ABB S203MT-K40 3-pole 40 A miniature circuit breaker with K characteristic tripping curve and 10 kA breaking capacity for railway, traction and industrial circuit protection.
£229.36
The ABB S203MT-K40 is a robust 3-pole miniature circuit breaker (MCB) designed for dependable overload and short circuit protection in railway, traction and demanding industrial applications. As part of the specialised ABB S200MT miniature circuit breaker series, it provides compact, reliable circuit protection for installations where performance, safety and long-term durability are essential.
This circuit breaker combines delayed thermal overload protection with electromagnetic short circuit protection. Its K characteristic tripping curve is designed for circuits with higher inrush currents, making it suitable for inductive loads such as motors, transformers, solenoids and auxiliary railway equipment.
With a 40 A rated current, 3-pole configuration and 10 kA breaking capacity, the ABB S203MT-K40 provides effective protection for three-phase electrical systems. Its DIN rail mounted design enables straightforward installation in rolling stock electrical systems, industrial control panels, distribution boards and machine cabinets.
The ABB S200MT range is engineered for railway and traction environments where reliable low voltage protection is critical. These miniature circuit breakers help protect conductors, control equipment and downstream devices from damage caused by overloads and short circuits.
The K curve characteristic of the S203MT-K40 provides a higher instantaneous trip threshold than standard general-purpose curves. This makes it well suited to circuits where temporary start-up currents may occur, helping reduce nuisance tripping while maintaining effective protection under fault conditions.
| Current | 40 A |
|---|---|
| Phase | Three Phase |
| Manufacturer | ABB |
| Series | S200MT |
| Model | S203MT-K40 |
| Product type | Miniature circuit breaker (MCB) |
| Rated current | 40 A |
| Number of poles | 3 |
| Tripping characteristic | K |
| Rated short circuit breaking capacity | 10 kA |
| Rated operational voltage | 400 V AC / 440 V AC |
| Rated insulation voltage | 440 V |
| Rated impulse withstand voltage | 4 kV |
| Frequency | 50 / 60 Hz |
| Protection rating | IP20 |
| Mounting type | DIN rail |
| Current limiting class | Class 3 |
| Typical applications | Railway, rolling stock, traction systems, industrial control panels and inductive three-phase circuits |
| HS Code | 85362010 |
| Country of Manufacture | Germany |
The S203MT-K40 is used to protect three-phase electrical circuits against overloads and short circuits in railway, traction and industrial applications.
The ABB S203MT-K40 has a 40 A rated current.
The K curve is designed for circuits with higher inrush currents, making it suitable for inductive loads such as motors, transformers and control equipment.
This model has a 3-pole configuration, making it suitable for three-phase circuit protection.
Yes, the S200MT range is designed for traction and railway applications, including rolling stock electrical systems and transport control panels.
ABB S200MT miniature circuit breakers are trusted by railway engineers, panel builders and industrial electrical professionals for reliable circuit protection, compact installation and long service life in demanding low voltage systems.
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LED Controls is a specialist distributor of factory automation and industrial controls, supplying OEMs, machine builders, panel builders and end users throughout the UK and worldwide. As a trusted UK distributor for many of the world’s leading automation manufacturers, we provide industrial control products, technical expertise and bespoke automation solutions backed by outstanding customer service.
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...