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Thermal Magnetic Circuit Breakers

Find thermal magnetic circuit breakers to help protect electrical circuits against overloads and short circuits. As you compare options, check amperage, voltage rating, pole count, and interrupting capacity, and confirm that the breaker is listed for use with your electrical panel and meets your circuit’s requirements.

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  1. HQRP - Thermal Circuit Breaker Switch 98 Series 15 A Push-Button Reset, UL Listed, Waterproof Cover, Quick Connect - Black

    SKU: J3ZSL2L5C8

    Product Description

    A black thermal circuit breaker with push-button reset, waterproof cover, and quick connect terminals for versatile protection.
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    Your price for this item is $12.40

  2. Square D - HomeLine 30 amps Surge Single Pole Circuit Breaker

    SKU: J7GK4JZ7Y2

    Product Description

    A 30-amp single-pole circuit breaker providing overload and short-circuit protection, rated 120/240V with 10,000-AIC and UL-listed.
    See all Amp Accessories & Installation Parts
    Your price for this item is $25.15

  3. Square D - HomeLine 40 amps Surge 2-Pole Circuit Breaker

    SKU: J7GK4JZ7S3

    Product Description

    A 40-amp double-pole circuit breaker with plug-on neutral design, 120/240V AC operation, and 10kA interrupting capacity.
    See all Amp Accessories & Installation Parts
    Your price for this item is $36.60

  4. Square D - HomeLine 15 amps Surge 2-Pole Circuit Breaker

    SKU: J7GK4JZ7PY

    Product Description

    A 15-amp two-pole thermal-magnetic breaker offering overload and short-circuit protection, 120/240VAC rating, and 10,000-AIR interrupt capacity.
    See all Amp Accessories & Installation Parts
    Your price for this item is $36.16

  5. Square D - HomeLine 100 amps Surge 2-Pole Circuit Breaker

    SKU: J7GK4JZ7RL

    Product Description

    A 100-amp, 120/240V miniature surge circuit breaker with two poles for electrical protection.
    See all Amp Accessories & Installation Parts
    Your price for this item is $84.25

  6. Square D - HomeLine 20 amps Surge 2-Pole Circuit Breaker

    SKU: J7GK4JZ7PH

    Product Description

    A durable 20-amp double-pole circuit breaker for 120/240V systems with thermal-magnetic tripping and 10,000 AIC rating.
    See all Amp Accessories & Installation Parts
    Your price for this item is $36.60

  7. Square D - HomeLine 30 amps Surge 2-Pole Circuit Breaker

    SKU: J7GK4JZ7PF

    Product Description

    A 30-amp double-pole circuit breaker with plug-on neutral design, 120/240V AC operation, and 10kA interrupting capacity.
    See all Amp Accessories & Installation Parts
    Your price for this item is $36.60

  8. Square D - Homeline 15 amps Plug In Single Pole Miniature Circuit Breaker

    SKU: J7GK4JZ7LX

    Product Description

    A 15-amp single-pole thermal-magnetic circuit breaker with plug-on neutral, 120V operation, 10kA protection, and UL listing.
    See all Amp Accessories & Installation Parts
    Your price for this item is $25.15

  9. Schneider Electric - Square D 15/20 amps Tandem Single Pole Circuit Breaker

    SKU: J7GK4JWZRZ

    Product Description

    A thermal-magnetic tandem circuit breaker providing 15/20 amp overcurrent protection for AC and DC systems.
    See all Amp Accessories & Installation Parts
    Your price for this item is $49.60
    Save $0
    The previous price was $49.91

  10. Square D - QO 20 amps Plug In Single Pole Circuit Breaker

    SKU: J7GK42KQKV

    Product Description

    A 20-amp, single-pole circuit breaker with thermal-magnetic protection, plug-on neutral installation, Visi-Trip indicator, and 10kA capacity.
    See all Amp Accessories & Installation Parts
    Your price for this item is $32.24

