The Siemens 5SM1614-6BA is a Type A residual current protective device (FI protector) in the 5SM6 series, rated 40 A, 2-pole, with a rated residual current IΔn of 0.3 A at 230 V. The Type A designation means it detects pulsating DC residual currents in addition to sinusoidal AC — essential for circuits supplying single-phase rectifiers, switched-mode power supplies, or variable-speed drives where standard AC-only RCDs would be blind to the fault. The 2-module width (2 TE) and 55 mm depth fit standard DIN-rail enclosures.
Deployment context — where this RCD belongs
The Type A characteristic makes it the right choice for sub-distribution boards feeding IT equipment, EV chargers, or any load with downstream rectification where the manufacturer specifies Type A protection. The 0.3 A IΔn provides a balance between personnel protection and nuisance-trip immunity on circuits with natural leakage.