The Doepke DFS 4 B/B+ equipment series provides a compact AC-DC sensitive residual current circuit-breaker. With high operating frequencies in the kilohertz range, systems such as photovoltaic installations, frequency converters, high-frequency converters and UPS equipment make high demands on protection devices that the normal Type A circuit breakers do not satisfy. On the other hand, the Doepke 4 B/B+ AC-DC sensitive series guarantees safe disconnection from the supply even in the case of smooth direct residual currents and alternating residual currents up to 100 kHz, which may occur in these systems.
For many applications, the use of an AC-DC sensitive residual current circuit-breaker is required by VDE regulations and the safety provisions of health and safety authorities. They stipulate that Type B residual current devices must be used in systems with operating equipment that can generate smooth DC currents. The AC-DC sensitive DFS 4 B/B+ series circuit-breakers comply with these regulations, as well as the relevant national and international standards (IEC).
The different products in this series enable targeted selection of the best circuit-breaker for every type of application. Therefore, the DFS 4 B SK can be used in facilities where there is no risk of fire. Its tripping threshold of 2 A at frequencies above 2 kHz provides protection against high leakage currents. This prevents unintended switch off and increases the availability of the system.
In systems where there is a risk of fire, for example in agriculture, biogas systems, paint shops, carpentry workshops, fuel tank systems and warehouses, the DFS 4 B NK series provides fire protection up to 100 kHz for a maximum residual current of 300 mA, while the B+ series provides protection up to 20 kHz. Furthermore, the equipment provides protection for direct contact.
