ZN63(VBM7)-12 Side-Mounted Indoor Vacuum Circuit Breaker 630-1250A 20-31.5kA

Product Overview

The ZN63(VBM7)-12 side-mounted is a three-phase 50 Hz indoor high-voltage vacuum circuit breaker rated 12 kV for control and protection in power networks and in industrial and mining enterprises. Rated currents of 630 A and 1250 A pair with breaking capacities of 20 kA, 25 kA and 31.5 kA, suiting frequent operation at rated current and repeated interruption of short-circuit currents in fixed-pattern metal-enclosed switchgear.

Product Display

ZN63(VBM7)-12 Side-Mounted Indoor High Voltage Vacuum Circuit Breaker - display

ZN63(VBM7)-12 Side-Mounted Indoor High Voltage Vacuum Circuit Breaker - poster_display

Model Designation

ZN63(VBM7)-12 Side-Mounted Indoor High Voltage Vacuum Circuit Breaker - model

Model format: ZN 63 − 12 / □ − □

Z — Vacuum circuit breaker
N — Indoor installation
63 — Design sequence number
12 — Rated voltage (kV)
First □ — Rated current (A)
Second □ — Rated short-circuit breaking current (kA)

Example: ZN63(VBM7)-12 / 1250 − 31.5 denotes a 12 kV indoor vacuum circuit breaker with 1250 A rated current, 31.5 kA rated short-circuit breaking current and a VBM7 permanent-magnet mechanism. ZN63 is the GB type code; VS1 is the equivalent common trade name.

Service Conditions

Ambient temperature: −40 °C to +40 °C
Altitude: not above 1000 m (higher sites require a correspondingly raised insulation level)
Seismic intensity: not above degree 8
Relative humidity: daily average ≤ 95%, monthly average ≤ 90%
Environment: free from fire, explosion hazard, serious pollution, chemical corrosion and violent vibration

Construction

The VBM7 double-stable permanent-magnet mechanism holds the closed and open positions with permanent magnets instead of a stored spring, so the drive train is short and the number of moving parts is small. Reliability and mechanical life are greatly improved, reaching 10000 operations with minimal maintenance.

The arc is extinguished in a sealed, maintenance-free ceramic vacuum interrupter integrated with the mechanism on a common frame, giving long electrical life with no fire or explosion risk. The compact side-mounted structure is bolted into fixed-pattern metal-enclosed switchgear and supports electric, manual and remote operation with the required interlocking.

Technical Data

Item	Unit	20kA	25kA	31.5kA
Rated Voltage	kV	12
Rated Frequency	Hz	50
Rated Current	A	630–1250	1250	1250
Rated Short-Circuit Breaking Current	kA	20	25	31.5
Rated Short-Circuit Making Current (Peak)	kA	50	63	80
Rated Peak Withstand Current	kA	50	63	80
Rated Short-Time Withstand Current (4 s)	kA	20	25	31.5
Power Frequency Withstand Voltage 1 min (48 across open contacts)	kV	42
Lightning Impulse Withstand Voltage (85 across open contacts)	kV	75
Rated Operating Sequence	—	O – 0.3 s – CO – 180 s – CO
Mechanical Life	Operations	10000
Breaking Operations at Rated Short-Circuit Current	Times	50
Closing / Opening Voltage of Mechanism	V	AC/DC 220, 110
Contact Gap	mm	11 ± 1

Selection note: select the breaking-capacity variant from the prospective three-phase short-circuit current at the installation point and confirm the making and peak withstand ratings of 50, 63 or 80 kA are also satisfied.

Standards

Designed and type-tested to GB/T 1984 and IEC 62271-100 for AC high-voltage circuit breakers, with manufacturing and inspection in accordance with DL/T 402.

Technical note: values beyond the published tables are subject to technical agreement; final parameters follow the nameplate and the approved specification.

Installation & Dimensions

Installation Diagram

ZN63(VBM7)-12 Side-Mounted Indoor High Voltage Vacuum Circuit Breaker - installation

The side-mounted fixed-type breaker is installed inside fixed-pattern metal-enclosed switchgear; each pole is bolted to the panel through its mounting frame. The primary circuit connects to the busbar and cable side through static contacts or cable lugs and the secondary circuit to the control and protection loop through the terminal block; the breaker and frame must be reliably earthed before commissioning.

Item (Side-Mounted Type 650)	Dimension (mm)
Overall Width	840
Overall Height	634
Overall Depth	400
Pole Center Spacing	210
Base Fixing	4 × M12, hole span 820
Bushing Flange (View A)	φ56 / M18

Safety notice: installation, operation and maintenance must be carried out by qualified personnel. Verify type, rated voltage, rated current and breaking current against the nameplate before energising, keep the breaker open, earthed and de-energised during service, and never bypass the interlocks or commission a breaker with a lost-vacuum interrupter.

FAQs

Z denotes a vacuum breaker, N indoor use, 63 the design number and 12 the rated voltage in kV; the two following boxes give rated current in amperes and rated short-circuit breaking current in kiloamperes. ZN63 is the GB type code and VS1 the equivalent trade name.

The VBM7 permanent-magnet mechanism holds the open and closed positions with permanent magnets instead of a stored spring, so it has far fewer moving parts, a shorter drive chain, higher reliability and a mechanical life of 10000 operations.

A side-mounted breaker is bolted into fixed-pattern switchgear and wired directly, whereas a handcart unit can be racked out for isolation. The fixed type is compact and lower cost where draw-out maintenance is not required.

Calculate the prospective three-phase short-circuit current at the installation point and select 20, 25 or 31.5 kA to cover it, checking that the making and peak withstand currents of 50, 63 or 80 kA are also satisfied.

Yes. The vacuum interrupter and permanent-magnet mechanism are designed for frequent operation at rated current and repeated interruption of short-circuit currents, which suits feeder and motor duty.

Please state rated voltage, rated current, rated short-circuit breaking current, short-time duration, operating mechanism, the switchgear type the breaker will be mounted in, and any special service conditions.

ZN63(VBM7)-12 Side-Mounted Indoor High Voltage Vacuum Circuit Breaker