Bussmann 150A Type III Circuit Breaker — Ignition-Protected Flush-Mount, Waterproof (1 Piece)

The Bussmann Series CB185 150A Type III is a flush-mount, ignition-protected circuit breaker designed to protect high-amperage accessory and charging circuits in trucks, RVs, buses and marine installations.

This genuine Bussmann circuit breaker offers reliable overcurrent protection for multi-battery systems, battery isolators and heavy accessory loads. Built with a sealed, waterproof housing and engineered to meet SAE J1171 ignition-protection requirements, the CB185 is intended for environments where exposure to moisture, vibration and elevated currents is common. It installs flush for a neat panel appearance and provides a durable solution for mobile and marine electrical systems.

What kind of systems is the CB185 150A best used with?

The CB185 is tailored for high-current accessory circuits and battery-charging applications in vehicles that demand robust protection. It's commonly applied to battery isolators, alternator outputs, inverter feeds and auxiliary power feeds on trucks, RVs, buses and boats. The Type III construction helps ensure consistent operation in mobile environments.

• Protects battery charging circuits and alternator output lines
• Used with battery isolators in multi-battery setups
• Suitable for heavy accessory loads like winches, inverters and HVAC systems
• Compatible with automotive, RV and marine electrical panels

How does the CB185 handle wet or harsh environments?

The CB185’s sealed, waterproof housing resists moisture and contaminants that commonly affect vehicle and marine electrical systems. Its flush-mount design reduces exposure to snagging or accidental contact, and the robust construction withstands vibration and road or sea conditions. This makes it a practical choice where durability matters.

• Waterproof sealed enclosure protects internal contacts
• Flush mounting minimizes exposure to external hazards
• Durable build tolerates vibration and shock in mobile use
• Designed for long-term, maintenance-friendly installation

Does the CB185 meet ignition protection and safety standards?

Yes — the CB185 complies with the SAE J1171 standard for ignition protection, which helps reduce the risk of ignition in flammable atmospheres typical of fuel-equipped vehicles and vessels. This compliance makes it suitable for installations where code and manufacturer recommendations require ignition-protected components. Always follow vehicle or vessel wiring diagrams and fuse/breaker placement guidelines.

• Meets SAE J1171 ignition protection requirements
• Designed to minimize sparking under fault conditions
• Acceptable for fuel-system-adjacent electrical locations
• Supports safer battery and charging system configurations

How do I install and size the CB185 for my system?

Install the CB185 in the panel or location where its flush mount and sealed housing best protect it from direct exposure while keeping wiring runs short to reduce voltage drop. Choose the 150A rating to match or slightly exceed expected continuous load while staying within conductor ampacity and manufacturer recommendations. When in doubt, consult vehicle wiring standards and a qualified technician for proper torque, wire gauge and terminal preparation.

• Select conductor gauge rated for 150 amps and environmental conditions
• Mount flush to maintain sealing and reduce snag risk
• Use proper terminal crimping and torque values for reliable contact
• Position near the battery or isolator to limit voltage drop

Who is this for: The Bussmann CB185 150A Type III circuit breaker is aimed at professional installers, fleet technicians and owner-operators who need dependable, ignition-protected overcurrent protection for high-amperage vehicle or marine circuits. It's a good fit when you require a sealed, flush-mount breaker for battery-charging systems, multi-battery isolators, heavy accessory feeds or any application that calls for SAE J1171-compliant components.