ABB SX201-B40 Flexline Miniature Circuit Breaker 40A 1P B-Char 6kA 2CDS251003R0405

Overcurrent protection in residential and commercial installations demands a device that reacts instantly to overloads and short circuits. The ABB SX201-B40 Flexline miniature circuit breaker (MCB) provides exactly that, combining a 40 A rated current with a B tripping characteristic to safeguard cables and equipment from thermal and magnetic faults.

Who is it for

Electricians and panel builders who need a reliable, DIN-rail mountable MCB for single-phase circuits up to 40 A. It suits distribution boards in homes, offices, and light industrial environments where standard inrush currents are expected.

Main features

• Rated current 40 A, 1-pole, B characteristic
• Short-circuit breaking capacity 6 kA at 230/400 V AC
• Energy limiting class 3 for effective current limitation
• Dual terminal capacity: 0.75–35 mm² rigid, 0.75–25 mm² flexible
• Mounts on 35 mm DIN rail (TH35-7.5 / TH35-15)

Specifications

• Rated operational voltage: 230/400 V AC
• Rated frequency: 50/60 Hz
• Power loss: 3.6 W per pole
• Electrical endurance: 10,000 cycles
• Mechanical endurance: 20,000 cycles
• Degree of protection: IP20 (terminals), IP40 (enclosure)
• Ambient operating temperature: -25 to +55 °C
• Standards: IEC/EN 60898-1, IEC/EN 60947-2

Tips

Select the B characteristic for circuits with moderate inrush currents, such as lighting and socket outlets. For motor or transformer loads, consider a C or D curve instead.