1.Structural Components

• Insulating Support: Typically made of ceramic or composite materials, providing mechanical support and electrical insulation.

• Fuse Tube: Consists of an inner arc-extinguishing tube (such as steel paper tube or phenolic paper tube) and an outer epoxy glass cloth tube, with a fuse installed inside.

• Moving and Fixed Contacts: The moving contact is connected to the fuse tube, while the fixed contact is mounted on the insulating support, maintaining a closed state through fuse tension.

2.Operating Principle

• Normal Operation: The fuse is tensioned across the fuse tube, keeping the contacts closed to conduct electricity.

• Fault Protection: When current exceeds the fuse rating, the fuse blows and creates an arc. The arc-extinguishing tube decomposes to produce gas, creating high pressure to extinguish the arc. The fuse tube drops due to gravity, forming a visible break point.

1.Core Functions

• Overload/Short Circuit Protection: Rapidly interrupts fault currents to protect lines and equipment.

• Isolation Function: Forms a visible break point after dropping, facilitating maintenance work.

2.Typical Application Scenarios

• Distribution Line Branching: Minimizes power outage areas.

• Distribution Transformer Protection: Serves as the primary protective device.

• Outdoor Environments: Suitable for areas without conductive dust, corrosive gases, and flammable/explosive locations.
  
  

• 三.Common Models and Technical ParametersCommon models
• RW7, RW11, RW12: suitable for 10kV systems.
• DRW13 series: rated voltage 12kV, breaking current 12.5kA/16kA.
  Key technical parameters:

• Rated voltage: 6～35kV

• Rated current: 100A, 200A

• Breaking capacity: maximum 200MVA, minimum 20MVA (for 200A models)
  Environmental conditions:

• Temperature: -40℃ to +40℃

• Altitude: ≤1000m
  
  
  

• 四.Key Points of Installation and OperationInstallation Requirements:

• Angle: The angle between the fuse tube axis and vertical line should be 25°±2° to ensure reliable tripping.

• Spacing: Phase-to-phase distance ≥500mm, ground distance ≥4.5m (for 10kV system).

• Fuse tension: Apply 24.5N tension during installation to avoid poor contact.
  Operation Specifications:

• Closing sequence: Close the side phases first, then the middle phase.

• Opening sequence: Open the middle phase first, then the side phases.

• Prohibit operation under load: Avoid accidents caused by arc spraying.
  
  五.Common Faults and Maintenance:

• Typical Faults:

  • Fuse tube fails to trip: Incorrect tube size, stuck rotation axis, or angle deviation.

  • Premature fuse blowing: Improper selection, poor contact, or high ambient temperature.

  • Contact erosion: Insufficient spring elasticity or oxidation leading to increased contact resistance.

• Maintenance Measures:

  • Regular inspection: Conduct night patrol monthly to check for discharge sparks.

  • Fuse replacement: Only use standard fuses, prohibit copper wire substitution.

  • Cleaning and lubrication: Remove dirt and lubricate moving parts.