3DN1–3DN4 — outdoor disconnectors 40.5–800 kV (center-rotating, double-break, pantograph, vertical-break)
3DN1–3DN4 are high-voltage outdoor disconnectors for switchyards at voltages from 36–40.5 to 800 kV, with rated currents up to 5000 A and short-circuit currents up to 80 kA for 1 s. They are installed in the switchyards of 35–750 kV substations, power plants, HVDC facilities and test laboratories.
- Rated voltage
- 36/40.5–800 kV (up to 1200 kV per the brochure)
- Rated current
- up to 5000 A (3DN1 up to 4000 A)
- Short-circuit current
- up to 80 kA (1 s)
- Types
- 3DN1 center-rotating; 3DN2 double-break with rotating middle column; 3DN3 pantograph; 3DN4 vertical-break
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
According to the manufacturer, about 123 000 disconnectors have been delivered to more than 110 countries, and some versions reach 1200 kV. Production is spread over a global network of plants. In Brazil the company inherited more than 80 years of experience and makes the local line EVL, DAL, RDA, BC, EVR, LAV, LAH.
The 3DN line is built from identical modules: the current path, the contact system, post and rotating insulators, the frame, linkages and the drive. 3DN1 has two rotating insulators on a common frame and is the world's most widespread center-rotating type. The current path opens sideways, so the phase spacing is large in parallel installation. 3DN2 has three columns, and the middle one rotates and carries the blades. This double-break device is used in substations with limited phase-to-phase space and can be combined with a surge arrester. 3DN3 is a pantograph type with a vertical break and scissor connection to flexible or rigid busbars, and takes up minimal area. 3DN4 is a vertical-break type with a double blade movement. It reduces phase spacing and works well in salt fog.
The contacts are self-spring cylindrical lamellas with a silver–graphite coating and no pressure springs. They are self-lubricating and self-cleaning, and contact pressure increases under short-circuit currents. The contacts need no maintenance, with a service interval of 25 years.
The devices are designed for ice loads of 10–20 mm, temperatures from −60 to +55 °C, coastal areas and high seismicity. Extended radio-interference limits are available. For bus transfer there are arcing horns that switch equalizing currents under Annex B of IEC 62271-102. Drives are motor-operated or manual, in an IP54 stainless steel housing. Poles arrive assembled and adjusted. Arcing horns can be fitted to any disconnector type, and their type tests cover more than 100 current make-and-break cycles. The 3DV8 drive of the Brazilian line needs inspection only after 1000 operations, and the locking system with dual kinematics holds the contact even at short-circuit currents above 50 kA.
The disconnectors have been tested to IEC 62271-102, ANSI, GOST R and GB. The quality system is certified to ISO 9001.
Technical specifications
| Rated voltage | 36/40.5–800 kV (up to 1200 kV per the brochure) |
|---|---|
| Rated current | up to 5000 A (3DN1 up to 4000 A) |
| Short-circuit current | up to 80 kA (1 s) |
| Types | 3DN1 center-rotating; 3DN2 double-break with rotating middle column; 3DN3 pantograph; 3DN4 vertical-break |
| Contacts | self-spring lamellas with Ag/graphite coating, no springs, no grease |
| Ice load | 10/20 mm |
| Temperature | −60 (−55)…+55 °C |
| Drive | motor-operated/manual, IP54 stainless steel housing |
| Standards | IEC 62271-102, ANSI, GOST R, GB; ISO 9001 |
Request a price and lead time
3DN1–3DN4 — outdoor disconnectors 40.5–800 kV (center-rotating, double-break, pantograph, vertical-break). We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8535 30 10 00 8535 30 90 00 |
|---|---|
| HS, 6 digits | 8535 30 |
| CN (EU) | 8535 30 10 8535 30 90 |
| HTSUS (USA) | 8535 30 00 80 |
| China customs tariff | 8535 30 90 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
Which 3DN disconnector type suits a tight switchyard?
The pantograph 3DN3 with a vertical break takes up the least area. Where phase-to-phase space is limited, the double-break 3DN2 and the vertical-break 3DN4 are also suitable.
What rated current do 3DN disconnectors have?
The line is rated for currents up to 5000 A and short-circuit current up to 80 kA for 1 s. The center-rotating 3DN1 is made for currents up to 4000 A.
Do 3DN disconnectors work in heavy icing?
Yes, the devices are designed for ice loads of 10–20 mm and temperatures from −60 to +55 °C. The drive is housed in an IP54 stainless steel enclosure.
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