The Siemens 5SM2847-8 is a selective RCD unit from the SENTRON series, designed for 4-pole (3-phase + neutral) installations. It's a Type A residual-current device — catches sinusoidal AC fault currents plus pulsating DC fault currents up to 1000 mA rated tripping current. The 'selective' design means it has a deliberate short time delay (not adjustable — OFF-delay time is fixed) so that downstream RCDs trip first during a fault, keeping this unit as the backup. That's your coordination play: put this upstream of standard RCDs on a distribution board to avoid a whole-panel blackout on a single branch fault.
Rated 100 A at AC. Derates to 93 A at 40 °C, 90 A at 50 °C, 80 A at 70 °C.
Snap-on DIN rail mount (REG fastening method), 5 modular width units. Dimensions: 124 mm wide × 90 mm high × 70 mm deep. The unit is designed for the 5SP4 distribution board series but fits any standard DIN-rail enclosure with the right cutout. Not sealable — no padlock hasp for lockout/tagout on the device itself.