ABB 2CDS273001R0505 S203M-B50 3P 50A 10kA B-Curve 230/400V AC Miniature Circuit Breaker

The ABB S203M-B50 miniature circuit breaker (MCB), catalog number S203M-B50 and SKU 2CDS273001R0505, is a high-performance 3-pole, 50A, B-curve device rated at 230/400V AC with a 10kA breaking capacity. Part of ABB's S200M series, this MCB is engineered for reliable overload and short-circuit protection in industrial control panels, commercial buildings, and critical power distribution systems.

Technical Specifications

Certifications & Standards

• IEC/EN 60898-1: International and European standard for household and similar circuit breakers for overcurrent protection
• IEC/EN 60947-2: Low-voltage switchgear and controlgear — circuit breakers for industrial applications
• IEC 60898-1: Core IEC standard for miniature circuit breakers used in AC installations
• EN 60898-1: European adoption of IEC 60898-1 for overcurrent protection devices
• IEC/EN 60898: Combined IEC/EN standard for miniature circuit breakers
• IEC 60898-1400: IEC standard variant for MCB performance and endurance
• IEC 60947-2440: IEC standard variant for industrial circuit breaker requirements
• IEC 60068-2: Environmental testing standard — compliance ensures reliability under temperature, humidity, and vibration conditions
• EN 60898: European standard for circuit breakers for overcurrent protection in household and similar installations
• EN 60947-2: European low-voltage switchgear and controlgear standard for circuit breakers
• EN45555: General methods for the assessment of the ability of energy-related products to be repaired, reused, and recycled
• EN60664: Insulation coordination for equipment within low-voltage systems
• EN60898: European MCB standard for domestic and similar installations
• EN60947: European low-voltage switchgear and controlgear standard series
• CSA 22.2 No. 235: Canadian Standards Association standard for supplementary protectors
• UL 1077: Underwriters Laboratories standard for supplementary protectors for use in electrical equipment
• UL1077: UL supplementary protector listing for electrical equipment applications
• CSA: Canadian Standards Association certified for use in North American applications
• CE: Conformité Européenne — meets EU health, safety, and environmental requirements
• UKCA: UK Conformity Assessed — compliant for Great Britain market post-Brexit
• RoHS: Restriction of Hazardous Substances — free from restricted hazardous materials
• REACH: Compliant with EU chemical safety regulations for substances of very high concern
• WEEE: Waste Electrical and Electronic Equipment directive compliance for responsible end-of-life disposal

Applications & Use Cases

• Industrial control panels and distribution boards requiring robust 3-pole overcurrent protection
• Commercial building electrical installations with 400V three-phase circuits up to 50A
• Machine tool and automation system protection where B-curve characteristics suit resistive and lightly inductive loads
• Power distribution in manufacturing facilities and process plants
• OEM equipment integration where UL1077 and CSA compliance is required for North American markets