The vacuum circuit-breakers of type VD4-12/24/40.5 are intended for indoor installation in air-insulated switchgear systems.
They have a switching capacity capable of handling the loads occurring at start-up and shutdown of equipment and plant units both in normal and in fault state.
Vacuum circuit-breakers have particular advantages for use in networks where there is a high switching frequency in the working current range and/or where a certain number of short-circuit breaking operations are expected.
TypeVD4-12/24/40.5vacuum circuit-breakers are suitable for autoreclosing, and have exceptionally high operating reliability and long life.
The vacuum circuit-breakers of typeVD4-12/24/40.5, designed in column form, can be supplied both as individual units for switchgear Type SM6, Uniswitch, HXGN, etc.
Main technical data
|2||Rated insulation level||1 min Rated short time power frequency withstand voltage||42||65||95|
|3||Rated lighting impulse withstand voltage (peak)||75||125||185|
|6||Rated short circuit breaking current||kA||20||25||31.5||40|
|7||Rated short time withstand current||20||25||31.5||40|
|8||Rated peak withstand current||50||63||80||100|
|9||Rated short circuit making current (peak)||50||63||80||100|
|10||4S thermal stability current||20||25||31.5||40|
|11||Rated dynamic stability current||50||63||80||100|
|12||Rated capacitor bank making inrush current||12.5(The frequency is not more than 1000Hz)|
|13||Rated single/back-to-back capacitor bank breaking current||A||630/400|
|14||Rated short circuit duration||S||4|
|15||Secondary loop power frequency withstand voltage||V||2000|
|16||Rated operation voltage||Closing coil||AC 110/220 DC 110/220|
|Tripping coil||AC 110/220 DC 110/220|
|Energy storage motor||AC 110/220 DC 110/220|
|17||Closing time (rated voltage)||ms||20~50|
|18||Tripping time (rated voltage)||30~70|
|19||Dynamic, static contacts permit abrasion total thickness||mm||3|
|20||Energy storage time||s||≤15|
|21||Contact opening distance||mm||9±1|
|23||Contact bouncing time||ms||≤2|
|24||Different period of three-phase break and close brake||≤2|
|25||The average opening velocity1||ms||0.9~1.3|
|26||The average opening velocity2||0.4~1.0|
|27||Contact opening rebound amplitude||mm||≤2|
|28||The main circuit resistance||Rate current(A)||Handcart type(μΩ)||Fixed type(μΩ)|
|2500 and above||25||20|
|29||Rated operating sequence3||C-2S-CO-180-CO|
VD4/R - VD4/L - VD4/UniAir - VD4/UniMix - VD4/R-SEC - VD4/L-SEC
Installation and operating instructions
The VD4-R each pole houses a vacuum interrupter which is encased in the resin when the cylinder is moulded thanks to a special manufacturing process.
This construction method protects the vacuum interrupter from shock, pollution and condensation.
The operating mechanism is the EL trip-free stored energy type with independent opening and closing regardless of the opera-tor’s action. The EL operating mechanism is widely used in all VD4 series circuit-breakers with frontal control.
The circuit-breaker can be remote controlled when fitted with dedicated electrical accessories (gearmotor, opening and closing release).
The operating mechanism, the three poles and the current sensors (if provided) are installed on a metal frame without wheels. The construction is particularly compact, sturdy and of limited weight.
VD4 series circuit-breakers with lateral operating mechanisms are life-long sealed pressure devices
(Standards IEC 62271-100).