Overview of the ABB Molded-Case Circuit Breaker S5N300TW

Up your system’s safety and performance with the ABB S5N300TW, a rugged, high-capacity molded-case circuit breaker engineered for demanding industrial environments.

Key Specifications

• Model: S5N300TW

• Manufacturer: ABB (Asea Brown Boveri) 

• Series: SACE Isomax (S5N family) 

• Rated Current: 300 A

• Poles: 3 (three-phase)

• Voltage Rating:

  • 600 VAC

  • Suitable for up to 500 VDC

• Interrupting Capacity: 35 kA @ 480 V AC 

• Trip Mechanism: Thermal-magnetic (LI — Long-Time & Instantaneous) 

• Connection Type: Bolt-On frame—secure installation, ideal for heavy load switching

• Weight: ~10–12 lbs depending on configuration 

Highlights & Applications

• Designed for industrial motor protection, distribution panels, and overload applications where fast, reliable circuit interruption is critical

• Part of ABB’s trusted Isomax line, delivering robust performance and safety compliance

• High interrupting capacity (35 kA) ensures dependable operation under short-circuit conditions

• Thermal-magnetic mechanism offers fast response to both long-term overloads and immediate fault currents

• Bolt-On design simplifies mounting in switchgear and electrical panels

Data sheet

manual

broucher

Robust Design and High Performance

The ABB Molded-Case Circuit Breaker S5N300TW, part of the SACE Isomax Series, is engineered for dependable electrical protection in industrial and commercial applications. Designed to interrupt a wide range of fault currents, it ensures the safety and longevity of electrical systems. The robust construction allows it to withstand harsh environments, offering consistent performance and reliability. Its advanced breaking capacity aligns with strict safety standards, minimizing downtime and preventing damage to sensitive equipment. Ideal for demanding settings, this circuit breaker combines precision engineering with durable materials to provide exceptional electrical safeguarding.

Advanced Safety Features

Safety is paramount in electrical systems, and the ABB Molded-Case Circuit Breaker S5N300TW excels in this area. It features precise trip units that detect overloads, short circuits, and ground faults with high accuracy, ensuring quick disconnection when dangerous conditions arise. The SACE Isomax Series incorporates thermal-magnetic protection mechanisms that adjust dynamically to electrical loads, ensuring sensitive, yet reliable operation. Moreover, its optional accessories enhance monitoring capabilities and remote control, improving overall system safety and maintenance efficiency in modern electrical installations.

Efficient Installation and Maintenance

The ABB Molded-Case Circuit Breaker S5N300TW stands out for its ease of installation and maintenance. Designed with user-friendly features and standardized dimensions, it fits seamlessly into existing electrical panels and switchboards. The modular build simplifies replacement and upgrades while minimizing downtime during maintenance. Additionally, the circuit breaker’s clear labeling and diagnostic options help technicians quickly identify issues and perform routine checks. This combination of practicality and smart design reduces operational costs and extends the lifecycle of electrical protection systems in various applications.