Why Choose the ABB 2CDS383103R0557 S303P-K40NA Miniature Circuit Breaker?
The ABB 2CDS383103R0557, also identified as the S303P-K40NA, is a heavy-duty miniature circuit breaker (MCB) designed to provide reliable protection against overloads and short circuits in demanding industrial electrical installations. As part of the proven ABB System pro M compact S300P series, it delivers outstanding breaking performance and dependable operation for machinery, power distribution and automation systems.
Featuring a Type K tripping characteristic, this circuit breaker is particularly suitable for protecting motors, transformers, compressors and other inductive loads with high inrush currents. The combination of thermal overload protection and rapid magnetic tripping helps minimise downtime while safeguarding valuable equipment.
With a rated current of 40 A, a 3P+N configuration and a rated operational voltage of up to 415 V AC, the S303P-K40NA is ideal for industrial control panels, switchboards and OEM machinery. Its 25 kA ultimate breaking capacity and compact DIN rail mounting make it suitable for demanding industrial applications worldwide.
Key Advantages
Industrial miniature circuit breaker for overload and short-circuit protection.
40 A rated current for demanding industrial power distribution.
3P+N pole configuration for three-phase systems with neutral.
Type K tripping characteristic designed for motors and inductive loads.
25 kA breaking capacity at 415 V AC.
Integrated trip indication for rapid fault identification.
Compatible with ABB System pro M compact accessories.
Key Features
ABB System pro M compact S300P series.
S303P-K40NA model.
40 A rated current.
415 V AC rated operational voltage.
3P+N pole arrangement.
Type K tripping characteristic.
25 kA ultimate short-circuit breaking capacity.
50 / 60 Hz operation.
35 mm DIN rail mounting.
Front-mounted contact and trip position indication.
Reliable Circuit Protection for Industrial Installations
The ABB S303P-K40NA automatically disconnects electrical circuits whenever overload or short-circuit conditions occur, helping protect electrical infrastructure, machinery and connected equipment. Its industrial-grade construction ensures dependable long-term operation in demanding environments.
Its Type K tripping characteristic is specifically developed for circuits supplying motors and other inductive loads with high starting currents. This allows reliable start-up without nuisance tripping while maintaining rapid protection during fault conditions.
Typical Applications
Industrial machinery.
Motor control centres.
Factory automation systems.
Electrical distribution panels.
OEM machine building.
Compressors, pumps and fans.
Industrial switchboards.
Technical Specifications
Current
40 A
Phase
Three Phase
Manufacturer
ABB
Series
System pro M compact S300P
Model
S303P-K40NA
Product ID
2CDS383103R0557
EAN
4016779076821
Product type
Miniature circuit breaker
Rated current
40 A
Number of poles
3P+N
Protected poles
3
Neutral pole
Switched
Tripping characteristic
Type K
Rated operational voltage
415 V AC
Voltage type
AC/DC
Rated frequency
50 / 60 Hz
Rated insulation voltage
500 V
Impulse withstand voltage
6 kV
Ultimate short-circuit breaking capacity
25 kA at 415 V AC
Service breaking capacity
12.5 kA at 415 V AC
Protection rating
IP20 (IP40 when installed in a suitable enclosure)
Mounting type
35 mm DIN rail
Terminal capacity
0.75 to 35 mm² solid, 0.75 to 25 mm² flexible
Operating temperature
-40 to +70 °C
Approximate dimensions (H × W × D)
88 × 70 × 69 mm
Approximate weight
0.496 kg
HS Code
85362010
Country of Manufacture
Germany
Frequently Asked Questions
What is the ABB 2CDS383103R0557 used for?
It protects industrial three-phase electrical circuits against overloads and short circuits, especially circuits supplying motors, transformers and other inductive equipment.
What is the rated current of this circuit breaker?
The ABB S303P-K40NA has a rated current of 40 A.
What does the Type K tripping characteristic provide?
Type K breakers are designed for inductive loads with high inrush currents, reducing nuisance tripping while maintaining reliable fault protection.
What is the short-circuit breaking capacity?
The breaker provides a rated ultimate short-circuit breaking capacity of 25 kA at 415 V AC.
How is the ABB S303P-K40NA installed?
The breaker mounts directly onto a standard 35 mm DIN rail inside industrial control panels and electrical distribution boards.
Trusted Industrial Protection from ABB
ABB System pro M compact S300P miniature circuit breakers are trusted worldwide for delivering dependable overload and short-circuit protection in industrial power distribution, automation and machine building applications.
Current
40 A
Phase
Three Phase
Manufacturer
ABB
Series
System pro M compact S300P
Model
S303P-K40NA
Product ID
2CDS383103R0557
EAN
4016779076821
Product type
Miniature circuit breaker
Rated current
40 A
Number of poles
3P+N
Protected poles
3
Neutral pole
Switched
Tripping characteristic
Type K
Rated operational voltage
415 V AC
Voltage type
AC/DC
Rated frequency
50 / 60 Hz
Rated insulation voltage
500 V
Impulse withstand voltage
6 kV
Ultimate short-circuit breaking capacity
25 kA at 415 V AC
Service breaking capacity
12.5 kA at 415 V AC
Protection rating
IP20 (IP40 when installed in a suitable enclosure)
Mounting type
35 mm DIN rail
Terminal capacity
0.75 to 35 mm² solid, 0.75 to 25 mm² flexible
Operating temperature
-40 to +70 °C
Approximate dimensions (H × W × D)
88 × 70 × 69 mm
Approximate weight
0.496 kg
HS Code
85362010
Country of Manufacture
Germany
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
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Customers supported
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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...