8DQ1 — SF6 GIS 245–550 kV
8DQ1 is the top model of the 8D series of gas-insulated switchgear for the 245, 420 and 550 kV classes. It is installed at key substations of the 330–750 kV class, at power evacuation substations of large power plants, in cities and confined conditions, and in seismically active regions.
- Rated voltage
- up to 245 / 420 / 550 kV
- Short-circuit breaking current
- up to 80 kA (245 kV), up to 63 kA (420 and 550 kV), break time < 2 cycles
- Rated current
- busbars up to 6300 A, feeders up to 5000 A
- Test voltage
- up to 460 / 650 / 740 kV
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The 8D series has been built since 1968, and more than 24,000 bays have been installed. The 8DQ1 has a metal grounded enclosure and SF6 insulation. The breakers with self-compression interrupters are fitted with a spring-operated mechanism, and disconnectors, earthing switches, and current and voltage transformers are built into the bay.
In the 245 kV version (60 Hz) the switchgear is rated for a breaking current of up to 80 kA with a peak withstand current of 216 kA. The power-frequency test voltage here reaches 460 kV and the lightning impulse 1050 kV. It was the 245 kV breakers in the PSE&G project at the Bergen substation (USA) that first in the world interrupted a current of 80 kA. The 420 and 550 kV versions (50/60 Hz) break up to 63 kA with a peak withstand current of 170 kA. For them the test voltage is 650 and 740 kV, the lightning impulse 1425 and 1550 kV, and the switching impulse 1050 and 1175 kV respectively.
The rated busbar current reaches 6300 A, and the feeder current 5000 A. Interruption takes less than 2 cycles, and the short-time withstand is up to 3 s. The duty cycle is O-0.3 s-CO-3 min-CO or CO-15 s-CO. The 245 kV bay is 2200 mm wide and weighs about 11 t, with a height and depth of about 3.8×5.8 m. The 420–550 kV bay is wider, 3600 mm, weighs about 21 t and measures 4.8×10 m.
Versions up to 245 kV can be installed indoors and outdoors at −30…+55 °C. The 420–550 kV switchgear is designed for indoor installation at −25…+55 °C. Gas leakage in type tests is below 0.1 % per year per compartment. The first major overhaul is carried out no earlier than after 25 years, and the expected service life is over 50 years.
Gas-insulated busducts for 420 kV are also built on the basis of the 8DQ1. Low-power instrument transformers LPIT are offered for this class. The switchgear complies with IEC, IEEE and GOST standards.
Technical specifications
| Rated voltage | up to 245 / 420 / 550 kV |
|---|---|
| Short-circuit breaking current | up to 80 kA (245 kV), up to 63 kA (420 and 550 kV), break time < 2 cycles |
| Rated current | busbars up to 6300 A, feeders up to 5000 A |
| Test voltage | up to 460 / 650 / 740 kV |
| Lightning impulse | up to 1050 / 1425 / 1550 kV |
| Switching impulse | up to 1050 kV (420 kV), up to 1175 kV (550 kV) |
| Bay width / weight | 2200 mm / 11 t (up to 245 kV); 3600 mm / 21 t (420–550 kV) |
| Temperature | −30…+55 °C (245 kV), −25…+55 °C (420–550 kV) |
| Gas leakage | < 0.1 % per year |
| Standards | IEC, IEEE, GOST |
Request a price and lead time
8DQ1 — SF6 GIS 245–550 kV. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8537 20 99 00 |
|---|---|
| HS, 6 digits | 8537 20 |
| CN (EU) | 8537 20 99 |
| HTSUS (USA) | 8537 20 00 00 |
| China customs tariff | 8537 20 11 00 8537 20 19 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
What breaking current does the 8DQ1 have at 330 kV and above?
The 420 and 550 kV versions break up to 63 kA with a peak withstand current of 170 kA. The 245 kV version is rated for 80 kA.
Does the 8DQ1 allow outdoor installation?
Versions up to 245 kV can be installed outdoors, in the temperature range −30…+55 °C. The 420–550 kV switchgear is intended for indoor use at −25…+55 °C.
What are the dimensions and weight of an 8DQ1 bay at 550 kV?
The 420–550 kV bay is 3600 mm wide, weighs about 21 t and measures 4.8×10 m in height and depth. The 245 kV bay is narrower, 2200 mm, and weighs about 11 t.
Similar equipment from other manufacturers
