Doepke DFS2 040-2/0,03-B SK Residual Current Circuit Breaker Type B 40A 2-Pole 30mA

With a rated residual operating current of just 30 mA and Type B tripping characteristics, this Doepke RCCB delivers uncompromising protection against AC, pulsating DC, and smooth DC residual currents—making it a critical safeguard for modern electrical installations with frequency inverters, EV charging, or medical equipment.

Overview

The Doepke DFS2 040-2/0,03-B SK is a 2-pole residual current circuit breaker (RCCB) engineered for reliable earth fault protection in single-phase 230 V AC systems. Its Type B classification ensures detection of all residual current types, including smooth DC, which is essential for circuits with rectifiers, three-phase bridge circuits, or energy storage systems. With a rated current of 40 A and a compact 2-module width, it fits standard DIN rails and is suitable for residential, commercial, and industrial applications.

What stands out

• Type B RCD: Detects AC, pulsating DC, and smooth DC residual currents for comprehensive protection.
• High breaking capacity: Withstands short-circuit currents up to 10 kA with appropriate upstream protection.
• Voltage-independent tripping: Maintains functionality even if the mains voltage fails, ensuring continuous safety.
• Wide terminal capacity: Accepts conductors from 1.5 mm² to 50 mm² (rigid) or 35 mm² (flexible), simplifying installation.
• Robust design: IP40 housing and IP20 terminals provide protection against dust and accidental contact.

Technical details

• Device type: Residual Current Circuit Breaker (RCCB)
• RCD type: Type B
• Number of poles: 2
• Rated current (In): 40 A
• Rated residual operating current (IΔn): 30 mA
• Rated voltage: 230 V AC
• Rated frequency: 50 Hz
• Short-circuit withstand capability: 10 kA (with suitable upstream protection)
• Rated impulse withstand voltage: 4 kV
• Surge current withstand capability: 3 kA
• Mounting: DIN rail
• Modular width: 2 modules (36 mm)
• Degree of protection: IP20 (terminals), IP40 (housing)
• Operating temperature range: -25 °C to +40 °C
• Terminal capacity (rigid): 1.5 - 50 mm²
• Terminal capacity (flexible): 1.5 - 35 mm²
• Tripping characteristic: Independent of mains voltage

Our verdict

The Doepke DFS2 040-2/0,03-B SK is a premium RCCB that excels in demanding environments where DC residual currents must be detected. Its Type B sensitivity, robust construction, and ease of installation make it an excellent choice for electricians and panel builders seeking reliable protection without compromise.