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CKJ3 Vacuum Contactor for Frequent MV Motor Switching
Reliable 1.14kV–7.2kV Switching Solution for Motor Control and Capacitor Banks
The CKJ3 vacuum contactor is designed for medium-voltage AC circuits (1.14kV–7.2kV), offering compact, long-life switching for induction motors, transformers, and power factor correction systems. Its arc-extinguishing chamber uses sealed vacuum interrupters, ensuring high electrical durability and low maintenance compared to traditional air contactors.
This contactor is ideal for repetitive switching environments, such as coal mines, metallurgy, and cement plants, where rapid operation and high mechanical reliability are critical.
🔧 Key Features
Model: CKJ3 series
Rated Voltage: 1.14kV, 3.6kV, 7.2kV
Rated Current: 250A / 400A / 630A
Frequency: 50Hz or 60Hz
Control Voltage: 110V / 220V / 380V (AC/DC)
Poles: 3-phase
Applicable Standards: IEC 60947-4-1, GB/T 14808
⚙️ Technical Specifications
| Parameter | Value |
|---|---|
| Rated Insulation Voltage | 12kV |
| Rated Operating Voltage | 1.14–7.2kV |
| Rated Frequency | 50Hz / 60Hz |
| Rated Current | 250A / 400A / 630A |
| Mechanical Endurance | ≥1 million operations |
| Electrical Life | ≥100,000 operations |
| Auxiliary Contacts | 2NO + 2NC (standard) |
| Control Voltage Options | 110V / 220V / 380V (AC/DC) |
| Installation Mode | Vertical or horizontal |
🏭 Application Scenarios
The CKJ3 series is purpose-built for:
✅ MV Motor Starting & Stopping
Seamlessly switches motors in industrial machinery, especially in continuous operation environments like mining hoists and rolling mills.
✅ Capacitor Switching in PFC Panels
Handles high inrush currents during capacitor bank energization, reducing the need for detuned reactors.
✅ Power Transformers Control
Safe transformer energization in urban substation panels or containerized MV units.
✅ Underground and Harsh Environments
Designed with anti-dust and anti-moisture enclosures, suitable for tunnel systems or mobile substations.
🧱 Structural Highlights
Vacuum Interrupter: Extinguishes arc within milliseconds, with minimal contact erosion
Spring Operating Mechanism: Ensures consistent contact pressure for long service life
Electromagnetic Drive: Quiet and efficient actuation, with low coil power consumption
Arc Chutes & Barriers: Internal layout minimizes flashover and improves dielectric strength
Optional Bypass Contact: Reduces on-state energy loss and contact wear
✅ Product Certifications
Passed type tests for electrical endurance, temperature rise, and short-time withstand
Manufactured under ISO 9001:2015 quality system
Compatible with ABB, Schneider, and CHINT MV switchgear integration
❓ Frequently Asked Questions
• What is the difference between CKJ3 and CKJ5 contactors?
CKJ3 has a simpler structure, a lower power coil, and is better suited for frequent duty switching. CKJ5 is often used for heavier loads or higher fault-level installations.
• Can it replace air-break contactors directly?
Yes, CKJ3 offers a longer lifespan and lower maintenance compared to air-break designs.
• Is the mechanical interlock supported?
Yes, it can be configured with mechanical interlock kits for reverse motor applications.
• How is arc handling different from circuit breakers?
CKJ3 handles arcs within a sealed vacuum interrupter, making it much faster and cleaner than breakers.
• Is a remote control available?
Yes, via auxiliary relay output and DC coil control, it supports remote start/stop signals.
📞 Technical Consultation & Quote
Thor – Medium Voltage Contactor Specialist
📞 Tel: +86-0577-62788197
📱 WhatsApp: +86 159 5777 0984
📧 Email: thor@weishoelec.com
Get professional advice on selecting and integrating the CKJ3 series into your MV control panels.
