COS fittings

1. Fuse Holder (Mounting Bracket/Support)

• Function:
  The fuse holder is the mounting base that secures the fuse in place within a circuit, panel, or switchgear, ensuring mechanical stability and proper alignment.

• Key Features:

  • Material: Typically made of corrosion-resistant metals (e.g., zinc-plated steel, aluminum) or insulating materials (e.g., flame-retardant thermoplastics).

  • Design: Includes clip-on, screw-mounted, or DIN rail-compatible configurations for versatile installation.

  • Insulation: Some holders feature insulating linings or coatings to prevent short circuits.

  • Thermal Management: May incorporate ventilation slots or heat sinks to dissipate heat.

2. Insert Fittings (Contacts/Terminals)

• Function:
  These conductive components connect the fuse to the circuit, ensuring low-resistance current flow and reliable electrical contact.

• Components:

  • Contacts:

    • Made of copper alloys (brass, bronze) or silver-/tin-plated for oxidation resistance.

    • Designed as spring clips, bolt-on, or blade-type connectors for secure fuse retention.

  • Terminals:

    • Screw terminals, crimp connectors, or quick-connect tabs for external wire attachment.

  • Arc Suppression: High-voltage fittings may include arc chutes or ceramic barriers to quench arcs during fuse operation.

3. System Integration

• Mechanical Stability: Holders and fittings work together to withstand vibration/shock.

• Electrical Performance: Low-contact-resistance fittings paired with insulated holders ensure safe operation.

• Serviceability: Modular designs enable quick fuse replacement or maintenance.

Typical Applications

• Low-voltage fuses (e.g., NH, RT types): DIN rail holders with spring contacts.

• High-voltage fuses (e.g., expulsion-type): Porcelain insulator holders with tungsten-copper contacts.

• Electronics: PCB-mount or socket holders for miniature fuses.

Selection Criteria

• Rated Current/Voltage: Must match fuse specifications.

• Environment: Corrosion-/heat-resistant materials for harsh conditions.

• Compliance: IEC, UL, or other standards (e.g., IEC 60269).