  11. Square D - QO 60 amps Plug In 2-Pole Circuit Breaker

    SKU: J7GK42KQ5R

    Product Description

    A 60-amp, 120/240V AC, 2-pole plug-in circuit breaker with thermal-magnetic protection and Visi-Trip indication.
    See all Amp Accessories & Installation Parts
    Your price for this item is $52.07

  12. Square D - QO 50 amps Plug In 2-Pole Circuit Breaker

    SKU: J7GK42KQ5G

    Product Description

    A 50-amp, 120/240V AC two-pole circuit breaker with thermal-magnetic protection, plug-on installation, and Visi-Trip indication.
    See all Amp Accessories & Installation Parts
    Your price for this item is $52.07

  13. Schneider Electric - Square D QO 30 amps Plug In 2-Pole Circuit Breaker

    SKU: J7GK42KQ4L

    Product Description

    A durable 2-pole circuit breaker with thermal magnetic technology and Visi-Trip indicator for reliable protection.
    See all Amp Accessories & Installation Parts
    Your price for this item is $52.07
    Save $0
    The previous price was $52.40

  14. Square D - QO 20 amps Plug In 2-Pole Circuit Breaker

    SKU: J7GK42KQ4J

    Product Description

    A 20-amp, 120/240V AC, 2-pole thermal-magnetic circuit breaker with 10kA capacity and Visi-Trip indicator.
    See all Amp Accessories & Installation Parts
    Your price for this item is $52.07

  15. Eaton - 30 amps Plug In Single Pole Circuit Breaker

    SKU: J3258QLWXV

    Product Description

    A single-pole circuit breaker offering 30-amp thermal-magnetic protection for residential branch circuits.
    See all Amp Accessories & Installation Parts
    Your price for this item is $31.43

  16. Eaton - 40 amps Plug In 2-Pole Circuit Breaker

    SKU: J3258RVJH6

    Product Description

    A thermal-magnetic breaker designed for safe, easy plug-in installation in 240-volt residential branch circuits.
    See all Amp Accessories & Installation Parts
    Your price for this item is $47.55

  17. Eaton - 60 amps Plug In 2-Pole Circuit Breaker

    SKU: J32266KX2W

    Product Description

    A plug-in 2-pole breaker providing 60-amp thermal-magnetic protection for 240V high-load circuits.
    See all Amp Accessories & Installation Parts
    Your price for this item is $47.55

  18. Eaton - 20 amps Plug In Single Pole Circuit Breaker

    SKU: J3258QLWX7

    Product Description

    A single-pole circuit breaker offering 20-amp thermal-magnetic protection for residential branch circuits.
    See all Amp Accessories & Installation Parts
    Your price for this item is $31.42

  19. Eaton - 20/20 amps Tandem 2-Pole Circuit Breaker

    SKU: J3226P5PS5

    Product Description

    A duplex double-pole circuit breaker designed to protect wiring from overheating or short-circuiting at 240 volts.
    See all Amp Accessories & Installation Parts
    Your price for this item is $51.56
    Save $4
    The previous price was $55.96

  20. Eaton - 15 amps Plug In Single Pole Circuit Breaker

    SKU: J32266KX4J

    Product Description

    A single-pole, 15-amp thermal-magnetic breaker offering reliable overcurrent protection for residential circuits.
    See all Amp Accessories & Installation Parts
    Your price for this item is $25.45
    Save $1
    The previous price was $26.95

  21. Eaton - 30 amps Plug In 2-Pole Circuit Breaker

    SKU: J3258R6XJJ

    Product Description

    A resettable 2-pole circuit breaker that protects wiring from overloads and short circuits.
    See all Amp Accessories & Installation Parts
    Your price for this item is $43.96

  22. Eaton - 20/40 amps Plug In 4-Pole Circuit Breaker

    SKU: J3253H9WYJ

    Product Description

    A four-pole circuit breaker designed for BR type load centers, protecting against overloads and short circuits.
    See all Amp Accessories & Installation Parts
    Your price for this item is $52.83
    Save $4
    The previous price was $57.38

