Live Electrical 125A 3 Pole + Neutral Metal Interlocked Fused Switch IP20 – MFS125

The Live Electrical MFS125 is a metal-enclosed, door-interlocked fused switch designed for reliable isolation and overcurrent protection in electrical distribution and industrial applications. It is supplied complete with a 125A isolation switch, 3-pole 125A fuse holder and 100A 22 × 58mm fuse, providing a ready-to-install solution for applications requiring secure switching and fused protection.

The unit has an IP20 degree of protection and is designed for operation at 400VAC, 50Hz. The enclosure measures approximately 396mm high × 230mm wide × 116mm deep, making it suitable for wall-mounted installation where a robust enclosed switching arrangement is required.

The fitted fuse holder accepts 22 × 58mm fuses, with the supplied FU100A22 fuse rated at 500V and 120kA breaking capacity. The accompanying WS18-125/3P fuse holder is rated at 125A, with a maximum terminal capacity of 50mm² and a terminal torque of 2.5Nm.

The integrated isolation switch is rated for demanding switching duties, with the datasheet providing ratings for AC-21A/B, AC-22A/B, AC-23A/B and DC-21B applications. It has a conventional free-air thermal current of 125A, 800V rated insulation voltage, 8kV rated impulse withstand voltage and 10,000 mechanical operations.

Key Features

• 125A metal-enclosed interlocked fused switch
• IP20 protection
• Supplied with 125A isolation switch
• 3-pole 125A fuse holder
• Supplied with 100A 22 × 58mm fuse
• 400VAC, 50Hz operating voltage
• Manufactured to BS EN 60947-3
• Approx. dimensions: 396 × 230 × 116mm
• Fuse breaking capacity: 120kA
• Terminal capacity up to 50mm²
• Isolation switch rated thermal current: 125A
• Rated insulation voltage: 800V
• Rated impulse withstand voltage: 8kV
• Mechanical endurance: 10,000 operations

Technical Specification

The datasheet also specifies a rated conditional short-circuit current of 25kA at 415V when fuse protected, together with a 5kA rated short-time withstand current for 0.3 seconds.

Installation note: Installation should be carried out by a suitably qualified person in accordance with the applicable IET Wiring Regulations and relevant health and safety requirements. The manufacturer also specifies that electrical connections should be checked for correct tightness before commissioning and inspected periodically.

MFS125 Data Sheet