Live Electrical 125A 3 Pole + Neutral Metal Interlocked Fused Switch IP65 – MFS125P

The Live Electrical MFS125P is a robust 125A metal-enclosed, door-interlocked fused switch designed to provide reliable electrical isolation and fused protection in industrial and commercial installations. The enclosed construction and IP66 degree of protection make it suitable for applications where enhanced protection against dust and water is required.

The MFS125P is supplied fitted with a 125A isolation switch, a 3-pole 125A fuse holder and a 100A 22 × 58mm fuse, providing a complete enclosed switching and protection solution. It operates at 400VAC, 50Hz and is manufactured to BS EN 60947-3.

The metal enclosure measures approximately 400mm high × 300mm wide × 148mm deep, providing a substantial protective housing for the switching and fuse components.

Key Features

• 125A metal-enclosed interlocked fused switch
• IP66 protection rating
• Fitted with 125A isolation switch
• Fitted with 3-pole 125A fuse holder
• Supplied with 100A 22 × 58mm fuse
• 400VAC operating voltage
• 50Hz rated frequency
• Manufactured to BS EN 60947-3
• Metal enclosure dimensions: 400 × 300 × 148mm
• Suitable for demanding commercial and industrial electrical installations

Fuse & Fuse Holder Specification

The supplied FU100A22 fuse is a 22 × 58mm gG fuse, rated at 500V with a 120kA breaking capacity. The WS18-125/3P fuse holder is rated at 125A, accepts 22 × 58mm fuses and has a rated voltage of 690V AC. Its specified terminal capacity is 50mm², with a terminal torque of 2.5Nm.

Isolation Switch Specification

The fitted IS4125 isolation switch has a conventional free-air thermal current of 125A. The datasheet provides operational ratings across AC-21A/B, AC-22A/B, AC-23A/B and DC-21B duty categories. It has a rated insulation voltage of 800V, 8kV rated impulse withstand voltage and 10,000 mechanical operations.

For AC-23A/B applications, the datasheet specifies a rated operational power of 55kW at the listed operating conditions. The switch also has a specified terminal cross-sectional area of 10–70mm² and a torque setting of 5–6Nm.

Technical Specification

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

Installation

Installation should be undertaken by a suitably qualified person and must comply with the applicable IET Wiring Regulations and relevant legislation. The datasheet highlights the importance of correct component selection, cable sizing, protective devices and earth bonding, with all connections checked for correct tightness before commissioning and inspected periodically.

MFS125P Data Sheet