Moeller LX-AK/FS-250IEC 250A 400V Fuse Switch Disconnector

The Moeller LX-AK/FS-250IEC is a high-performance fuse switch disconnector rated for 250A at 400V AC. Engineered for industrial power distribution and motor control centers, this device combines reliable switching with integrated fuse protection. Its robust construction ensures safe isolation of electrical circuits even under full load conditions, meeting IEC 60947-3 standards.

Technical Specifications

Rated operational current: 250A. Rated insulation voltage: 800V. Rated impulse withstand voltage: 8kV. Short-circuit making capacity up to 50kA with appropriate fuses. The LX-AK/FS-250IEC features triple-pole configuration with front-operated rotary handle. Mechanical endurance exceeds 10,000 operations, while electrical endurance reaches 5,000 switching cycles at rated current. Terminal capacity accommodates copper cables from 50mm² to 120mm².

Key Features and Design

The device incorporates Testa Blindos technology, providing fully shielded fuse holders that prevent accidental contact with live parts. This safety feature allows maintenance personnel to replace fuses without exposure to hazardous voltages. The integrated test position enables quick verification of control circuits before commissioning. Portafusibili PLC compatibility ensures seamless integration with programmable logic controller systems for remote monitoring and diagnostics. Visible break contacts guarantee positive indication of switch status.

Applications and Installation

Typical applications include main switchgear in industrial plants, distribution boards, capacitor banks, and HVAC systems. The compact design saves panel space while allowing front or rear cabling options. Operating temperature range from -25°C to +70°C makes it suitable for harsh environments. Auxiliary contact blocks can be added for feedback signaling to PLC input modules. Mounting is straightforward using standard DIN rail or screw fixing.

Safety and Compliance

Certified to CE, CCC, and UKCA marks. The LX-AK/FS-250IEC complies with RoHS directives and offers IP20 finger-safe protection on the front side. Its double-break contacts ensure rapid arc extinction, prolonging contact life. For systems requiring high fault clearance, the device coordinates with gG type fuses up to 250A. Periodic inspection is simplified through accessible terminal covers and clear labeling.

Integration with Automation Systems

When paired with PLC platforms, the auxiliary switches transmit status data such as open/closed condition and fuse integrity. This enables automated shutdown sequences or alarm generation in central control rooms. The LX-AK/FS-250IEC is backward compatible with legacy Moeller panels and supports modern industrial communication protocols via add-on modules. Its standardized dimensions ensure drop-in replacement for existing fuse switch units.

Conclusion

Engineers seeking a durable, safe, and PLC-ready fuse disconnector for 250A circuits will find the Moeller LX-AK/FS-250IEC an optimal solution. Its combination of mechanical strength, electrical performance, and operator safety features aligns with global industrial standards. For detailed sizing and coordination studies, refer to the product datasheet and application notes provided by Moeller.