Siemens GMSG Instruction Manual page 66

Appendix
Circuit Nominal
breaker type voltage class
1
kV
5-GMSG-250-
4.16
xxxx-97
5-GMSG-350-
4.16
xxxx-132
7-GMSG-500-
7.2
xxxx-111
15-GMSG-500-
13.8
xxxx-62
15-GMSG-750-
13.8
xxxx-97
15-GMSG-
13.8
1,000-xxxx-130
Table 14: Type GMSG vacuum circuit breaker ratings (historic "constant MVA" ratings basis)
These ratings are in accordance with:
ANSI/IEEE C37.04-1979 Standard Rating
Structure for AC High-Voltage Circuit
Breakers Rated on a Symmetrical
Current Basis
ANSI C37.06-1987 AC High-Voltage
Circuit Breakers Rated on a Symmetrical
Current Basis - Preferred Ratings and
Related Required Capabilities
ANSI/IEEE C37.09-1979 Standard Test
Procedure for AC High-Voltage Circuit
Breakers Rated on a Symmetrical
Current Basis
ANSI/IEEE C37.010-1979 Application
Guide for AC High-Voltage Circuit
Breakers Rated on a Symmetrical
Current Basis.
66
Nominal Maximum
three-phase design
MVA class 9 voltage (V)
MVA kV rms
250 4.76
350 4.76
500 8.25
500 15.0
750 15.0
1,000 15.0
Footnotes:
"xxxx" in type designation refers to the
1.
continuous current rating 1,200 A, 2,000 A
or 3,000 A, as appropriate. The 4,000 A fan-
cooled rating is achieved using a 3,000 A circuit
breaker, in combination with fan cooling as
indicated in Footnote 4.
Maximum design voltage for which the circuit
2.
breaker is designed and the upper limit for
operation.
K is the ratio of the rated maximum design
3.
voltage to the lower limit of the range of
operating voltage in which the required
symmetrical and asymmetrical interrupting
capabilities vary in inverse proportion to the
operating voltage.
4,000FC indicates that fan cooling is included in
4.
the switchgear structure for this rating. 4,000 A
rating is not available in outdoor equipment.
Continuous Voltage range
current factor (K)
4
2
A rms ----
1,200, 2,000 1.24
1,200, 2,000,
1.19
3,000, 4,000FC
1,200, 2,000 1.25
1,200, 2,000 1.30
1,200, 2,000,
1.30
3,000, 4,000FC
1,200, 2,000,
1.30
3,000, 4,000FC
5.
6.
7.
Withstand voltage levels
3
Power Lightning
frequency impulse (BIL)
kV rms kV crest
19
19
36
36
36
36
To obtain the required symmetrical interrupting
capability of a circuit breaker at an operating
voltage between 1/K times rated maximum
design voltage and rated maximum design
voltage, the following formula shall be used:
Required symmetrical interrupting capability =
rated short-circuit current (I) x [(rated maximum
design voltage)/(operating voltage)]. For
operating voltages below 1/K times maximum
design voltage, the required symmetrical
interrupting capability of the circuit breaker shall
be equal to K times rated short-circuit current.
Within the limitations stated in
ANSI/IEEE C37.04-1979, all values apply to
polyphase and line-to-line faults. For single
phase-to-ground faults, the specific conditions
stated in clause 5.10.2.3 of
ANSI/IEEE C37.04-1979 apply.
Current values in this row are not to be
exceeded even for operating voltage below
1/K times rated maximum design voltage. For
operating voltages between rated maximum
design voltage and 1/K times rated maximum
design voltage, follow Footnote 5.
60
60
95
95
95
95