Eaton CB123-40B automotive circuit breaker - 1.5 kAIC
Part Number: CB123-40B
Quick Summary
The Eaton CB123-40B automotive circuit breaker protects automotive electrical systems by interrupting fault currents. In tight automotive harnesses, space and reliability are critical, and nuisance trips can drive downtime and repair costs. This unit is RoHS compliant and designed as Type III, heavy-duty protection with a 22 Vdc rating and 40 A current interrupting capability (1.5 kAIC at 12 Vdc), ensuring dependable operation across automotive DC networks. For design engineers and procurement teams, it offers straightforward installation using #10-32 TPI studs and compatibility with the Eaton Bussmann line, supporting consistent maintenance and inventory control. This combination of rugged performance and clear documentation supports faster design wins and reduced lifecycle risk.
Product Information
Extended Description
CB123-40B Eaton: Eaton Bussmann series C.B.123-B automotive circuit breaker, 22 Vdc, 40A, 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
CB123-40B
UPC
051712601733
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
40 A
Interrupt rating
1.5 kAIC at 12 Vdc
Voltage rating
22 Vdc
Connection
#10-32 TPI stud
Bussmann series 4-foot automotive planogram no.10730
Bussmann series full line retail catalog no. 5084
Bussmann series full line retail catalog no. 5084
Bussmann series full line retail catalog no. 5084
Bussmann series Fuseology
Eaton Specification Sheet - CB123-40B
Feature: Type III, heavy-duty design provides rugged protection in harsh automotive environments. Benefit: Reduces nuisance trips and wiring damage, enabling higher uptime and lower maintenance costs in vehicle assemblies. Application: Engine compartments and power distribution Where reliability is essential. Feature: Electrical ratings of 22 Vdc, 40 A, and 1.5 kAIC at 12 Vdc. Benefit: Fast and predictable fault interruption to protect wires and loads, improving system safety and longevity. Application: DC power networks in passenger cars, commercial vehicles, and fleet applications. Feature: #10-32 TPI stud connections with compact dimensions (0.58 in depth, 1.35 in height, 1.8 in width). Benefit: Easy, drop-in mounting and secure electrical termination, reducing installation time and rework. Application: Harness assemblies and modular panels where space is constrained. Feature: RoHS compliance and clear Eaton Bussmann lineage. Benefit: Regulatory peace of mind and streamlined procurement with compatible catalogs and planograms. Application: Compliance-driven programs and multi-brand BOMs where traceability matters. Feature: Documentation availability (datasheet, catalogs, planogram) supporting quick quoting and design validation. Benefit: Accelerates design reviews, BOM accuracy, and supplier onboarding. Application: Engineering design reviews and procurement workflows in automotive programs.
Get a Quick Quote for a Eaton CB123-40B
Chat with us on WhatsApp - fast responses guaranteed
Need to speak with someone? We'll call you back within 2 hours during business hours
Interested in Eaton CB123-40B?
Enquire Now
FAQs
CB123-40B uses #10-32 TPI stud terminals, making secure termination essential for vibration-prone environments. Plan for proper mounting clearance, align the stud orientation with the harness routing, and ensure connectors and wiring maintain adequate insulation. Use standard automotive practices for torque, strain relief, and harness protection to maximize longevity and reliability.
The CB123-40B is rated for 22 Vdc, 40 A, with an interrupt rating of 1.5 kAIC at 12 Vdc. It is designed as a Type III, heavy-duty automotive circuit breaker, providing robust protection against short circuits and overloads in DC automotive power systems while remaining RoHS compliant.
Yes. The CB123-40B is a Type III, heavy-duty automotive circuit breaker built for rugged DC networks. Its RoHS compliance and automotive-grade construction support durable protection in engine bays and power distribution trunks, where exposure to vibration, dust, and temperature variation demands reliable interruption of fault currents.
Documentation includes the Eaton Specification Sheet for CB123-40B, plus Bussmann catalogs and planograms. Access the datasheet, catalog imagery, and planogram PDFs through Eaton’s resources and the provided downloads, which aid BOM creation, design validation, and procurement workflows.
RoHS compliance ensures regulatory alignment across many markets, while the rugged Type III design reduces unplanned downtime from nuisance trips. The device’s straightforward replacement and compatibility with the Bussmann line simplify spares stocking, maintenance planning, and cost control in fleet and warranty programs.