Why Choose the ABB S203MT-K4NA Miniature Circuit Breaker?
The ABB S203MT-K4NA is a durable and compact miniature circuit breaker (MCB) designed for overload and short-circuit protection in low-voltage electrical installations. As part of the ABB S200MT miniature circuit breaker range, it is engineered for demanding applications including industrial control panels, railway systems, traction equipment and commercial distribution boards.
This circuit breaker features a K curve tripping characteristic, making it suitable for circuits with higher inrush currents while maintaining reliable protection against electrical faults. Its current limiting design helps reduce fault energy, supporting improved safety and protection for cables, equipment and connected loads.
With a rated current of 4 A and a 3-pole plus neutral configuration, the ABB S203MT-K4NA is ideal for three-phase circuits where the neutral conductor needs to be switched alongside the protected phases. Its DIN rail mounting format enables quick and secure installation inside electrical enclosures, switchgear cabinets and machinery control systems.
Key Advantages
- Compact miniature circuit breaker for circuit protection.
- 4 A rated current for low-current electrical circuits.
- 3-pole plus neutral configuration for three-phase systems with switched neutral.
- K curve tripping characteristic suitable for circuits with higher inrush currents.
- 10 kA breaking capacity for dependable short-circuit protection.
- DIN rail mounting for fast installation in electrical enclosures.
Key Features
- ABB S200MT miniature circuit breaker series.
- 4 A nominal current rating.
- 3 protected poles plus neutral.
- K type tripping curve for reliable protection of inductive loads.
- Thermal tripping mechanism for overload protection.
- Electromechanical tripping mechanism for short-circuit protection.
- Current limiting performance to reduce fault energy.
- Modular DIN rail design for control panels and distribution boards.
Miniature circuit breakers such as the ABB S203MT-K4NA protect electrical circuits by automatically disconnecting the supply when overloads or short-circuit faults occur. This helps prevent cable damage, equipment failure and unsafe fault conditions in control and distribution systems.
The K curve characteristic is designed for circuits that may experience higher starting or inrush currents, such as control transformers, motors and inductive loads. This allows the S203MT-K4NA to provide reliable fault protection while helping reduce nuisance tripping during normal start-up conditions.
Typical Applications
- Industrial control panels and automation systems.
- Railway and traction electrical installations.
- Three-phase circuits requiring switched neutral protection.
- Distribution boards and switchgear assemblies.
- Control transformers, inductive loads and auxiliary circuits.
- Machine building and OEM electrical systems.
