Overview
The ABB T5N300TWS4 is a heavy-duty Tmax molded case circuit breaker designed for industrial power distribution and protection. Rated at 300A and 600V AC with a T5 400/600A frame, this 3-pole breaker provides robust short-circuit and overload protection using thermal-magnetic trip technology. The unit is CSA/UL listed and IEC rated for global acceptance, making it suitable for retrofit and new-build applications across industrial, commercial, and utility environments.
Key Features
- Thermal-Magnetic Trip Unit: Delivers reliable overload and short-circuit protection with precise magnetic response for coordination with downstream devices.
- High Interrupt Rating: 16–18 kA interrupt capacity ensures safe clearing of fault currents in industrial systems.
- Compact Molded Case Design: Allows horizontal or vertical panel mounting with minimal footprint; suitable for reverse-feed applications without performance derating.
- CSA/UL and IEC Certifications: Global compliance for acceptance in North American and international markets.
- Position-Indicating Toggle: Clear contact-position indication ensures safe operation and status verification.
- Field-Serviceable Accessories: CSA/UL listed internal accessory installation without exposure to live parts.
Technical Specifications
The T5N300TWS4 accommodates wire sizes from 250 to 500 kcmil and delivers adjustable trip settings between 1500–3000A for application-specific coordination. Thermal-magnetic trip unit provides both overload sensing and magnetic short-circuit detection with precise performance across 50/60 Hz systems.
Typical Applications
- Industrial power distribution and feeder protection in large plants and manufacturing facilities.
- Commercial building main disconnect and sub-feeder circuits.
- Utility and backup generator panel protection.
- Process control and machinery branch circuit protection where high fault current coordination is required.
- Retrofit installations in existing switchboards and panelboards.
Compatibility & Replacements
The ABB T5N300TWS4 is part of the Tmax T5 family, which shares a common 400/600A frame with other ABB Tmax breakers up to 400A. Direct replacement models include the non-switch versions (T5N300TW) and accessory-equipped variants. For field upgrades, confirm voltage, frame size, and trip-unit compatibility. The unit is compatible with ABB standard mounting hardware and front/rear terminal configurations. Check manufacturer documentation for exact interchangeability with Eaton, Schneider, or other OEM equivalents in legacy systems.
