Primary Distribution Switchgear
The Electroalfa primary distribution switchgear are designed for 7,2 and 24 kV rated voltages and rated currents up to 4000 A. Compliant with the technical standards of nationwide power generation, transport and distribution companies such as Transelectrica (the national transmission operator), CEZ Group, E.ON Group, Electrica Group (area distribution operators).
The Electroalfa switchgear for primary distribution, of the S 12xx range, for a maximum voltage of 12KV c.a., have been tested for values of the continuous rated current of up to 5,000A and values of the rated peak withstand current of 50 KA/ 1s. This type of gear withstands the action of the internal electric arc, with a classification index of up to IAC AFLR 50KA, 1s. The switchgear from the range of S 24xx, for a voltage of 24 KV c.a. have been tested for values of the continuous rated current of up to 2.500A and values of the rated peak withstand current of 25 KA/ 1s. This type of gear withstands the action of the internal electric arc, with a classification index of up to IAC AFLR 25KA/ 1s.
The switchgear ensures the continuity of service, according to the standard classification LSC2B. From the point of view of the separation of compartments, the classification of these switchgears is PM. The switchgear for primary distribution is made up of a metallic cabinet made up of sheet panels assembled with special rivets, fittings or electric point welding, which includes the equipment of low voltage required for the exploitation specifications, including the withdrawable circuit-breaker and the measure, command, protection and signaling low voltage equipment.
The withdrawable circuit-breaker has three functional positions: in operation, test and withdrawn. It can go from one to another position smoothly and shock-free, on the circuit path.
Beside the classical variant, when this trip is made by manual command, Electroalfa ensures the possibility of automated command of the withdrawable circuit breaker for the new range of switchgear of 24KV, 1250A, 25KA, launched in 2016. The same facility is provided for the manual or automatic control of grounding blades. This option can be opted for when ordering the switchgear or after commissioning. Based on the experienced accumulated in the field, the concept and design of the withdrawable medium voltage switchgear allows mounting in the type of cabinet created by Electroalfa of a large range of circuit breakers, from various producers, with minimal adaptation, depending on their constructive particularities. Until now, in the Electroalfa switchgear we integrated products made by Siemens, ABB, Schneider Electric and Eaton. Due to the competence of the engineering team of the company, there is a possibility to quickly integrate other types of circuit breakers in the switchgear.
|Rated voltage Ur||12kV||24kV|
|Rated current Ir||Maximum 4000A||Maximum 2500A|
|Rated short-time withstand current Ik||Maximum 50kA||Maximum 25kA|
|Rated peak withstand current Ip||125kA||63kA|
|Resistence to frontal and side electric arc||Maximum 50kA||Maximum 25kA|
Secondary Distribution Switchgear with double bar system
The medium voltage switchgear with double bar system is designed for the primary distribution on the medium voltage part of transformation stations from the power distribution systems and combines the new technologies with the existing infrastructure.
The medium voltage switchgear with double bar system is an indoor electrical equipment, in metallic compartments cabinet, with insulation in the air, being formed of a vacuum breaker and air bar separator.
|Rated voltage||7,2 – 24 kV|
|Rated lightning impulse withstand voltage (phase-grounding, phase-phase)||60 – 125 kV|
|Rated impulse withstand voltage at 50 Hz||20 – 50 kV|
|Rated current (In)||maximum 2500 A|
|Breaking current||maximum 25 kA|
|Rated peak current||63kA|
|Rated short-time withstand current||63kA|
|Secondary and control circuits voltage||24; 48; 60; 110; 220 Vcc|
|100; 110; 230 Vca|
|Protection degree of IP cabinet||3X|
|Bar insulation from the main circuits||aer|
|Free electric arc resistance, inside the cabinet||25 kA|
|Ambient temperature for operation||-5° … +45°C|
|Average temperature for 24 ore||+35°C|
|Air relative humidity||maximum 90% at 35°C|
|Maximum altitude||1000 m|
|Atmosphere||normal, non-corrosive, non-flammable, non-contaminated|