Doepke DFS6 040-4/0.03-B SK NU Residual Current Circuit Breaker 4-Pole 40A 30mA Type B 09134899

The Doepke DFS6 040-4/0.03-B SK NU is a 4-pole residual current circuit breaker (RCCB) engineered for all-current sensitive protection in three-phase networks. Its Type B tripping characteristic reliably detects AC, pulsating DC, and smooth DC residual currents, making it indispensable for systems with frequency inverters, EV charging stations, or medical equipment. With a rated current of 40 A and a residual operating current of 30 mA, it provides personal and fire protection while maintaining high system availability.

Advantages

Type B sensitivity ensures comprehensive fault current detection, including smooth DC, which standard RCCBs cannot handle. The compact 4-module design fits standard DIN rails, saving space in distribution boards. Screw terminals accept conductors up to 50 mm², enabling secure connections for high-load circuits. The neutral conductor is positioned bottom right (NU), simplifying wiring in common installations. Surge current resistance of 3 kA prevents nuisance tripping from lightning or switching transients.

Suitable for

• Three-phase circuits with frequency converters or UPS systems
• EV charging infrastructure requiring DC-sensitive protection
• Industrial machinery with rectifiers or variable speed drives
• Medical locations (Group 2) per IEC 60364-7-710
• Photovoltaic installations with transformerless inverters

Key specifications

• Rated residual current: 30 mA (0.03 A)
• Rated current: 40 A
• Number of poles: 4
• Rated voltage: 230/400 V AC, 50/60 Hz
• Short-circuit withstand: 10 kA with suitable pre-fuse
• Mounting: DIN rail EN 60715, 4 modules wide
• Protection degree: IP20 (terminals), IP40 (installed)
• Operating temperature: -25 °C to +40 °C

Recommendations

For optimal protection, pair this RCCB with a suitable miniature circuit breaker (MCB) as backup overcurrent protection. Verify that the upstream protective device meets the 10 kA conditional short-circuit rating. In installations with high leakage currents, consider a short-time delayed version to avoid false trips.