ABB S303P-B50NA miniature circuit breaker with a 50 A rated current, Type B tripping characteristic, 3P+N configuration and up to 25 kA breaking capacity for industrial and commercial circuit protection.
£195.00
The ABB S303P-B50NA, product code 2CDS383103R0505, is a high-performance miniature circuit breaker (MCB) designed to protect industrial and commercial electrical installations against overloads and short circuits. Part of the proven ABB System pro M compact S300P series, it provides dependable circuit protection, high breaking capacity and compliance with international electrical standards.
Featuring a Type B tripping characteristic, the S303P-B50NA is suitable for circuits with relatively low inrush currents. It is particularly well suited to resistive loads, heating equipment, general power distribution and other applications where rapid magnetic fault interruption is required.
With a rated current of 50 A, a 3P+N configuration and a rated operational voltage of up to 415 V AC, this circuit breaker is suitable for three-phase systems requiring protection of all three phase conductors and simultaneous neutral switching. Its compact DIN rail design supports efficient installation in distribution boards, switchboards and industrial control panels.
Miniature circuit breakers disconnect electrical circuits automatically when an overload or short circuit occurs. The ABB S303P-B50NA combines a thermal release for sustained overload protection with a magnetic release for rapid interruption of severe fault currents, helping protect cables, distribution equipment and connected loads.
Its Type B characteristic is intended for circuits that do not normally produce high starting currents. This makes the breaker suitable for resistive heating, general distribution, socket circuits and other predictable loads where fast short-circuit response is required.
| Current | 50 A |
|---|---|
| Phase | Three Phase |
| Manufacturer | ABB |
| Series | System pro M compact S300P |
| Model | S303P-B50NA |
| Product ID | 2CDS383103R0505 |
| Product type | Miniature circuit breaker |
| Rated current | 50 A |
| Tripping characteristic | Type B |
| Pole configuration | 3P+N |
| Total number of poles | 4 |
| Number of protected poles | 3 |
| Rated operational voltage | 240 / 415 V AC |
| Maximum AC operating voltage | 480Y / 277 V AC |
| Maximum DC operating voltage | 125 V DC |
| Frequency | 50 / 60 Hz |
| Ultimate short-circuit breaking capacity | 25 kA at 415 V AC |
| Breaking capacity at 440 V AC | 15 kA |
| Rated insulation voltage (Ui) | 500 V |
| Rated impulse withstand voltage (Uimp) | 6 kV |
| Protection rating | IP20, up to IP40 in a suitable enclosure |
| Mounting type | DIN rail mounting |
| Maximum solid conductor capacity | 35 mm² |
| Maximum flexible conductor capacity | 25 mm² |
| Dimensions (H × W × D) | approximately 88 × 70 × 69 mm |
| Weight | approximately 0.50 kg |
| EAN | 4016779076876 |
| Applicable standards | IEC/EN 60947-2, IEC/EN 60898-1, UL and CSA standards where applicable |
| HS Code | 85362010 |
| Country of Manufacture | Germany |
The ABB S303P-B50NA protects three-phase industrial and commercial circuits against overloads and short circuits, particularly circuits with resistive or low-inrush loads.
The S303P-B50NA has a rated current of 50 A.
A Type B miniature circuit breaker provides rapid magnetic tripping at relatively low multiples of its rated current, making it suitable for resistive loads and circuits with minimal starting current.
The S303P-B50NA has an ultimate short-circuit breaking capacity of up to 25 kA at 415 V AC and 15 kA at 440 V AC.
The circuit breaker mounts onto a standard DIN rail inside an electrical distribution board, switchboard or industrial control-panel enclosure.
ABB System pro M compact miniature circuit breakers are widely specified by electrical engineers, panel builders and contractors for reliable circuit protection, high fault-breaking performance and straightforward integration into modern electrical installations.
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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...