Siemens 5SU1656-7KV10 FI/LS Protector Type A, 10A C-Curve, 3

The Siemens 5SU1656-7KV10 is an FI/LS combination unit — a residual current circuit breaker with integral overcurrent protection (RCBO) — in a 1+N-pole form factor. It combines Type A residual current detection at 300 mA with a C-curve thermal-magnetic trip rated at 10 A, all in a single 70 mm wide module that snaps onto DIN rail. The Type A classification means it detects pulsating DC residual currents in addition to sinusoidal AC — a requirement for circuits with single-phase rectifiers, switched-mode power supplies, or variable-speed drives. The 300 mA sensitivity is typical for fire-protection or sub-distribution, not personnel protection (which would be 30 mA). The C-curve (10 A) handles moderate inrush from motorized or capacitive loads without nuisance tripping. Breaking capacity is rated at 6 kA, sufficient for most residential and light commercial sub-distribution boards where the prospective short-circuit current stays below that threshold. The 1+N-pole construction switches both phase and neutral, with the neutral pole opening after the phase pole for safety.