Blue Sea 4131 Lockout Slide 2 Position 3 Pole C-Series

The Blue Sea 4131 Lockout Slide 2 Position 3 Pole C-Series is a critical safety device designed to prevent dual-source AC power conflicts in marine electrical systems. This lockout mechanism ensures that only one of a pair of double pole or triple pole AC circuit breakers can be activated at any time, eliminating the risk of mixing power from two independent sources—such as shore power and a generator or inverter setup. This is essential for protecting sensitive electronics and preventing damage from back-feeding or phase conflicts common in dual-power installations.

The 4131 lockout slide is engineered for seamless integration with all C-Series double pole and triple pole circuit breakers without requiring any panel modifications. It utilizes the existing circuit breaker mounting screw holes for installation, making retrofit work straightforward and cost-effective. The 2-position design physically prevents simultaneous activation, enforcing a mechanical lock-out that operators cannot override, providing fail-safe assurance that AC power transfer occurs in a controlled, sequential manner. This design eliminates the operator error that manual switching procedures often introduce.

Vessel operators managing dual AC power sources—whether cruising sailboats with inverter systems, larger motorboats with genset backup, or fixed offshore installations—rely on the 4131 to enforce safe power management protocols. Marine electricians and systems integrators use this lockout slide as a code-compliant solution to meet ABYC (American Boat and Yacht Council) standards for AC electrical safety. Its compact 3 x 2 x 8 inch profile and lightweight design make it practical for tight panel spaces, while its straightforward installation reduces labor time during system upgrades or new builds.