VS1-12 Permanent Magnet Indoor Vacuum Circuit Breaker 630-2500A 20-40kA | YC Mechanism KYN28 IEC GB Thomas Electric

Product Overview

The VS1-12 with permanent-magnet mechanism is a three-phase 50 Hz indoor high-voltage vacuum circuit breaker rated 12 kV for protection and control in power networks and in industrial and mining enterprises. Rated currents from 630 A to 2500 A combine with breaking capacities of 20 kA to 40 kA, suiting frequent operation at rated current and repeated interruption of short-circuit currents.

Product Display

VS1-12 Permanent Magnet Indoor High Voltage Vacuum Circuit Breaker - display

VS1-12 Permanent Magnet Indoor High Voltage Vacuum Circuit Breaker - poster_display

Model Designation

VS1-12 Permanent Magnet Indoor High Voltage Vacuum Circuit Breaker - model

Model format: VS 1 − 12 / □ − □ YC

VS — Indoor high-voltage vacuum circuit breaker
1 — Design sequence number
12 — Rated voltage (kV)
First □ — Rated current (A)
Second □ — Rated short-circuit breaking current (kA)
YC — Permanent-magnet operating mechanism

Example: VS1-12/1250-31.5 YC denotes a 12 kV indoor vacuum circuit breaker with 1250 A rated current, 31.5 kA rated short-circuit breaking current and a permanent-magnet operating mechanism.

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

A double-stable permanent-magnet mechanism holds the contacts in both the closed and the open position, so latching needs no long mechanical linkage. Moving parts and the transmission chain are greatly reduced compared with a spring mechanism, raising reliability and extending mechanical life to 10000 operations.

Each pole carries a sealed ceramic vacuum interrupter that extinguishes the arc with low arcing energy and short burn time, clearing fault currents within a few cycles without fire or explosion risk. The mechanism and body share one integrated frame, so the same breaker serves as a fixed unit or, with a racking truck, as a withdrawable handcart for metal-clad switchgear.

Technical Data

Item	Unit	20kA	25kA	31.5kA	40kA
Rated Voltage	kV	12
Rated Frequency	Hz	50
Rated Current	A	630 1250	630 1250	1250 1600 2000 2500	1250 1600 2000 2500
Rated Short-Circuit Breaking Current	kA	20	25	31.5	40
Rated Short-Time Withstand Current (4 s, rms)	kA	20	25	31.5	40
Rated Peak Withstand / Making Current (peak)	kA	50	63	80	100
Power Frequency Withstand Voltage 1 min (to earth / between phases)	kV	42 / 48
Lightning Impulse Withstand Voltage (to earth / between phases)	kV	75 / 85
Rated Operating Sequence	—	O – 0.3 s – CO – 180 s – CO		O – 180 s – CO – 180 s – CO
Mechanical Life	Operations	10000
Secondary Circuit 1 min Power Frequency Withstand Voltage	V	2000

Selection note: select the breaking-capacity variant from the prospective short-circuit current at the installation point, coordinated with the rated short-time withstand current and the 4 s short-circuit duration.

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 and configurations beyond the published tables are subject to technical agreement; final parameters follow the nameplate and the approved specification.

Installation & Dimensions

Installation Diagram

VS1-12 Permanent Magnet Indoor High Voltage Vacuum Circuit Breaker - installation

The breaker is installed as a fixed unit or, with a dedicated racking mechanism, as a withdrawable handcart truck for metal-clad switchgear such as the KYN28 cubicle. The main circuit connects through the static contacts of the truck and the control and protection wiring through a secondary plug; the frame and mechanism must be reliably earthed before energisation.

Item (Handcart 800 Frame)	Dimension (mm)
Overall Width	648
Base Width	652 / 681
Overall Height	637
Overall Depth	598
Handcart Wheelbase	433

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

FAQs

VS is the indoor high voltage vacuum circuit breaker, 1 is the design number and 12 is the rated voltage in kV. The first figure 1250 is the rated current in amperes, the second 31.5 is the rated short-circuit breaking current in kA, and YC indicates the permanent-magnet operating mechanism.

Permanent magnets hold the contacts in both the closed and the open position, so far fewer moving parts and a shorter transmission chain are needed than in a spring mechanism. This raises reliability and greatly increases mechanical life, which reaches 10000 operations.

Both. The mechanism and the body share one integrated frame, so the breaker can be installed as a fixed unit or fitted with a racking truck to form a withdrawable handcart for metal-clad switchgear such as the KYN28 cubicle.

It is chosen from the prospective short-circuit current at the installation point, in the 20, 25, 31.5 and 40 kA steps, and must be coordinated with the rated short-time withstand current and the 4 s short-circuit duration.

Yes. It is designed for service requiring frequent operation at rated current and repeated interruption of short-circuit current, and the permanent-magnet mechanism with a 10000-operation mechanical life supports heavy duty such as motor feeder control.

Please state rated voltage, rated current, rated short-circuit breaking current, short-circuit duration, operating mechanism, fixed or handcart mounting, and any special service conditions such as altitude or temperature.

VS1-12 Permanent Magnet Indoor High Voltage Vacuum Circuit Breaker