Why Choose the ABB DSE203NMB50A300 Electronic RCBO?
The ABB DSE203NMB50A300 is a high performance 3P+N electronic residual current circuit breaker with overcurrent protection (eRCBO) designed to provide reliable protection against overloads, short circuits and earth leakage faults in commercial and industrial electrical installations. As part of the advanced ABB DSE203N M series, it combines multiple protection functions into a compact three-module device, making it ideal for distribution boards, switchgear and OEM control panels.
Designed for demanding electrical applications, the DSE203NMB50A300 features Type A residual current protection, enabling detection of both alternating and pulsating DC earth fault currents. Its electronic operating mechanism delivers dependable protection while reducing installation space and simplifying panel layouts. The neutral pole remains unswitched, ensuring reliable protection across three-phase systems.
With a 50 A B-curve rating, 300 mA residual current sensitivity and compatibility with three-phase 400/415 V AC systems, this electronic RCBO is ideal for protecting industrial machinery, commercial electrical installations and OEM equipment where dependable circuit protection is essential.
Key Advantages
Compact 3P+N electronic RCBO combining MCB and RCD protection.
50 A B-curve suitable for circuits with low inrush currents.
300 mA Type A residual current protection.
Protects against overloads, short circuits and earth leakage faults.
Space-saving three-module construction.
Reliable ABB engineering for commercial and industrial applications.
Key Features
ABB DSE203N M electronic RCBO series.
50 A rated current.
B characteristic trip curve.
300 mA Type A residual current sensitivity.
3P+N configuration with unswitched neutral.
10 kA rated short-circuit capacity.
DIN rail mounting for quick and straightforward installation.
Mechanical endurance of approximately 20,000 operating cycles.
Reliable Protection for Three-Phase Electrical Systems
Electronic RCBOs combine miniature circuit breaker and residual current protection into a single device, providing comprehensive protection against overloads, short circuits and earth leakage faults while reducing installation space and simplifying electrical installations.
The ABB DSE203N M series has been developed for commercial, industrial and OEM applications where dependable protection, easy installation and long service life are essential. Electronic residual current technology ensures consistent performance under demanding operating conditions.
Typical Applications
Industrial distribution boards.
Commercial electrical installations.
OEM machinery and automation systems.
Motor control panels.
Manufacturing facilities.
Three-phase electrical distribution systems.
Technical Specifications
Current
50 A
Phase
Three Phase
Function
3P+N electronic residual current circuit breaker with overcurrent protection (eRCBO).
Type of Residual Current
Type A.
Number of Poles
3P+N with unswitched neutral.
Operating Characteristic
Instantaneous.
Connecting Capacity
Busbar 10 mm²; rigid 1–25 mm²; flexible 1–16 mm².
Position of Neutral Terminals
Left.
Electrical Endurance
10,000 cycles.
Mechanical Endurance
20,000 cycles.
Weight
0.549 kg.
Frequently Asked Questions
What is the ABB DSE203NMB50A300 used for?
It protects three-phase electrical circuits against overloads, short circuits and earth leakage faults in commercial and industrial installations.
What trip curve does this RCBO use?
The device features a B characteristic, making it suitable for circuits with relatively low inrush currents.
What type of residual current protection does it provide?
The DSE203NMB50A300 provides Type A 300 mA residual current protection, detecting both alternating and pulsating DC residual currents.
How many poles does the device have?
It features a 3P+N configuration with an unswitched neutral.
Where is this RCBO typically installed?
It is designed for DIN rail installation inside industrial control panels, switchboards and commercial distribution boards.
Trusted by Electrical Professionals Worldwide
ABB DSE203N M electronic RCBOs are trusted by electricians, panel builders and industrial engineers for delivering dependable circuit protection, robust construction and reliable long-term performance.
Current
50 A
Phase
Three Phase
Function
3P+N electronic residual current circuit breaker with overcurrent protection (eRCBO).
Type of Residual Current
Type A.
Number of Poles
3P+N with unswitched neutral.
Operating Characteristic
Instantaneous.
Connecting Capacity
Busbar 10 mm²; rigid 1–25 mm²; flexible 1–16 mm².
Position of Neutral Terminals
Left.
Electrical Endurance
10,000 cycles.
Mechanical Endurance
20,000 cycles.
Weight
0.549 kg.
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
500 +
Stock lines ready to ship
1,000 +
Same day dispatches
3500 +
Customers supported
28
Trusted Manfacturers
● frequently asked questions
Common questions about our products and support
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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...