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VD4/P-24 Unigear ZS1 Switchgear (24KV) Withdrawable Vacuum Circuit Breaker

Nov 04, 2017

Basic Info

  • Model NO.: VD4/P-24

  • Operation: Electric Type

  • Arc-extinguishing Medium: Vacuum

  • Structure: MCB

  • Type: Circuit Breaker

  • Certification: VDE, ISO9001-2000, CE, UL, CB, CCC

  • Rated Voltage: 24kv

  • Withstand Voltage at 50 Hz: 50kv

  • Impulse Withstand Voltage: 125kv

  • Transport Package: Wooden

  • Origin: China

  • Breaking Capacity: High Voltage Circuit Breakers

  • Speed: High-Speed Circuit Breaker

  • Installation: Insert

  • Poles Number: 3

  • Function: Circuit-Breaker Failure Protection

  • Standards: IEC 62271-100

  • Rated Insulation Voltage: 24kv

  • Rated Frequency: 50-60Hz

  • Specification: 24KV

  • HS Code: 8535210000

Product Description

Withdrawable circuit-breakers
Withdrawable version circuit-breakers
for UniGear ZS1 switchgear (24 kV)

VD4 series medium voltage vacuum circuit-breakers with lateral operating mechanism feature the separate pole construction technique.
The operating mechanism is the EL trip-free stored energy type with independent opening and closing regardless of the operator'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 installed) are assembled on a metal frame without wheels. The construction is extremely compact, strongly built and low in weight. 
VD4 series circuit-breakers with lateral operating mechanisms are life-long sealed pressure devices (Standards IEC 62271-100 and CEI EN 62271-100). 
Additionally, VD4 series circuit-breakers have been type tested for low temperature and marine applications (Germanischer Lloyd).
VD4 vacuum circuit breakers have been designed for indoor use and air insulated switchboards.
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. VD4 vacuum circuit- breakers are suitable for auto reclosing and have exceptionally high operating reliability and long life. The circuit- breakers are notable for their compact design, small dimensions together with high capacity. The operating mechanisms have a low maintenance requirement and the interrupters are maintenance- free throughout their service lives. They are well suited to all load breaking operations which occur in practice, and in particular:

  • Short-circuit currents;

  • Overhead lines under load and, no-load conditions;

  • Cables under load and no-load conditions;

  • Transformers under load and no-load conditions;

  • Generators under load and no-load conditions;

  • Ripple control system;

  • Capacitor banks(also parallel switching) and Motors with starting currents above 600A;

Fields of application
Below is the list of SM6 range units used in MV/LV transformer substations and industrial distribution substations:

  • Cable control and protection

  • Overhead control and protection

  • Transformers and distribution substations

  • Motor and transformer control and protection

  • Generator control and protection

  • Capacitor bank control and protection


Circuit-breaker operating mechanism

A Open/closed auxiliary contacts
B Geared motor for closing spring charging
C Built-in closing spring charging lever
D Mechanical signalling device for circuit-breaker open/closed
E Mechanical operation counter
F Plug-socket connectors of electrical accessories in the truck
G Signalling device for closing springs charged/discharged
H Service releases
I Closing pushbutton
L Opening pushbutton
M Operating mechanism locking electromagnet
N Additional shunt opening release
O Transient contact
P Contacts for signalling spring charged/discharged

Main characteristics

Circuit-breaker VD4/P-24
Standards IEC 62271-100
Rated voltageUr [kV]24
Rated insulation voltageUs [kV]24
Withstand voltage at 50 HzUd (1 min) [kV]50
Impulse withstand voltageUp [kV]125
Rated frequencyfr [Hz]50-60
Rated normal currentIr [A]630 / 1250 / 1600 / 2000 / 2500 / 3150
Rated breaking capacity (rated short-circuit breaking current symmetrical)Isc [kA]16 / 20 / 25 / 31.5 / 40
Rated short-time withstand current (3s)Ik [kA]16 / 20 / 25 / 31.5 / 40
Making capacityIp [kA]40 / 50 / 63 / 80 / 100 / 125
Operation sequence [O - 0.3 s - CO - 15 s - CO]
Opening time[ms]33 ~ 60
Arcing time[ms]10 ~ 15
Total breaking time[ms]43 ~ 75
Closing time[ms]30 ~ 60
Operating  temperature[°C]-5 ~ +  40