The Siemens 5SM6021-2 is a SENTRON arc-fault detection device (AFDD) unit block designed to mount onto a compatible miniature circuit breaker (MCB) or residual current circuit breaker (RCBO) to add series arc-fault protection in a 1P+N, 2-pole configuration. Rated for 1-16 A at 230 V AC, 50 Hz, this AFDD occupies 1 modular width unit (18 mm) on a DIN rail, while the paired protective device (MCB or RCBO) requires 2 modular width units, for a combined 3-unit footprint. The unit block is designed for use with Siemens 5SY and 5SL4 MCBs, and 5SU1 RCBOs, making it a drop-in addition for new or existing SENTRON distribution boards where arc-fault protection is required by code or specification.
The 230 V AC, 50 Hz rating matches standard single-phase mains supply in European and many Asian markets. The 1P+N pole design means it switches the line conductor only; the neutral is switched by the paired RCBO or MCB. Mechanical service life of 10,000 operating cycles is typical for a protective device in this class — adequate for normal panel operation where the AFDD is not cycled frequently. The unit is designed for continuous duty, not as a switching device. IP20 protection with connected conductors means the AFDD is suitable for installation inside a distribution board or enclosure that provides additional environmental protection. It is not rated for wet or outdoor locations without a higher-rated enclosure. The -40 °C minimum is relevant for unheated utility rooms or seasonal cold storage.
Snap-on DIN rail (REG) mounting with any orientation. The 68.5 mm depth, 54 mm width, and 95 mm height match the standard SENTRON modular device footprint, so it aligns with adjacent breakers and accessories on the same rail. The supply connection is at the bottom of the unit, consistent with standard panel wiring practice for incoming feeders.
No official successor has been announced for this active part. For BOM planning, the 5SM6021-2 remains the current SENTRON AFDD unit block for 1P+N applications with 5SY/5SL4/5SU1 devices.