Type A RCCBs trip both with sinusoidal AC fault currents and with pulsating DC fault currents. The protective devices are mainly used for single-phase loads with electrical components in the power supply. Single-phase frequency converters are used in many modern devices, such as washing machines or heating pumps. These can generate residual currents from a frequency mixture with frequency components in the kHz range. Type F residual current operated circuit breakers, which have a surge current strength of > 3 kA and a load capacity with smooth DC fault currents of up to 10 mA, protect against this.

To protect against smooth DC residual currents, SIQUENCE 5SV3 type B/B+ universal current-sensitive RCCBs with an integrated SIGRES function are used. They have an additional converter for the separate detection of DC residual currents and are suitable for use in three-phase systems upstream of input circuits with rectifiers.

RC units according to DIN EN 61009-1 (VDE 0664-20) are suitable for the attachment of miniature circuit breakers. Combined with a miniature circuit breaker, they provide the same functionality as RCBOs. They enable a high degree of flexibility in use and high protection functions.

RCBOs (Residual current operated circuit breakers with overcurrent protection) combine residual current detection and overcurrent protection in a single device. The 5SV1 RCBOs for the first time combine residual current and overload protection in one modular width (MW). Thus more protection devices can be installed in the distribution board and existing installations can easily be expanded with new protection functions in a space-saving solution. The protection devices can also be connected in a 5SM6 AFD unit - thus offering personal, line and preventive fire protection.

5SU1 RCBOs in 2-, 3-, and 4-pole versions combine residual current circuit breakers and miniature circuit breakers in one device. They protect people from fault currents and systems from short circuits and overloads. They ensure all-pole protection of final circuits with 2, 3 or 4 outer conductors as well as protection of the N conductor against overload due to harmonics in non-linear consumers such as PC power supplies, energy-saving lamps or consumer electronics.

5SU1 RCBOs combine residual current detection and overcurrent protection in one device. The protective devices can also be connected to a 5SM6 AFD unit and thus offer perfect all-round protection with rated currents of up to 40 A and 10 kA switching capacity.