GN19-12ST/1250A Indoor Isolator Switch
12kV 1250A Triple-Position Isolator for High-Capacity Indoor Systems
The GN19-12ST/1250A indoor isolator switch is a three-position isolator rated for 1250A and 12kV, widely used in medium voltage switchgear, busbar sections, and transformer input circuits. It features ON-OFF-EARTH switching positions, providing reliable isolation and integrated grounding within a compact indoor layout.
Designed for heavy-duty indoor systems, this model ensures visible disconnection, enhanced operator safety, and compliance with IEC 62271-102 and GB 1985-2004.
🔧 Key Features
Rated Voltage: 12kV
Rated Current: 1250A
Switching Positions: ON / OFF / EARTH
Installation Type: Indoor, panel-mounted
Insulation Medium: Air-insulated
Drive Mechanism: Manual lever / rotating shaft
Standard Compliance: IEC 62271-102 / GB 1985-2004
🌍 Application Scenarios
Busbar sectioning and isolation in MV switchgear
Transformer incomer switching with grounding capability
Isolation for capacitor banks, ring main units, and feeder lines
MV distribution panels for industrial substations, urban substations, and renewable energy hubs
Its triple-position structure makes it suitable for applications that require built-in grounding and quick maintenance isolation.
📊 Technical Specifications
| Parameter | Value |
|---|---|
| Rated Voltage | 12kV |
| Rated Current | 1250A |
| Power Frequency Withstand | 42kV / 1 min |
| Lightning Impulse Withstand | 75kV |
| Short-Time Withstand Current | 25kA / 4s |
| Peak Withstand Current | 63kA |
| Mechanical Endurance | ≥2000 operations |
| Contact Type | Knife-blade, rotary movement |
| Operation | Manual handle or remote rod |
| Mounting Type | Horizontal/vertical baseplate |
🧱 Structural Advantages
Three-position contact system (ON-OFF-EARTH) ensures full functional isolation
High current-carrying contacts support continuous operation at 1250A
Silver-plated blades reduce resistance and prevent overheating
Spring-loaded mechanism for fast and reliable switching
Compact footprint fits in narrow panel enclosures
Optional mechanical interlocking with vacuum circuit breakers
❓ Frequently Asked Questions
• What is the benefit of a three-position Isolator switch?
It allows not only ON/OFF switching but also grounding, enhancing operational safety during maintenance.
• Can this be used with 12kV VCB panels?
Yes. It's compatible with most indoor VCB configurations and can be interlocked mechanically.
• Does it support horizontal and vertical mounting?
Yes. It can be installed in both orientations depending on the panel layout.
• Is motorized operation available?
GN19-12ST is typically manual, but motorization can be offered on special request.
• Does it comply with international standards?
Yes. Fully compliant with IEC 62271-102 and Chinese GB 1985-2004.
📞 Contact for Selection or Drawings
Looking to integrate a 1250A Isolator switch in your switchgear system?
Reach our engineering team for datasheets, CAD drawings, or technical configuration advice:
Thor – MV Panel Switchgear Engineer
📞 Tel: +86-0577-62788197
📱 WhatsApp: +86 159 5777 0984
📧 Email: [email protected]












