About This Product

The Blue Sea Systems 187-Series is a switchable thermal circuit breaker for DC marine circuits where circuit protection and a manual reset switch need to sit in the same accessible device. This 48V DC breaker family covers amperage ratings from 25A to 200A, with panel-mount and surface-mount versions for different electrical layouts on board.

Each breaker uses a thermally responsive bi-metal blade and Type III switchable manual-reset operation. The trip-free mechanism means the lever cannot be held closed against a fault, which matters on battery feeds, windlass circuits, inverter feeds, charging circuits, and other DC loads where fault current needs to be interrupted safely.

The range uses 5/16 inch-18 terminal studs, accepts #10 or M5 mounting screws, and has published interrupt ratings of 5000A at 14V DC, 3000A at 28V DC, and 1500A at 48V DC. The operating temperature range is -40 C to 85 C, giving it room for engine room heat, exposed lockers, and colder storage conditions.

Key Features

• Thermal circuit breaker
• Works with DC systems up to 48V
• Clear, single lever operation
• Combines switching and circuit protection into a single device
• Applications: Windlasses
• 1500 - 5000A interrupt capacity depending on voltage"Trip Free" design cannot be held "ON" during fault current condition
• Self-trimming, waterproof case eliminates need for mounting panels or trim bezels
• Large clearance around terminal studs accepts heavy-gauge wire lugs
• Robust 5/16"-18 terminals for high torque connections
• Ignition protected safe for installation aboard gasoline powered boats
• Waterproof protected against water from heavy seas