Blue Sea Systems C-Series UL-489 Circuit Breaker, 1-Pole, 80V DC, Flat Rocker, 10,000A Interrupt Capacity

Overview

The Blue Sea Systems UL-489 Circuit Breaker is a single-pole DC circuit breaker range with a flat rocker actuator, built for marine electrical panels that need UL-489 style protection up to 80V DC. The range covers 5A, 10A, 15A, 20A, 30A, 50A, and 100A ratings, so it can be matched to the wire size and load requirements of the circuit being protected.

This breaker uses a magnetic hydraulic, trip-free mechanism with a 10,000A interrupt capacity. The trip-free action is important on board because the breaker cannot be held closed during a fault condition, helping protect branch circuits, control circuits, and other DC loads in demanding marine installations.

The flat rocker sits flush when in the ON position, which helps reduce accidental switching on crowded helm, cabin, or equipment panels. Operating temperature is rated from -40 C to 85 C, making this range suitable for electrical spaces exposed to wide seasonal and engine-room temperature changes.

Key features

• Single-pole DC breaker range for marine circuits up to 80V DC.
• Available amperage ratings from 5A to 100A for matching protection to the load and conductor size.
• Magnetic hydraulic, trip-free breaker action so the circuit cannot be forced closed during a fault.
• Flat rocker actuator sits flush in the ON position to help limit accidental switching on panels.
• 10,000A interrupt capacity for demanding DC protection layouts.
• #10-32 tin-plated brass screw terminals on 5A through 50A versions, with a 1/4-20 stud terminal on the 100A version.
• #6-32 stainless steel mounting screws support secure panel installation.
• Suitable for installations where UL-489 specifications are required, including vessels covered under CFR 46.

Variants

This product is offered in multiple amperage ratings across the same flat rocker, single-pole UL-489 circuit breaker family. The selectable ratings are 5A, 10A, 15A, 20A, 30A, 50A, and 100A.

The main difference across the range is current rating, with the 100A version also using a stud-style terminal rather than the screw terminal used on the lower amperage versions. The voltage rating, pole count, actuator style, breaker type, interrupt capacity, operating temperature range, and mounting screw specification remain consistent across the listed configurations.

Installation and fit

Use the breaker rating that matches the protected circuit and wire size, following the vessel wiring plan and applicable marine electrical standards. This is not a general-purpose switch replacement; it is circuit protection, so sizing should be based on the conductor and load rather than only the equipment nameplate.

The flat rocker format makes sense for panels where accidental contact is a concern, such as helm switch panels, navigation stations, cabin distribution panels, or service panels in tighter equipment spaces. Terminal torque and mounting torque should be followed during installation so the electrical connection and panel fit stay secure under vibration.

Electrical and system integration

This range is for DC systems up to 80V DC, which makes it useful across many boat electrical layouts, including 12V, 24V, 36V, and 48V DC installations when the circuit rating and wiring are appropriate. The breaker can be used in distribution and equipment protection layouts where a resettable breaker is preferred over replacing a fuse after a trip.

The 5A through 50A versions use #10-32 tin-plated brass screw terminals with a 15 to 20 in-lb terminal torque range. The 100A version uses a 1/4-20 stud terminal with a 30 to 35 in-lb terminal torque range, giving the higher-current model a connection style suited to heavier conductors and lugs.

Use cases on board

This breaker range is a good match for boat builders, refit yards, and owners upgrading DC distribution panels where UL-489 circuit protection is part of the specification. It is also useful for commercial, patrol, military, and inspected vessel projects where documentation and circuit protection standards matter as much as basic fit.