This Product Selection Guide contains information to help select products in the Circuit Breakers category on DigiKey.com
A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by excess current from an overload or short circuit. Its basic function is to interrupt current flow after a fault is detected. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.
SelectionCharacteristics
Mounting Type: Indicates how the device is attached.
Breaker Type: Indicates the operating principle of the device, which influences response and reset characteristics.
Current Rating (Amps): Indicates the current level at which the breaker is designed to trip, i.e. a 15A-rated breaker will activate and break the circuit when current levels in the circuit rises to 15A
Voltage Rating - AC: Typically this represents the maximum AC voltage rating to which a device will meet its given specifications. Exceeding this voltage rating may damage the device and other system components.
Voltage Rating - DC: Typically this represents the maximum DC voltage rating to which a device will meet its given specifications. Exceeding this voltage rating may damage the device and other system components.
Actuator Type: The form factor of the circuit breaker’s reset device, determining how the circuit breaker can be reset after tripping.
Number of Poles: Indicates the number of independent, isolated circuits a device is capable of accommodating or controlling simultaneously.
Illumination: Defines whether or not the circuit breaker includes illumination sources in its construction, and if so what color that illumination is.
Illumination Voltage (Nominal): Indicates the nominal operating voltage of a product’s illumination or backlighting feature, for products equipped therewith.
Approval Agency: An indication that the product meets the minimum safety standards of an approving agency. These agencies are either government entities or private third-party labs that protect consumer safety.
ProductExamples
| MFR PART # | 2477930000 |
|---|---|
| DIGIKEY PART # | 281-2477930000-ND |
| MANUFACTURER | Weidmüller |
| DESCRIPTION | Circuit Breaker Thermal Magnetic 15A 277 V AC 60 V DC Lever DIN Rail |
| DATASHEET | Click Here |
| MFR PART # | W57-XB7A4A10-15 |
|---|---|
| DIGIKEY PART # | PB534-ND |
| MANUFACTURER | TE Connectivity Potter & Brumfield Relays |
| DESCRIPTION | Circuit Breaker Thermal 15A 250 V AC DC Push to Reset Panel Mount |
| DATASHEET | Click Here |
| MFR PART # | 1620-1-20A |
|---|---|
| DIGIKEY PART # | 302-1365-ND |
| MANUFACTURER | E-T-A |
| DESCRIPTION | Circuit Breaker Thermal 20A AC 14.5 V DC Automatic Reset Holder |
| DATASHEET | Click Here |
| MFR PART # | GSB633PC40 |
|---|---|
| DIGIKEY PART # | 1864-2356-ND |
| MANUFACTURER | Carlo Gavazzi Inc. |
| DESCRIPTION | Circuit Breaker Thermal Magnetic 40A 480 V AC DC Lever DIN Rail |
| DATASHEET | Click Here |
SchematicSymbol
Schematic symbol courtesy of Scheme-it. Please see their website for more information and symbols.
MediaLinks
Videos
Sensata University | Circuit Breakers 101
Digikey Content Library - Circuit Breaker Videos
Articles
Circuit Breaker
Protecting Machinery w/ Hydraulic Circuit Breakers
Product Training Modules
Common Circuit Protection Mistakes - E-T-A
DIN Rail Mount Circ Breakers - American Electrical
TA35 Series Thermal Circuit Breakers - SCHURTER
Blogs
Basics of Circuit Breakers
TechForum
Sensata-Airpax Circuit Breaker Numbering
E-T-A 2-5200 series thermal circuit breaker - Suffix KF
TE Connectivity W57 Series Circuit Breaker Part Number Breakdown
Qualtek QMB circuit breaker Part Numbering