ABB 2CDS631031R0505 BMS311B50 1P 50A 3kA B-Curve Miniature Circuit Breaker MCB Basic M BMS Series

The ABB BMS311B50 (SKU: 2CDS631031R0505) is a 1-pole, 50 A, B-curve miniature circuit breaker (MCB) from the Basic M BMS series, rated for 230 V AC per IEC 60898-1 and 440 V AC per IEC 60947-2, with a breaking capacity of 3 kA. Designed for reliable overcurrent and short-circuit protection in residential, commercial, and light industrial installations, the BMS311B50 delivers dependable performance in a compact 17.5 mm wide DIN rail mount package weighing just 93 g.

Technical Specifications

Certifications & Standards

• IEC 60898-1: Miniature circuit breakers for overcurrent protection in household and similar installations
• IEC 60947-2: Low-voltage switchgear and controlgear — circuit breakers for industrial applications
• IEC/EN 60664-1: Insulation coordination for equipment within low-voltage systems
• IEC/EN 60664: Insulation coordination standard for low-voltage equipment
• IEC 60898: General requirements for circuit breakers for overcurrent protection
• IEC 60947: Low-voltage switchgear and controlgear — general rules
• EN 60664: European harmonised insulation coordination standard
• RoHS: Restriction of Hazardous Substances — compliant with EU Directive 2011/65/EU
• EU Directive 2011/65/EU (RoHS 2): European Union restriction of hazardous substances in electrical and electronic equipment
• Amendment 2015/863: EU RoHS amendment restricting additional hazardous substances
• REACH: Registration, Evaluation, Authorisation and Restriction of Chemicals compliance
• WEEE: Waste Electrical and Electronic Equipment Directive — compliant with European e-waste regulations

Applications & Use Cases

• Overcurrent and short-circuit protection in residential distribution boards
• Commercial building electrical panels and consumer units
• Light industrial control panels and machinery protection
• Final circuit protection for lighting and general power circuits
• DIN rail mounted switchgear assemblies