ETNB,a DC circuit breaker for nuclear power plants,is a product applied to protect DC power supply systems such as generators,motor pumps,and batteries,which are the core parts of nuclear power plants.

ETNB,the first Q-Class DC circuit breaker for nuclear power plants developed by our company,applied the spring shaft control method,the epoxy resin frame,and the air blocking method,and designed and manufactured products in accordance with the international standard ANSI C37.14 (1999). The safety has been reinforced.

The breaking capability,one of the important performances of a circuit breaker,was verified by passing short-circuit and load opening and closing tests at CESI in Italy and KERI,and passed the Q-Class certification tests and documents related to vibration resistance tests and BOM. Recognized for quality and performance.

In addition,by applying a digital overcurrent relay that accurately operates by supplementing the shortcomings of the existing mechanical overcurrent relay (OCR),the operation reliability of the DC circuit breaker has been improved by accurately judging the load current and the accident current. Saved and added the function to analyze the fault current for the trip. In addition to this,it is possible to change the setting value from a distance using RS-485 communication.


-Quality and performance verification by satisfying Q-Class grade test


-Secure driver safety through interlock function between open operation and safety lock

-Simple mechanism structure makes it easy to withdraw the blocking part

Other technical notes

-FRTU integrated digital relay provides overcurrent protection function