Datasheet · EN — Official 2025 technical datasheet for the 8DQ1 gas-insulated switchgear family, covering four rating classes from 245 kV to 550 kV. It tabulates insulation withstand levels, normal-current and short-circuit ratings, operating sequence, bay dimensions and weights, ambient temperature range, and service-life figures (first major inspection after more than 25 years, expected lifetime beyond 50 years) for indoor or outdoor installation to IEC, IEEE, and GOST standards.
This datasheet presents the technical data of the 8DQ1 gas-insulated switchgear (GIS), a Siemens Energy Grid Technologies product line for high-voltage substations. The family spans four rating classes with rated voltages of 245 kV, two 420 kV variants, and 550 kV, and is suitable for both indoor and outdoor installation.
Across all classes the circuit-breaker uses a stored energy spring drive mechanism, and each gas compartment is type-tested to a leakage rate below 0.1 % per year. The switchgear is designed for a first major inspection after more than 25 years and an expected lifetime of more than 50 years. The 245 kV class is rated to IEEE standards; the 420 kV and 550 kV classes are rated to IEC / IEEE / GOST. Other values are available on request.
The table below reproduces the electrical ratings for the four classes. The two 420 kV columns differ chiefly in short-circuit performance: one is rated up to 63 kA breaking / 170 kA peak withstand, the other up to 80 kA breaking / 216 kA peak withstand. No switching impulse withstand voltage is specified for the 245 kV class. The rated operating sequence for all classes is O-0.3 s-CO-3 min-CO | CO-15 s-CO.
| Characteristic | 245 kV | 420 kV | 420 kV | 550 kV |
|---|---|---|---|---|
| Rated voltage (up to) | 245 kV | 420 kV | 420 kV | 550 kV |
| Rated frequency | 60 Hz | 50/60 Hz | 50/60 Hz | 50/60 Hz |
| Rated short-duration power-frequency withstand voltage (1 min) | up to 460 kV | up to 650 kV | up to 650 kV | up to 740 kV |
| Rated lightning impulse withstand voltage (1.2 / 50 μs) | up to 1050 kV | up to 1425 kV | up to 1425 kV | up to 1550 kV |
| Rated switching impulse withstand voltage (250 / 2500 μs) | - | up to 1050 kV | up to 1050 kV | up to 1175 kV |
| Rated normal current busbar | up to 6300 A | up to 6300 A | up to 6300 A | up to 6300 A |
| Rated normal current feeder | up to 5000 A | up to 5000 A | up to 5000 A | up to 5000 A |
| Rated short-circuit breaking current (< 2 cycles) | up to 80 kA | up to 63 kA | up to 80 kA | up to 63 kA |
| Rated peak withstand current | up to 216 kA | up to 170 kA | up to 216 kA | up to 170 kA |
| Rated short-time withstand current (up to 3 s) | up to 80 kA | up to 63 kA | up to 80 kA | up to 63 kA |
| Leakage rate per year and gas compartment (type-tested) | < 0.1 % | < 0.1 % | < 0.1 % | < 0.1 % |
| Drive mechanism of circuit-breaker | stored energy spring | stored energy spring | stored energy spring | stored energy spring |
| Rated operating sequence | O-0.3 s-CO-3 min-CO | CO-15 s-CO | O-0.3 s-CO-3 min-CO | CO-15 s-CO | O-0.3 s-CO-3 min-CO | CO-15 s-CO | O-0.3 s-CO-3 min-CO | CO-15 s-CO |
Mechanical and environmental data are grouped into two size classes: the 245 kV / first 420 kV variant shares a 2200 mm bay width, 3800 mm x 5800 mm bay height and depth (depending on bay arrangement), and 11 t bay weight with a -30 °C to +55 °C ambient range; the second 420 kV variant and the 550 kV class use a 3600 mm bay width, 4800 mm x 10000 mm bay envelope, and 21 t bay weight with a -25 °C to +55 °C ambient range. All classes are suitable for indoor or outdoor installation.
| Characteristic | 245 kV / 420 kV (63 kA class) | 420 kV (80 kA class) / 550 kV |
|---|---|---|
| Bay width | 2200 mm | 3600 mm |
| Bay height, depth (depending on bay arrangement) | 3800 mm x 5800 mm | 4800 mm x 10000 mm |
| Bay weight | 11 t | 21 t |
| Ambient temperature range | -30 °C up to +55 °C | -25 °C up to +55 °C |
| Installation | indoor / outdoor | indoor / outdoor |
| First major inspection | > 25 years | > 25 years |
| Expected lifetime | > 50 years | > 50 years |
| Standards | IEEE (245 kV) / IEC / IEEE / GOST | IEC / IEEE / GOST |
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