ABB S203MT-K4NAH10 miniature circuit breaker with K characteristic, 4 A rated current, 3P+N configuration and 10 kA breaking capacity for industrial, railway and control circuit protection.
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Why Choose the ABB S203MT-K4NAH10 Miniature Circuit Breaker?
The ABB S203MT-K4NAH10 is a robust three-pole plus neutral (3P+N) miniature circuit breaker (MCB) designed for reliable circuit protection in industrial, railway and traction applications. As part of the specialist ABB S200MT miniature circuit breaker series, it provides dependable protection against overloads and short circuits in demanding electrical installations.
With a K tripping characteristic, the S203MT-K4NAH10 is suited to circuits with higher inrush currents, such as control transformers, motors, solenoids and inductive loads. Its delayed magnetic tripping behaviour helps prevent unwanted nuisance tripping while maintaining effective protection for cables and equipment.
Rated at 4 A with a 10 kA breaking capacity, this ABB MCB is ideal for compact DIN rail distribution boards, industrial control panels, transportation systems and OEM machinery where reliable low-voltage protection is essential.
Key Advantages
Compact 3P+N miniature circuit breaker for demanding industrial applications.
4 A rated current for low-current control and auxiliary circuits.
K characteristic suitable for inductive loads and higher inrush currents.
10 kA short-circuit breaking capacity for dependable fault protection.
Designed for DIN rail mounting in modular electrical panels.
Suitable for railway, traction and industrial automation environments.
Key Features
ABB S200MT miniature circuit breaker series.
4 A rated current.
K tripping characteristic.
3 protected poles plus switched neutral (3P+N).
10 kA rated breaking capacity.
Thermal overload and magnetic short-circuit protection.
Current-limiting design for improved installation safety.
Compatible with ABB System pro M compact accessories.
Reliable Protection for Control and Inductive Circuits
The ABB S203MT-K4NAH10 protects electrical circuits by combining delayed thermal overload protection with electromechanical short-circuit tripping. This helps maintain safe operation while reducing the risk of equipment damage caused by overcurrent conditions.
Its K characteristic makes it particularly useful for circuits where temporary inrush currents are expected. This allows the breaker to support reliable operation of control transformers, coils and inductive devices without unnecessary interruptions.
Typical Applications
Industrial control panels.
Railway and traction electrical systems.
Control transformers and auxiliary circuits.
Motor control and automation systems.
OEM machinery and equipment panels.
Low-voltage distribution boards.
Technical Specifications
Current
4 A
Phase
Three Phase
Manufacturer
ABB
Series
S200MT
Model
S203MT-K4NAH10
Product type
Miniature Circuit Breaker (MCB)
Rated current
4 A
Tripping characteristic
K
Number of poles
3P+N
Protected poles
3
Rated short-circuit breaking capacity
10 kA
Frequency
50 / 60 Hz
Mounting type
DIN rail
Terminal type
Screw terminals
Product range
System pro M compact
Standards
IEC/EN 60898-1, IEC/EN 60947-2
Frequently Asked Questions
What is the ABB S203MT-K4NAH10 used for?
It is used to protect three-phase electrical circuits with a switched neutral against overloads and short circuits in industrial, railway and automation applications.
What does the K tripping characteristic mean?
The K characteristic is designed for circuits with higher inrush currents, making it suitable for inductive loads such as transformers, coils and motor control circuits.
What is the rated current of this MCB?
The ABB S203MT-K4NAH10 has a rated current of 4 A.
What is the breaking capacity of the S203MT-K4NAH10?
This miniature circuit breaker has a rated short-circuit breaking capacity of 10 kA.
Where is this circuit breaker installed?
It is designed for DIN rail mounting inside electrical distribution boards, control cabinets and industrial panel assemblies.
Trusted by Electrical Professionals Worldwide
ABB S200MT miniature circuit breakers are trusted by panel builders, railway engineers and industrial automation specialists for dependable protection, compact installation and long service life in demanding low-voltage systems.
Current
4 A
Phase
Three Phase
Manufacturer
ABB
Series
S200MT
Model
S203MT-K4NAH10
Product type
Miniature Circuit Breaker (MCB)
Rated current
4 A
Tripping characteristic
K
Number of poles
3P+N
Protected poles
3
Rated short-circuit breaking capacity
10 kA
Frequency
50 / 60 Hz
Mounting type
DIN rail
Terminal type
Screw terminals
Product range
System pro M compact
Standards
IEC/EN 60898-1, IEC/EN 60947-2
No documents available for this product.
Delivery
We offer fast UK delivery on all stocked items. Orders placed before 3pm Monday to Friday are eligible for next-day delivery.
Standard delivery: 2–3 working days
Next-day delivery: available on in-stock items when ordered before 3pm
Express options available — contact us for details
Returns
If you need to return an item, please contact our sales team within 30 days of receipt. Items must be returned unused in their original packaging.
Our service agreements are built to support long term procurement relationships. By working closely with engineering teams and procurement departments, we help streamline purchasing processes while ensuring consistent access to critical components and sourcing support when it matters most.
Priority sourcing and supply support
Flexible payment terms for qualifying organisations
Support for engineering, maintenance, and operations
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Same day dispatches
3500 +
Customers supported
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● frequently asked questions
Common questions about our products and support
At Led Controls Ltd we help engineers source the right automation and control gear with confidence. below are quick answers to what we are asked most often.
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We supply all leading manfacturers in our industry. we offer next day delivery on most poplour products.
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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...