Radial Leads Thermal Cutoffs and Thermal Fuses

Last Updated: April 1, 2025

Description

Radial Leads Thermal Cutoffs and Thermal Fuses are safety devices designed to interrupt the flow of electricity in a circuit when a predetermined temperature is exceeded. They serve as a critical component in preventing overheating and potential fire hazards by breaking the electrical connection when excessive heat is detected.

Working Principle

Radial Leads Thermal Cutoffs and Thermal Fuses operate based on a temperature-sensitive mechanism. When the ambient temperature around the device rises to a specific threshold, the thermal element inside the fuse melts or changes state, causing the electrical circuit to open and stop the flow of current. This action prevents further temperature increase and potential damage to the device or system. These fuses are particularly useful because they provide a reliable and automatic response to overheating, ensuring safety without requiring manual intervention.

Applications

These thermal cutoffs and fuses are widely used in various consumer and industrial products. Specific examples include hair dryers, irons, electric motors, microwave ovens, refrigerators, hot coffee makers, dishwashers, and battery chargers . They are essential in any application where overheating could lead to equipment failure or safety hazards.

Advantages over other Thermal Cutoffs and Thermal Fuses

One of the main advantages of Radial Leads Thermal Cutoffs and Thermal Fuses is their ability to provide a one-time, fail-safe response to overheating. Unlike resettable thermal protectors, these devices do not require manual resetting, which can be advantageous in applications where immediate and automatic response is critical. Additionally, they are often more compact and can be integrated into smaller devices where space is a constraint.

Limitations

A significant limitation of these devices is that they are "one-shot" components, meaning that once they have been triggered, they must be replaced. This can lead to increased maintenance costs and downtime, especially in applications where frequent overheating occurs .

Considerations

When selecting Radial Leads Thermal Cutoffs and Thermal Fuses, several factors should be considered. Initial costs can vary depending on the specific type and rating of the fuse. Operating expenses may include the cost of replacements, as these devices are not resettable. Durability is generally high, but accuracy in response to temperature changes is crucial for effective operation. Replacement and maintenance costs can add up over time, particularly in environments where overheating is a common issue. It is also important to consider the ambient temperature and real-world operating conditions, as these can affect the performance and reliability of the thermal cutoffs and fuses .

18 Results
Creep Action Thermal Protector In An Exceptionally Small Package -- N
from Portage Electric Products, Inc.

A creep action thermal protector in an exceptionally small package. Low internal resistance and gold diffused contacts makes this device suitable for use in low voltage/low current applications. Features. Conductive bimetal construction; the bimetallic element carries the circuit current. Creep... [See More]

  • Thermal Cutoff Style: Radial Leads
  • Rated Voltage: 120
  • Cutoff Temperature: 130
  • Rated Current: 2.6 to 100
Thermal Cutoffs (Thermal Fuses) -- 285-1901-ND [DFP10112 from TDK-Lambda Corporation]
from DigiKey

Thermal Cutoff (TCO) 250V AC DC 139 °C (282 °F) Radial [See More]

  • Thermal Cutoff Style: Radial Leads
  • Cutoff Temperature: 139
Creep-Action Thermal Protector -- G
from Portage Electric Products, Inc.

Creep-action thermal protector equipped with gold diffused contacts. Can be used in 120 VAC or low voltage/low current applications. Features. Conductive bimetal construction; the bimetallic element carries the circuit current. Creep action device; slow make/slow break switching action. No built-in... [See More]

  • Thermal Cutoff Style: Radial Leads
  • Rated Voltage: 120
  • Cutoff Temperature: 150
  • Rated Current: 2.5
Thermal Cutoffs (Thermal Fuses) -- MTR1R105-ND [MTR1 R105 from Canadian Thermostats & Control Devices LTD.]
from DigiKey

Thermal Cutoff (TCO) 250V AC DC 3A 108 °C (226 °F) Radial [See More]

  • Thermal Cutoff Style: Radial Leads
  • Cutoff Temperature: 108
Creep-Action Thermal Protector With A Shunted Bimetal Design -- L
from Portage Electric Products, Inc.

A creep-action thermal protector with a shunted bimetal design which lowers current sensitivity and slows the cycle rate of the device. A good choice for motors and transformers when space is limited. Features. Shunted bimetal construction; the bimetallic element does not carry the circuit current. [See More]

  • Thermal Cutoff Style: Radial Leads
  • Rated Voltage: 120
  • Cutoff Temperature: 150
  • Rated Current: 2.5
Creep-Action Thermal Protector With A Shunted Type Bimetal Design -- R
from Portage Electric Products, Inc.

A creep-action thermal protector with a shunted type bimetal design. This lowers the current sensitivity and slows the cycle rate of the device. Features. Shunted bimetal construction; the bimetallic element does not carry the circuit current. Creep action device; slow make/slow break switching... [See More]

  • Thermal Cutoff Style: Radial Leads
  • Rated Voltage: 120
  • Cutoff Temperature: 150
  • Rated Current: 2.5
Creep-Action Thermostat With Crimp Connections -- A
from Portage Electric Products, Inc.

A creep-action thermostat with crimp connections for fast, easy termination. Available in same end (Model A) or opposite (Model AA) termination. Designed for use on low-current 120 VAC loads. Features. Conductive bimetal construction; the bimetallic element carries the circuit current. Creep action... [See More]

  • Thermal Cutoff Style: Radial Leads
  • Voltage Type: AC Voltage
  • Cutoff Temperature: 5 to 150
  • Rated Voltage: 120
Creep-Action Thermostat/Thermal Protector -- A2
from Portage Electric Products, Inc.