  23. Eaton - 30/40 amps Plug In 4-Pole Circuit Breaker

    SKU: J3253H9WT8

    Product Description

    A quadplex circuit breaker that creates four circuits in two spaces, featuring independent trip and rejection tab.
    See all Amp Accessories & Installation Parts
    Your price for this item is $54.13
    Save $4
    The previous price was $58.68

  24. Eaton - 30/30 amps Plug In 4-Pole Circuit Breaker

    SKU: J3253H9WQJ

    Product Description

    A quadplex circuit breaker offering four circuits in two spaces with independent trip and rejection tab features.
    See all Amp Accessories & Installation Parts
    Your price for this item is $54.13
    Save $4
    The previous price was $58.68
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Thermal magnetic circuit breakers help protect electrical wiring from damage by interrupting current during sustained overloads and short circuits. These electrical safety devices combine two trip mechanisms: a thermal element that responds to prolonged excess current and a magnetic element that reacts rapidly to high fault current. Inside a typical thermal magnetic breaker, a bimetallic strip heats up and bends as an overload continues, eventually triggering the breaker to open the circuit. This time-delayed response allows brief, normal increases in current, such as those associated with some motor startups, without necessarily causing a trip. The magnetic trip mechanism uses an electromagnet to open the circuit quickly during a short circuit, helping limit the duration of potentially damaging fault current. Together, thermal overload protection and magnetic short-circuit protection make these breakers a common choice for branch circuits in residential electrical panels and many commercial power distribution systems. Unlike a fuse, which must be replaced after it operates, a circuit breaker can generally be reset after the cause of the trip has been identified and corrected, provided the breaker remains safe and serviceable. Choosing a thermal magnetic circuit breaker requires more than matching the amperage printed on an existing device. Important specifications include the rated current, voltage rating, number of poles, interrupting rating, and compatibility with the electrical panel or equipment where the breaker will be installed. A breaker’s interrupting rating must be sufficient for the available fault current at its installation point, while its amperage must be appropriate for the conductors and circuit application under applicable electrical codes. Trip characteristics also matter, particularly for equipment with startup current that differs from its normal operating load. Standard thermal magnetic circuit breakers do not provide the same specialized protection as ground-fault circuit interrupter (GFCI) or arc-fault circuit interrupter (AFCI) devices, although some breakers combine those functions with overload and short-circuit protection. For home electrical upgrades, appliance circuits, or commercial electrical maintenance, use only breakers listed or specifically classified for the intended panel and application, and follow manufacturer requirements. A licensed electrician can evaluate the circuit, confirm code requirements, and investigate frequent breaker trips rather than simply replacing a breaker with one that has a higher amperage rating.

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FAQ

A thermal magnetic circuit breaker is an electrical switching device with two trip mechanisms: a heat-responsive bimetal element and an electromagnetic element. These mechanisms operate mechanically, rather than relying on an electronic trip unit.

Thermal magnetic circuit breakers use physical thermal and magnetic components to trigger their trip mechanisms. Electronic circuit breakers use current sensors and electronic circuitry to control tripping. Electronic models may also include digital displays, communication features, and programmable settings.

Common mounting styles include plug-in, bolt-on, and DIN-rail designs. Plug-in breakers connect to compatible panel assemblies, bolt-on breakers use threaded connections, and DIN-rail breakers attach to a standardized mounting rail. Compatibility depends on the panel or enclosure's specified breaker family.

Thermal magnetic circuit breakers are available with AC ratings, DC ratings, or both. An AC designation does not automatically indicate DC compatibility. Manufacturer specifications identify the supported current type, voltage ratings, and any required wiring configuration.

Depending on the breaker family, accessories may include auxiliary contacts, alarm contacts, shunt-trip modules, and external operating handles. Auxiliary contacts communicate breaker position, while alarm contacts indicate a tripped state. Shunt-trip modules accept an external electrical signal to trip the breaker, and external handles provide operation from outside an enclosure.