FN5 12kV 24kV Indoor Load Break Switch

The FN5 series indoor high voltage load break switch is an air insulated medium voltage switching device designed for 12kV and 24kV AC power distribution systems.

It is widely used in ring main units (RMU), compact substations, switchgear panels, and industrial distribution networks for load switching, overload protection, and short-circuit interruption when combined with high voltage current limiting fuses.

The FN5 load switch features compact structure, reliable arc extinguishing performance, and integrated grounding capability.

Product Features

• Rated voltage: 12kV / 24kV
• Rated current: 400A / 630A
• Indoor air insulated structure
• Three-position operation: ON / OFF / EARTH
• Reliable load breaking performance
• Fuse combination available
• Compact modular design
• Manual or motorized operating mechanism optional
• Visible isolation gap
• Integrated grounding switch optional
• Suitable for RMU and compact substations
• High mechanical and electrical endurance

Technical Specifications

Working Principle

The FN5 indoor load break switch adopts an air arc extinguishing chamber combined with a spring operating mechanism. During opening operations, the contacts separate rapidly and the generated arc is cooled and extinguished by the arc chamber. Fuse-switch combination versions can automatically interrupt short-circuit currents to provide transformer and cable protection.

Main Configurations

FN5 Standard Load Break Switch

• Basic load switching function
• Suitable for line and cable switching
• Compact indoor installation

FN5-R Fuse Combination Type

• Integrated current limiting fuse holders
• Transformer protection application
• Enhanced short-circuit interruption capability

FN5-D with Earthing Switch

• Integrated grounding switch
• Mechanical interlocking protection
• Improved operational safety

Applications

The FN5 indoor load break switch is widely used in:

• Ring Main Units (RMU)
• Indoor switchgear panels
• Compact transformer substations
• Industrial power distribution systems
• Utility substations
• Cable distribution systems
• Renewable energy substations
• Urban medium voltage distribution networks

Product Advantages

Reliable Switching Performance

Provides stable load interruption and safe switching operation under normal load conditions.

Compact Structure

Small size and lightweight design suitable for compact switchgear applications.

Integrated Protection

Fuse combination type offers reliable overload and short-circuit protection.

Safe Operation

Mechanical interlocking prevents incorrect grounding and switching operations.

Optional Accessories

• CS6-1 manual operating mechanism
• Motor operating mechanism
• Auxiliary contacts
• Fuse trip mechanism
• Grounding switch
• Remote control system
• Mechanical interlock

Overall and installation dimensions