ABB S203MT-K4 miniature circuit breaker, a 3-pole K curve 4 A MCB from the S200MT range designed for reliable circuit protection in traction, railway and industrial control applications.
£196.61
The ABB S203MT-K4 is a compact and robust 3-pole miniature circuit breaker (MCB) designed for reliable overload and short-circuit protection in demanding traction, railway and industrial control applications. As part of the specialist ABB S200MT miniature circuit breaker range, it provides dependable protection for electrical circuits where safety, durability and consistent operation are essential.
This miniature circuit breaker uses thermal overload protection together with an electromagnetic short-circuit trip mechanism. The K characteristic is suitable for circuits with higher inrush currents, helping reduce nuisance tripping while maintaining effective protection for cables, control equipment and auxiliary electrical systems.
With a rated current of 4 A, a 3-pole configuration and a rated short-circuit breaking capacity of 10 kA, the S203MT-K4 is well suited to low-current three-phase circuits used in control panels, signalling systems, automation equipment and transport-related installations. Its modular DIN rail design allows straightforward installation in electrical cabinets and distribution boards.
Miniature circuit breakers such as the ABB S203MT-K4 protect electrical circuits by automatically disconnecting the supply during overload or short-circuit conditions. This helps reduce the risk of cable damage, equipment failure and unsafe operating conditions in critical auxiliary and control systems.
The ABB S200MT range is designed for traction and railway environments, offering robust circuit protection for rolling stock, signalling equipment and industrial control panels. Its compact construction, high breaking capacity and accessory compatibility make it a practical choice for engineers and panel builders.
| Current | 4 A |
|---|---|
| Phase | Three Phase |
| Manufacturer | ABB |
| Series | S200MT |
| Model | S203MT-K4 |
| Product type | Miniature circuit breaker |
| Number of poles | 3P |
| Rated current | 4 A |
| Tripping characteristic | K curve |
| Rated voltage | 440 V AC |
| Frequency | 50 / 60 Hz |
| Rated breaking capacity | 10 kA |
| Rated impulse withstand voltage | 4 kV |
| Current limiting class | 3 |
| Protection rating | IP20 |
| Mounting type | DIN rail mounting |
| Built-in depth | approx. 69 mm |
| HS Code | 85362010 |
| Country of Manufacture | Germany |
The ABB S203MT-K4 is used to protect low-current three-phase circuits from overloads and short circuits, particularly in traction, railway and industrial control applications.
The S203MT-K4 has a rated current of 4 A.
This miniature circuit breaker has a 3-pole configuration.
The K curve tripping characteristic is designed for circuits with higher inrush currents, helping reduce nuisance tripping while still providing effective overload and short-circuit protection.
The S203MT-K4 has a rated short-circuit breaking capacity of 10 kA.
ABB S200MT miniature circuit breakers are trusted by electrical engineers, panel builders and transport system specialists to deliver reliable circuit protection in demanding traction, railway and industrial control environments.
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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...