Blue Sea Systems C-Series White Toggle Circuit Breaker, Triple Pole, Magnetic Hydraulic Trip Free, 65V DC

Overview

The Blue Sea Systems C-Series White Toggle Circuit Breaker is a triple pole magnetic hydraulic breaker for high-current marine circuits that need both overcurrent protection and manual switching in one panel-mounted unit. This white toggle version is available in 250A and 300A DC ratings, with three poles, trip-free operation, and a maximum rating of 120V AC, 240V AC, or 65V DC.

It is suited to heavy onboard loads such as inverters, bow thrusters, and windlasses, where a resettable breaker can simplify service compared with fuse-only protection. The breaker uses 1/4-20 tin-plated brass terminal studs and has a 5000A interrupt capacity at 65V DC, which are important checks when matching it to battery banks, cable size, and available fault current.

Key features

• Triple pole C-Series breaker with a white toggle actuator for marine electrical panels.
• Available in 250A DC and 300A DC versions for high-current circuit protection.
• Magnetic hydraulic trip-free mechanism cannot be held closed after a fault trip.
• Combines switching and circuit protection in one device, reducing the need for a separate switch in many installations.
• Rated for 120V AC, 240V AC, and 65V DC systems when installed within the breaker specifications.
• 5000A interrupt capacity at 65V DC for use in properly engineered DC distribution systems.
• 1/4-20 tin-plated brass terminal studs with 35 in-lb terminal stud torque.
• Operating temperature range from -40 C to 85 C for engine spaces, equipment lockers, and exposed electrical compartments with suitable panel protection.
• Double and triple pole C-Series breakers trip all poles when any one pole trips.
• Rated for 10000 switching cycles, supporting regular manual operation as part of system control.

Variants

This product is offered in two amperage configurations. Both are triple pole white toggle C-Series circuit breakers intended for high-current marine electrical circuits.

The amperage rating changes between variants. The general construction and core specifications remain consistent across these two versions, including the toggle actuator, three-pole layout, trip-free magnetic hydraulic breaker type, 1/4-20 tin-plated brass terminal studs, and 5000A interrupt capacity at 65V DC.

• 7270, 250A. This version fits installations where the protected circuit is specified for a 250A breaker, commonly around large DC loads such as inverter, thruster, or windlass feeds.
• 7271, 300A. This version is the higher-amperage option in this pair and fits circuits engineered around a 300A breaker rating.

Compatibility and fit

This breaker should be matched to the vessel wiring plan, conductor ampacity, expected load, battery source, and available short-circuit current. The 65V DC maximum makes it appropriate for common low-voltage DC boat systems when the complete installation stays within the breaker rating, while the 120V AC and 240V AC ratings allow use in AC panel applications where the circuit design calls for this breaker type.

For AC main use, a triple pole breaker can switch both hot lines and neutral in a 120/240V system when that layout is required by the panel design. For DC use, the paralleled-pole configuration uses a 5/16 inch stud on the bus side, so the panel, bus work, and cable terminations should be planned around the breaker geometry before installation.

Installation and setup

Install the breaker where the toggle is easy to reach and the terminals are protected from loose gear, spray, and accidental contact. Use the specified #6-32 stainless steel mounting screws and tighten them to 6 in-lb, then torque the terminal studs to 35 in-lb after the correct lugs and cable routing are in place.

Because this is a high-current breaker, cable size, lug quality, strain relief, and clean contact surfaces matter. It belongs in a properly enclosed marine electrical panel or distribution assembly, with enough clearance for service and enough labeling for quick identification during a fault or shutdown.

Use cases on board

This breaker is a practical match for boats with large intermittent or continuous loads, including cruising boats with inverter systems, fishing boats with windlasses, and vessels using bow thrusters for close-quarters handling. It gives the operator a clear manual switch point while still opening the circuit during an overcurrent condition.

It is also useful where a skipper or technician wants a resettable protection device at the panel instead of relying only on a fuse located near the battery or equipment feed. The breaker rating still needs to follow the vessel electrical design, not just the size of the equipment it serves.