Eaton CB123-20B automotive circuit breaker - 1.5 kAIC at 12 V
Part Number: CB123-20B
Quick Summary
CB123-20B automotive circuit breaker protects DC automotive circuits in harsh environments. This helps engineers mitigate nuisance trips and reduce downtime by providing reliable, quick interruption when faults occur. RoHS compliant design and Type III heavy-duty construction support robust automotive usage, while the compact form and #10-32 TPI stud connection simplify integration into tight enclosures. For buyers, this means safer power distribution, easier sourcing within the Eaton Bussmann family, and predictable performance across standard vehicle electrical systems. In practice, it enables lower total cost of ownership through longer service intervals and fewer field replacements, while keeping critical loads safeguarded with consistent trip characteristics.
Product Information
Extended Description
CB123-20B Eaton: Eaton Bussmann series C.B.123-B automotive circuit breaker, 25 Vdc, 20A, 1.5 kAIC at 12 Vdc, Type III, Heavy duty, 10-32 TPI stud
Product Name
Eaton Bussmann series CB123-B automotive circuit breaker
Catalog Number
CB123-20B
UPC
051712601719
Product Length/Depth
0.58 in
Product Height
1.35 in
Product Width
1.8 in
Product Weight
0.54 lb
Compliances
Contact factory RoHS Compliant
Amperage Rating
20 A
Interrupt rating
1.5 kAIC at 12 Vdc
Voltage rating
25 Vdc
Connection
#10-32 TPI stud
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Eaton Specification Sheet - CB123-20B
Feature → Business Impact → Application: 25 Vdc voltage rating ensures protection for low-voltage DC automotive circuits while preventing arcing and insulation stress in vehicle power trains, delivering safer operation and reduced risk of system damage. This translates to improved reliability for engine bays and under-hood assemblies, where space is limited and vibration is high, making CB123-20B ideal for power distribution in cars, vans, and light trucks. Feature → Business Impact → Application: 20 A amperage rating provides precise current limiting to protect wiring and fuses without nuisance trips during normal loads, boosting system uptime and reducing maintenance costs in fleet applications. This is critical for ECUs, sensors, and lighting circuits that demand stable, predictable protection. Feature → Business Impact → Application: 1.5 kAIC at 12 Vdc interrupt rating delivers strong fault clearance for short-circuit events, minimizing collateral damage to wiring and components. Applicable to high-current feeds from battery banks and starter circuits where rapid isolation is essential. Feature → Business Impact → Application: Type III construction and heavy-duty design enhance durability under vibration and temperature swings, supporting long service life in off-road, mining, and agricultural equipment. This reduces replacement cycles and supports compliance with rugged-environment use cases. Feature → Business Impact → Application: 10-32 TPI stud connections enable robust, vibration-resistant mounting and straightforward installation in existing Bussmann series footprints. This simplifies aftermarket replacement and OEM integration, especially in crowded electrical cabinets and sub-panels. Feature → Business Impact → Application: RoHS compliant materials and streamlines procurement by aligning with modern regulatory expectations, reducing risk in multi-country deployments and ensuring easier supplier audits. This is particularly valuable for fleets and manufacturers pursuing green manufacturing practices.
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FAQs
CB123-20B uses a #10-32 TPI stud for secure mounting, matching Eaton Bussmann series footprint. Verify enclosure clearance, torque the studs to manufacturer specifications, and ensure the mounting surface is clean to maintain reliable electrical contact in vibration-prone environments.
The 25 Vdc rating defines the maximum controlled voltage, 20 A indicates the continuous current the device protects, and 1.5 kAIC at 12 Vdc is the interrupt capacity at that lower operating voltage. Together they indicate suitability for standard automotive DC power rails and the ability to safely interrupt faults without damage to the breaker or wiring.
Yes. The CB123-20B features Type III heavy-duty construction designed for rugged environments. The 10-32 TPI stud connection supports strong mechanical and electrical contact, reducing the risk of loosening under vibration and ensuring consistent protection in off-road or industrial vehicle applications.
The data lists RoHS compliance for the CB123-20B, which helps with regulatory alignment in many regions. Specific CE or IP classifications are not provided in the data; verify with Eaton for any additional certifications required for your project or region and consider factory-confirmed documentation during audits.
CB123-20B is a single-pole protective device intended for permanent installation with rugged duty ratings. For maintenance, monitor for signs of chattering, overheating, or corrosion at the stud connections. Replace after a fault event or if mechanical wear reduces contact integrity, and source genuine Eaton Bussmann replacement parts to maintain performance and warranty coverage.