3AP — SF6 live tank circuit breakers 72.5–1100 kV
3AP is the main line of SF6 live tank circuit breakers for air-insulated switchgear of 72.5–1100 kV substations. The breakers make and break load and short-circuit currents and carry the rated current continuously. They are used in transmission and distribution networks and at substations of power plants and industrial enterprises.
- Rated voltage
- 72.5–1100 kV
- Versions
- 3AP1 (up to 300 kV, 1 interrupter unit per pole), 3AP2 (up to 550 kV, 2 units), 3AP3 (362–550 kV with closing resistors), 3AP4/3AP5 (4 units per pole, 3AP5 with resistors)
- Operating mechanism
- spring (stored-energy spring), three-pole (FG) or single-pole (FE, FI) control
- Interruption principle
- self-compression / dynamic self-compression, SF6
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
In a live tank breaker the interrupter operates at line potential and stands on a supporting insulator column. This distinguishes it from the dead tank design. The company uses the same interrupter units, mechanisms and controls in its SF6 gas-insulated switchgear (GIS), so the 3AP is in effect the base apparatus for both types of switchgear. The company reports more than 220,000 breakers delivered to 150 countries.
The line is built on a modular principle. The 3AP1 for voltages up to 300 kV has one interrupter unit per pole, the 3AP2 up to 550 kV has two units. For the 362–550 kV classes there is the 3AP3 with closing resistors. The 3AP4 for higher classes (up to 800 kV) carries four units per pole, and the 3AP5 differs from it by resistors. There are three control schemes. Three-pole control on a common frame is designated FG, single-pole control on a common frame FE, and single-pole design on separate bases FI. Insulators are porcelain or composite.
The arc is extinguished by the self-compression or dynamic self-compression principle, patented since 1973. The arc's own thermal energy is used to interrupt it, so the mechanism needs only little energy. This made it possible to use the same spring-operated mechanism up to 1100 kV. The mechanism together with the control equipment is housed in a compact cabinet. The guaranteed endurance is 10,000 cycles, and the service interval is 25 years or 6000 operations.
Breakers up to 300 kV are shipped fully assembled and after routine acceptance tests. Installation of one unit by one supervising engineer takes about one and a half days, and commissioning and maintenance are carried out on request. All types have been tested to IEC and ANSI, and the company's own laboratory in Berlin is accredited to IEC 17025 and is a member of PEHLA and STL. Factories operate in Germany, the USA, Mexico, Brazil, China and India.
The family also includes DCB disconnecting circuit breakers for 145 and 420 kV. They combine switching with a visible isolating gap and reduce the substation footprint. The PSD controlled switching controller, the SiCEA01 contact wear analyzer and the Sensgear digital monitoring system are supplied as options.
Technical specifications
| Rated voltage | 72.5–1100 kV |
|---|---|
| Versions | 3AP1 (up to 300 kV, 1 interrupter unit per pole), 3AP2 (up to 550 kV, 2 units), 3AP3 (362–550 kV with closing resistors), 3AP4/3AP5 (4 units per pole, 3AP5 with resistors) |
| Operating mechanism | spring (stored-energy spring), three-pole (FG) or single-pole (FE, FI) control |
| Interruption principle | self-compression / dynamic self-compression, SF6 |
| Insulators | porcelain or composite |
| Mechanical endurance | 10,000 cycles (guaranteed) |
| Maintenance | maintenance-free for 25 years or 6000 cycles |
| Testing | IEC, ANSI; laboratory in Berlin accredited to IEC 17025, member of PEHLA and STL |
| Manufacturing | Germany (Berlin), USA, Mexico, Brazil, China, India |
Request a price and lead time
3AP — SF6 live tank circuit breakers 72.5–1100 kV. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8535 29 00 00 |
|---|---|
| HS, 6 digits | 8535 29 |
| CN (EU) | 8535 29 00 |
| HTSUS (USA) | 8535 29 00 40 |
| China customs tariff | 8535 29 00 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
Which 3AP version should be chosen for the 550 kV class?
For voltages up to 550 kV the 3AP2 with two interrupter units per pole is intended, and the 3AP3 with closing resistors is supplied for 362–550 kV. The 3AP1 with one unit is rated only up to 300 kV.
When does a 3AP breaker need its first maintenance?
The service interval is 25 years or 6000 operations. The mechanical endurance of the mechanism is guaranteed at 10,000 cycles.
To which standards are 3AP breakers tested?
All types have been tested to IEC and ANSI. The laboratory in Berlin is accredited to IEC 17025 and is a member of PEHLA and STL.
Similar equipment from other manufacturers
