuit- breaker insulation
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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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