GN19-12ST/1250A Indoor High Voltage Isolator Switch

The GN19-12ST-1250A indoor isolator switch is designed for three-phase AC 50Hz, rated voltage 12kV, and rated current up to 1250A. It is primarily used in indoor medium voltage switchgear panels to isolate equipment during maintenance or in emergency conditions.

Key Technical Specifications

Parameter	Value
Rated Voltage	12kV
Rated Current	1250A
Power Frequency Withstand Voltage (1 min)	42kV
Lightning Impulse Withstand Voltage (BIL)	75kV
Rated Short-Time Withstand Current	31.5kA / 4s
Rated Peak Withstand Current	80kA
Operating Mode	Manual (motor drive optional)
Number of Poles	3
Installation Type	Indoor panel-mounted
Standard Compliance	GB/T 1985, IEC 62271-102

Structure and Operation

The GN19-12ST adopts a three-pole horizontal rotary structure with a visible isolating gap. The switch is equipped with a spring-operated manual mechanism and can be upgraded to a motorized drive system if required.

Variants Available:

GN19-12ST/630A
GN19-12ST/1000A
GN19-12ST/1250A
GN19-12ST with grounding switch (optional)

Features

Compact design for easy integration into 12kV panels
Visible break for safety assurance during maintenance
Silver-plated contact surfaces for improved conductivity and thermal stability
Optional earthing switch for enhanced system protection
Reliable mechanical interlock prevents incorrect operations

Installation and Mounting

Installed vertically inside the switchgear panel
Busbar connections are supported via fixed terminals
Manual handle or motorized mechanism available upon request
Grounding terminal provided for base plate

🛠 Installation drawing and wiring layout available in the technical file.

Standards and Testing

Conforms to GB/T 1985 and IEC 62271-102
Passed type tests for dielectric, mechanical endurance, and temperature rise
Available with factory routine test reports and type test certificates upon request