Appendix

Table 12: Type 38-3AH3 vacuum circuit breaker ratings (new "constant kA" ratings basis)

 

 

Measured parameter

Units

Circuit breaker type1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

38-3AH3-31

38-3AH3-40

 

 

 

 

 

 

 

 

 

General

 

 

Nominal voltage class

kV

38.0

38.0

 

 

 

 

 

 

 

Rated

Rated

Maximum design voltage (V)2

kV rms

38.0

38.0

values

voltage

 

 

 

 

 

 

 

Voltage range factor (K)3

----

1.0

1.0

 

 

 

 

 

 

 

 

 

 

Insulation

Withstand

 

 

Power-frequency

kV rms

80

80

 

levels

voltage levels

 

 

 

 

 

 

 

Lightning-impulse (BIL)

kV peak

150

150

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rated

 

 

 

Continuous4

A rms

1,200, 2,000,

1,200, 2,000,

 

current

 

 

 

 

 

3,000FC

3,000FC

 

 

Short-circuit (at rated maximum design voltage)

kA rms sym

31.5

40

 

 

 

 

 

(I)5, 6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Interrupting time7

Cycles/ms

5/83

5/83

 

 

 

 

 

 

 

 

 

Permissible tripping delay (Y)

Sec

2

2

 

 

 

 

 

 

 

Related

Current

Rated maximum design voltage (V) divided by K =

kA rms

38.0

38.0

required

 

 

 

 

(V/K)

 

 

 

 

 

 

 

 

capabilities

 

Maximum symmetrical (sym) interrupting (K x I)

kA rms sym

31.5

40

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

%dc component

%

47

47

 

 

 

 

 

 

 

 

 

Short-time current (K x I) (three-seconds)

kA rms sym

31.5

40

 

 

 

 

 

 

 

 

 

Closing and

 

Asymmetrical (1.55 x I)

kA rms

49

62

 

latching

 

 

 

 

 

 

 

 

 

 

 

Peak (2.6 x I)

kA peak

82

104

 

(momentary)

 

 

 

 

 

 

 

 

 

 

 

 

These ratings are in accordance with:

ANSI/IEEE C37.04-1999 Standard Rating Structure for AC High-Voltage Circuit Breakers

ANSI/IEEE C37.06-2009 AC High- Voltage Circuit Breakers Rated on a Symmetrical Current Basis - Preferred Ratings and Related Required Capabilities

ANSI/IEEE C37.09-1999 Standard Test Procedure for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis

ANSI/IEEE C37.010-1999 Application Guide for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis.

Footnotes:

1"xxxx" in type designation refers to the continuous current rating 1,200, 2,000 or 3,000 A, as appropriate. The 3,000 A fan- cooled rating is achieved using fan cooling as indicated in Footnote 4.

2Maximum design voltage the circuit breaker is designed for and the upper limit for operation.

3K is listed for informational purposes only. For circuit breakers rated on a "constant kA basis," the voltage range factor is 1.0.

43000FC indicates fan cooling is included in the switchgear structure for this rating. 3000 A rating is not available in outdoor equipment.

5All values apply to polyphase and line-to-line faults.

6Standard duty cycle is O - 0.3s - CO - 3 min. - CO.

7Three-cycle (50 ms) interrupting is optionally available.

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Siemens 38-3AH3 38 kV Maximum design voltage, Values Voltage Voltage range factor K3 Insulation Withstand, Continuous4

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.