INDUSTRY COMPONENT

Thermal Fuse

A thermal fuse is a non-resettable temperature-sensitive safety device that permanently interrupts electrical circuits when excessive temperatures occur.

View Specifications

Component Specifications

Definition
A thermal fuse is a critical safety component designed to protect electrical equipment from overheating by permanently breaking the circuit when a predetermined temperature threshold is reached. Unlike circuit breakers or resettable thermal cutoffs, thermal fuses operate through irreversible physical or chemical changes, typically involving a fusible alloy or pellet that melts at the specified temperature, thereby severing the electrical connection. These devices are essential for preventing fire hazards, equipment damage, and electrical failures in applications where temperature control is vital.
Working Principle
The thermal fuse operates on the principle of thermal expansion and phase change. It contains a fusible element (usually a low-melting-point alloy or organic material) that remains solid under normal operating temperatures. When the ambient temperature exceeds the rated temperature (e.g., 72°C, 94°C, 130°C), the fusible element melts or deforms, causing a spring-loaded mechanism to disconnect the electrical contacts permanently. This irreversible action ensures the circuit remains open even after cooling, requiring replacement of the fuse to restore functionality.
Materials
Housing: Phenolic resin, ceramic, or high-temperature plastic; Fusible element: Eutectic alloys (e.g., tin-bismuth, lead-tin), organic compounds, or low-melting-point metals; Contacts: Copper alloy or silver-plated materials; Insulation: Fiberglass or mica.
Technical Parameters
  • Response Time Less than 5 seconds at 10°C above rated temperature
  • Current Rating 1A to 15A
  • Voltage Rating 250V AC/DC
  • Rated Temperature 72°C to 240°C (common range: 72°C, 94°C, 130°C)
  • Dielectric Strength 1500V AC for 1 minute
  • Holding Temperature Rated temperature ±5°C
  • Insulation Resistance >100 MΩ at 500V DC
Standards
ISO 8820, DIN 43653, UL 248, IEC 60127

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Thermal Fuse.

thermal fuse temperature fuse electrical safety device overheating protection non-resettable fuse surge protector component thermal cutoff IEC 60127 UL 248 Thermal Fuse in Electrical Equipment Manufacturing

Parent Products

This component is used in the following industrial products

Surge Protection Module

A protective electronic component designed to limit transient voltage spikes in electrical circuits.

View Product Details

Engineering Analysis

Risks & Mitigation
  • Incorrect temperature rating leading to premature failure or inadequate protection
  • Poor installation causing thermal lag or inaccurate response
  • Exposure to moisture or chemicals degrading performance
  • Using non-compliant fuses violating safety regulations
FMEA Triads
Trigger: Excessive ambient temperature due to blocked ventilation or component failure
Failure: Thermal fuse fails to activate, allowing overheating and potential fire
Mitigation: Regular maintenance of cooling systems, use of fuses with appropriate temperature ratings, and redundancy with temperature sensors
Trigger: Mechanical stress or vibration damaging the fusible element
Failure: False activation or open circuit under normal conditions
Mitigation: Secure mounting with shock-absorbing materials, selecting robust housing designs
Trigger: Corrosion from humidity or contaminants
Failure: Increased resistance or intermittent connections, reducing reliability
Mitigation: Apply conformal coatings, use sealed fuses, and control environmental exposure

Industrial Ecosystem

Compatible With

Interchangeable Parts

Compliance & Inspection

Tolerance
Temperature rating ±5°C, current rating ±10% under standard test conditions
Test Method
Testing per ISO 8820: Thermal cycling, dielectric strength verification, and response time measurement in controlled ovens or environmental chambers

Buyer Feedback

★★★★☆ 4.9 / 5.0 (22 reviews)

"Standard OEM quality for Electrical Equipment Manufacturing applications. The Thermal Fuse arrived with full certification."

"Great transparency on the Thermal Fuse components. Essential for our Electrical Equipment Manufacturing supply chain."

"The Thermal Fuse we sourced perfectly fits our Electrical Equipment Manufacturing production line requirements."

Related Components

Alignment System
Precision alignment system for industrial wireless power transfer modules ensuring optimal energy coupling efficiency.
Winding Spindle
A precision rotating shaft in transformer winding machines that holds and rotates the coil form during wire winding operations.
Arc Plates
Arc plates are metallic plates within circuit breaker arc chutes that split and cool electrical arcs during interruption to ensure safe circuit disconnection.
Insulating Housing
Insulating housing for circuit breaker arc chutes that provides electrical isolation and thermal protection.

Frequently Asked Questions

What is the difference between a thermal fuse and a thermal cutoff?

A thermal fuse is non-resettable and must be replaced after activation, while a thermal cutoff (like a bimetallic strip) can reset automatically after cooling. Thermal fuses provide more reliable protection in critical applications.

How do I select the right thermal fuse for my application?

Choose based on rated temperature (slightly above normal operating temperature), current/voltage ratings, response time, and environmental conditions. Always refer to manufacturer datasheets and safety standards like UL or IEC.

Can a thermal fuse be used in series with other fuses?

Yes, thermal fuses are often used in series with electrical fuses for comprehensive protection—thermal fuses guard against overheating, while electrical fuses protect against overcurrent.

Can I contact factories directly?

Yes, each factory profile provides direct contact information.

Get Quote for Thermal Fuse

Thermal Cutoff Thermal Interface Baseplate