VM51, MCCBs with thermal magnetic trip units

• VA51 series air circuit breaker is applied to distribute electrical energy and protecte circuit and power supply equipments in AC power distribution network with 50 Hz, rated voltage up to 660 V (690 V) and rated current from 630 A to 6300 A to prevent it from overload, under voltage, short circuit, single phase rounding hazards and other faults.

• The circuit breaker has intelligent protecting functions, and the selective protection accuracy, which can improve the reliability of power supply and avoid unnecessary power faults. it has an open communication interface for “four remote patterns” to meet the requirements of control centers and automation systems.

• The circuit breaker has a pulse withstand voltage of 8000 V at an altitude of 2000 meters (it will be modified according to the different altitudes, and the maximum is no more than 12000 V).

• The circuit breaker can be used as an isolator without an intelligent controller and sensor.

• The circuit breaker complies with standard IEC 60947-2, Lowvoltage switchgear and controlgear-Part 2: Circuit-breakers.

Normal work and installation conditions

• Ambient temperature:-5 ℃～+40 ℃;

• The altitude of the installation site does not exceed 2000 m; Air conditions: Relative humidity not exceed 50 % at the max temperature of +40°C, higher relative humidity is allowable under lower temperature,for example,RH could be 90 % at +20℃. Special measures should be taken to occurrence of dews.

• Pollution grade: Grade 3;

• Installation category of main circuit lll,Istalltion category of auxiliary circuit and control circuit: ll ;

• The circuit breaker is available for electromagnetic environment A; Installed in an environment which is not enough to erode the metal or destroy the insulating gas and without explosive danger; Installed in an environment without attack from rain and snow. Storage conditions:-40 ℃～+70 ℃.

Technical data and performance