Appendix – Siemens vacuum circuit breaker 38-3AH3 38 kV User Manual
Page 64
Appendix
Measured parameter
Units
Circuit breaker type
1
38-3AH3-31
38-3AH3-40
General
Nominal voltage class
kV
38.0
38.0
Rated
values
Rated
voltage
Maximum design voltage (V)
2
kV rms
38.0
38.0
Voltage range factor (K)
3
----
1.0
1.0
Insulation
levels
Withstand
voltage levels
Power-frequency
kV rms
80
80
Lightning-impulse (BIL)
kV peak
150
150
Rated
current
Continuous
4
A rms
1,200, 2,000,
3,000FC
1,200, 2,000,
3,000FC
Short-circuit (at rated maximum design voltage)
(I)
5, 6
kA rms sym
31.5
40
Interrupting time
7
Cycles/ms
5/83
5/83
Permissible tripping delay (Y)
Sec
2
2
Related
required
capabilities
Current
Rated maximum design voltage (V) divided by K =
(V/K)
kA rms
38.0
38.0
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
latching
(momentary)
Asymmetrical (1.55 x I)
kA rms
49
62
Peak (2.6 x I)
kA peak
82
104
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.
2
Maximum design voltage the circuit breaker is
designed for and the upper limit for operation.
3
K is listed for informational purposes only. For
circuit breakers rated on a "constant kA basis,"
the voltage range factor is 1.0.
4
3000FC indicates fan cooling is included in the
switchgear structure for this rating. 3000 A
rating is not available in outdoor equipment.
5
All values apply to polyphase and line-to-line
faults.
6
Standard duty cycle is O - 0.3s - CO - 3 min. -
CO.
7
Three-cycle (50 ms) interrupting is optionally
available.
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.
Table 12: Type 38-3AH3 vacuum circuit breaker ratings (new "constant kA" ratings basis)
64