ZH_CN
（1）DGK is mainly used in small current systems with rated current＜630A, and rated breaking current ≤200kA.
（2）DGK can limit the current and cut off the short-circuit current within 10ms, so that the current actually appearing in the fault circuit is only (15 ~ 50) % of the expected short-circuit current.
（3） TXB3=DGK+ switch cabinet with different configurations. TXB3 is made up of DGK and general switching equipment such as vacuum circuit breaker, load switch or disconnector in series. For normal switching operation and operation of load current or overload current, it is completed by the switching equipment (load switch or circuit breaker) in TXB3 device.
（4）The product not only realizes low-cost switching off of short-circuit current, but also avoids improving the dynamic and thermal stability parameters of related electrical equipment on the branch circuit, thus achieves the rational design of the circuit and reduces the investment of engineering equipment.
Main technical parameters：
| number | Parameter name | Unit | Technical date | |
|---|---|---|---|---|
1 | Rated voltage | kV | 3.6~24 | |
2 | Rated current | A | 6.3~500 | |
3 | Rated pre-expected short-circuit breaking current | kA | 20-120 | |
4 | Current limit coefficient = cut-off current / the peak Value of Pre-expected Fault Current | % | 15~50 | |
5 | Insulation level | Power frequency withstand voltage | kV/1min | 42/48 |
Lightning impulse withstand voltage | kV | 75/85kV | ||
Product features and advantages：
◆Breaking speed is fast (High speed): Total breaking duration:<10ms
◆The breaking process has obvious current limiting characteristics (Current limiting)
◆It is mainly used for small rated current systems.
◆Non-standard cabinet types are assembled according to the engineering requirements. There are various configuration schemes.
◆The cost of replacing a large number of switches and other main equipment in a transformer substation is reduced.
Product Usage：
◆The rapid short circuit protection of auxiliary branch buses in hydropower plants, limit and quick break the high-amplitude short circuit current, avoids using the expensive generator circuit breakers, improves technical economy.
◆Outlet of large synchronous motor
◆It is used for quick disconnection of the feeders prone to short circuit fault and quick isolation of the fault points.
