Overview
The ABB S201U-K8 is a compact, high-performance miniature circuit breaker designed for 240 VAC, 50/60 Hz applications. Rated at 8 amps with a 10 kA interrupt capacity, this single-pole, DIN rail-mounted breaker delivers dual-mechanism protection: delayed thermal tripping for overload protection and electromechanic action for short-circuit fault clearing. The K-curve characteristic makes it ideal for circuits with moderate inrush currents, such as motors and transformers in industrial automation and control systems.
Key Features
- K-curve thermal-magnetic trip mechanism for selective overcurrent protection
- Current limiting design reduces let-through energy and protects downstream components
- Compact DIN rail mounting (92 mm H × 17.5 mm W × 71 mm D) fits tight control panels
- Toggle actuator provides clear trip indication and manual reset capability
- Finger-safe, multi-function terminals with screw connection for secure wire termination
- Wide operating temperature range from −25 °C to +55 °C
Technical Specifications
- Rated Voltage: 240 VAC
- Frequency: 50/60 Hz
- Rated Current: 8 A
- Interrupt Capacity: 10 kA
- Number of Poles: 1
- Trip Characteristic: K-Curve (thermal-magnetic)
- Mounting: DIN Rail (35 mm rail)
- Wire Gauge: 18 to 4 AWG
- Enclosure Rating: IP20
- Operating Temperature: −25 °C to +55 °C
- Dimensions: 92 mm H × 17.5 mm W × 71 mm D
- Certifications: IEC/EN 60947-2, UL489, CSA 22.2 No. 5
Typical Applications
The S201U-K8 is well-suited for branch circuit protection in motor control centers, distribution panels, and industrial control cabinets. The K-curve trip characteristic accommodates functional peak currents without nuisance tripping, making it ideal for protecting motors, transformers, and auxiliary circuits. Typical installations include:
- Motor branch protection (NEMA motor starters and soft starters)
- Transformer inrush protection
- PLC and automation equipment supply circuits
- Lighting and receptacle circuits in commercial facilities
- Industrial control system protection
Compatibility & Replacements
Compatible With
- DIN rail mounting systems (35 mm standard)
- Auxiliary contact modules and trip indicators (ABB S200 series)
- Industrial control panels and enclosures rated for 240 VAC
- Manual and automated disconnect switches rated for 240 VAC circuits
Replaces / Drop-In Replacement For
- ABB S201-K8 (480Y/277 VAC variant—verify voltage compatibility before substituting)
- Other ABB S200U series single-pole, 8A breakers in 240V applications
Works With
- Siemens SIMATIC control systems
- Allen-Bradley CompactLogix and ControlLogix PLCs
- Mitsubishi FX series automation controllers
- Omron CJ and CP series programmable logic controllers
- Standard low-voltage control circuits and switching logic (no protocol-specific requirements)