A creep-action thermostat/thermal protector with highest contact rating of all Model A Series thermostats. Available with gold diffused contacts for use in low voltage/low current applications, or with fine silver contacts for 120 VAC applications. Features. Conductive bimetal construction; the... [See More]

  • Thermal Cutoff Style: Radial Leads
  • Rated Voltage: 120
  • Cutoff Temperature: 200
  • Rated Current: 5
Creep-Action Thermostat/Thermal Protector -- B
from Portage Electric Products, Inc.

A creep-action thermostat/thermal protector. Shunted type bimetal design allows for higher contact ratings. Equipped with gold diffused contacts for use in low voltage/low current applications. Features. Shunted bimetal construction; the bimetallic element does not carry the circuit current. Creep... [See More]

  • Thermal Cutoff Style: Radial Leads
  • Rated Voltage: 120
  • Cutoff Temperature: 150
  • Rated Current: 8
Multipurpose Creep Action Thermostat/Thermal Protector -- C
from Portage Electric Products, Inc.

Versatile, multipurpose creep action thermostats/ thermal protectors for temperature sensing applications, heaters, motors and more. Available with gold-diffused contacts for exceptionally low contact resistance in critical low-voltage/ low current circuits. Features. Conductive bimetal... [See More]

  • Thermal Cutoff Style: Radial Leads
  • Rated Voltage: 120
  • Cutoff Temperature: 200
  • Rated Current: 6
Snap-Action Thermal Protector -- VA
from Portage Electric Products, Inc.

A family of snap-action thermal protectors in an electrically isolated plastic case. Offers both overcharge and short-circuit protection in rechargeable battery packs. Low internal resistance for maximum protection and minimal effect on battery pack performance. Designed to meet tighter space... [See More]

  • Thermal Cutoff Style: Radial Leads
  • Voltage Type: DC Voltage
  • Cutoff Temperature: 50 to 100
  • Rated Voltage: 12 to 24
Temperature Fuse -- FBTF1079
from Ningbo Best Group Co., Ltd.

Temperature Fuse 1079. Established in 1997, Best Group (FBELE), is Chinese leading manufacturer and trader in electronic components. We can offer high quality products in very competitive price for electronics components, as well as best service, in time delivery, small order acceptable, etc. Our... [See More]

  • Thermal Cutoff Style: Radial Leads
Mechanical Thermal Cutoffs - 0.5 to 7 Amp
from Thermtrol

Thermal cutoffs are single action devices that open when a preset temperature is reached. They do not reset. The active component of a thermal cutoff is a fusible alloy surrounded by a special resin. Under normal operating temperatures the fusible alloy joins the two lead wires within the body of... [See More]

  • Thermal Cutoff Style: Axial Leads; Radial Leads
  • Rated Current: 0.5000 to 7
Thermal Cutoffs
from OptiFuse

Thermal cut-offs are designed to open on temperature rather than amperage. The fuses are availble in 2A, 3A, 5A, 10A and 15A across a wide spectrum of temperatures [See More]

  • Thermal Cutoff Style: Axial Leads; Radial Leads
  • Voltage Type: AC Voltage
  • Cutoff Temperature: 66 to 240
  • Rated Voltage: 150 to 250
Thermal Overload Protection 1, 2, and 3 Series
from Process Technology

Alerts operators to identify and remedy the cause of overtemp conditions. FEATURES. The Protector 1 overtemperature control system utilizes a heat sensitive fuse to detect overheat conditions. The protector, placed inside a thermowell, positioned in contact with the heater sheath, will cut power to... [See More]

  • Thermal Cutoff Style: Radial Leads
  • Cutoff Temperature: 82 to 150
ELUCT A5MC Series Radial Thermal Cutoff -- A5MC-100J
from Chatham Components, Inc.

ELCUT Thermal Cutoffs are available with axial or radial lead wires, both having the same basic design. The fusible thermal element is a eutectic alloy that is welded across a pair of lead wires. The eutectic alloy is coated with a special compound to protect it from oxidation. This ensures stable... [See More]

  • Thermal Cutoff Style: Radial Leads
  • Voltage Type: AC Voltage
  • Cutoff Temperature: 139
  • Rated Voltage: 250
Temperature Fuse -- FBTF1082
from Ningbo Best Group Co., Ltd.

Temperature Fuse 1082. Established in 1997, Best Group (FBELE), is Chinese leading manufacturer and trader in electronic components. We can offer high quality products in very competitive price for electronics components, as well as best service, in time delivery, small order acceptable, etc. Our... [See More]

  • Thermal Cutoff Style: Radial Leads
Mechanical Thermal Cutoffs - 15 Amp
from Thermtrol

The Thermal DF Series Thermal Cutoffs are single action devices that open when a preset temperature is reached. They do not reset. The active component of a thermal cutoff is an electrically insulated thermal pellet. This pellet holds a spring loaded contact against a fixed contact under normal... [See More]

  • Thermal Cutoff Style: Axial Leads; Radial Leads
  • Rated Voltage: 125 to 250
  • Voltage Type: AC Voltage
  • Rated Current: 10 to 15