Blue Sea Systems UL-489 Circuit Breaker, 1-Pole, 240V AC, Flat Rocker

Overview

The Blue Sea Systems UL-489 Circuit Breaker is a 1-pole AC magnetic hydraulic breaker with a flat rocker actuator for marine AC distribution panels where UL-489 specifications are required. This range covers 5A, 10A, 15A, 20A, 30A, and 50A AC ratings, with a maximum voltage of 240V AC and a 5000A interrupt capacity.

It is suited to vessels that need UL-489 circuit protection, including Navy, Army, Coast Guard, and other vessels covered under CFR 46. The flat rocker sits flush in the ON position, which helps reduce accidental switching in busy helm, cabin, or electrical panel locations.

The breaker uses #10-32 screw terminals in tin-plated brass, with a magnetic hydraulic, trip-free mechanism. Operating temperature coverage from -40 C to 85 C makes it practical for onboard electrical spaces that see wide temperature swings.

Key features

• UL-489 circuit breaker range for marine AC panels where UL-489 specifications are required.
• Available amperage ratings from 5A to 50A AC for matching individual branch circuit requirements.
• 1-pole format for single-pole AC circuit protection in compatible panel layouts.
• Maximum voltage rating of 240V AC for marine AC distribution applications.
• Magnetic hydraulic, trip-free breaker type for circuit protection that cannot be held closed after a trip condition.
• Flat rocker actuator sits flush in the ON position to help limit accidental switching at the panel.
• #10-32 screw terminals in tin-plated brass support secure panel wiring connections.
• 5000A interrupt capacity, with an operating temperature range from -40 C to 85 C.
• Uses #6-32 stainless steel mounting screws, with 7-9 in-lb mounting screw torque and 15-20 in-lb terminal torque.

Variants

This Blue Sea Systems UL-489 flat rocker breaker range varies by amperage rating: 5A, 10A, 15A, 20A, 30A, and 50A AC. The available ratings let the panel builder or installer match the breaker to the protected AC circuit rather than oversizing protection.

Across these listed versions, the shared configuration is the 1-pole flat rocker format, 240V AC maximum voltage, magnetic hydraulic trip-free breaker type, #10-32 tin-plated brass terminals, and 5000A interrupt capacity.

Installation and fit

This breaker belongs in a properly planned AC distribution panel where the circuit rating, conductor size, load type, and applicable marine electrical standards have been checked together. It is a good match for refits, panel builds, and replacement work where a flat rocker breaker with UL-489 compliance is needed.

Use the stated terminal torque and mounting screw torque during installation. Correct torque matters on boats because vibration, heat cycling, and service access can all affect panel connections over time.

Electrical use on board

The amperage choice should follow the circuit being protected, not only the connected equipment label. Typical onboard use may include AC branch circuits in cabins, utility spaces, or service panels, provided the selected rating and installation match the vessel electrical design.

For commercial, government, or inspected vessels, the UL-489 and CFR 46 relevance is especially important because breaker selection is often part of a broader compliance and inspection requirement.