T Tocas 300A Manual Reset Circuit Breaker 3/8" Studs — Waterproof IP67, 12–48V DC

The T Tocas E9 is a reusable 300 amp manual-reset circuit breaker with 3/8" studs, designed for waterproof, ignition-protected DC protection across 12–48V systems.

Built to replace single-use fuses, the E9 offers a switchable, Type 3 manual reset design that combines heavy-duty current interruption with IP67-level water resistance and industry safety approvals. Its durable UL 94V-0 housing and stainless steel 3/8"-16 hardware make it appropriate for harsh environments where reliable overcurrent protection is essential—trucks, RVs, marine craft, trolling motors, DC audio and other 12V to 48V installations.

How does the E9 protect electrical systems during overloads?

When current exceeds safe limits, the E9 interrupts the circuit mechanically, preventing damage to wiring and components. After the fault is corrected, the breaker can be manually reset rather than replaced, saving time and consumables.

• 300 amp interrupt rating suitable for high-current feeders
• Trip characteristics sized for automotive and marine DC loads
• Manual reset avoids fuse replacement downtime
• Ignition-protected construction reduces spark risk in fuel-vapor areas

What electrical specifications and performance ratings matter?

The E9 functions across common DC service voltages and withstands very high prospective currents for short durations. It lists specific short-circuit withstand numbers and is rated to operate across extreme temperatures.

• Operating voltage range: 12V to 48V DC
• High short-circuit withstand: 2,500A at 14Vdc, 1,500A at 48Vdc
• Replaces standard 300A fuses while providing reset capability
• Operating temperature range: -32°C to 82°C

Is the E9 suitable for wet or marine environments?

Yes—the unit is engineered for exposure to moisture and splash conditions. Its IP67 rating and robust housing meet automotive and marine safety standards, making it a practical choice for boats and outdoor equipment.

• IP67 waterproof protection keeps internal parts dry under temporary submersion
• UL 94V-0 flame-retardant casing for elevated safety
• Corrosion-resistant stainless steel hardware for saltwater resilience
• Meets SAE and UL specifications used in vehicle and marine installations

How does installation and maintenance look in everyday use?

Installation is straightforward: two 3/8"-16 studs make secure bolted connections to battery cables or bus bars. Routine maintenance is minimal—inspect fasteners and housing seals, then reset the breaker if it trips after resolving the cause of overload.

• 3/8"-16 stainless steel studs with insulators for secure connections
• Mounting options compatible with battery boxes, panels, and posts
• Manual-reset switch design simplifies restoration of service
• Serves as a reusable alternative to disposable 300A fuses

Who this is for: The T Tocas E9 300A manual-reset breaker is intended for installers, fleet technicians, marine owners, RV and off-grid system builders, and audio or trolling-motor enthusiasts who need robust overcurrent protection that withstands water exposure and heavy currents. Choose it when you want a resettable, ignition-protected solution that replaces 300A fuses and adheres to recognized automotive and marine standards.