The ABB DSE203NMC50A10 is a compact 3P+N electronic residual current circuit breaker with overcurrent protection (eRCBO) designed to protect compatible three-phase electrical circuits against overloads, short circuits and earth leakage faults. Part of the ABB DSE203N M series, it combines overcurrent and residual current protection within one modular device, helping simplify distribution-board design and conserve enclosure space.
Developed for commercial, industrial and OEM installations, the DSE203NMC50A10 provides dedicated protection for an individual circuit. Its electronic residual current monitoring supports reliable leakage-current detection, while the 3P+N configuration makes it suitable for three-phase systems incorporating a neutral conductor.
Featuring a 50 A rated current, Type C tripping characteristic, 10 mA Type A residual current sensitivity and 10 kA short-circuit breaking capacity, this ABB RCBO is suited to higher-load circuits with moderate starting currents where sensitive earth leakage protection is required.
Key Advantages
Combines overload, short-circuit and residual current protection in one device.
50 A rated current for higher-load three-phase final circuits.
Type C tripping characteristic accommodates moderate equipment inrush currents.
10 mA Type A residual current protection provides a sensitive leakage-current threshold.
10 kA breaking capacity supports dependable short-circuit interruption.
Compact DIN rail format helps reduce distribution-board space requirements.
Individual circuit protection can improve fault isolation and limit disruption.
Key Features
ABB DSE203N M electronic RCBO series.
3 poles plus neutral configuration.
50 A rated current.
Type C overcurrent tripping curve.
10 mA rated residual operating current.
Type A residual current classification.
10 kA short-circuit breaking capacity.
Electronic residual current detection.
DIN rail mounting for modular electrical enclosures.
Combined Protection for Three-Phase Circuits
The ABB DSE203NMC50A10 monitors the protected circuit for excessive current and leakage to earth. If an overload, short circuit or residual current fault occurs, the RCBO disconnects the affected circuit to help reduce the risk of conductor damage, equipment failure, electrical fire and electric shock.
Integrating these protective functions within one device also allows the circuit to be isolated independently instead of relying on a shared residual current device. This can reduce the number of unrelated loads affected by an earth leakage fault and make fault identification more straightforward.
Type C Overcurrent Protection
The Type C tripping characteristic is intended for circuits that can experience moderate inrush currents during normal operation. Potential applications include appropriately assessed motors, pumps, transformers, commercial lighting equipment, industrial machinery and control systems.
Suitability must be confirmed against the connected load, conductor size, prospective fault current, earthing arrangement and required disconnection time. Protective-device selection should always be completed by a suitably qualified electrical professional.
Sensitive 10 mA Type A Residual Current Detection
As a Type A RCBO, the DSE203NMC50A10 is designed to detect sinusoidal alternating residual currents and pulsating direct residual currents. This makes it suitable for many modern circuits containing electronic controls, rectifiers, switched-mode power supplies and similar equipment.
Its 10 mA residual current sensitivity provides a lower operating threshold than a commonly specified 30 mA device. This enhanced sensitivity may be appropriate for specifically assessed applications, although normal operational leakage from connected equipment must be considered to minimise unwanted tripping.
Typical Applications
Commercial three-phase distribution boards.
Industrial switchboards and control panels.
Machine-building and OEM electrical systems.
Manufacturing and process-control equipment.
Three-phase motors and pumps with suitable starting characteristics.
Commercial lighting and higher-load power circuits.
Equipment incorporating electronic power supplies or control systems.
Circuits requiring sensitive 10 mA residual current protection.
Installation Considerations
The ABB DSE203NMC50A10 is intended for DIN rail installation within a compatible electrical enclosure. Before installation, the system designer should verify the supply voltage, circuit load, conductor capacity, prospective short-circuit current, earthing arrangement and required residual current sensitivity.
Installation, testing and periodic inspection must be performed by a competent electrical professional in accordance with applicable wiring regulations and ABB installation instructions. The device test function should be operated at the intervals specified for the installation.
Technical Specifications
Current
50 A
Phase
Three Phase
Function
3P+N electronic residual current circuit breaker with overcurrent protection (eRCBO).
Protection
Against short-circuit, overload, earth fault currents, indirect contacts, and direct contact (30 mA versions).
Poles
3 protected poles plus unswitched neutral.
Type of Residual Current
Type A.
Connection
Bottom power supply connection.
Current Rating
C50 A (50 Amperes).
Terminal Capacity
Busbar 10 mm², rigid 1–25 mm², flexible 1–16 mm².
Mechanical Endurance
20,000 cycles.
Electrical Endurance
10,000 cycles.
Neutral Terminal Position
Left side.
Frequently Asked Questions
What is the ABB DSE203NMC50A10 used for?
The ABB DSE203NMC50A10 provides combined overload, short-circuit and earth leakage protection for compatible three-phase circuits incorporating a neutral conductor.
What is the rated current of the DSE203NMC50A10?
The ABB DSE203NMC50A10 has a rated current of 50 A.
What does the Type C tripping characteristic mean?
A Type C characteristic is suitable for appropriately designed circuits with moderate inrush currents, including selected motors, pumps, transformers, lighting equipment and industrial control loads.
What residual current protection does this RCBO provide?
It provides 10 mA Type A residual current protection, detecting sinusoidal AC residual currents and pulsating DC residual currents.
What is the breaking capacity of the ABB DSE203NMC50A10?
The device has a rated short-circuit breaking capacity of 10 kA, subject to the applicable installation conditions and product standard.
Is the DSE203NMC50A10 suitable for electronic equipment?
Its Type A classification makes it suitable for many circuits containing electronic equipment capable of producing pulsating DC leakage currents. The complete load profile must still be assessed before installation.
Where is this ABB RCBO installed?
It is designed for DIN rail mounting inside compatible commercial or industrial distribution boards, switchboards and electrical control panels.
Can a 10 mA RCBO be used instead of a 30 mA RCBO?
Not automatically. A 10 mA RCBO has a more sensitive operating threshold, so normal circuit leakage, discrimination requirements and applicable wiring regulations must be considered by the system designer.
Professional Circuit Protection from ABB
The ABB DSE203NMC50A10 combines 50 A Type C overcurrent protection with sensitive 10 mA Type A residual current detection, providing a compact protective solution for appropriately designed three-phase electrical circuits.
Current
50 A
Phase
Three Phase
Function
3P+N electronic residual current circuit breaker with overcurrent protection (eRCBO).
Protection
Against short-circuit, overload, earth fault currents, indirect contacts, and direct contact (30 mA versions).
Poles
3 protected poles plus unswitched neutral.
Type of Residual Current
Type A.
Connection
Bottom power supply connection.
Current Rating
C50 A (50 Amperes).
Terminal Capacity
Busbar 10 mm², rigid 1–25 mm², flexible 1–16 mm².
Mechanical Endurance
20,000 cycles.
Electrical Endurance
10,000 cycles.
Neutral Terminal Position
Left side.
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Standard delivery: 2–3 working days
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Express options available — contact us for details
Returns
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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...